International Nuclear Information System (INIS)
Liu, James T.; Sabra, W.A.
2005-01-01
The boundary stress tensor approach has proven extremely useful in defining mass and angular momentum in asymptotically anti-de Sitter spaces with CFT duals. An integral part of this method is the use of boundary counterterms to regulate the gravitational action and stress tensor. In the presence of matter, however, ambiguities may arise that are related to the addition of possible finite counterterms. We demonstrate this explicitly for R-charged black holes in AdS 5 , where introduction of a finite counterterm proportional to φ 2 is necessary to properly reproduce the expected mass/charge relation for the black holes
Localized Gravity on Branes in anti-de Sitter Spaces
Halyo, Edi
1999-01-01
We discuss the conditions under which 4D gravity is localized on domain walls in 5D anti-de Sitter spaces. Our approach is based on considering the limits in which the localized gravity decouples. We find that gravity is localized if the wall is located a finite distance from the boundary of the anti-de Sitter space and has a finite tension. In addition, it has to be a $\\delta$-function source of gravity.
The broken string in Anti-de Sitter space
Vegh, David
2018-02-01
This paper describes an efficient method for solving the classical string equations of motion in (2+1)-dimensional anti-de Sitter spacetime. Exact string solutions are identified that are the analogs of piecewise linear strings in flat space. They can be used to approximate any smooth string motion to arbitrary accuracy. Cusps on the string move with the speed of light and their collisions are described by a reflection formula. Explicit examples are shown with the string ending on two boundary quarks. The technique is ideally suited for numerical simulations.
Black hole remnant in asymptotic anti-de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Wen, Wen-Yu [Chung Yuan Christian University, Department of Physics, Center for High Energy Physics, Chung Li City (China); National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei (China); Wu, Shang-Yu [National Chiao Tung University, Department of Electrophysics, Hsinchu (China)
2015-12-15
The solution of a remnant was suggested for the black hole ground state after surface gravity is corrected for the loop quantum effect. On the other hand, a Schwarzschild black hole in asymptotic anti-de Sitter space would tunnel into the thermal soliton solution known as the Hawking-Page phase transition. In this letter, we investigate the low temperature phase of a three-dimensional Banados-Teitelboim-Zanelli (BTZ) black hole and four-dimensional AdS Schwarzschild black hole. We find that the thermal soliton is energetically favored rather than the remnant solution at low temperature in three dimensions, while a Planck-size remnant is still possible in four dimensions. Though the BTZ remnant seems energetically disfavored, we argue that it is still possible to find in the overcooled phase if strings were present, and its implication is discussed. (orig.)
Black hole remnant in asymptotic anti-de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Wen, Wen-Yu, E-mail: steve.wen@gmail.com [Department of Physics, Center for High Energy Physics, Chung Yuan Christian University, Chung Li City, Taiwan (China); Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, 106, Taipei, Taiwan (China); Wu, Shang-Yu, E-mail: loganwu@gmail.com [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China)
2015-12-21
The solution of a remnant was suggested for the black hole ground state after surface gravity is corrected for the loop quantum effect. On the other hand, a Schwarzschild black hole in asymptotic anti-de Sitter space would tunnel into the thermal soliton solution known as the Hawking–Page phase transition. In this letter, we investigate the low temperature phase of a three-dimensional Banados–Teitelboim–Zanelli (BTZ) black hole and four-dimensional AdS Schwarzschild black hole. We find that the thermal soliton is energetically favored rather than the remnant solution at low temperature in three dimensions, while a Planck-size remnant is still possible in four dimensions. Though the BTZ remnant seems energetically disfavored, we argue that it is still possible to find in the overcooled phase if strings were present, and its implication is discussed.
Supersymmetry breaking in anti-de Sitter space
International Nuclear Information System (INIS)
Burgess, C.P.
1985-01-01
The quantum properties of supergravity theories on a four-dimensional anti-de Sitter space background are investigated. It is shown that if supersymmetry is unbroken at the classical level then the one-loop vacuum is supersymmetric if and only if the one-loop vacuum energy vanishes. The unrenormalized vacuum energy is calculated and shown to be zero in an arbitrary theory if the classical background in supersymmetric, thereby showing that one-loop corrections always respect the supersymmetry of the vacuum. Although the bare vacuum energy vanishes, the renormalized vacuum energy need not. The renormalized vacuum energy is shown to be determined by the infinite part of the one-loop effective action, and so is easily calculable. The resulting quantum correction to the background curvature is calculated and shown to vanish in any supersymmetric one-loop finite theory on AdS. In all cases calculated the quantum corrections, if nonzero, tend to reduce the background curvature
Difference between anti-de Sitter and de Sitter spaces: wave equation approach
International Nuclear Information System (INIS)
Myung, Y S; Kim, N J
2004-01-01
We study the wave equation for a massive scalar field in three-dimensional anti-de Sitter (AdS) black hole and de Sitter (dS) spaces to find what are the differences and similarities between the two spaces. Here the AdS black hole is provided by the J = 0 BTZ black hole. To investigate its event (cosmological) horizons, we compute the absorption cross section, quasinormal modes and study the AdS(dS)/CFT correspondences. Although there remains an unclear point in defining the ingoing flux near infinity of the BTZ black hole, quasi-normal modes are obtained and the AdS/CFT correspondence is confirmed. However, we do not find quasi-normal modes and thus do not confirm the assumed dS/CFT correspondence. This difference between AdS black hole and dS spaces is very interesting, because their global structures are similar to each other
Penrose inequality in anti-de Sitter space
Husain, Viqar; Singh, Suprit
2017-11-01
For asymptotically flat spacetimes the Penrose inequality gives an initial data test for the weak cosmic censorship hypothesis. We give a formulation of this inequality for asymptotically anti-de Sitter (AAdS) spacetimes, and show that the inequality holds for time asymmetric data in spherical symmetry. Our analysis is motivated by the constant-negative-spatial-curvature form of the AdS black hole metric.
Heavy-Ion Collisions and Black Holes in Anti-de-Sitter Space
Ellis, John R.
1999-07-02
Recent developments linking non-perturbative quantum gauge theories in Minkowski space to classical gravity theories in anti-de-Sitter space are reviewed at a simple level. It is suggested how these spectacular advances may be extended to discuss the quark-gluon phase transition in terms of black holes in anti-de-Sitter space, with possible relevance to heavy-ion collisions.
Phase space localization for anti-de Sitter quantum mechanics and its zero curvature limit
Elgradechi, Amine M.
1993-01-01
Using techniques of geometric quantization and SO(sub 0)(3,2)-coherent states, a notion of optimal localization on phase space is defined for the quantum theory of a massive and spinning particle in anti-de Sitter space time. It is shown that this notion disappears in the zero curvature limit, providing one with a concrete example of the regularizing character of the constant (nonzero) curvature of the anti-de Sitter space time. As a byproduct a geometric characterization of masslessness is obtained.
Some exact solutions for maximally symmetric topological defects in Anti de Sitter space
Alvarez, Orlando; Haddad, Matthew
2018-03-01
We obtain exact analytical solutions for a class of SO( l) Higgs field theories in a non-dynamic background n-dimensional anti de Sitter space. These finite transverse energy solutions are maximally symmetric p-dimensional topological defects where n = ( p + 1) + l. The radius of curvature of anti de Sitter space provides an extra length scale that allows us to study the equations of motion in a limit where the masses of the Higgs field and the massive vector bosons are both vanishing. We call this the double BPS limit. In anti de Sitter space, the equations of motion depend on both p and l. The exact analytical solutions are expressed in terms of standard special functions. The known exact analytical solutions are for kink-like defects ( p = 0 , 1 , 2 , . . . ; l = 1), vortex-like defects ( p = 1 , 2 , 3; l = 2), and the 't Hooft-Polyakov monopole ( p = 0; l = 3). A bonus is that the double BPS limit automatically gives a maximally symmetric classical glueball type solution. In certain cases where we did not find an analytic solution, we present numerical solutions to the equations of motion. The asymptotically exponentially increasing volume with distance of anti de Sitter space imposes different constraints than those found in the study of defects in Minkowski space.
Quantum corrections in thermal states of fermions on anti-de Sitter space-time
Ambruş, Victor E.; Winstanley, Elizabeth
2017-12-01
We study the energy density and pressure of a relativistic thermal gas of massless fermions on four-dimensional Minkowski and anti-de Sitter space-times using relativistic kinetic theory. The corresponding quantum field theory quantities are given by components of the renormalized expectation value of the stress-energy tensor operator acting on a thermal state. On Minkowski space-time, the renormalized vacuum expectation value of the stress-energy tensor is by definition zero, while on anti-de Sitter space-time the vacuum contribution to this expectation value is in general nonzero. We compare the properties of the vacuum and thermal expectation values of the energy density and pressure for massless fermions and discuss the circumstances in which the thermal contribution dominates over the vacuum one.
Entanglement entropy of black holes and anti-de Sitter space/conformal-field-theory correspondence.
Solodukhin, Sergey N
2006-11-17
A recent proposal by Ryu and Takayanagi for a holographic interpretation of entanglement entropy in conformal field theories dual to supergravity on anti-de Sitter space is generalized to include entanglement entropy of black holes living on the boundary of anti-de Sitter space. The generalized proposal is verified in boundary dimensions d=2 and d=4 for both the uv-divergent and uv-finite terms. In dimension d=4 an expansion of entanglement entropy in terms of size L of the subsystem outside the black hole is considered. A new term in the entropy of dual strongly coupled conformal-field theory, which universally grows as L(2)lnL and is proportional to the value of the obstruction tensor at the black hole horizon, is predicted.
BRST quantization in anti-de Sitter space
Kallosh, Renata E
2000-01-01
We discuss the status of the superstring theory on ad S/sub 5/*S/sup 5/ space and difficulties with its quantization due to the nonlinear realization of the SU(2,2 4) superconformal symmetry. We propose a toy model in two dimensions where this symmetry is realized linearly and supertwistors are used as `quarks' of this supergroup. A possible relation between the string theory and the toy model is studied in the case of a massive particle propagating in AdS/sub 5/ space: a generalized twistor construction is shown to lead to a quadratic action and simple BRST quantization. We hope that these results will help to also eventually quantize the string on ad S/sub 5/*S/sup 5/. (10 refs).
Abundant stable gauge field hair for black holes in anti-de Sitter space.
Baxter, J E; Helbling, Marc; Winstanley, Elizabeth
2008-01-11
We present new hairy black hole solutions of SU(N) Einstein-Yang-Mills (EYM) theory in asymptotically anti-de Sitter (AdS) space. These black holes are described by N+1 independent parameters and have N-1 independent gauge field degrees of freedom. Solutions in which all gauge field functions have no zeros exist for all N, and for a sufficiently large (and negative) cosmological constant. At least some of these solutions are shown to be stable under classical, linear, spherically symmetric perturbations. Therefore there is no upper bound on the amount of stable gauge field hair with which a black hole in AdS can be endowed.
Anti-De Sitter Space, Thermal Phase Transition, and Confinement in Gauge Theories
Witten, Edward
2014-03-01
The correspondence between supergravity (and string theory) on AdS space and boundary conformal field theory relates the thermodynamics of N = 4 super Yang-Mills theory in four dimensions to the thermodynamics of Schwarzschild black holes in Anti-de Sitter space. In this description, quantum phenomena such as the spontaneous breaking of the center of the gauge group, magnetic confinement, and the mass gap are coded in classical geometry. The correspondence makes it manifest that the entropy of a very large AdS Schwarzschild black hole must scale "holographically" with the volume of its horizon. By similar methods, one can also make a speculative proposal for the description of large N gauge theories in four dimensions without supersymmetry.
Null polygonal Wilson loops and minimal surfaces in Anti-de-Sitter space
International Nuclear Information System (INIS)
Alday, Luis F.; Maldacena, Juan
2009-01-01
We consider minimal surfaces in three dimensional anti-de-Sitter space that end at the AdS boundary on a polygon given by a sequence of null segments. The problem can be reduced to a certain generalized Sinh-Gordon equation and to SU(2) Hitchin equations. We describe in detail the mathematical problem that needs to be solved. This problem is mathematically the same as the one studied by Gaiotto, Moore and Neitzke in the context of the moduli space of certain supersymmetric theories. Using their results we can find the explicit answer for the area of a surface that ends on an eight-sided polygon. Via the gauge/gravity duality this can also be interpreted as a certain eight-gluon scattering amplitude at strong coupling. In addition, we give fairly explicit solutions for regular polygons.
Non-topological gravitating defects in five-dimensional anti-de Sitter space
Giovannini, Massimo
2006-01-01
A class of five-dimensional warped solutions is presented. The geometry is everywhere regular and tends to five-dimensional anti-de Sitter space for large absolute values of the bulk coordinate. The physical features of the solutions change depending on the value of an integer parameter. In particular, a set of solutions describes generalized gravitating kinks where the scalar field interpolates between two different minima of the potential. The other category of solutions describes instead gravitating defects where the scalar profile is always finite and reaches the same constant asymptote both for positive and negative values of the bulk coordinate. In this sense the profiles are non-topological. The physical features of the zero modes are discussed.
Holographic calculations of Euclidean Wilson loop correlator in Euclidean anti-de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Ziama, Sannah [Department of Physics and Astronomy, University of Kentucky,505 Rose Street, Lexington, KY 40506-0055 (United States)
2015-04-07
The correlation functions of two or more Euclidean Wilson loops of various shapes in Euclidean anti-de Sitter space are computed by considering the minimal area surfaces connecting the loops. The surfaces are parametrized by Riemann theta functions associated with genus three hyperelliptic Riemann surfaces. In the case of two loops, the distance L by which they are separated can be adjusted by continuously varying a specific branch point of the auxiliary Riemann surface. When L is much larger than the characteristic size of the loops, then the loops are approximately regarded as local operators and their correlator as the correlator of two local operators. Similarly, when a loop is very small compared to the size of another loop, the small loop is considered as a local operator corresponding to a light supergravity mode.
Quantum groups, roots of unity and particles on quantized Anti-de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Steinacker, Harold [Univ. of California, Berkeley, CA (United States). Dept. of Physics
1997-05-23
Quantum groups in general and the quantum Anti-de Sitter group U_{q}(so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin ≥ 1, "naive" representations are unitarizable only after factoring out a subspace of "pure gauges", as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U_{q}(g), which plays the role of a BRST operator in the case of U_{q}(so(2,3)) at roots of unity, for any spin ≥ 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard "truncated" tensor product as well as many-particle representations.
Stability of anti-de sitter space in Einstein-Gauss-Bonnet gravity.
Deppe, Nils; Kolly, Allison; Frey, Andrew; Kunstatter, Gabor
2015-02-20
Recently it has been argued that in Einstein gravity anti-de Sitter spacetime is unstable against the formation of black holes for a large class of arbitrarily small perturbations. We examine the effects of including a Gauss-Bonnet term. In five dimensions, spherically symmetric Einstein-Gauss-Bonnet gravity has two key features: Choptuik scaling exhibits a radius gap, and the mass function goes to a finite value as the horizon radius vanishes. These suggest that black holes will not form dynamically if the total mass-energy content of the spacetime is too small, thereby restoring the stability of anti-de Sitter spacetime in this context. We support this claim with numerical simulations and uncover a rich structure in horizon radii and formation times as a function of perturbation amplitude.
Violating the Weak Cosmic Censorship Conjecture in Four-Dimensional Anti-de Sitter Space
Crisford, Toby; Santos, Jorge E.
2017-05-01
We consider time-dependent solutions of the Einstein-Maxwell equations using anti-de Sitter (AdS) boundary conditions, and provide the first counterexample to the weak cosmic censorship conjecture in four spacetime dimensions. Our counterexample is entirely formulated in the Poincaré patch of AdS. We claim that our results have important consequences for quantum gravity, most notably to the weak gravity conjecture.
Bjoraker; Hosotani
2000-02-28
A continuum of new monopole and dyon solutions in the Einstein-Yang-Mills theory in asymptotically anti-de Sitter space are found. They are regular everywhere and specified by their mass and their non-Abelian electric and magnetic charges. A class of monopole solutions which have no node in non-Abelian magnetic fields is shown to be stable against spherically symmetric linear perturbations.
Critical phenomena of regular black holes in anti-de Sitter space-time
Energy Technology Data Exchange (ETDEWEB)
Fan, Zhong-Ying [Peking University, Center for High Energy Physics, Beijing (China)
2017-04-15
In General Relativity, addressing coupling to a non-linear electromagnetic field, together with a negative cosmological constant, we obtain the general static spherical symmetric black hole solution with magnetic charges, which is asymptotic to anti-de Sitter (AdS) space-times. In particular, for a degenerate case the solution becomes a Hayward-AdS black hole, which is regular everywhere in the full space-time. The existence of such a regular black hole solution preserves the weak energy condition, while the strong energy condition is violated. We then derive the first law and the Smarr formula of the black hole solution. We further discuss its thermodynamic properties and study the critical phenomena in the extended phase space where the cosmological constant is treated as a thermodynamic variable as well as the parameter associated with the non-linear electrodynamics. We obtain many interesting results such as: the Maxwell equal area law in the P-V (or S-T) diagram is violated and consequently the critical point (T{sub *},P{sub *}) of the first order small-large black hole transition does not coincide with the inflection point (T{sub c},P{sub c}) of the isotherms; the Clapeyron equation describing the coexistence curve of the Van der Waals (vdW) fluid is no longer valid; the heat capacity at constant pressure is finite at the critical point; the various exponents near the critical point are also different from those of the vdW fluid. (orig.)
Generic cosmic-censorship violation in anti-de Sitter space.
Hertog, Thomas; Horowitz, Gary T; Maeda, Kengo
2004-04-02
We consider (four-dimensional) gravity coupled to a scalar field with potential V(phi). The potential satisfies the positive energy theorem for solutions that asymptotically tend to a negative local minimum. We show that for a large class of such potentials, there is an open set of smooth initial data that evolve to naked singularities. Hence cosmic censorship does not hold for certain reasonable matter theories in asymptotically anti-de Sitter spacetimes. The asymptotically flat case is more subtle. We suspect that potentials with a local Minkowski minimum may similarly lead to violations of cosmic censorship in asymptotically flat spacetimes, but we do not have definite results.
Bjorken flow from an anti-de Sitter space Schwarzschild black hole.
Alsup, James; Siopsis, George
2008-07-18
We consider a large black hole in asymptotically anti-de Sitter spacetime of arbitrary dimension with a Minkowski boundary. By performing an appropriate slicing as we approach the boundary, we obtain via holographic renormalization a gauge theory fluid obeying Bjorken hydrodynamics in the limit of large longitudinal proper time. The metric we obtain reproduces to leading order the metric recently found as a direct solution of the Einstein equations in five dimensions. Our results are also in agreement with recent exact results in three dimensions.
Remarks on quantum field theory on de Sitter and anti-de Sitter ...
Indian Academy of Sciences (India)
2012-06-14
Jun 14, 2012 ... Quantum field theory on de Sitter and anti-de Sitter space-times the permuted extended tuboids contains all the non-coinciding points of the 'Euclidean' de Sitter world, i.e.. {(z1,..., zn) ∈ Sn d : zj = zk. ∀ j = k}. (3.19). 3.4 Perturbation theory. Perturbation theory can be set up in de Sitter space-time, as it is a ...
Minic, Djordje; Pleimling, Michel
2008-12-01
We point out that the recent discussion of nonrelativistic anti-de Sitter space and conformal field theory correspondence has a direct application in nonequilibrium statistical physics, a fact which has not been emphasized in the recent literature on the subject. In particular, we propose a duality between aging in systems far from equilibrium characterized by the dynamical exponent z=2 and gravity in a specific background. The key ingredient in our proposal is the recent geometric realization of the Schrödinger group. We also discuss the relevance of the proposed correspondence for the more general aging phenomena in systems where the value of the dynamical exponent is different from 2.
Graviton n-point functions for UV-complete theories in Anti-de Sitter space
Brustein, Ram
2012-01-01
We calculate graviton n-point functions in an anti-de Sitter black brane background for effective gravity theories whose linearized equations of motion have at most two time derivatives. We compare the n-point functions in Einstein gravity to those in theories whose leading correction is quadratic in the Riemann tensor. The comparison is made for any number of gravitons and for all physical graviton modes in a kinematic region for which the leading correction can significantly modify the Einstein result. We find that the n-point functions of Einstein gravity depend on at most a single angle, whereas those of the corrected theories may depend on two angles. For the four-point functions, Einstein gravity exhibits linear dependence on the Mandelstam variable s versus a quadratic dependence on s for the corrected theory.
Superfield approach to anti de Sitter supersymmetry
International Nuclear Information System (INIS)
Ivanov, E.A.
1979-01-01
A self-contained superfield approach to global supersymmetry in anti de Sitter space (OSp(1.4)) is developed. General transformation laws for OSp(1.4)-superfields are established, and all basic elements of the OSp(1.4)-covariant formalism in the real basis, such as covariant superfield derivatives, invariant integration measure over the superspace OSp(1.4)/O(1.3), etc., are explicitly given. The reducibility questions are analyzed and realizations of OSp(1.4) in the left- and right-handed chiral superspaces are found
Radial dimensional reduction: (anti) de Sitter theories from flat
Biswas, Tirthabir; Siegel, Warren
2002-07-01
We propose a new form of dimensional reduction that constrains dilatation instead of a component of momentum. It corresponds to replacing toroidal compactification in a cartesian coordinate with that in the logarithm of the radius. Massive theories in de Sitter or anti de Sitter space are thus produced from massless (scale invariant) theories in one higher space or time dimension. As an example, we derive free massive actions for arbitrary representations of the (anti) de Sitter group in arbitrary dimensions. (Previous general results were restricted to symmetric tensors.) We also discuss generalizations to interacting theories.
Remarks on quantum field theory on de Sitter and anti-de Sitter ...
Indian Academy of Sciences (India)
2012-06-14
Jun 14, 2012 ... The literature devoted to quantum field theory (QFT) on the de Sitter and anti-de Sitter space-times is enormous. This short review is limited to work done in recent years with the authors quoted in the abstract. The most significant results described here are the two explicit Källén–Lehmann representations ...
Quantum fields in anti-de Sitter wormholes
Barcelo, Carlos; Garay, Luis J.
1997-01-01
We study the effects of asymptotically anti-de Sitter wormholes in low-energy field theory and give a general prescription for obtaining the local effective interaction terms induced by them. The choice of vacuum for the matter fields selects a basis of the Hilbert space of anti-de Sitter wormholes whose elements can be interpreted as states containing a given number of particles. This interpretation is subject to the same kind of ambiguity in the definition of a particle as that arising from...
The zero mass limit of Kerr and Kerr-(anti-)de-Sitter space-times: exact solutions and wormholes
Birkandan, T.; Hortaçsu, M.
2018-03-01
Heun-type exact solutions emerge for both the radial and the angular equations for the case of a scalar particle coupled to the zero mass limit of both the Kerr and Kerr-(anti)de-Sitter spacetime. Since any type D metric has Heun-type solutions, it is interesting that this property is retained in the zero mass case. This work further refutes the claims that M going to zero limit of the Kerr metric is both locally and globally the same as the Minkowski metric.
One-loop effective action and Schwinger effect in (anti-) de Sitter space
Cai, Rong-Gen; Kim, Sang Pyo
2014-09-01
We study the Schwinger mechanism by a uniform electric field in dS2 and AdS2 and the curvature effect on the Schwinger effect, and further propose a thermal interpretation of the Schwinger formula in terms of the Gibbons-Hawking temperature and the Unruh temperature for an accelerating charge in dS2 and an analogous expression in AdS2. The exact one-loop effective action is found in the proper-time integral in each space, which is determined by the effective mass, the Maxwell scalar, and the scalar curvature, and whose pole structure gives the imaginary part of the effective action and the exact pair-production rate. The exact pair-production rate is also given the thermal interpretation.
The large dimension limit of a small black hole instability in anti-de Sitter space
Herzog, Christopher P.; Kim, Youngshin
2018-02-01
We study the dynamics of a black hole in an asymptotically AdS d × S d space-time in the limit of a large number of dimensions, d → ∞. Such a black hole is known to become dynamically unstable below a critical radius. We derive the dispersion relation for the quasinormal mode that governs this instability in an expansion in 1 /d. We also provide a full nonlinear analysis of the instability at leading order in 1 /d. We find solutions that resemble the lumpy black spots and black belts previously constructed numerically for small d, breaking the SO( d + 1) rotational symmetry of the sphere down to SO( d). We are also able to follow the time evolution of the instability. Due possibly to limitations in our analysis, our time dependent simulations do not settle down to stationary solutions. This work has relevance for strongly interacting gauge theories; through the AdS/CFT correspondence, the special case d = 5 corresponds to maximally supersymmetric Yang-Mills theory on a spatial S 3 in the microcanonical ensemble and in a strong coupling and large number of colors limit.
Analytical Solutions of the Gravitational Field Equations in de Sitter and Anti-de Sitter Spacetimes
Da Rocha, R.; Capelas Oliveira, E.
2009-01-01
The generalized Laplace partial differential equation, describing gravitational fields, is investigated in de Sitter spacetime from several metric approaches—such as the Riemann, Beltrami, Börner-Dürr, and Prasad metrics—and analytical solutions of the derived Riccati radial differential equations are explicitly obtained. All angular differential equations trivially have solutions given by the spherical harmonics and all radial differential equations can be written as Riccati ordinary differential equations, which analytical solutions involve hypergeometric and Bessel functions. In particular, the radial differential equations predict the behavior of the gravitational field in de Sitter and anti-de Sitter spacetimes, and can shed new light on the investigations of quasinormal modes of perturbations of electromagnetic and gravitational fields in black hole neighborhood. The discussion concerning the geometry of de Sitter and anti-de Sitter spacetimes is not complete without mentioning how the wave equation behaves on such a background. It will prove convenient to begin with a discussion of the Laplace equation on hyperbolic space, partly since this is of interest in itself and also because the wave equation can be investigated by means of an analytic continuation from the hyperbolic space. We also solve the Laplace equation associated to the Prasad metric. After introducing the so called internal and external spaces—corresponding to the symmetry groups SO(3,2) and SO(4,1) respectively—we show that both radial differential equations can be led to Riccati ordinary differential equations, which solutions are given in terms of associated Legendre functions. For the Prasad metric with the radius of the universe independent of the parametrization, the internal and external metrics are shown to be of AdS-Schwarzschild-like type, and also the radial field equations arising are shown to be equivalent to Riccati equations whose solutions can be written in terms of
Nashed, Gamal G. L.
2011-10-01
We give a class of spherically symmetric-Anti de Sitter (Ads), exact solution in the teleparallel equivalent of general relativity (TEGR). The solution depends on an arbitrary function {F}(R) and reproduce the metric of Schwarzschild Ads space-time. In the context of the Hamiltonian formulation of the TEGR we compute the gravitational energy of this class. The calculation is carried out by means of an expression for the energy of the gravitational field that naturally arises from the integral form of the constraint equations of the formalism. We show that the form of the energy depends on the arbitrary function. We make a constrain on this arbitrary function to give the correct form of energy.
Noronha, Jorge; Gyulassy, Miklos; Torrieri, Giorgio
2009-03-13
We show that far zone Mach and diffusion wake "holograms" produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict N_{c}-->infinity supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium "neck" zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence.
Biswas, Tirthabir; Koshelev, Alexey S.; Mazumdar, Anupam
2017-01-01
In this paper we provide the criteria for any generally covariant, parity preserving, and torsion-free theory of gravity to possess a stable de Sitter (dS) or anti-de Sitter (AdS) background. By stability we mean the absence of tachyonic or ghostlike states in the perturbative spectrum that can lead
Khayrul, Hasan, M.; Sultana, Kausari; Shahjalal, Md.
2017-10-01
We probe the plausibility of weak equivalence principle for a circular motion at the radial distance of photon sphere of the Schwarzschild?(Anti-)de Sitter black hole. We switch the static Schwarzschild?(Anti-)de Sitter space-time to rotational by means of the transformation with constant angular velocity. The fiducial observers revolving along the trajectory of photon orbit of the Schwarzschild?(Anti-)de Sitter black hole are supposed to agree on the result of any physical experiment when their angular velocities are uniform, which give rise to the constancy in their accelerations, meaning the observers are equivalent. Our study, in contrast, finds that the observers do not measure similar results, claiming the invalidity of the principle of weak equivalence. However, the aim of our work is not to defy the principle absolutely, rather we focus our attention on the very cause for which the dispute arises, namely the rotational motion.
Quantization of a scalar field in two Poincaré patches of anti-de Sitter space and AdS/CFT
Directory of Open Access Journals (Sweden)
Ippei Fujisawa
2014-09-01
Full Text Available Two sets of modes of a massive free scalar field are quantized in a pair of Poincaré patches of Lorentzian anti-de Sitter (AdS space, AdSd+1 (d≥2. It is shown that in Poincaré coordinates (r,t,x→, the two boundaries at r=±∞ are connected. When the scalar mass m satisfies a condition 0<ν=(d2/4+(mℓ2<1, there exist two sets of mode solutions to Klein–Gordon equation, with distinct fall-off behaviors at the boundary. By using the fact that the boundaries at r=±∞ are connected, a conserved Klein–Gordon norm can be defined for these two sets of scalar modes, and these modes are canonically quantized. Energy is also conserved. A prescription within the approximation of semi-classical gravity is presented for computing two- and three-point functions of the operators in the boundary CFT, which correspond to the two fall-off behaviours of scalar field solutions.
On electric field in anti-de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Cheong, Lee Yen, E-mail: lee-yencheong@petronas.com.my, E-mail: chewxy01813@gmail.com, E-mail: dennis.ling@petronas.com.my; Yan, Chew Xiao, E-mail: lee-yencheong@petronas.com.my, E-mail: chewxy01813@gmail.com, E-mail: dennis.ling@petronas.com.my; Ching, Dennis Ling Chuan, E-mail: lee-yencheong@petronas.com.my, E-mail: chewxy01813@gmail.com, E-mail: dennis.ling@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Bandar Seri Iskandar, Tronoh 31750, Perak (Malaysia)
2014-10-24
In this paper we calculate the electromagnetic field produced using retarded Green's function in Anti-de Sitter spacetime (AdS). Since this spacetime is non-globally hyperbolic and has no Cauchy surface, we only consider the field originated from a charge moving along its geodesic in the region consists of points covered by future null geodesic of the charge.
Noncommutative Relativistic Spacetimes and Worldlines from 2 + 1 Quantum (Anti-de Sitter Groups
Directory of Open Access Journals (Sweden)
Ángel Ballesteros
2017-01-01
Full Text Available The κ-deformation of the (2 + 1D anti-de Sitter, Poincaré, and de Sitter groups is presented through a unified approach in which the curvature of the spacetime (or the cosmological constant is considered as an explicit parameter. The Drinfel’d-double and the Poisson–Lie structure underlying the κ-deformation are explicitly given, and the three quantum kinematical groups are obtained as quantizations of such Poisson–Lie algebras. As a consequence, the noncommutative (2 + 1D spacetimes that generalize the κ-Minkowski space to the (anti-de Sitter ones are obtained. Moreover, noncommutative 4D spaces of (time-like geodesics can be defined, and they can be interpreted as a novel possibility to introduce noncommutative worldlines. Furthermore, quantum (anti-de Sitter algebras are presented both in the known basis related to 2 + 1 quantum gravity and in a new one which generalizes the bicrossproduct one. In this framework, the quantum deformation parameter is related to the Planck length, and the existence of a kind of “duality” between the cosmological constant and the Planck scale is also envisaged.
Instability of charged anti-de Sitter black holes
International Nuclear Information System (INIS)
Gwak, Bogeun; Lee, Bum-Hoon; Ro, Daeho
2016-01-01
We have studied the instability of charged anti-de Sitter black holes in four- or higher-dimensions under fragmentation. The unstable black holes under fragmentation can be broken into two black holes. Instability depends not only on the mass and charge of the black hole but also on the ratio between the fragmented black hole and its predecessor. We have found that the near extremal black holes are unstable, and Schwarzschild-AdS black holes are stable. These are qualitatively similar to black holes in four dimensions and higher. The detailed instabilities are numerically investigated.
Cosmic censorship of rotating Anti-de Sitter black hole
Energy Technology Data Exchange (ETDEWEB)
Gwak, Bogeun; Lee, Bum-Hoon, E-mail: rasenis@sogang.ac.kr, E-mail: bhl@sogang.ac.kr [Center for Quantum Spacetime, Sogang University, Seoul 04107 (Korea, Republic of)
2016-02-01
We test the validity of cosmic censorship in the rotating anti-de Sitter black hole. For this purpose, we investigate whether the extremal black hole can be overspun by the particle absorption. The particle absorption will change the mass and angular momentum of the black hole, which is analyzed using the Hamilton-Jacobi equations consistent with the laws of thermodynamics. We have found that the mass of the extremal black hole increases more than the angular momentum. Therefore, the outer horizon of the black hole still exists, and cosmic censorship is valid.
Delayed collapses of Bose-Einstein condensates in relation to anti-de Sitter gravity.
Biasi, Anxo F; Mas, Javier; Paredes, Angel
2017-03-01
We numerically investigate spherically symmetric collapses in the Gross-Pitaevskii equation with attractive nonlinearity in a harmonic potential. Even below threshold for direct collapse, the wave function bounces off from the origin and may eventually become singular after a number of oscillations in the trapping potential. This is reminiscent of the evolution of Einstein gravity sourced by a scalar field in anti de Sitter space where collapse corresponds to black-hole formation. We carefully examine the long time evolution of the wave function for continuous families of initial states in order to sharpen out this qualitative coincidence which may bring new insights in both directions. On the one hand, we comment on possible implications for the so-called Bosenova collapses in cold atom Bose-Einstein condensates. On the other hand, Gross-Pitaevskii provides a toy model to study the relevance of either the resonance conditions or the nonlinearity for the problem of anti de Sitter instability.
Supersymmetry of anti-de Sitter black holes
International Nuclear Information System (INIS)
Caldarelli, Marco M.; Klemm, Dietmar
1999-01-01
We examine supersymmetry of four-dimensional asymptotically anti-de Sitter (AdS) dyonic black holes in the context of gauged N = 2 supergravity. Our calculations concentrate on black holes with unusual topology and their rotating generalizations, but we also reconsider the spherical rotating dyonic Ker-Newman-AdS black hole, whose supersymmetry properties have previously been investigated by Kostelecky and Perry within another approach. We find that in the case of spherical, toroidal or cylindrical event horizon topology, the black holes must rotate in order to preserve some supersymmetry; the non-rotating supersymmetric configurations representing naked singularities. However, we show that this is no more true for black holes whose event horizons are Riemann surfaces of genus g > 1, where we find a non-rotating extremal solitonic black hole carrying magnetic charge and permitting one Killing spinor. For the non-rotating supersymmetric configurations of various topologies, all Killing spinors are explicitly constructed
Flow equation, conformal symmetry, and anti-de Sitter geometry
Aoki, Sinya; Yokoyama, Shuichi
2018-03-01
We argue that the anti-de Sitter (AdS) geometry in d+1 dimensions naturally emerges from an arbitrary conformal field theory in d dimensions using the free flow equation. We first show that an induced metric defined from the flowed field generally corresponds to the quantum information metric, called the Bures or Helstrom metric, if the flowed field is normalized appropriately. We next verify that the induced metric computed explicitly with the free flow equation always becomes the AdS metric when the theory is conformal. We finally prove that the conformal symmetry in d dimensions converts to the AdS isometry in d+1 dimensions after d-dimensional quantum averaging. This guarantees the emergence of AdS geometry without explicit calculation.
Covariant fields on anti-de Sitter spacetimes
Cotăescu, Ion I.
2018-02-01
The covariant free fields of any spin on anti-de Sitter (AdS) spacetimes are studied, pointing out that these transform under isometries according to covariant representations (CRs) of the AdS isometry group, induced by those of the Lorentz group. Applying the method of ladder operators, it is shown that the CRs with unique spin are equivalent with discrete unitary irreducible representations (UIRs) of positive energy of the universal covering group of the isometry one. The action of the Casimir operators is studied finding how the weights of these representations (reps.) may depend on the mass and spin of the covariant field. The conclusion is that on AdS spacetime, one cannot formulate a universal mass condition as in special relativity.
Real forms of complex quantum anti-de-Sitter algebra Uq(Sp(4;C)) and their contraction schemes
International Nuclear Information System (INIS)
Lukierski, J.; Nowicki, A.; Ruegg, H.
1991-01-01
We describe four types of inner involutions of the Cartan-Weyl basis providing (for vertical strokeqvertical stroke=1 and q real) three types of real quantum Lie algebras: U q (O(3, 2)) (quantum D=4 anti-de-Sitter), U q (O(4, 1)) (quantum D=4 de-Sitter) and U q (O(5)). We give also two types of inner involutions of the Cartan-Chevalley basis of U q (Sp(4; C)) which cannot be extended to inner involutions of the Cartan-Weyl basis. We outline twelve contraction schemes for quantum D=4 anti-de-Sitter algebra. All these contractions provide four commuting translation generators, but only two (one for vertical strokeqvertical stroke=1, the second for q real) lead to the quantum Poincare algebra with an undeformed space rotation O(3) subalgebra. (orig.)
Discrete Torsion, (Anti) de Sitter D4-Brane and Tunneling
Singh, Abhishek K.; Pandey, P. K.; Singh, Sunita; Kar, Supriya
2014-06-01
We obtain quantum geometries on a vacuum created pair of a (DDbar)3-brane, at a Big Bang singularity, by a local two form on a D4-brane. In fact our analysis is provoked by an established phenomenon leading to a pair creation by a gauge field at a black hole horizon by Stephen Hawking in 1975. Importantly, the five dimensional microscopic black holes are described by an effective non-perturbative curvature underlying a discrete torsion in a second order formalism. In the case for a non-propagating torsion, the effective curvature reduces to Riemannian, which in a low energy limit may describe Einstein vacuum in the formalism. In particular, our analysis suggests that a non-trivial space begin with a hot de Sitter brane-Universe underlying a nucleation of a vacuum pair of (DDbar)-instanton at a Big Bang. A pair of instanton nucleats a D-particle which in turn combines with an anti D-particle to describe a D-string and so on. The nucleation of a pair of higher dimensional pair of brane/anti-brane from a lower dimensional pair may be viewed via an expansion of the brane-Universe upon time. It is in conformity with the conjecture of a branes within a brane presumably in presence of the non-zero modes of two form. Interestingly, we perform a thermal analysis underlying various emergent quantum de Sitter vacua on a D4-brane and argue for the plausible tunneling geometries underlying a thermal equilibrium. It is argued that a de Sitter Schwarzschild undergoes quantum tunneling to an AdS-brane Schwarzschild via Nariai and de Sitter topological black hole.
Discrete Torsion, (Anti) de Sitter D4-Brane and Tunneling
International Nuclear Information System (INIS)
Singh, Abhishek K.; Pandey, P.K.; Singh, Sunita; Kar, Supriya
2014-01-01
We obtain quantum geometries on a vacuum created pair of a (DD ¯ ) 3 -brane, at a Big Bang singularity, by a local two form on a D 4 -brane. In fact our analysis is provoked by an established phenomenon leading to a pair creation by a gauge field at a black hole horizon by Stephen Hawking in 1975. Importantly, the five dimensional microscopic black holes are described by an effective non-perturbative curvature underlying a discrete torsion in a second order formalism. In the case for a non-propagating torsion, the effective curvature reduces to Riemannian, which in a low energy limit may describe Einstein vacuum in the formalism. In particular, our analysis suggests that a non-trivial space begin with a hot de Sitter brane-Universe underlying a nucleation of a vacuum pair of (DD ¯ )-instanton at a Big Bang. A pair of instanton nucleats a D-particle which in turn combines with an anti D-particle to describe a D-string and so on. The nucleation of a pair of higher dimensional pair of brane/anti-brane from a lower dimensional pair may be viewed via an expansion of the brane-Universe upon time. It is in conformity with the conjecture of a branes within a brane presumably in presence of the non-zero modes of two form. Interestingly, we perform a thermal analysis underlying various emergent quantum de Sitter vacua on a D 4 -brane and argue for the plausible tunneling geometries underlying a thermal equilibrium. It is argued that a de Sitter Schwarzschild undergoes quantum tunneling to an AdS-brane Schwarzschild via Nariai and de Sitter topological black hole
Non-linear realization of supersymmetry in de Sitter space
Zumino, B
1977-01-01
The author derives the non-linear transformation law and the non- linear Lagrangian for a Goldstone spinor corresponding to spontaneous breaking of global supersymmetry in a de Sitter space with O(3,2) invariance (anti de Sitter space). With a suitable choice of the Goldstone spinor field the Lagrangian agrees with the form suggested by the coupling to supergravity. The construction is also valid for the case of extended supersymmetry. (21 refs).
Simulation of black hole collisions in asymptotically Anti-de Sitter spacetimes.
Bantilan, Hans; Romatschke, Paul
2015-02-27
We present results from the evolution of spacetimes that describe the merger of asymptotically global anti-de Sitter black holes in 5D with an SO(3) symmetry. Prompt scalar field collapse provides us with a mechanism for producing distinct trapped regions on the initial slice, associated with black holes initially at rest. We evolve these black holes towards a merger, and follow the subsequent ring down. The boundary stress tensor of the dual conformal field theory is conformally related to a stress tensor in Minkowski space that inherits an axial symmetry from the bulk SO(3). We compare this boundary stress tensor to its hydrodynamic counterpart with viscous corrections of up to second order, and compare the conformally related stress tensor to ideal hydrodynamic simulations in Minkowski space, initialized at various time slices of the boundary data. Our findings reveal far-from-hydrodynamic behavior at early times, with a transition to ideal hydrodynamics at late times.
Thermodynamic stability of asymptotically anti-de Sitter rotating black holes in higher dimensions
International Nuclear Information System (INIS)
Dolan, Brian P
2014-01-01
Conditions for thermodynamic stability of asymptotically anti-de Sitter (AdS) rotating black holes in D-dimensions are determined. Local thermodynamic stability requires not only positivity conditions on the specific heat and the moment of inertia tensor but it is also necessary that the adiabatic compressibility be positive. It is shown that, in the absence of a cosmological constant, neither rotation nor charge is sufficient to ensure full local thermodynamic stability of a black hole. Thermodynamic stability properties of AdS Myers–Perry black holes are investigated for both singly spinning and multi-spinning black holes. Simple expressions are obtained for the specific heat and moment of inertia tensor in any dimension. An analytic expression is obtained for the boundary of the region of parameter space in which such space-times are thermodynamically stable. (paper)
Eikonal instability of Gauss-Bonnet-(anti-)-de Sitter black holes
Konoplya, R. A.; Zhidenko, A.
2017-05-01
Here we have shown that asymptotically anti-de Sitter (AdS) black holes in the Einstein-Gauss-Bonnet (GB) theory are unstable under linear perturbations of space-time in some region of parameters. This (eikonal) instability develops at high multipole numbers. We found the exact parametric regions of the eikonal instability and extended this consideration to asymptotically flat and de Sitter cases. The approach to the threshold of instability is driven by purely imaginary quasinormal modes, which are similar to those found recently in Grozdanov, Kaplis, and Starinets, [J. High Energy Phys. 07 (2016) 151, 10.1007/JHEP07(2016)151] for the higher curvature corrected black hole with the planar horizon. The found instability may indicate limits of holographic applicability of the GB-AdS backgrounds. Recently, through the analysis of critical behavior in AdS space-time in the presence of the Gauss-Bonnet term, it was shown [Deppe et al, Phys. Rev. Lett. 114, 071102 (2015), 10.1103/PhysRevLett.114.071102], that, if the total energy content of the AdS space-time is small, then no black holes can be formed with mass less than some critical value. A similar mass gap was also found when considering collapse of mass shells in asymptotically flat Gauss-Bonnet theories [Frolov, Phys. Rev. Lett. 115, 051102 (2015), 10.1103/PhysRevLett.115.051102]. The found instability of all sufficiently small Einstein-Gauss-Bonnet-AdS, dS and asymptotically flat black holes may explain the existing mass gaps in their formation.
Perturbation of Large Anti-deSitter Black Holes and AdS/CFT Correspondence
Ahmadzadegan, Aida
As the main goal of this thesis, the canonical form of the perturbation metric of anti-de Sitter black holes in four dimensions is derived by choosing the Regge-Wheeler gauge in the standard Schwarzschild coordinates (t, r, theta, ϕ). By assuming the perturbations to be small, the differential equations governing the perturbations are obtained from the equations deltaRmunu(h ) = 0. Then, by taking the limit of m > > R where R is the radius of AdS space, the perturbation metric and field equations of large AdS black holes are found. Finally, under the shadow of AdS/CFT correspondence, these perturbations can be compared to their corresponding three-dimensional theory of fluid dynamics on the dual space, R x S2. Furthermore, by using the definitions of stress-energy tensor and its perturbation, we can find energy density, pressure and shear viscosity which are the quantities we need to describe the behavior of the fluid on the boundary of the AdS space.
Anti-de-Sitter regular electric multipoles: towards Einstein-Maxwell-AdS solitons
Herdeiro, Carlos; Radu, Eugen
2015-01-01
We discuss electrostatics in Anti-de-Sitter ($AdS$) spacetime, in global coordinates. We observe that the multipolar expansion has two crucial differences to that in Minkowski spacetime. First, there are everywhere regular solutions, with finite energy, for every multipole moment except for the monopole. Second, all multipole moments decay with the same inverse power of the areal radius, $1/r$, as spatial infinity is approached. The first observation suggests there may be regular, self-gravit...
Viscous plasma evolution from gravity using anti-de sitter/conformal-field-theory correspondence.
Janik, Romuald A
2007-01-12
We analyze the anti-de Sitter/conformal-field-theory dual geometry of an expanding boost-invariant plasma. We show that the requirement of nonsingularity of the dual geometry for leading and subasymptotic times predicts, without any further assumptions about gauge theory dynamics, hydrodynamic expansion of the plasma with viscosity coefficient exactly matching the one obtained earlier in the static case by Policastro, Son, and Starinets.
Thin-shell bubbles and information loss problem in anti de Sitter background
Energy Technology Data Exchange (ETDEWEB)
Sasaki, Misao [Yukawa Institute for Theoretical Physics,Kyoto University, Kyoto 606-8502 (Japan); Tomsk State Pedagogical University,634050 Tomsk (Russian Federation); Yeom, Dong-han [Yukawa Institute for Theoretical Physics,Kyoto University, Kyoto 606-8502 (Japan); Leung Center for Cosmology and Particle Astrophysics, National Taiwan University,Taipei 10617, Taiwan (China)
2014-12-24
We study the motion of thin-shell bubbles and their tunneling in anti de Sitter (AdS) background. We are interested in the case when the outside of a shell is a Schwarzschild-AdS space (false vacuum) and the inside of it is an AdS space with a lower vacuum energy (true vacuum). If a collapsing true vacuum bubble is created, classically it will form a Schwarzschild-AdS black hole. However, this collapsing bubble can tunnel to a bouncing bubble that moves out to spatial infinity. Then, although the classical causal structure of a collapsing true vacuum bubble has the singularity and the event horizon, quantum mechanically the wavefunction has support for a history without any singularity nor event horizon which is mediated by the non-perturbative, quantum tunneling effect. This may be regarded an explicit example that shows the unitarity of an asymptotic observer in AdS, while a classical observer who only follows the most probable history effectively lose information due to the formation of an event horizon.
Toward de Sitter space from ten dimensions
Moritz, Jakob; Retolaza, Ander; Westphal, Alexander
2018-02-01
Using a 10D lift of nonperturbative volume stabilization in type IIB string theory, we study the limitations for obtaining de Sitter vacua. Based on this we find that the simplest Kachru, Kallosh, Linde, and Trivedi vacua with a single Kähler modulus stabilized by a gaugino condensate cannot be uplifted to de Sitter. Rather, the uplift flattens out due to stronger backreaction on the volume modulus than has previously been anticipated, resulting in vacua which are metastable and supersymmetry breaking, but that are always anti-de Sitter (AdS). However, we also show that setups such as racetrack stabilization can avoid this issue. In these models it is possible to obtain supersymmetric AdS vacua with a cosmological constant that can be tuned to zero while retaining finite moduli stabilization. In this regime, it seems that de Sitter uplifts are possible with negligible backreaction on the internal volume. We exhibit this behavior also from the 10D perspective.
International Nuclear Information System (INIS)
Daghigh, Ramin G; Green, Michael D
2009-01-01
We analyze analytically the asymptotic regions of the quasinormal mode frequency spectra with infinitely large overtone numbers for D-dimensional Schwarzschild black holes in anti de Sitter spacetimes. In this limit, we confirm the analytic results obtained previously in the literature using different methods. In addition, we show that in certain spacetime dimensions these techniques imply the existence of other regions of the asymptotic quasinormal mode frequency spectrum which have not previously appeared in the literature. For large black holes, some of these modes have a damping rate of 1.2T H , where T H is the Hawking temperature. This is less than the damping rate of the lowest overtone quasinormal mode calculated by other authors. It is not completely clear whether these modes actually exist or are an artifact of an unknown flaw in the analytic techniques being used. We discuss the possibility of the existence of these modes and explore some of the consequences. We also examine the possible connection between the asymptotic quasinormal modes of Schwarzschild-anti de Sitter black holes and the quantum level spacing of their horizon area spectrum.
Configurational entropy of anti-de Sitter black holes
Braga, Nelson R. F.; da Rocha, Roldão
2017-04-01
Recent studies indicate that the configurational entropy is an useful tool to investigate the stability and (or) the relative dominance of states for diverse physical systems. Recent examples comprise the connection between the variation of this quantity and the relative fraction of light mesons and glueballs observed in hadronic processes. Here we develop a technique for defining a configurational entropy for an AdS-Schwarzschild black hole. The achieved result corroborates consistency with the Hawking-Page phase transition. Namely, the dominance of the black hole configurational entropy will be shown to increase with the temperature. In order to verify the consistency of the new procedure developed here, we also consider the case of black holes in flat space-time. For such a black hole, it is known that evaporation leads to instability. The configurational entropy obtained for the flat space case is thoroughly consistent with the physical expectation. In fact, we show that the smaller the black holes, the more unstable they are. So, the configurational entropy furnishes a reliable measure for stability of black holes.
Configurational entropy of anti-de Sitter black holes
Directory of Open Access Journals (Sweden)
Nelson R.F. Braga
2017-04-01
Full Text Available Recent studies indicate that the configurational entropy is an useful tool to investigate the stability and (or the relative dominance of states for diverse physical systems. Recent examples comprise the connection between the variation of this quantity and the relative fraction of light mesons and glueballs observed in hadronic processes. Here we develop a technique for defining a configurational entropy for an AdS-Schwarzschild black hole. The achieved result corroborates consistency with the Hawking–Page phase transition. Namely, the dominance of the black hole configurational entropy will be shown to increase with the temperature. In order to verify the consistency of the new procedure developed here, we also consider the case of black holes in flat space-time. For such a black hole, it is known that evaporation leads to instability. The configurational entropy obtained for the flat space case is thoroughly consistent with the physical expectation. In fact, we show that the smaller the black holes, the more unstable they are. So, the configurational entropy furnishes a reliable measure for stability of black holes.
Configurational entropy of anti-de Sitter black holes
International Nuclear Information System (INIS)
Braga, Nelson R.F.; Rocha, Roldão da
2017-01-01
Recent studies indicate that the configurational entropy is an useful tool to investigate the stability and (or) the relative dominance of states for diverse physical systems. Recent examples comprise the connection between the variation of this quantity and the relative fraction of light mesons and glueballs observed in hadronic processes. Here we develop a technique for defining a configurational entropy for an AdS-Schwarzschild black hole. The achieved result corroborates consistency with the Hawking–Page phase transition. Namely, the dominance of the black hole configurational entropy will be shown to increase with the temperature. In order to verify the consistency of the new procedure developed here, we also consider the case of black holes in flat space-time. For such a black hole, it is known that evaporation leads to instability. The configurational entropy obtained for the flat space case is thoroughly consistent with the physical expectation. In fact, we show that the smaller the black holes, the more unstable they are. So, the configurational entropy furnishes a reliable measure for stability of black holes.
Configurational entropy of anti-de Sitter black holes
Energy Technology Data Exchange (ETDEWEB)
Braga, Nelson R.F., E-mail: braga@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RJ 21941-972 (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC – UFABC, 09210-580, Santo André (Brazil)
2017-04-10
Recent studies indicate that the configurational entropy is an useful tool to investigate the stability and (or) the relative dominance of states for diverse physical systems. Recent examples comprise the connection between the variation of this quantity and the relative fraction of light mesons and glueballs observed in hadronic processes. Here we develop a technique for defining a configurational entropy for an AdS-Schwarzschild black hole. The achieved result corroborates consistency with the Hawking–Page phase transition. Namely, the dominance of the black hole configurational entropy will be shown to increase with the temperature. In order to verify the consistency of the new procedure developed here, we also consider the case of black holes in flat space-time. For such a black hole, it is known that evaporation leads to instability. The configurational entropy obtained for the flat space case is thoroughly consistent with the physical expectation. In fact, we show that the smaller the black holes, the more unstable they are. So, the configurational entropy furnishes a reliable measure for stability of black holes.
Reissner–Nordström Anti-de Sitter Black Holes in Mimetic F(R Gravity
Directory of Open Access Journals (Sweden)
V. K. Oikonomou
2016-05-01
Full Text Available In this paper, we study under which conditions the Reissner–Nordström anti-de Sitter black hole can be a solution of the vacuum mimetic F ( R gravity with Lagrange multiplier and mimetic scalar potential. As the author demonstrates, the resulting picture in the mimetic F ( R gravity case is a trivial extension of the standard F ( R approach, and in effect, the metric perturbations in the mimetic F ( R gravity case, for the Reissner–Nordström anti-de Sitter black hole metric, at the first order of the perturbed variables are the same at the leading order.
Noncommutative de Sitter and FRW spaces
International Nuclear Information System (INIS)
Burić, Maja; Madore, John
2015-01-01
Several versions of fuzzy four-dimensional de Sitter space are constructed using the noncommutative frame formalism. Although all noncommutative spacetimes which are found have commutative de Sitter metric as a classical limit, the algebras and the differential calculi which define them have many differences, which we derive and discuss
Noncommutative de Sitter and FRW spaces
Energy Technology Data Exchange (ETDEWEB)
Burić, Maja, E-mail: majab@ipb.ac.rs [Faculty of Physics, University of Belgrade, P.O. Box 44, 11001, Belgrade (Serbia); Madore, John, E-mail: madore@th.u-psud.fr [Laboratoire de Physique Théorique, 91405, Orsay (France)
2015-10-24
Several versions of fuzzy four-dimensional de Sitter space are constructed using the noncommutative frame formalism. Although all noncommutative spacetimes which are found have commutative de Sitter metric as a classical limit, the algebras and the differential calculi which define them have many differences, which we derive and discuss.
Anti-de Sitter gravity associated with the supergroup $SU(1,1|2)\\times SU(1,1|2)$
David, Justin R.
1999-01-01
We construct the anti-de Sitter supergravity in three dimensions associated with the supergroup $SU(1,1|2)\\times SU(1,1|2)$. The field content and the action are inferred using the fact that $AdS$ supergravity theories in three dimensions are Chern-Simons theories.
Hawking evaporation time scale of topological black holes in anti-de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Ong, Yen Chin, E-mail: yenchin.ong@nordita.org
2016-02-15
It was recently pointed out that if an absorbing boundary condition is imposed at infinity, an asymptotically anti-de Sitter Schwarzschild black hole with a spherical horizon takes only a finite amount of time to evaporate away even if its initial mass is arbitrarily large. We show that this is a rather generic property in AdS spacetimes: regardless of their horizon topologies, neutral AdS black holes in general relativity take about the same amount of time to evaporate down to the same size of order L, the AdS length scale. Our discussion focuses on the case in which the black hole has toral event horizon. A brief comment is made on the hyperbolic case, i.e. for black holes with negatively curved horizons.
Nonlinear Evolution and Final Fate of Charged Anti-de Sitter Black Hole Superradiant Instability.
Bosch, Pablo; Green, Stephen R; Lehner, Luis
2016-04-08
We describe the full nonlinear development of the superradiant instability for a charged massless scalar field coupled to general relativity and electromagnetism, in the vicinity of a Reissner-Nordström-anti-de Sitter black hole. The presence of the negative cosmological constant provides a natural context for considering perfectly reflecting boundary conditions and studying the dynamics as the scalar field interacts repeatedly with the black hole. At early times, small superradiant perturbations grow as expected from linearized studies. Backreaction then causes the black hole to lose charge and mass until the perturbation becomes nonsuperradiant, with the final state described by a stable hairy black hole. For large gauge coupling, the instability extracts a large amount of charge per unit mass, resulting in greater entropy increase. We discuss the implications of the observed behavior for the general problem of superradiance in black hole spacetimes.
Spin Interaction under the Collision of Two Kerr-(Anti-de Sitter Black Holes
Directory of Open Access Journals (Sweden)
Bogeun Gwak
2017-12-01
Full Text Available We investigate herein the spin interaction during collisions between Kerr-(anti-de Sitter black holes. The spin interaction potential depends on the relative rotation directions of the black holes, and this potential can be released as gravitational radiation upon collision. The energy of the radiation depends on the cosmological constant and corresponds to the spin interaction potential in the limit that one of the black holes has negligibly small mass and angular momentum. We then determine the approximate overall behaviors of the upper bounds on the radiation using thermodynamics. The results indicate that the spin interaction can consistently contribute to the radiation. In addition, the radiation depends on the stability of the black hole produced by the collision.
From the Schwarzschild Anti-de Sitter Black Hole to the Conformal Field Theory
Directory of Open Access Journals (Sweden)
Akram Sadat Sefiedgar
2015-01-01
Full Text Available The emergence of the quantum gravitational effects in a very high energy regime necessitates some corrections to the thermodynamics of black holes. In this letter, we investigate a possible modification to the thermodynamics of Schwarzschild anti-de Sitter (SAdS black holes due to rainbow gravity model. Using the correspondence between a (d+1-dimensional SAdS black hole and a conformal filed theory in d-dimensional spacetime, one may find the corrections to the Cardy-Verlinde formula from the modified thermodynamics of the black hole. Furthermore, we show that the corrected Cardy-Verlinde formula can also be derived by redefining the Virasoro operator and the central charge.
The holographic Hadamard condition on asymptotically anti-de Sitter spacetimes
Wrochna, Michał
2017-12-01
In the setting of asymptotically anti-de Sitter spacetimes, we consider Klein-Gordon fields subject to Dirichlet boundary conditions, with mass satisfying the Breitenlohner-Freedman bound. We introduce a condition on the b-wave front set of two-point functions of quantum fields, which locally in the bulk amounts to the usual Hadamard condition, and which moreover allows to estimate wave front sets for the holographically induced theory on the boundary. We prove the existence of two-point functions satisfying this condition and show their uniqueness modulo terms that have smooth Schwartz kernel in the bulk and have smooth restriction to the boundary. Finally, using Vasy's propagation of singularities theorem, we prove an analogue of Duistermaat and Hörmander's theorem on distinguished parametrices.
de Sitter space as a tensor network: Cosmic no-hair, complementarity, and complexity
Bao, Ning; Cao, ChunJun; Carroll, Sean M.; Chatwin-Davies, Aidan
2017-12-01
We investigate the proposed connection between de Sitter spacetime and the multiscale entanglement renormalization ansatz (MERA) tensor network, and ask what can be learned via such a construction. We show that the quantum state obeys a cosmic no-hair theorem: the reduced density operator describing a causal patch of the MERA asymptotes to a fixed point of a quantum channel, just as spacetimes with a positive cosmological constant asymptote to de Sitter space. The MERA is potentially compatible with a weak form of complementarity (local physics only describes single patches at a time, but the overall Hilbert space is infinite dimensional) or, with certain specific modifications to the tensor structure, a strong form (the entire theory describes only a single patch plus its horizon, in a finite-dimensional Hilbert space). We also suggest that de Sitter evolution has an interpretation in terms of circuit complexity, as has been conjectured for anti-de Sitter space.
Compact space-like hypersurfaces in de Sitter space
Jinchi Lv
2005-01-01
We present some integral formulas for compact space-like hypersurfaces in de Sitter space and some equivalent characterizations for totally umbilical compact space-like hypersurfaces in de Sitter space in terms of mean curvature and higher-order mean curvatures.
Gravitational quasinormal modes of static Einstein-Gauss-Bonnet anti-de Sitter black holes
Ma, Hong; Li, Jin
2018-04-01
In this paper, we describe quasinormal modes (QNMs) for gravitational perturbations of Einstein-Gauss-Bonnet black holes (BHs) in higher dimensional spacetimes, and derive the corresponding parameters of such black holes in three types of spacetime (flat, de Sitter (dS) and anti-de Sitter (AdS)). Our attention is concentrated on discussing the (in)stability of Einstein-Gauss-Bonnet AdS BHs through the temporal evolution of all types of gravitational perturbation fields (tensor, vector and scalar). It is concluded that the potential functions in vector and scalar gravitational perturbations have negative regions, which suppress quasinormal ringing. Furthermore, the influences of the Gauss-Bonnet coupling parameter α, the number of dimensions n and the angular momentum quantum number l on the Einstein-Gauss-Bonnet AdS BHs quasinormal spectrum are analyzed. The QNM frequencies have greater oscillation and lower damping rate with the growth of α. This indicates that QNM frequencies become increasingly unstable with large α. Meanwhile, the dynamic evolutions of the perturbation field are compliant with the results of computation from the Horowitz and Hubeny method. Because the number of extra dimensions is connected with the string scale, the relationship between α and properties of Einstein-Gauss-Bonnet AdS BHs might be beneficial for the exploitation of string theory and extra-dimensional brane worlds. Supported by FAPESP (2012/08934-0), National Natural Science Foundation of China (11205254, 11178018, 11375279, 11605015), the Natural Science Foundation Project of CQ CSTC (2011BB0052), and the Fundamental Research Funds for the Central Universities (106112016CDJXY300002, 106112017CDJXFLX0014, CDJRC10300003)
Geodesic Motions near a Five-dimensional Reissner–Nordström Anti-de Sitter black hole
International Nuclear Information System (INIS)
Guha, Sarbari; Bhattacharya, Pinaki
2012-01-01
We have studied the geodesics of neutral particles near a non-rotating, charged five-dimensional Reissner–Nordström Anti-de Sitter black hole using the effective potential analysis and the dynamical systems analysis. The effective potential analysis is used to determine the location of the horizon and to study radial and circular trajectories. The dynamical systems method is used to determine the stability and the fixed points of the phase trajectories.
Charged black lens in de Sitter space
Tomizawa, Shinya
2018-02-01
We obtain a charged black lens solution in the five-dimensional Einstein-Maxwell-Chern-Simons theory with a positive cosmological constant. It is shown that the solution obtained here describes the formation of a black hole with the spatial cross section of a sphere from that of the lens space of L (n ,1 ) in five-dimensional de Sitter space.
Spherical and planar three-dimensional anti-de Sitter black holes
International Nuclear Information System (INIS)
Zanchin, Vilson T; Miranda, Alex S
2004-01-01
The technique of dimensional reduction was used in a recent paper (Zanchin V T, Kleber A and Lemos J P S 2002 Phys. Rev. D 66 064022) where a three-dimensional (3D) Einstein-Maxwell-dilaton theory was built from the usual four-dimensional (4D) Einstein-Maxwell-Hilbert action for general relativity. Starting from a class of 4D toroidal black holes in asymptotically anti-de Sitter (AdS) spacetimes several 3D black holes were obtained and studied in such a context. In the present work we choose a particular case of the 3D action which presents Maxwell field, dilaton field and an extra scalar field, besides gravity field and a negative cosmological constant, and obtain new 3D static black hole solutions whose horizons may have spherical or planar topology. We show that there is a 3D static spherically symmetric solution analogous to the 4D Reissner-Nordstroem-AdS black hole, and obtain other new 3D black holes with planar topology. From the static spherical solutions, new rotating 3D black holes are also obtained and analysed in some detail
Quintessence Reissner Nordström Anti de Sitter Black Holes and Joule Thomson Effect
Ghaffarnejad, H.; Yaraie, E.; Farsam, M.
2018-02-01
In this work we investigate corrections of the quintessence regime of the dark energy on the Joule-Thomson (JT) effect of the Reissner Nordström anti de Sitter (RNAdS) black hole. The quintessence dark energy has equation of state as p q = ω ρ q in which -1Hawking temperature on the T-P plan. We determine position of the inverse point versus different numerical values of the mass M and the charge Q of the quintessence AdS RN black hole. The cooling-heating phase transition (JT effect) is happened for M > Q in which the causal singularity is still covered by the horizon. Our calculations show sensitivity of the inverse point {T i , P i } position on the T-P plan to existence of the quintessence dark energy just for large numerical values of the AdS RN black holes charge Q. In other words the quintessence dark energy dose not affect on position of the inverse point when the AdS RN black hole takes on small charges.
International Nuclear Information System (INIS)
Peng Junjin; Wu Shuangqing
2008-01-01
Motivated by the success of the recently proposed method of anomaly cancellation to derive Hawking fluxes from black hole horizons of spacetimes in various dimensions, we have further extended the covariant anomaly cancellation method shortly simplified by Banerjee and Kulkarni to explore the Hawking radiation of the (3+1)-dimensional charged rotating black strings and their higher dimensional extensions in anti-de Sitter spacetimes, whose horizons are not spherical but can be toroidal, cylindrical or planar, according to their global identifications. It should be emphasized that our analysis presented here is very general in the sense that the determinant of the reduced (1+1)-dimensional effective metric from these black strings need not be equal to one (√(-g)≠1). Our results indicate that the gauge and energy-momentum fluxes needed to cancel the (1+1)-dimensional covariant gauge and gravitational anomalies are compatible with the Hawking fluxes. Besides, thermodynamics of these black strings are studied in the case of a variable cosmological constant
Wang, Mengjie; Herdeiro, Carlos; Jing, Jiliang
2017-11-01
We study Dirac quasinormal modes of Schwarzschild-anti-de Sitter (Schwarzschild-AdS) black holes, following the generic principle for allowed boundary conditions proposed in [M. Wang, C. Herdeiro, and M. O. P. Sampaio, Phys. Rev. D 92, 124006 (2015)., 10.1103/PhysRevD.92.124006]. After deriving the equations of motion for Dirac fields on the aforementioned background, we impose vanishing energy flux boundary conditions to solve these equations. We find a set of two Robin boundary conditions are allowed. These two boundary conditions are used to calculate Dirac normal modes on empty AdS and quasinormal modes on Schwarzschild-AdS black holes. In the former case, we recover the known normal modes of empty AdS; in the latter case, the two sets of Robin boundary conditions lead to two different branches of quasinormal modes. The impact on these modes of the black hole size, the angular momentum quantum number and the overtone number are discussed. Our results show that vanishing energy flux boundary conditions are a robust principle, applicable not only to bosonic fields but also to fermionic fields.
Rainbow valley of colored (anti) de Sitter gravity in three dimensions
Energy Technology Data Exchange (ETDEWEB)
Gwak, Seungho; Joung, Euihun; Mkrtchyan, Karapet; Rey, Soo-Jong [School of Physics & Astronomy and Center for Theoretical Physics, Seoul National University,Seoul 08826 (Korea, Republic of); Gauge, Gravity & Strings, Center for Theoretical Physics of the Universe,Institute for Basic Sciences,Daejeon 34047 (Korea, Republic of)
2016-04-11
We propose a theory of three-dimensional (anti) de Sitter gravity carrying Chan-Paton color charges. We define the theory by Chern-Simons formulation with the gauge algebra (gl{sub 2}⊕gl{sub 2})⊗u(N), obtaining a color-decorated version of interacting spin-one and spin-two fields. We also describe the theory in metric formulation and show that, among N{sup 2} massless spin-two fields, only the singlet one plays the role of metric graviton whereas the rest behave as colored spinning matter that strongly interacts at large N. Remarkably, these colored spinning matter acts as Higgs field and generates a non-trivial potential of staircase shape. At each extremum labelled by k=0,…,[((N−1)/2)], the u(N) color gauge symmetry is spontaneously broken down to u(N−k)⊕u(k) and provides different (A)dS backgrounds with the cosmological constants ((N/(N−2k))){sup 2} Λ. When this symmetry breaking takes place, the spin-two Goldstone modes combine with (or are eaten by) the spin-one gauge fields to become partially-massless spin-two fields. We discuss various aspects of this theory and highlight physical implications.
Discrete Torsion, (Anti) de Sitter D{sub 4}-Brane and Tunneling
Energy Technology Data Exchange (ETDEWEB)
Singh, Abhishek K.; Pandey, P.K.; Singh, Sunita; Kar, Supriya, E-mail: skkar@physics.du.ac.in
2014-06-15
We obtain quantum geometries on a vacuum created pair of a (DD{sup ¯}){sub 3}-brane, at a Big Bang singularity, by a local two form on a D{sub 4}-brane. In fact our analysis is provoked by an established phenomenon leading to a pair creation by a gauge field at a black hole horizon by Stephen Hawking in 1975. Importantly, the five dimensional microscopic black holes are described by an effective non-perturbative curvature underlying a discrete torsion in a second order formalism. In the case for a non-propagating torsion, the effective curvature reduces to Riemannian, which in a low energy limit may describe Einstein vacuum in the formalism. In particular, our analysis suggests that a non-trivial space begin with a hot de Sitter brane-Universe underlying a nucleation of a vacuum pair of (DD{sup ¯})-instanton at a Big Bang. A pair of instanton nucleats a D-particle which in turn combines with an anti D-particle to describe a D-string and so on. The nucleation of a pair of higher dimensional pair of brane/anti-brane from a lower dimensional pair may be viewed via an expansion of the brane-Universe upon time. It is in conformity with the conjecture of a branes within a brane presumably in presence of the non-zero modes of two form. Interestingly, we perform a thermal analysis underlying various emergent quantum de Sitter vacua on a D{sub 4}-brane and argue for the plausible tunneling geometries underlying a thermal equilibrium. It is argued that a de Sitter Schwarzschild undergoes quantum tunneling to an AdS-brane Schwarzschild via Nariai and de Sitter topological black hole.
Phase transitions in de Sitter space
Directory of Open Access Journals (Sweden)
Alexander Vilenkin
1983-10-01
Full Text Available An effective potential in de Sitter space is calculated for a model of two interacting scalar fields in one-loop approximation and in a self-consistent approximation which takes into account an infinite set of diagrams. Various approaches to renormalization in de Sitter space are discussed. The results are applied to analyze the phase transition in the Hawking-Moss version of the inflationary universe scenario. Requiring that inflation is sufficiently large, we derive constraints on the parameters of the model.
Krein Spaces in de Sitter Quantum Theories
Czech Academy of Sciences Publication Activity Database
Gazeau, J.P.; Siegl, Petr; Youssef, A.
2010-01-01
Roč. 6, - (2010), 011/1-011/23 ISSN 1815-0659 Institutional research plan: CEZ:AV0Z10480505 Keywords : de Sitter group * undecomposable representations * Krein spaces Subject RIV: BE - Theoretical Physics Impact factor: 0.856, year: 2010
Conamhna, Oisín A. P. Mac
2008-12-01
The supergravity description of various configurations of supersymmetric M-fivebranes wrapped on calibrated cycles of special holonomy manifolds is studied. The description is provided by solutions of eleven-dimensional supergravity which interpolate smoothly between a special holonomy manifold and an event horizon with Anti-de Sitter geometry. For known examples of Anti-de Sitter solutions, the associated special holonomy metric is derived. One explicit Anti-de Sitter solution of M-theory is so treated for fivebranes wrapping each of the following cycles: Kähler cycles in Calabi-Yau two, three- and four-folds; special lagrangian cycles in three- and four-folds; associative three- and co-associative four-cycles in G 2 manifolds; complex lagrangian four-cycles in Sp(2) manifolds; and Cayley four-cycles in Spin(7) manifolds. In each case, the associated special holonomy metric is singular, and is a hyperbolic analogue of a known metric. The analogous known metrics are respectively: Eguchi-Hanson, the resolved conifold and the four-fold resolved conifold; the deformed conifold, and the Stenzel four-fold metric; the Bryant-Salamon-Gibbons-Page-Pope G 2 metrics on an {mathbb{R}^4} bundle over S 3, and an {mathbb{R}^3} bundle over S 4 or {mathbb{CP}^2} ; the Calabi hyper-Kähler metric on {T^*mathbb{CP}^2} ; and the Bryant-Salamon-Gibbons-Page-Pope Spin(7) metric on an {mathbb{R}^4} bundle over S 4. By the AdS/CFT correspondence, a conformal field theory is associated to each of the new singular special holonomy metrics, and defines the quantum gravitational physics of the resolution of their singularities.
Constraining de Sitter Space in String Theory.
Kutasov, David; Maxfield, Travis; Melnikov, Ilarion; Sethi, Savdeep
2015-08-14
We argue that the heterotic string does not have classical vacua corresponding to de Sitter space-times of dimension four or higher. The same conclusion applies to type II vacua in the absence of Ramond-Ramond fluxes. Our argument extends prior supergravity no-go results to regimes of high curvature. We discuss the interpretation of the heterotic result from the perspective of dual type II orientifold constructions. Our result suggests that the genericity arguments used in string landscape discussions should be viewed with caution.
M-theory and stringy corrections to anti-de Sitter black holes and conformal field theories
International Nuclear Information System (INIS)
Caldarelli, Marco M.; Klemm, Dietmar
1999-01-01
We consider black holes in anti-de Sitter space AdS p+2 (p = 2, 3, 5), which have hyperbolic, flat or spherical event horizons. The O(α' 3 ) corrections (or the leading corrections in powers of the eleven-dimensional Planck length, in the case of M-theory compactifications) to the black hole metrics are computed for the various topologies and dimensions. We investigate the consequences of the stringy or M-theory corrections for the black hole thermodynamics. In particular, we show the emergence of a stable branch of small spherical black holes. Surprisingly, for any of the considered dimension and topologies, the corrected thermodynamical quantities turn out to coincide with those calculated within a simplified approach, which uses only the unperturbed metric. We obtain the corrected Hawking-Page transition temperature for black holes with spherical horizons, and show that for p = 3 this phase transition disappears at a value of α' considerably smaller than that estimated previously by Gao and Li. Using the AdS/CFT correspondence, we determine the S 1 x S 3 N = 4 SYM phase diagram for sufficiently large 't Hooft coupling, and show that the critical point at which the Hawking-Page transition disappears (the correspondence point of Horowitz-Polchinski), occurs at g 2 YM N ∼ 20.5. The d = 4 and d = 7 black hole phase diagrams are also determined, and connection is made with the corresponding boundary CFTs. Finally, for flat and hyperbolic horizons, we show that the leading stringy or M-theory corrections do not give rise to any phase transition. However, if the horizon is compactified to a torus T p or to a quotient of hyperbolic space, H p /Γ, the appearance of light winding modes around non-contractible cycles signal new phase transitions, which in the toroidal case have previously been discussed by Barbon et al. We comment on these phase transitions for SYM on H p /Γ and on T p , when the moduli of the torus are taken into account
Page, Don N.
2018-01-01
In an asymptotically flat spacetime of dimension d >3 and with the Newtonian gravitational constant G , a spherical black hole of initial horizon radius rh and mass M ˜rhd -3/G has a total decay time to Hawking emission of td˜rhd -1/G ˜G2 /(d -3 )M(d -1 )/(d -3 ) which grows without bound as the radius rh and mass M are taken to infinity. However, in asymptotically anti-de Sitter spacetime with a length scale ℓ and with absorbing boundary conditions at infinity, the total Hawking decay time does not diverge as the mass and radius go to infinity but instead remains bounded by a time of the order of ℓd-1/G .
Energy Technology Data Exchange (ETDEWEB)
Lin Kai, E-mail: lk314159@126.co [Institute of Theoretical Physics, China West Normal University, NanChong, SiChuan 637002 (China); Yang Shuzheng, E-mail: szyangcwnu@126.co [Institute of Theoretical Physics, China West Normal University, NanChong, SiChuan 637002 (China)
2009-10-12
Applying the method beyond semiclassical approximation, fermion tunneling from higher-dimensional anti-de Sitter Schwarzschild black hole is researched. In our work, the 'tortoise' coordinate transformation is introduced to simplify Dirac equation, so that the equation proves that only the (r-t) sector is important to our research. Because we only need to study the (r-t) sector, the Dirac equation is decomposed into several pairs of equations spontaneously, and we then prove the components of wave functions are proportional to each other in every pair of equations. Therefore, the suitable action forms of the wave functions are obtained, and finally the correctional Hawking temperature and entropy can be determined via the method beyond semiclassical approximation.
Quasilocal thermodynamics of Kerr and Kerr--anti-de Sitter spacetimes and the AdS/CFT correspondence
International Nuclear Information System (INIS)
Dehghani, M. H.; Mann, R. B.
2001-01-01
We consider the quasilocal thermodynamics of rotating black holes in asymptotically flat and asymptotically anti--de Sitter (AdS) spacetimes. Using the minimal number of intrinsic boundary counterterms inspired by the AdS/conformal field theory correspondence, we find that we are able to carry out an analysis of the thermodynamics of these black holes for virtually all possible values of the rotation parameter and cosmological constant that leave the quasilocal boundary well defined, going well beyond what is possible with background subtraction methods. Specifically, we compute the quasilocal energy E and angular momentum J for arbitrary values of the rotation, mass, and cosmological constant parameters for the (3+1)-dimensional Kerr, Kerr-AdS black holes, and (2+1)-dimensional Banados-Teitelboim-Zannelli (BTZ) black hole. We perform a quasilocal stability analysis and find phase behavior that is commensurate with previous analyses carried out at infinity
Applications of gauge/gravity dualities with charged Anti-de Sitter black holes
Energy Technology Data Exchange (ETDEWEB)
Grass, Viviane Theresa
2010-05-17
In this thesis, we deal with different applications of the Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence. The AdS/CFT correspondence, which is also more generally referred to as gauge/gravity duality, is a conjectured duality in superstring theory between strongly-coupled four-dimensional N=4 superconformal Yang-Mills theory and weakly-coupled type IIB string theory in five-dimensional AdS spacetime. This duality provides a powerful method to investigate strongly-coupled low-energy systems in four dimensions by substitutionally carrying out calculations in five-dimensional weakly-coupled supergravity. In this work, we use the AdS/CFT correspondence to explore three different strongly-coupled systems, namely a brane world accommodating a strongly-coupled field theory, a strongly-coupled fluid on a three-sphere and a strongly-coupled p-wave superfluid. In all these cases, the dual supergravity descriptions involve charged AdS black holes. The first system studied here is a Randall-Sundrum brane world moving in the background of a five-dimensional non-extremal black hole of N=2 gauged supergravity. The equations of motion of the brane are found to be equal to the Friedmann-Robertson-Walker (FRW) equations for a closed universe. The closed brane universe has special thermodynamic properties. The energy of the brane field theory exhibits a subextensive Casimir contribution, and the entropy can be expressed as a Cardy-Verlinde-type formula. We show that the equations for both quantities can take forms that strongly resemble the two FRW equations. At the horizon of the black hole, these two sets of equations are shown to even merge with each other which might suggest the existence of a common underlying theory. In addition, as a by-product result, the non-extremal black hole solutions considered here are found to admit an alternative description in terms of first-order flow equations similar to those which are well-known from the attractor mechanism of
Fuzzy Euclidean wormholes in de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Chen, Pisin; Hu, Yao-Chieh; Yeom, Dong-han, E-mail: pisinchen@phys.ntu.edu.tw, E-mail: r04244003@ntu.edu.tw, E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)
2017-07-01
We investigate Euclidean wormholes in Einstein gravity with a massless scalar field in de Sitter space. Euclidean wormholes are possible due to the analytic continuation of the time as well as complexification of fields, where we need to impose the classicality after the Wick-rotation to the Lorentzian signatures. For some parameters, wormholes are preferred than Hawking-Moss instantons, and hence wormholes can be more fundamental than Hawking-Moss type instantons. Euclidean wormholes can be interpreted in three ways: (1) classical big bounce, (2) either tunneling from a small to a large universe or a creation of a collapsing and an expanding universe from nothing, and (3) either a transition from a contracting to a bouncing phase or a creation of two expanding universes from nothing. These various interpretations shed some light on challenges of singularities. In addition, these will help to understand tensions between various kinds of quantum gravity theories.
Gravity mediated Dark Matter models in the de Sitter space
Vancea, Ion V.
2018-01-01
In this paper, we generalize the simplified Dark Matter models with graviton mediator to the curved space-time, in particular to the de Sitter space. We obtain the generating functional of the Green's functions in the Euclidean de Sitter space for the covariant free gravitons. We determine the generating functional of the interacting theory between Dark Matter particles and the covariant gravitons. Also, we calculate explicitly the 2-point and 3-point interacting Green's functions for the sym...
Principle of space existence and De Sitter metric
International Nuclear Information System (INIS)
Mal'tsev, V.K.
1990-01-01
The selection principle for the solutions of the Einstein equations suggested in a series of papers implies the existence of space (g ik ≠ 0) only in the presence of matter (T ik ≠0). This selection principle (principle of space existence, in the Markov terminology) implies, in the general case, the absence of the cosmological solution with the De Sitter metric. On the other hand, the De Sitter metric is necessary for describing both inflation and deflation periods of the Universe. It is shown that the De Sitter metric is also allowed by the selection principle under discussion if the metric experiences the evolution into the Friedmann metric
International Nuclear Information System (INIS)
Uchikata, Nami; Yoshida, Shijun
2011-01-01
We investigate quasinormal modes of a massless charged scalar field on a small Reissner-Nordstroem-anti-de Sitter (RN-AdS) black hole both with analytical and numerical approaches. In the analytical approach, by using the small black hole approximation (r + + /L→0, where r + and L stand for the black hole event horizon radius and the AdS scale, respectively. We then show that the small RN-AdS black hole is unstable if its quasinormal modes satisfy the superradiance condition and that the instability condition of the RN-AdS black hole in the limit of r + /L→0 is given by Q>(3/eL)Q c , where Q, Q c , and e are the charge of the black hole, the critical (maximum) charge of the black hole, and the charge of the scalar field, respectively. In the numerical approach, we calculate the quasinormal modes for the small RN-AdS black holes with r + + =0.2L, 0.1L, and 0.01L become unstable against scalar perturbations with eL=4 when the charge of the black hole satisfies Q > or approx. 0.8Q c , 0.78Q c , and 0.76Q c , respectively.
Superradiant instability of D-dimensional Reissner-Nordström-anti-de Sitter black hole mirror system
Huang, Yang; Liu, Dao-Jun; Li, Xin-Zhou
In this paper, a detailed analysis for superradiant stability of the system composed by a D-dimensional Reissner-Nordström-anti-de Sitter (RN-AdS) black hole and a reflecting mirror under charged scalar perturbations are presented in the linear regime. It is found that the stability of the system is heavily affected by the mirror radius as well as the mass of the scalar perturbation, AdS radius and the dimension of spacetime. In a higher dimensional spacetime, the degree of instability of the superradiant modes will be severely weakened. Nevertheless, the degree of instability can be magnified significantly by choosing a suitable value of the mirror radius. Remarkably, when the mirror radius is smaller than a threshold value the system becomes stable. We also find that massive charged scalar fields cannot trigger the instabilities in the background of D-dimensional asymptotically flat RN black hole. For a given scalar charge, a small RN-AdS black hole can be superradiantly unstable, while a large one may be always stable under charged scalar field with or without a reflecting mirror. We also show that these results can be easily expounded and understood with the help of factorized potential analysis.
Phase structure of the Born-Infeld-anti-de Sitter black holes probed by non-local observables
Energy Technology Data Exchange (ETDEWEB)
Zeng, Xiao-Xiong [Chongqing Jiaotong University, School of Material Science and Engineering, Chongqing (China); Chinese Academy of Sciences, Institute of Theoretical Physics, Beijing (China); Liu, Xian-Ming [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA (United States); Hubei University for Nationalities, Center for Theoretical Physics, School of Sciences, Enshi, Hubei (China); Li, Li-Fang [Chinese Academy of Sciences, State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Beijing (China)
2016-11-15
With the non-local observables such as two point correlation function and holographic entanglement entropy, we probe the phase structure of the Born-Infeld-anti-de Sitter black holes. For the case bQ > 0.5, where b is the Born-Infeld parameter and Q is the charge of the black hole, the phase structure is found to be similar to that of the Van der Waals phase transition, namely the black hole undergoes a first order phase transition and a second order phase transition before it reaches a stable phase. While for the case bQ < 0.5, a new phase branch emerges besides the Van der Waals phase transition. For the first order phase transition, the equal area law is checked, and for the second order phase transition, the critical exponent of the heat capacity is obtained. All these results are found to be the same as that observed in the entropy-temperature plane. (orig.)
Quantum physics of an elementary system in de Sitter space
International Nuclear Information System (INIS)
Rabeie, A.
2012-01-01
We present the coherent states of a scalar massive particle on 1+3-de Sitter space. These states are vectors in Hilbert space, and they are labeled by points in the associated phase space. To do this, we use the fact that the phase space of a scalar massive particle on 1+3-de Sitter space is a cotangent bundle T * (S 3 ) which is isomorphic with the complex sphere S C 3 . Then by using the heat kernel on '' S C 3 '' that was presented by Hall-Mitchell, we construct our coherent states. At the end, by these states we quantize the classical kinetic energy on de Sitter space. (orig.)
On a canonical quantization of 3D Anti de Sitter pure gravity
Kim, Jihun; Porrati, Massimo
2015-10-01
We perform a canonical quantization of pure gravity on AdS 3 using as a technical tool its equivalence at the classical level with a Chern-Simons theory with gauge group SL(2,{R})× SL(2,{R}) . We first quantize the theory canonically on an asymptotically AdS space -which is topologically the real line times a Riemann surface with one connected boundary. Using the "constrain first" approach we reduce canonical quantization to quantization of orbits of the Virasoro group and Kähler quantization of Teichmüller space. After explicitly computing the Kähler form for the torus with one boundary component and after extending that result to higher genus, we recover known results, such as that wave functions of SL(2,{R}) Chern-Simons theory are conformal blocks. We find new restrictions on the Hilbert space of pure gravity by imposing invariance under large diffeomorphisms and normalizability of the wave function. The Hilbert space of pure gravity is shown to be the target space of Conformal Field Theories with continuous spectrum and a lower bound on operator dimensions. A projection defined by topology changing amplitudes in Euclidean gravity is proposed. It defines an invariant subspace that allows for a dual interpretation in terms of a Liouville CFT. Problems and features of the CFT dual are assessed and a new definition of the Hilbert space, exempt from those problems, is proposed in the case of highly-curved AdS 3.
On a Canonical Quantization of 3D Anti de Sitter Pure Gravity
Kim, Jihun
2015-10-14
We perform a canonical quantization of pure gravity on AdS3 using as a technical tool its equivalence at the classical level with a Chern-Simons theory with gauge group SL(2,R)xSL(2,R). We first quantize the theory canonically on an asymptotically AdS space --which is topologically the real line times a Riemann surface with one connected boundary. Using the "constrain first" approach we reduce canonical quantization to quantization of orbits of the Virasoro group and Kaehler quantization of Teichmuller space. After explicitly computing the Kaehler form for the torus with one boundary component and after extending that result to higher genus, we recover known results, such as that wave functions of SL(2,R) Chern-Simons theory are conformal blocks. We find new restrictions on the Hilbert space of pure gravity by imposing invariance under large diffeomorphisms and normalizability of the wave function. The Hilbert space of pure gravity is shown to be the target space of Conformal Field Theories with continuous sp...
Gauge gravity in noncommutative de Sitter space and pair creation
Energy Technology Data Exchange (ETDEWEB)
Mebarki, N; Khodja, L; Aisaoui, H [Laboratoire de Physique Mathematique et Subatomique, Faculte des Sciences, Mentouri University, Constantine (Algeria); Zaim, S [Departement de Physique, Faculte des Sciences, Universite Hadj Lakhdar, Batna (Algeria)], E-mail: zaimslimane@yahoo.fr
2008-10-15
From the invariance of the generalized space-time non-commutative commutation relations, local Poincare and general coordinate transformations are derived. Moreover, a generalized Dirac equation is obtained. Applied to the de Sitter universe, it is shown that the space-time non-commutativity contributes to the particle creation process and induces a Casimir-like effect.
On a canonical quantization of 3D Anti de Sitter pure gravity
Energy Technology Data Exchange (ETDEWEB)
Kim, Jihun [Center for Cosmology and Particle Physics, Department of Physics,New York University, 4 Washington Place, New York, NY 10003 (United States); Porrati, Massimo [Center for Cosmology and Particle Physics, Department of Physics,New York University, 4 Washington Place, New York, NY 10003 (United States); CERN PH-TH, CH 1211,Geneva 23 (Switzerland)
2015-10-14
We perform a canonical quantization of pure gravity on AdS{sub 3} using as a technical tool its equivalence at the classical level with a Chern-Simons theory with gauge group SL(2,ℝ)×SL(2,ℝ). We first quantize the theory canonically on an asymptotically AdS space –which is topologically the real line times a Riemann surface with one connected boundary. Using the “constrain first” approach we reduce canonical quantization to quantization of orbits of the Virasoro group and Kähler quantization of Teichmüller space. After explicitly computing the Kähler form for the torus with one boundary component and after extending that result to higher genus, we recover known results, such as that wave functions of SL(2,ℝ) Chern-Simons theory are conformal blocks. We find new restrictions on the Hilbert space of pure gravity by imposing invariance under large diffeomorphisms and normalizability of the wave function. The Hilbert space of pure gravity is shown to be the target space of Conformal Field Theories with continuous spectrum and a lower bound on operator dimensions. A projection defined by topology changing amplitudes in Euclidean gravity is proposed. It defines an invariant subspace that allows for a dual interpretation in terms of a Liouville CFT. Problems and features of the CFT dual are assessed and a new definition of the Hilbert space, exempt from those problems, is proposed in the case of highly-curved AdS{sub 3}.
The rest mass of an asymptotically Anti-de Sitter spacetime
Chen, Po-Ning; Hung, Pei-Ken; Wang, Mu-Tao; Yau, Shing-Tung
2015-01-01
We study the space of Killing fields on the four dimensional AdS spacetime $AdS^{3,1}$. Two subsets $\\mathcal{S}$ and $\\mathcal{O}$ are identified: $\\mathcal{S}$ (the spinor Killing fields) is constructed from imaginary Killing spinors, and $\\mathcal{O}$ (the observer Killing fields) consists of all hypersurface orthogonal, future timelike unit Killing fields. When the cosmology constant vanishes, or in the Minkowski spacetime case, these two subsets have the same convex hull in the space of ...
Thermodynamics of Born-Infeld-anti-de Sitter black holes in the grand canonical ensemble
International Nuclear Information System (INIS)
Fernando, Sharmanthie
2006-01-01
The main objective of this paper is to study thermodynamics and stability of static electrically charged Born-Infeld black holes in AdS space in D=4. The Euclidean action for the grand canonical ensemble is computed with the appropriate boundary terms. The thermodynamical quantities such as the Gibbs free energy, entropy and specific heat of the black holes are derived from it. The global stability of black holes are studied in detail by studying the free energy for various potentials. For small values of the potential, we find that there is a Hawking-Page phase transition between a BIAdS black hole and the thermal-AdS space. For large potentials, the black hole phase is dominant and is preferred over the thermal-AdS space. Local stability is studied by computing the specific heat for constant potentials. The nonextreme black holes have two branches: small black holes are unstable and the large black holes are stable. The extreme black holes are shown to be stable both globally as well as locally. In addition to the thermodynamics, we also show that the phase structure relating the mass M and the charge Q of the black holes is similar to the liquid-gas-solid phase diagram
Hawking radiation from black holes in de Sitter spaces
International Nuclear Information System (INIS)
Jiang Qingquan
2007-01-01
Recently, Hawking radiation has been treated, by Robinson and Wilczek (2005 Phys. Rev. Lett. 95 011303), as a compensating flux of the energy-momentum tensor required to cancel a gravitational anomaly at the event horizon (EH) of a Schwarzschild-type black hole. In this paper, motivated by this work, Hawking radiation from the event horizon (EH) and the de Sitter cosmological horizon (CH) of black holes in de Sitter spaces, specifically including the purely de Sitter black hole and the static, spherically symmetric Schwarzschild-de Sitter black hole as well as the rotating Kerr-de Sitter black hole, have been studied by anomalies. The results show that the gauge-current and energy-momentum tensor fluxes, required to restore gauge invariance and general coordinate covariance at the EH and the CH, are precisely equal to those of Hawking radiation from the EH and the CH, respectively. It should be noted that gauge and gravitational anomalies taking place at the CH arise from the fact that the effective field theory is formulated inside the CH to integrate out the classically irrelevant outgoing modes at the CH, which are different from those at the black hole horizon
Holographic central charge for 2-dimensional de Sitter space
International Nuclear Information System (INIS)
Medved, A.J.M.
2003-01-01
Recently, investigations have begun into a holographic duality for two-dimensional de Sitter space. In this paper we evaluate the associated central charge, using a modified version of the canonical Hamiltonian method that was first advocated by Catelani and co-workers. Our computation agrees with that of a prior work (Cadoni et al.), but we argue that the method used here is, perhaps, aesthetically preferable on holographic grounds. We also confirm an agreement between the Cardy and thermodynamic entropy, thus providing further support for the conjectured two-dimensional de Sitter-conformal field theory correspondence
Consistency of scalar potentials from quantum de Sitter space
Espinosa, José R.; Fortin, Jean-François; Trépanier, Maxime
2016-06-01
Consistency of the unconventional view of de Sitter space as a quantum theory of gravity with a finite number of degrees of freedom requires that Coleman-De Luccia tunneling rates to vacua with negative cosmological constant should be interpreted as recurrences to low-entropy states. This demand translates into two constraints, or consistency conditions, on the scalar potential that are generically as follows: (1) the distance in field space between the de Sitter vacuum and any other vacuum with negative cosmological constant must be of the order of the reduced Planck mass or larger and (2) the fourth root of the vacuum energy density of the de Sitter vacuum must be smaller than the fourth root of the typical scale of the scalar potential. These consistency conditions shed a different light on both outstanding hierarchy problems of the standard model of particle physics: the scale of electroweak symmetry breaking and the scale of the cosmological constant. Beyond the unconventional interpretation of quantum de Sitter space, we complete the analytic understanding of the thin-wall approximation of Coleman-De Luccia tunneling, extend its numerical analysis to generic potentials and discuss the role of gravity in stabilizing the standard model potential.
Kinematics of a relativistic particle with de Sitter momentum space
Energy Technology Data Exchange (ETDEWEB)
Arzano, Michele [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Leuvenlaan 4, Utrecht 3584 TD (Netherlands); Kowalski-Glikman, Jerzy, E-mail: marzano@uu.nl, E-mail: jkowalskiglikman@ift.uni.wroc.pl [Institute for Theoretical Physics, University of Wroclaw, Pl. Maxa Borna 9, Pl-50-204 Wroclaw (Poland)
2011-05-21
We discuss kinematical properties of a free relativistic particle with deformed phase space in which momentum space is given by (a submanifold of) de Sitter space. We provide a detailed derivation of the action, Hamiltonian structure and equations of motion for such a free particle. We study the action of deformed relativistic symmetries on the phase space and derive explicit formulae for the action of the deformed Poincare group. Finally we provide a discussion on parametrization of the particle worldlines stressing analogies and differences with ordinary relativistic kinematics.
ADM Mass for Asymptotically de Sitter Space-Time
International Nuclear Information System (INIS)
Huang Shiming; Yue Ruihong; Jia Dongyan
2010-01-01
In this paper, an ADM mass formula for asymptotically de Sitter(dS) space-time is derived from the energy-momentum tensor. We take the vacuum dS space as the background and investigate the ADM mass of the (d + 3)-dimensional sphere-symmetric space with a positive cosmological constant, and find that the ADM mass of asymptotically dS space is based on the ADM mass of Schwarzschild field and the cosmological background brings some small mass contribution as well. (general)
Holographic Entropy on the Brane in de Sitter Schwarzschild Space
Ogushi, Sachiko
2001-01-01
The relationship between the entropy of de Sitter (dS) Schwarzschild space and that of the CFT, which lives on the brane, is discussed by using Friedmann-Robertson-Walker (FRW) equations and Cardy-Verlinde formula. The cosmological constant appears on the brane with time-like metric in dS Schwarzschild background. On the other hand, in case of the brane with space-like metric in dS Schwarzschild background, the cosmological constant of the brane does not appear because we can choose brane ten...
de Sitter Space in Non-Critical String Theory
Energy Technology Data Exchange (ETDEWEB)
Silverstein, Eva M
2002-08-13
Supercritical string theories in D > 10 dimensions with no moduli are described, generalizing the asymmetric orientifold construction of one of the authors [1]. By taking the number of dimensions to be large and turning on fluxes, dilaton potentials are generated with nontrivial minima at arbitrarily small cosmological constant and D-dimensional string coupling, separated by a barrier from a flat-space linear dilaton region, but possibly suffering from strong coupling problems. The general issue of the decay of a de Sitter vacuum to flat space is discussed. For relatively small barriers, such decays are described by gravitational instantons. It is shown that for a sufficiently large potential barrier, the bubble wall crosses the horizon. At the same time the instanton decay time exceeds the Poincare recurrence time. It is argued that the inclusion of such instantons is neither physically meaningful nor consistent with basic principles such as causality. This raises the possibility that such de Sitter vacua are effectively stable. In the case of the supercritical flux models, decays to the linear dilaton region can be forbidden by such large barriers, but decays to lower flux vacua including AdS minima nevertheless proceed consistently with this criterion. These models provide concrete examples in which cosmological constant reduction by flux relaxation can be explored.
Holographic Entropy on the Brane in de Sitter Schwarzschild Space
Ogushi, Sachiko
The relationship between the entropy of de Sitter (dS) Schwarzschild space and that of the CFT, which lives on the brane, is discussed by using Friedmann-Robertson-Walker (FRW) equations and Cardy-Verlinde formula. The cosmological constant appears on the brane with time-like metric in dS Schwarzschild background. On the other hand, in case of the brane with space-like metric in dS Schwarzschild background, the cosmological constant of the brane does not appear because we can choose brane tension to cancel it. We show that when the brane crosses the horizon of dS Schwarzschild black hole, both for time-like and space-like cases, the entropy of the CFT exactly agrees with the black hole entropy of five-dimensional dS background as it happens in the AdS/CFT correspondence.
Geometrothermodynamics for black holes and de Sitter space
Kurihara, Yoshimasa
2018-02-01
A general method to extract thermodynamic quantities from solutions of the Einstein equation is developed. In 1994, Wald established that the entropy of a black hole could be identified as a Noether charge associated with a Killing vector of a global space-time (pseudo-Riemann) manifold. We reconstruct Wald's method using geometrical language, e.g., via differential forms defined on the local space-time (Minkowski) manifold. Concurrently, the abstract thermodynamics are also reconstructed using geometrical terminology, which is parallel to general relativity. The correspondence between the thermodynamics and general relativity can be seen clearly by comparing the two expressions. This comparison requires a modification of Wald's method. The new method is applied to Schwarzschild, Kerr, and Kerr-Newman black holes and de Sitter space. The results are consistent with previous results obtained using various independent methods. This strongly supports the validity of the area theorem for black holes.
Directory of Open Access Journals (Sweden)
Ran Li
2016-07-01
Full Text Available Reissner–Nordström Anti-de Sitter (RNAdS black holes are unstable against the charged scalar field perturbations due to the well-known superradiance phenomenon. We present the time domain analysis of charged scalar field perturbations in the RNAdS black hole background in general dimensions. We show that the instabilities of charged scalar field can be explicitly illustrated from the time profiles of evolving scalar field. By using the Prony method to fit the time evolution data, we confirm the mode that dominates the long time behavior of scalar field is in accordance with the quasinormal mode from the frequency domain analysis. The superradiance origin of the instability can also be demonstrated by comparing the real part of the dominant mode with the superradiant condition of charged scalar field. It is shown that all the unstable modes are superradiant, which is consistent with the analytical result in the frequency domain analysis. Furthermore, we also confirm there exists the rapid exponential growing modes in the RNAdS case, which makes the RNAdS black hole a good test ground to investigate the nonlinear evolution of superradiant instability.
De Sitter space in gauge/gravity duality
Directory of Open Access Journals (Sweden)
Lilia Anguelova
2015-10-01
Full Text Available We investigate gauge/gravity duality for gauge theories in de Sitter space. More precisely, we study a five-dimensional consistent truncation of type IIB supergravity, which encompasses a wide variety of gravity duals of strongly coupled gauge theories, including the Maldacena–Nunez solution and its walking deformations. We find several solutions of the 5d theory with dS4 spacetime and nontrivial profiles for (some of the scalars along the fifth (radial direction. In the process, we prove that one of the equations of motion becomes dependent on the others, for nontrivial warp factor. This dependence reduces the number of field equations and, thus, turns out to be crucial for the existence of solutions with (AdS4 spacetime. Finally, we comment on the implications of our dS4 solutions for building gravity duals of Glueball Inflation.
'Massless' spin-(3)/(2) fields in the de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Azizi, A. [Islamic Azad University, Department of Physics, Sanandaj Branch, Sanandaj (Iran, Islamic Republic of); Amiri, M. [Razi University, Department of Physics, Kermanshah (Iran, Islamic Republic of)
2014-03-15
In this paper, 'massless' spin-(3)/(2) fields in the de Sitter space are considered. This work is a continuation of a previous paper devoted to the quantization of the de Sitter 'massive' spin-(3)/(2) fields. Due to the appearance of gauge invariance and an indefinite metric, the covariant quantization of the 'massless' spin-(3)/(2) fields requires an indecomposable representation of the de Sitter group. The gauge fixing corresponding to the simplest Gupta-Bleuler structure is used, and a gauge invariant field is discussed. The field equation is obtained by using the Casimir operator of the de Sitter group. The solutions are written in terms of the coordinateindependent de Sitter plane waves. Finally, the generalized two-point function is calculated. (orig.)
International Nuclear Information System (INIS)
Dias, Goncalo A. S.; Lemos, Jose P. S.
2009-01-01
The Hamiltonian thermodynamics formalism is applied to the general d-dimensional Reissner-Nordstroem-anti-de Sitter black hole with spherical, planar, and hyperbolic horizon topology. After writing its action and performing a Legendre transformation, surface terms are added in order to guarantee a well-defined variational principle with which to obtain sensible equations of motion, and also to allow later on the thermodynamical analysis. Then a Kuchar canonical transformation is done, which changes from the metric canonical coordinates to the physical parameters coordinates. Again, a well-defined variational principle is guaranteed through boundary terms. These terms influence the falloff conditions of the variables and at the same time the form of the new Lagrange multipliers. Reduction to the true degrees of freedom is performed, which are the conserved mass and charge of the black hole. Upon quantization a Lorentzian partition function Z is written for the grand canonical ensemble, where the temperature T and the electric potential φ are fixed at infinity. After imposing Euclidean boundary conditions on the partition function, the respective effective action I * , and thus the thermodynamical partition function, is determined for any dimension d and topology k. This is a quite general action. Several previous results can be then condensed in our single general formula for the effective action I * . Phase transitions are studied for the spherical case, and it is shown that all the other topologies have no phase transitions. A parallel with the Bose-Einstein condensation can be established. Finally, the expected values of energy, charge, and entropy are determined for the black hole solution.
Holography and quantum states in elliptic de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Halpern, Illan F. [Department of Physics, University of California,Berkeley, CA, 94720 (United States); Neiman, Yasha [Perimeter Institute for Theoretical Physics,31 Caroline Street N, Waterloo, ON, N2L 2Y5 (Canada)
2015-12-10
We outline a program for interpreting the higher-spin dS/CFT model in terms of physics in the causal patch of a dS observer. The proposal is formulated in “elliptic” de Sitter space dS{sub 4}/ℤ{sub 2}, obtained by identifying antipodal points in dS{sub 4}. We discuss recent evidence that the higher-spin model is especially well-suited for this, since the antipodal symmetry of bulk solutions has a simple encoding on the boundary. For context, we test some other (free and interacting) theories for the same property. Next, we analyze the notion of quantum field states in the non-time-orientable dS{sub 4}/ℤ{sub 2}. We compare the physics seen by different observers, with the outcome depending on whether they share an arrow of time. Finally, we implement the marriage between higher-spin holography and observers in dS{sub 4}/ℤ{sub 2}, in the limit of free bulk fields. We succeed in deriving an observer’s operator algebra and Hamiltonian from the CFT, but not her S-matrix. We speculate on the extension of this to interacting higher-spin theory.
Instanton tunneling for de Sitter space with real projective spatial sections
Energy Technology Data Exchange (ETDEWEB)
Ong, Yen Chin [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Yeom, Dong-han, E-mail: ongyenchin@sjtu.edu.cn, E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)
2017-04-01
The physics of tunneling from one spacetime to another is often understood in terms of instantons. For some instantons, it was recently shown in the literature that there are two complementary ''interpretations'' for their analytic continuations. Dubbed ''something-to-something'' and ''nothing-to-something'' interpretations, respectively, the former involves situation in which the initial and final hypersurfaces are connected by a Euclidean manifold, whereas the initial and final hypersurfaces in the latter case are not connected in such a way. We consider a de Sitter space with real projective space RP{sup 3} spatial sections, as was originally understood by de Sitter himself. This original version of de Sitter space has several advantages over the usual de Sitter space with S{sup 3} spatial sections. In particular, the interpretation of the de Sitter entropy as entanglement entropy is much more natural. We discuss the subtleties involved in the tunneling of such a de Sitter space.
Temperature and entropy of Schwarzschild-de Sitter space-time
International Nuclear Information System (INIS)
Shankaranarayanan, S.
2003-01-01
In the light of recent interest in quantum gravity in de Sitter space, we investigate semiclassical aspects of four-dimensional Schwarzschild-de Sitter space-time using the method of complex paths. The standard semiclassical techniques (such as Bogoliubov coefficients and Euclidean field theory) have been useful to study quantum effects in space-times with single horizons; however, none of these approaches seem to work for Schwarzschild-de Sitter space-time or, in general, for space-times with multiple horizons. We extend the method of complex paths to space-times with multiple horizons and obtain the spectrum of particles produced in these space-times. We show that the temperature of radiation in these space-times is proportional to the effective surface gravity--the inverse harmonic sum of surface gravity of each horizon. For the Schwarzschild-de Sitter space-time, we apply the method of complex paths to three different coordinate systems--spherically symmetric, Painleve, and Lemaitre. We show that the equilibrium temperature in Schwarzschild-de Sitter space-time is the harmonic mean of cosmological and event horizon temperatures. We obtain Bogoliubov coefficients for space-times with multiple horizons by analyzing the mode functions of the quantum fields near the horizons. We propose a new definition of entropy for space-times with multiple horizons, analogous to the entropic definition for space-times with a single horizon. We define entropy for these space-times to be inversely proportional to the square of the effective surface gravity. We show that this definition of entropy for Schwarzschild-de Sitter space-time satisfies the D-bound conjecture
Vacuum states for gravitons field in de Sitter space
Bamba, Kazuharu; Rahbardehghan, Surena; Pejhan, Hamed
2017-11-01
In this paper, considering the linearized Einstein equation with a two-parameter family of linear covariant gauges in de Sitter spacetime, we examine possible vacuum states for the gravitons field with respect to invariance under the de Sitter group S O0(1 ,4 ) . Our calculations explicitly reveal that there exists no natural de Sitter-invariant vacuum state (the Euclidean or Bunch-Davies state) for the gravitons field. Indeed, on the foundation of a rigorous group-theoretical reasoning, we prove that if one insists on full covariance as well as causality for the theory, one has to give up the positivity requirement of the inner product. However, one may still look for states with as much symmetry as possible, more precisely, a restrictive version of covariance by considering the gravitons field and the associated vacuum state which are, respectively, covariant and invariant with respect to some maximal subgroup of the full de Sitter group. In this regard, we treat the S O (4 ) case and find a family of S O (4 )-invariant states. The associated S O (4 )-covariant quantum field is given, as well.
Massless Interacting Scalar Fields in de Sitter space
López Nacir, Diana
2016-10-28
We present a method to compute the two-point functions for an $O(N)$ scalar field model in de Sitter spacetime, avoiding the well known infrared problems for massless fields. The method is based on an exact treatment of the Euclidean zero modes and a perturbative one of the nonzero modes, and involves a partial resummation of the leading secular terms. This resummation, crucial to obtain a decay of the correlation functions, is implemented along with a double expansion in an effective coupling constant $\\sqrt\\lambda$ and in $1/N$. The results reduce to those known in the leading infrared approximation and coincide with the ones obtained directly in Lorentzian de Sitter spacetime in the large $N$ limit. The new method allows for a systematic calculation of higher order corrections both in $\\sqrt\\lambda$ and in $1/N$.
Perturbative S-matrix for massive scalar fields in global de Sitter space
International Nuclear Information System (INIS)
Marolf, Donald; Srednicki, Mark; Morrison, Ian A
2013-01-01
We construct a perturbative S-matrix for interacting massive scalar fields in global de Sitter space. Our S-matrix is formulated in terms of asymptotic particle states in the far past and future, taking appropriate care for light fields whose wavefunctions decay only very slowly near the de Sitter conformal boundaries. An alternative formulation expresses this S-matrix in terms of residues of poles in analytically-continued Euclidean correlators (computed in perturbation theory), making it clear that the standard Minkowski-space result is obtained in the flat-space limit. Our S-matrix transforms properly under CPT, is invariant under the de Sitter isometries and perturbative field redefinitions, and is unitary. This unitarity implies a de Sitter version of the optical theorem. We explicitly verify these properties to second order in the coupling for a general cubic interaction, including both tree- and loop-level contributions. Contrary to other statements in the literature, we find that a particle of any positive mass may decay at tree level to any number of particles, each of arbitrary positive masses. In particular, even very light fields (in the complementary series of de Sitter representations) are not protected from tree-level decays. (paper)
On the solution of the Dirac equation in de Sitter space
International Nuclear Information System (INIS)
Klishevich, V V; Tyumentsev, V A
2005-01-01
It is shown that the maximal number of first-order symmetry operators for the Dirac equation (including spin symmetries), both in arbitrary signature flat space and in de Sitter space, is equal. The isomorphic representation of 11-dimensional nonlinear symmetry algebra (W-algebra) of first-order operators for the Dirac operator in flat space and de Sitter space is considered. The algebra is an extension of the Lie algebra of the group of pseudo-orthogonal rotations and this extension is unique. We have found all linear Lie subalgebras in the nonlinear algebra that satisfy the conditions of the noncommutative integration theorem. Using one subalgebra we have integrated the Dirac equation in the generalized spherical system of coordinates and have constructed the complete class of exact solutions. The solution is found by a method that differs from the variable separation method and is new in the literature. The massive particle spectrum, models of particle into antiparticle transmutation, the disappearance of particles and the quantization conditions of the motion are discussed. One can use the results of the paper to pose the boundary problem for the Dirac equation in de Sitter space if the interval is used in the boundary condition. As an example, we consider a model of asymptotically flat space that is glued from the de Sitter space and flat space. We interpret the model as a gravitational well or barrier
Perturbative quantization of superstring theory in Anti de-Sitter spaces
Energy Technology Data Exchange (ETDEWEB)
Sundin, Per
2010-07-12
In this thesis we study superstring theory on AdS{sub 5} x S{sup 5}, AdS{sub 3} x S{sup 3} and AdS{sub 4} x CP{sub 3}. A shared feature of each theory is that their corresponding symmetry algebras allows for a decomposition under a Z{sub 4} grading. The grading can be realized through an automorphism which allows for a convenient construction of the string Lagrangians directly in terms of graded components. We adopt a uniform light-cone gauge and expand in a near plane wave limit, or equivalently, an expansion in transverse string coordinates. With a main focus on the two critical string theories, we perform a perturbative quantization up to quartic order in the number of fields. Each string theory is, through holographic descriptions, conjectured to be dual to lower dimensional gauge theories. The conjectures imply that the conformal dimensions of single trace operators in gauge theory should be equal to the energy of string states. What is more, through the use of integrable methods, one can write down a set of Bethe equations whose solutions encode the full spectral problem. One main theme of this thesis is to match the predictions of these equations, written in a language suitable for the light-cone gauge we employ, against explicit string theory calculations. We do this for a large class of string states and the perfect agreement we find lends strong support for the validity of the conjectures. (orig.)
The gravitational exclusion principle and null states in anti-de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Castro, Alejandra; Maloney, Alexander [Department of Physics, McGill University, Montreal, QC (Canada); Hartman, Thomas [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ (United States)
2011-10-07
The holographic principle implies a vast reduction in the number of degrees of freedom of quantum gravity. This idea can be made precise in AdS{sub 3}, where the the stringy or gravitational exclusion principle asserts that certain perturbative excitations are not present in the exact quantum spectrum. We show that this effect is visible directly in the bulk gravity theory: the norm of the offending linearized state is zero or negative. When the norm is negative, the theory is signalling its own breakdown as an effective field theory; this provides a perturbative bulk explanation for the stringy exclusion principle. When the norm vanishes the bulk state is null rather than physical. This implies that certain non-trivial diffeomorphisms must be regarded as gauge symmetries rather than spectrum-generating elements of the asymptotic symmetry group. This leads to subtle effects in the computation of one-loop determinants for Einstein gravity, higher spin theories and topologically massive gravity in AdS{sub 3}. In particular, heat kernel methods do not capture the correct spectrum of a theory with null states. Communicated by S Ross
Semiclassical relations and IR effects in de Sitter and slow-roll space-times
DEFF Research Database (Denmark)
B. Giddings, Steven; Sloth, Martin Snoager
2010-01-01
We calculate IR divergent graviton one-loop corrections to scalar correlators in de Sitter space, and show that the leading IR contribution may be reproduced via simple semiclassical consistency relations. One can likewise use such semiclassical relations to calculate leading IR corrections to co...... with a sharp perturbative calculation of "missing information" in Hawking radiation....
PURE STATE ENTANGLEMENT ENTROPY IN NONCOMMUTATIVE 2D DE SITTER SPACE TIME
Directory of Open Access Journals (Sweden)
M.F Ghiti
2014-12-01
Full Text Available Using the general modified field equation, a general noncommutative Klein-Gordon equation up to the second order of the noncommutativity parameter is derived in the context of noncommutative 2D De Sitter space-time. Using Bogoliubov coefficients and a special technics called conformal time; the boson-antiboson pair creation density is determined. The Von Neumann boson-antiboson pair creation quantum entanglement entropy is presented to compute the entanglement between the modes created presented.
New tortoise coordinate transformation and Hawking's radiation in de Sitter space
Ibohal, N.; Ibungochouba, T.
2013-01-01
Hawking's radiation effect of Klein-Gordon equation, Dirac particles and Maxwell's electromagnetic fields in the non-stationary rotating de Sitter cosmological space-time is investigated by using a new method of generalized tortoise coordinate transformation. It is found that the new transformation produces constant additional terms in the expressions of the surface gravities and the Hawking's temperatures. If the constant terms are set to zero, then the surface gravities and Hawking's temperatures will be equal to those obtained from the old generalized tortoise coordinate transformations. This shows that the new transformations are more reasonable. The Fermionic spectrum of Dirac particles displays a new spin-rotation coupling effect.
Vacuum state of the Dirac field in de Sitter space and entanglement entropy
Energy Technology Data Exchange (ETDEWEB)
Kanno, Sugumi [Department of Theoretical Physics and History of Science,University of the Basque Country,48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science,Maria Diaz de Haro 3, 48013, Bilbao (Spain); Sasaki, Misao [Center for Gravitational Physics,Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan); Tanaka, Takahiro [Department of Physics, Kyoto University,Kyoto 606-8502 (Japan); Center for Gravitational Physics,Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan)
2017-03-13
We compute the entanglement entropy of a free massive Dirac field between two causally disconnected open charts in de Sitter space. We first derive the Bunch-Davies vacuum mode functions of the Dirac field. We find there exists no supercurvature mode for the Dirac field. We then give the Bogoliubov transformation between the Bunch-Davies vacuum and the open chart vacua that makes the reduced density matrix diagonal. We find that the Dirac field becomes more entangled than a scalar field as m{sup 2}/H{sup 2} becomes small, and the difference is maximal in the massless limit.
Nonequilibrium Dynamics of the σ-Model Modes on the de Sitter Space
Directory of Open Access Journals (Sweden)
Ion V. Vancea
2017-01-01
Full Text Available The two-dimensional σ-model with the de Sitter target space is locally canonic in the north pole diamond of the Penrose diagram in the cosmological gauge. The left and right moving modes on the cylindrical base space are entangled among themselves and interact with the de Sitter metric. Firstly, we show that the untangled oscillators can be obtained from the entangled operators by applying a set of Bogoliubov transformations constrained by the requirement that the partial evolution generator be diagonal. Secondly, we determine the nonequilibrium dynamics of the untangled modes in the nonequilibrium thermofield dynamics formalism. The thermal modes are represented as thermal doublet oscillators that satisfy partial evolution equations of Heisenberg-type. From these we compute the local free one-body propagator of an arbitrary mode between two times. Thirdly, we discuss the field representation of the thermal modes. We show that there is a set of thermal doublet fields that satisfy the equal time canonical commutation relations, are solutions to the σ-model equations of motion, and can be decomposed in terms of thermal doublet oscillators. Finally, we construct a local partial evolution functional of Hamilton-like form for the thermal doublet fields.
Solutions to Yang-Mills Equations on Four-Dimensional de Sitter Space.
Ivanova, Tatiana A; Lechtenfeld, Olaf; Popov, Alexander D
2017-08-11
We consider pure SU(2) Yang-Mills theory on four-dimensional de Sitter space dS_{4} and construct a smooth and spatially homogeneous magnetic solution to the Yang-Mills equations. Slicing dS_{4} as R×S^{3}, via an SU(2)-equivariant ansatz, we reduce the Yang-Mills equations to ordinary matrix differential equations and further to Newtonian dynamics in a double-well potential. Its local maximum yields a Yang-Mills solution whose color-magnetic field at time τ∈R is given by B[over ˜]_{a}=-1/2I_{a}/(R^{2}cosh^{2}τ), where I_{a} for a=1, 2, 3 are the SU(2) generators and R is the de Sitter radius. At any moment, this spatially homogeneous configuration has finite energy, but its action is also finite and of the value -1/2j(j+1)(2j+1)π^{3} in a spin-j representation. Similarly, the double-well bounce produces a family of homogeneous finite-action electric-magnetic solutions with the same energy. There is a continuum of other solutions whose energy and action extend down to zero.
$O(N)$ model in Euclidean de Sitter space: beyond the leading infrared approximation
Nacir, Diana López; Trombetta, Leonardo G
2016-01-01
We consider an $O(N)$ scalar field model with quartic interaction in $d$-dimensional Euclidean de Sitter space. In order to avoid the problems of the standard perturbative calculations for light and massless fields, we generalize to the $O(N)$ theory a systematic method introduced previously for a single field, which treats the zero modes exactly and the nonzero modes perturbatively. We compute the two-point functions taking into account not only the leading infrared contribution, coming from the self-interaction of the zero modes, but also corrections due to the interaction of the ultraviolet modes. For the model defined in the corresponding Lorentzian de Sitter spacetime, we obtain the two-point functions by analytical continuation. We point out that a partial resummation of the leading secular terms (which necessarily involves nonzero modes) is required to obtain a decay at large distances for massless fields. We implement this resummation along with a systematic double expansion in an effective coupling c...
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Baxter, J. Erik, E-mail: e.baxter@shu.ac.uk [Department of Engineering and Mathematics, Sheffield Hallam University, Sheffield S11WB (United Kingdom)
2016-02-15
We investigate dyonic black hole and dyon solutions of four-dimensional su(N) Einstein-Yang-Mills theory with a negative cosmological constant. We derive a set of field equations in this case, and prove the existence of non-trivial solutions to these equations for any integer N, with 2N − 2 gauge degrees of freedom. We do this by showing that solutions exist locally at infinity, and at the event horizon for black holes and the origin for solitons. We then prove that we can patch these solutions together regularly into global solutions that can be integrated arbitrarily far into the asymptotic regime. Our main result is to show that dyonic solutions exist in open sets in the parameter space, and hence that we can find non-trivial dyonic solutions in a number of regimes whose magnetic gauge fields have no zeros, which is likely important to the stability of the solutions.
International Nuclear Information System (INIS)
Peter, I. J.
1995-06-01
The work deals with space-times with fixed background metric. The topics were arranged in a straight course, the first chapter collects basic facts on Lorentzian manifolds as time-orientability, causal structure, ... Further free neutral scalar fields and spinor fields described by the Klein-Gordon equation resp. the Dirac equation are dealt with. Having in mind the construction of the Weyl algebra and the Fermi algebra in the second chapter, it was put emphasis on the structure of the spaces of solutions of these equations: In the first case the space of solutions is a symplectic vector space in a canonical manner, in the second case a Hilbert space. It was made some effort to stay as general as possible. Most of the material in the second chapter already exists for several years, but it is largely scattered over various journal articles. In the third chapter the construction of a vacuum on the special example of deSitter universe is described. A close investigation of a recent work by J. Bros and U. Moschella made it possible to refine a result concerning temperature felt by an accelerated observer in deSitter space. The last part of this thesis is concerned with vacua for spinor fields on the two-dimensional deSitter universe. A procedure introduced by R. Haag, H. Narnhofer and U. Stein for four dimensional space-times does not seem to work in two dimensions. (author)
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Anciaux, Henri, E-mail: henri.anciaux@gmail.com [Université Libre de Bruxelles, CP 216, local O.7.110, Bd du Triomphe, 1050 Brussels (Belgium); Godoy, Yamile, E-mail: yamile.godoy@gmail.com [FaMAF-CIEM, Ciudad Universitaria, 5000 Córdoba (Argentina)
2015-02-15
We give local, explicit representation formulas for n-dimensional spacelike submanifolds which are marginally trapped in the Minkowski space ℝ{sub 1}{sup n+2}, the de Sitter space dS{sup n+2}, the anti-de Sitter space AdS{sup n+2} and the Lorentzian products S{sup n+1} × ℝ and ℍ{sup n+1} × ℝ of the sphere and the hyperbolic space by the real line.
Anti-de Sitter gravitational collapse
Husain, V; Preston, B; Birukou, M
2003-01-01
We describe a formalism for studying spherically symmetric collapse of the massless scalar field in any spacetime dimension, and for any value of the cosmological constant LAMBDA. The formalism is used for numerical simulations of gravitational collapse in four spacetime dimensions with negative LAMBDA. We observe critical behaviour at the onset of black-hole formation, and find that the critical exponent is independent of LAMBDA. (letter to the editor)
Higher Spins without (Anti-de Sitter
Directory of Open Access Journals (Sweden)
Stefan Prohazka
2018-01-01
Full Text Available Can the holographic principle be extended beyond the well-known AdS/CFT correspondence? During the last couple of years, there has been a substantial amount of research trying to find answers for this question. In this work, we provide a review of recent developments of three-dimensional theories of gravity with higher spin symmetries. We focus in particular on a proposed holographic duality involving asymptotically flat spacetimes and higher spin extended bms 3 symmetries. In addition, we also discuss developments concerning relativistic and nonrelativistic higher spin algebras. As a special case, Carroll gravity will be discussed in detail.
arXiv Spectator electric fields, de Sitter space-time and the Schwinger effect
Giovannini, Massimo
2018-03-15
During a de Sitter stage of expansion, the spectator fields of different spin are constrained by the critical density bound and by further requirements determined by their specific physical nature. The evolution of spectator electric fields in conformally flat background geometries is occasionally concocted by postulating the existence of ad hoc currents, but this apparently innocuous trick violates the second law of thermodynamics. Such a problem occurs, in particular, for those configurations (customarily employed for the analysis of the Schwinger effect in four-dimensional de Sitter backgrounds) leading to an electric energy density which is practically unaffected by the expansion of the underlying geometry. The obtained results are compared with more mundane situations where Joule heating develops in the early stages of a quasi-de Sitter phase.
Evidence for a bound on the lifetime of de Sitter space
International Nuclear Information System (INIS)
Freivogel, Ben; Lippert, Matthew
2008-01-01
Recent work has suggested a surprising new upper bound on the lifetime of de Sitter vacua in string theory. The bound is parametrically longer than the Hubble time but parametrically shorter than the recurrence time. We investigate whether the bound is satisfied in a particular class of de Sitter solutions, the KKLT vacua. Despite the freedom to make the supersymmetry breaking scale exponentially small, which naively would lead to extremely stable vacua, we find that the lifetime is always less than about exp(10 22 ) Hubble times, in agreement with the proposed bound. This result, however, is contingent on several estimates and assumptions; in particular, we rely on a conjectural upper bound on the Euler number of the Calabi-Yau fourfolds used in KKLT compactifications.
Mass Formulae for Broken Supersymmetry in Curved Space-Time
Ferrara, Sergio
2016-01-01
We derive the mass formulae for ${\\cal N}=1$, $D=4$ matter-coupled Supergravity for broken (and unbroken) Supersymmetry in curved space-time. These formulae are applicable to de Sitter configurations as is the case for inflation. For unbroken Supersymmetry in anti-de Sitter (AdS) one gets the mass relations modified by the AdS curvature. We compute the mass relations both for the potential and its derivative non-vanishing.
Ciufolini, Ignazio; Matzner, Richard; Gurzadyan, Vahe; Penrose, Roger
2017-12-01
In two previous papers we presented the LARES 2 space experiment aimed at a very accurate test of frame-dragging and at other tests of fundamental physics and measurements of space geodesy and geodynamics. We presented the error sources of the LARES 2 experiment, its error budget and Monte Carlo simulations and covariance analyses confirming an accuracy of a few parts in one thousand in the test of frame-dragging. Here we discuss the impact of the orbital perturbation known as the de Sitter effect, or geodetic precession, in the error budget of the LARES 2 frame-dragging experiment. We show that the uncertainty in the de Sitter effect has a negligible impact in the final error budget because of the very accurate results now available for the test of the de Sitter precession and because of its very nature. The total error budget in the LARES 2 test of frame-dragging remains at a level of the order of 0.2%, as determined in the first two papers of this series.
Energy Technology Data Exchange (ETDEWEB)
Ciufolini, Ignazio [Universita del Salento, Dipt. Ingegneria dell' Innovazione, Lecce (Italy); Centro Fermi, Rome (Italy); Matzner, Richard [University of Texas, Theory Group, Austin (United States); Gurzadyan, Vahe [Alikhanian National Laboratory and Yerevan State University, Center for Cosmology and Astrophysics, Yerevan (Armenia); Penrose, Roger [University of Oxford, Mathematical Institute, Oxford (United Kingdom)
2017-12-15
In two previous papers we presented the LARES 2 space experiment aimed at a very accurate test of frame-dragging and at other tests of fundamental physics and measurements of space geodesy and geodynamics. We presented the error sources of the LARES 2 experiment, its error budget and Monte Carlo simulations and covariance analyses confirming an accuracy of a few parts in one thousand in the test of frame-dragging. Here we discuss the impact of the orbital perturbation known as the de Sitter effect, or geodetic precession, in the error budget of the LARES 2 frame-dragging experiment. We show that the uncertainty in the de Sitter effect has a negligible impact in the final error budget because of the very accurate results now available for the test of the de Sitter precession and because of its very nature. The total error budget in the LARES 2 test of frame-dragging remains at a level of the order of 0.2%, as determined in the first two papers of this series. (orig.)
The de Sitter relativistic top theory
International Nuclear Information System (INIS)
Armenta, J.; Nieto, J.A.
2005-01-01
We discuss the relativistic top theory from the point of view of the de Sitter (or anti-de Sitter) group. Our treatment rests on the Hanson-Regge spherical relativistic top Lagrangian formulation. We propose an alternative method for studying spinning objects via Kaluza-Klein theory. In particular, we derive the relativistic top equations of motion starting with the geodesic equation for a point particle in 4+N dimensions. We compare our approach with Fukuyama's formulation of spinning objects, which is also based on Kaluza-Klein theory. We also report a generalization of our approach to a 4+N+D dimensional theory
International Nuclear Information System (INIS)
Joung, Euihun; Mourad, Jihad; Parentani, Renaud
2007-01-01
We use an algebraic approach based on representations of de Sitter group to construct covariant quantum fields in arbitrary dimensions. We study the complementary and the discrete series which correspond to light and massless fields and which lead new feature with respect to the massive principal series we previously studied (hep-th/0606119). When considering the complementary series, we make use of a non-trivial scalar product in order to get local expressions in the position representation. Based on these, we construct a family of covariant canonical fields parametrized by SU(1, 1)/U(1). Each of these correspond to the dS invariant alpha-vacua. The behavior of the modes at asymptotic times brings another difficulty as it is incompatible with the usual definition of the in and out vacua. We propose a generalized notion of these vacua which reduces to the usual conformal vacuum in the conformally massless limit. When considering the massless discrete series we find that no covariant field obeys the canonical commutation relations. To further analyze this singular case, we consider the massless limit of the complementary scalar fields we previously found. We obtain canonical fields with a deformed representation by zero modes. The zero modes have a dS invariant vacuum with singular norm. We propose a regularization by a compactification of the scalar field and a dS invariant definition of the vertex operators. The resulting two-point functions are dS invariant and have a universal logarithmic infrared divergence
Holography in three-dimensional Kerr-de Sitter space with a gravitational Chern-Simons term
International Nuclear Information System (INIS)
Park, Mu-In
2008-01-01
The holographic description of the three-dimensional Kerr-de Sitter space with a gravitational Chern-Simons term is studied, in the context of dS/CFT correspondence. The space has only one (cosmological) event horizon and its mass and angular momentum are identified from the holographic energy-momentum tensor at the asymptotic infinity. The thermodynamic entropy of the cosmological horizon is computed directly from the first law of thermodynamics, with the conventional Hawking temperature, and it is found that the usual Gibbons-Hawking entropy is modified. It is remarked that, due to the gravitational Chern-Simons term, (a) the results go beyond the analytic continuation from AdS, (b) the maximum-mass/N-bound conjecture may be violated and (c) the three-dimensional cosmology is chiral. A statistical mechanical computation of the entropy, from a Cardy-like formula for a dual CFT at the asymptotic boundary, is discussed. Some remarks on the technical differences in the Chern-Simons energy-momentum tensor, from the literature, are also made
Pejhan, Hamed; Rahbardehghan, Surena
2016-04-01
Respecting that any consistent quantum field theory in curved space-time must include black hole radiation, in this paper, we examine the Krein-Gupta-Bleuler (KGB) formalism as an inevitable quantization scheme in order to follow the guideline of the covariance of minimally coupled massless scalar field and linear gravity on de Sitter (dS) background in the sense of Wightman-Gärding approach, by investigating thermodynamical aspects of black holes. The formalism is interestingly free of pathological large distance behavior. In this construction, also, no infinite term appears in the calculation of expectation values of the energy-momentum tensor (we have an automatic and covariant renormalization) which results in the vacuum energy of the free field to vanish. However, the existence of an effective potential barrier, intrinsically created by black holes gravitational field, gives a Casimir-type contribution to the vacuum expectation value of the energy-momentum tensor. On this basis, by evaluating the Casimir energy-momentum tensor for a conformally coupled massless scalar field in the vicinity of a nonrotating black hole event horizon through the KGB quantization, in this work, we explicitly prove that the hole produces black-body radiation which its temperature exactly coincides with the result obtained by Hawking for black hole radiation.
Fate of inhomogeneity in Schwarzschild-deSitter space-time
Nambu, Yasusada
1994-03-01
We investigate the global structure of the space-time with a spherically symmetric inhomogeneity using a metric junction, and classify all possible types. We found that a motion with a negative gravitational mass is possible although the energy condition of the matter is not violated. Using the result, formation of black hole and worm hole during the inflationary era is discussed.
Holographic space-time from the Big Bang to the de Sitter era
Banks, Tom
2009-07-01
I review the holographic theory of space-time and its applications to cosmology. Much of this has appeared before, but this discussion is more unified and concise. I also include some material on work in progress, whose aim is to understand compactification in terms of finite-dimensional super-algebras. This is an expanded version of a lecture I gave at the conference on Liouville Quantum Gravity and Statistical Systems, in memory of Alexei Zamolodchikov, at the Poncelet Institute in Moscow, 21-24 June 2008.
Holographic space-time from the Big Bang to the de Sitter era
Energy Technology Data Exchange (ETDEWEB)
Banks, Tom [Deptartment of Physics/SCIPP, University of California, Santa Cruz, CA 95064 (United States); Deptartment of Physics and Astronomy/NHETC, Rutgers University, Piscataway, NJ 08854 (United States)
2009-07-31
I review the holographic theory of space-time and its applications to cosmology. Much of this has appeared before, but this discussion is more unified and concise. I also include some material on work in progress, whose aim is to understand compactification in terms of finite-dimensional super-algebras. This is an expanded version of a lecture I gave at the conference on Liouville Quantum Gravity and Statistical Systems, in memory of Alexei Zamolodchikov, at the Poncelet Institute in Moscow, 21-24 June 2008.
Directory of Open Access Journals (Sweden)
Waldyr A. Rodrigues
2016-01-01
Full Text Available We discuss the physics of interacting fields and particles living in a de Sitter Lorentzian manifold (dSLM, a submanifold of a 5-dimensional pseudo-Euclidean (5dPE equipped with a metric tensor inherited from the metric of the 5dPE space. The dSLM is naturally oriented and time oriented and is the arena used to study the energy-momentum conservation law and equations of motion for physical systems living there. Two distinct de Sitter space-time structures MdSL and MdSTP are introduced given dSLM, the first equipped with the Levi-Civita connection of its metric field and the second with a metric compatible parallel connection. Both connections are used only as mathematical devices. Thus, for example, MdSL is not supposed to be the model of any gravitational field in the General Relativity Theory (GRT. Misconceptions appearing in the literature concerning the motion of free particles in dSLM are clarified. Komar currents are introduced within Clifford bundle formalism permitting the presentation of Einstein equation as a Maxwell like equation and proving that in GRT there are infinitely many conserved currents. We prove that in GRT even when the appropriate Killing vector fields exist it is not possible to define a conserved energy-momentum covector as in special relativistic theories.
Holographic thermalization in charged dilaton anti-de Sitter spacetime
Directory of Open Access Journals (Sweden)
Shao-Jun Zhang
2015-07-01
Full Text Available We study holographic thermalization in spacetimes with a chemical potential and a non-trivial dilaton field. Three non-local observables are used to probe the whole process and investigate the effect of the ratio of the chemical potential over temperature χ and the dilaton-Maxwell coupling constant α. It is found that the saturation time is not always a monotonically increasing function of χ, the situation depends on α. When 0≤α≤1, larger χ yields longer saturation time, while for α>1, the situation becomes more complex. More interesting, we found that although α indeed has influence on the whole thermalization process, it nearly does not affect the saturation time, which indicates the universality of the saturation time for the dual one-parameter field theories.
Expanding plasmas from anti de Sitter black holes
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Camilo, Giancarlo [Instituto de Fisica, Universidade de Sao Paulo, Departamento de Fisica Matematica, Sao Paulo (Brazil)
2016-12-15
We introduce a new foliation of AdS{sub 5} black holes such that the conformal boundary takes the form of a 4-dimensional FLRW spacetime with scale factor a(t). The foliation employs Eddington-Finkelstein-like coordinates and is applicable to a large class of AdS black holes, supported by matter fields or not, considerably extending previous efforts in the literature. We argue that the holographic dual picture of a CFT plasma on a FLRW background provides an interesting prototype to study the nonequilibrium dynamics of expanding plasmas and use holographic renormalization to extract the renormalized energy-momentum tensor of the dual plasma. We illustrate the procedure for three black holes of interest, namely AdS-Schwarzschild, AdS-Gauss-Bonnet, and AdS-Reissner-Nordstroem. For the latter, as a by-product, we show that the nonequilibrium dynamics of a CFT plasma subject to a quench in the chemical potential (i.e., a time-dependent chemical potential) resembles a cosmological evolution with the scale factor a(t) being inversely related to the quench profile μ(t). (orig.)
Group averaging for de Sitter free fields
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Marolf, Donald; Morrison, Ian A, E-mail: marolf@physics.ucsb.ed, E-mail: ian_morrison@physics.ucsb.ed [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
2009-12-07
Perturbative gravity about global de Sitter space is subject to linearization-stability constraints. Such constraints imply that quantum states of matter fields couple consistently to gravity only if the matter state has vanishing de Sitter charges, i.e. only if the state is invariant under the symmetries of de Sitter space. As noted by Higuchi, the usual Fock spaces for matter fields contain no de Sitter-invariant states except the vacuum, though a new Hilbert space of de Sitter-invariant states can be constructed via so-called group-averaging techniques. We study this construction for free scalar fields of arbitrary positive mass in any dimension, and for linear vector and tensor gauge fields in any dimension. Our main result is to show in each case that group averaging converges for states containing a sufficient number of particles. We consider general N-particle states with smooth wavefunctions, though we obtain somewhat stronger results when the wavefunctions are finite linear combinations of de Sitter harmonics. Along the way we obtain explicit expressions for general boost matrix elements in a familiar basis.
Density fluctuations in the de Sitter universe
International Nuclear Information System (INIS)
Banerjee, N.; Mallik, S.
1991-01-01
The de Sitter space-time appears to be the most widely chosen manifold to study quantum field theories on curved space-time. The reason is, of course, its high symmetry and the related fact that the mode functions can be obtained exactly in terms of known functions. Thus the different problems of quantization on curved space-time, like the non-uniqueness of the vacuum, regularization and renormalization of the stress tensor, have all been studied extensively in this model. The other reason of interest in the de Sitter geometry is related to the inflationary scenario of the early universe. For a brief period, the energy density of the false (symmetric) vacuum may dominate the total energy density, giving rise to de Sitter space-time. The resulting inflation may solve a number of outstanding problems of cosmology and particle physics. The properties of a Higgs-type scalar field theory is of central importance in the investigation of such a scenario. In this paper, a scalar Higgs field theory in de Sitter space-time has been investigated using the real time formulation of Semenoff and Weiss. The authors calculate the two-point function at late times and use it to obtain a general expression for the amplitude of fluctuation in energy density on scales which come out of the de Sitter horizon
Quantum break-time of de Sitter
Dvali, Gia; Gómez, César; Zell, Sebastian
2017-06-01
The quantum break-time of a system is the time-scale after which its true quantum evolution departs from the classical mean field evolution. For capturing it, a quantum resolution of the classical background—e.g., in terms of a coherent state—is required. In this paper, we first consider a simple scalar model with anharmonic oscillations and derive its quantum break-time. Next, following [1], we apply these ideas to de Sitter space. We formulate a simple model of a spin-2 field, which for some time reproduces the de Sitter metric and simultaneously allows for its well-defined representation as quantum coherent state of gravitons. The mean occupation number N of background gravitons turns out to be equal to the de Sitter horizon area in Planck units, while their frequency is given by the de Sitter Hubble parameter. In the semi-classical limit, we show that the model reproduces all the known properties of de Sitter, such as the redshift of probe particles and thermal Gibbons-Hawking radiation, all in the language of quantum S-matrix scatterings and decays of coherent state gravitons. Most importantly, this framework allows to capture the 1/N-effects to which the usual semi-classical treatment is blind. They violate the de Sitter symmetry and lead to a finite quantum break-time of the de Sitter state equal to the de Sitter radius times N. We also point out that the quantum-break time is inversely proportional to the number of particle species in the theory. Thus, the quantum break-time imposes the following consistency condition: older and species-richer universes must have smaller cosmological constants. For the maximal, phenomenologically acceptable number of species, the observed cosmological constant would saturate this bound if our Universe were 10100 years old in its entire classical history.
International Nuclear Information System (INIS)
Aldrovandi, R; Almeida, J P Beltran; Pereira, J G
2007-01-01
A special relativity based on the de Sitter group is introduced, which is a theory that might hold up in the presence of a non-vanishing cosmological constant. Like ordinary special relativity, it retains the quotient character of spacetime, and a notion of homogeneity. As a consequence, the underlying spacetime will be a de Sitter spacetime, whose associated kinematics will differ from that of ordinary special relativity. The corresponding modified notions of energy and momentum are obtained, and the exact relationship between them, which is invariant under a re-scaling of the involved quantities, explicitly exhibited. Since the de Sitter group can be considered a particular deformation of the Poincare group, this theory turns out to be a specific kind of deformed (or doubly) special relativity. Some experimental consequences, as well as the causal structure of spacetime-modified by the presence of the de Sitter horizon-are briefly discussed
Energy Technology Data Exchange (ETDEWEB)
Kirchbach, M. [UASLP, Instituto de Fisica, San Luis Potosi (Mexico); Compean, C.B. [Instituto Tecnologico de San Luis Potosi, San Luis Potosi (Mexico)
2016-07-15
The real parts of the complex squared energies defined by the resonance poles of the transfer matrix of the Poeschl-Teller barrier, are shown to equal the squared energies of the levels bound within the trigonometric Scarf well potential. By transforming these potentials into parts of the Laplacians describing free quantum motions on the mutually orthogonal open-time-like hyperbolic-, and closed-space-like spherical geodesics on the conformally invariant de Sitter space-time, dS{sub 4}, the conformal symmetries of these interactions are revealed. On dS{sub 4} the potentials under consideration naturally relate to interactions within colorless two-body systems and to cusped Wilson loops. In effect, with the aid of the dS{sub 4} space-time as unifying geometry, a conformal symmetry based bijective correspondence (duality) between bound and resonant meson spectra is established at the quantum mechanics level and related to confinement understood as color charge neutrality. The correspondence allows to link the interpretation of mesons as resonance poles of a scattering matrix with their complementary description as states bound by an instantaneous quark interaction and to introduce a conformal symmetry based classification scheme of mesons. As examples representative of such a duality we organize in good agreement with data 71 of the reported light flavor mesons with masses below ∝ 2350 MeV into four conformal families of particles placed on linear f{sub 0}, π, η, and a{sub 0} resonance trajectories, plotted on the l/M plane. Upon extending the sec{sup 2} χ by a properly constructed conformal color dipole potential, shaped after a tangent function, we predict the masses of 12 ''missing'' mesons. We furthermore notice that the f{sub 0} and π trajectories can be viewed as chiral partners, same as the η and a{sub 0} trajectories, an indication that chiral symmetry for mesons is likely to be realized in terms of parity doubled conformal
De Sitter projective relativity
Licata, Ignazio; Benedetto, Elmo
2017-01-01
This book presents the Projective approach to de Sitter Relativity. It traces the development of renewed interest in models of the universe at constant positive curvature such as "vacuum" geometry. The De Sitter Theory of Relativity, formulated in 1917 with Willem De Sitter's solution of the Einstein equations, was used in different fields during the 1950s and 1960s, in the work of H. Bacry, J.M. LevyLeblond and F.Gursey, to name some important contributors. From the 1960s to 1980s, L. Fantappié and G. Arcidiacono provided an elegant group approach to the De Sitter universe putting the basis for special and general projective relativity. Today such suggestions flow into a unitary scenario, and this way the De Sitter Relativity is no more a "missing opportunity" (F. Dyson, 1972), but has a central role in theoretical physics. In this volume a systematic presentation is given of the De Sitter Projective relativity, with the recent developments in projective general relativity and quantum cosmology.
de Sitter thermodynamics: A glimpse into nonequilibrium
International Nuclear Information System (INIS)
Aros, Rodrigo
2008-01-01
In this article it is shown that the thermodynamical evolution of a Schwarzschild de Sitter space is the evaporation of its black hole. The result is extended in higher dimensions to Lovelock theories of gravity with a single positive cosmological constant
Energy Technology Data Exchange (ETDEWEB)
Kirchbach, M. [Instituto de Fisica, UASLP, San Luis Potosi (Mexico); Compean, C.B. [Instituto Tecnologico de San Luis Potosi, Soledad de Graciano Sanchez (Mexico)
2017-04-15
In the article under discussion the analysis of the spectra of the unflavored mesons lead us to some intriguing insights into the possible geometry of space-time outside the causal Minkowski light cone and into the nature of strong interactions. In applying the potential theory concept of geometrization of interactions, we showed that the meson masses are best described by a confining potential composed by the centrifugal barrier on the three-dimensional spherical space, S{sup 3}, and of a charge-dipole potential constructed from the Green function to the S{sup 3} Laplacian. The dipole potential emerged in view of the fact that S{sup 3} does not support single-charges without violation of the Gauss theorem and the superposition principle, thus providing a natural stage for the description of the general phenomenon of confined charge-neutral systems. However, in the original article we did not relate the charge-dipoles on S{sup 3} to the color neutral mesons, and did not express the magnitude of the confining dipole potential in terms of the strong coupling α{sub S} and the number of colors, N{sub c}, the subject of the addendum. To the amount S{sup 3} can be thought of as the unique closed space-like geodesic of a four-dimensional de Sitter space-time, dS{sub 4}, we hypothesized the space-like region outside the causal Einsteinian light cone (it describes virtual processes, among them interactions) as the (1+4)-dimensional subspace of the conformal (2+4) space-time, foliated with dS{sub 4} special relativity for strong interaction processes. The potential designed in this way predicted meson spectra of conformal degeneracy patterns, and in accord with the experimental observations. We now extract the α{sub s} values in the infrared from data on meson masses. The results obtained are compatible with the α{sub s} estimates provided by other approaches. (orig.)
Anderson, Paul R.; Mottola, Emil; Sanders, Dillon H.
2018-03-01
The decay rate of the Bunch-Davies state of a massive scalar field in the expanding flat spatial sections of de Sitter space is determined by an analysis of the particle pair creation process in real time. The Feynman definition of particle and antiparticle Fourier mode solutions of the scalar wave equation and their adiabatic phase analytically continued to the complexified time domain show conclusively that the Bunch-Davies state is not the vacuum state at late times. The closely analogous creation of charged particle pairs in a uniform electric field is reviewed and Schwinger's result for the vacuum decay rate is recovered by this same real time analysis. The vacuum decay rate in each case is also calculated by switching the background field on adiabatically, allowing it to act for a very long time, and then adiabatically switching it off again. In both the uniform electric field and de Sitter cases, the particles created while the field is switched on are verified to be real, in the sense that they persist in the final asymptotic flat zero-field region. In the de Sitter case, there is an interesting residual dependence of the rate on how the de Sitter phase is ended, indicating a greater sensitivity to spatial boundary conditions. The electric current of the created particles in the E -field case and their energy density and pressure in the de Sitter case are also computed, and the magnitude of their backreaction effects on the background field estimated. Possible consequences of the Hubble scale instability of the de Sitter vacuum for cosmology, vacuum dark energy, and the cosmological "constant" problem are discussed.
Some Peculiarities of Newton-Hooke Space-Times
Tian, Yu
2011-01-01
Newton-Hooke space-times are the non-relativistic limit of (anti-)de Sitter space-times. We investigate some peculiar facts about the Newton-Hooke space-times, among which the "extraordinary Newton-Hooke quantum mechanics" and the "anomalous Newton-Hooke space-times" are discussed in detail. Analysis on the Lagrangian/action formalism is performed in the discussion of the Newton-Hooke quantum mechanics, where the path integral point of view plays an important role, and the physically measurab...
Information metric on instanton moduli spaces in nonlinear σ models
International Nuclear Information System (INIS)
Yahikozawa, Shigeaki
2004-01-01
We study the information metric on instanton moduli spaces in two-dimensional nonlinear σ models. In the CP 1 model, the information metric on the moduli space of one instanton with the topological charge Q=k(k≥1) is a three-dimensional hyperbolic metric, which corresponds to Euclidean anti-de Sitter space-time metric in three dimensions, and the overall scale factor of the information metric is 4k 2 /3; this means that the sectional curvature is -3/4k 2 . We also calculate the information metric in the CP 2 model
International Nuclear Information System (INIS)
Silverstein, Eva
2008-01-01
We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. We find metastable de Sitter (dS) minima of the potential for moduli obtained from a compactification on a product of two nil three-manifolds (which have negative scalar curvature) combined with orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete quantum number is taken large, the curvature, field strengths, inverse volume, and four-dimensional string coupling become parametrically small, and the de Sitter Hubble scale can be tuned parametrically smaller than the scales of the moduli, Kaluza Klein (KK), and winding mode masses. A subtle point in the construction is that although the curvature remains consistently weak, the circle fibers of the nilmanifolds become very small in this limit (though this is avoided in illustrative solutions at modest values of the parameters). In the simplest version of the construction, the heaviest moduli masses are parametrically of the same order as the lightest KK and winding masses. However, we provide a method for separating these marginally overlapping scales, and more generally the underlying supersymmetry of the model protects against large corrections to the low-energy moduli potential
Lie-Hamilton systems on curved spaces: a geometrical approach
Herranz, Francisco J.; de Lucas, Javier; Tobolski, Mariusz
2017-12-01
A Lie-Hamilton system is a nonautonomous system of first-order ordinary differential equations describing the integral curves of a t-dependent vector field taking values in a finite-dimensional Lie algebra, a Vessiot-Guldberg Lie algebra, of Hamiltonian vector fields relative to a Poisson structure. Its general solution can be written as an autonomous function, the superposition rule, of a generic finite family of particular solutions and a set of constants. We pioneer the study of Lie-Hamilton systems on Riemannian spaces (sphere, Euclidean and hyperbolic plane), pseudo-Riemannian spaces (anti-de Sitter, de Sitter, and Minkowski spacetimes) as well as on semi-Riemannian spaces (Newtonian spacetimes). Their corresponding constants of motion and superposition rules are obtained explicitly in a geometric way. This work extends the (graded) contraction of Lie algebras to a contraction procedure for Lie algebras of vector fields, Hamiltonian functions, and related symplectic structures, invariants, and superposition rules.
De Sitter structured connection and gauge translations
International Nuclear Information System (INIS)
Aldinger, R.R.
1986-01-01
A local gauge field description of space-time is discussed using fiber bundle techniques as a theoretical framework. The basic idea is to endow ordinary Minkowski space, M 4 , with a somewhat richer structure than that implied by relativity by attaching to each position x epsilon M 4 a copy of a four-dimensional micro-space of constant curvature characterized by an elementary subatomic length parameter R of the order of a Fermi, thus allowing for additional internal degrees-of-freedom. Therefore, two sets of variables are introduced: (i) the usual space-time variables x which determine an element of M 4 and (ii) a second set zeta which are elements of an internal space F (which is identified with the fiber of a bundle constructed over M 4 ). Consequently, they consider a fiber bundle E(B,F,G,P) constructed over a four-dimensional base manifold B (which is taken to be the usual Minkowski space, M 4 ), possessing a four-dimensional fiber F, and associated with the principal bundle P=P(B,G) (on which the connection is defined). The structural (gauge) group G of the bundle plays the role of an internal symmetry group and therefore determines the possible motions of the internal degrees-of-freedom belonging to the fibers. As fiber they choose a four-dimensional pseudo-Riemannian space of constant (negative) curvature R:F = SO(4,1)/SO(3,1) (i.e., a de Sitter space) which contains, at each point of contact with base manifold M 4 , a tangent space which is isomorphic to Minkowski space. The structural group of the bundle is a de Sitter SO(4,1) which contains a Lorentz subgroup and a four parameter family of transformations (the de Sitter boosts), which in the limit R → ∞ corresponding to translations. 10 references
'Micromanaging de Sitter holography'
Energy Technology Data Exchange (ETDEWEB)
Dong, Xi; Horn, Bart; /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP; Silverstein, Eva; /Santa Barbara, KITP /SLAC /Stanford U., Phys. Dept.; Torroba, Gonzalo; /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP
2010-08-26
We develop tools to engineer de Sitter vacua with semi-holographic duals, using elliptic fibrations and orientifolds to uplift Freund-Rubin compactifications with CFT duals. The dual brane construction is compact and constitutes a microscopic realization of the dS/dS correspondence, realizing d-dimensional de Sitter space as a warped compactification down to (d-1)-dimensional de Sitter gravity coupled to a pair of large-N matter sectors. This provides a parametric microscopic interpretation of the Gibbons-Hawking entropy. We illustrate these ideas with an explicit class of examples in three dimensions, and describe ongoing work on four-dimensional constructions. The Gibbons-Hawking entropy of the de Sitter horizon [1] invites a microscopic interpretation and a holographic formulation of inflating spacetimes. Much progress was made in the analogous problem in black hole physics using special black holes in string theory whose microstates could be reliably counted, such as those analyzed in [2,3]; this led to the AdS/CFT correspondence [4]. In contrast, a microscopic understanding of the entropy of de Sitter space is more difficult for several reasons including its potential dynamical connections to other backgrounds (metastability), the absence of a non-fluctuating timelike boundary, and the absence of supersymmetry. In this paper, we develop a class of de Sitter constructions in string theory, built up from AdS/CFT dual pairs along the lines of [5], which are simple enough to provide a microscopic accounting of the parametric scaling of the Gibbons-Hawking entropy. These models realize microscopically a semi-holographic description of metastable de Sitter space which had been derived macroscopically in [6]. It would also be interesting to connect this to other approaches to de Sitter holography such as [7, 8] and to other manifestations of the de Sitter entropy such as [9]. The construction is somewhat analogous to neutral black branes analyzed in [11]. We will
Graviatoms with de Sitter Interior
Directory of Open Access Journals (Sweden)
Irina Dymnikova
2013-01-01
Full Text Available We present a graviatom with de Sitter interior as a new candidate to atomic dark matter generically related to a vacuum dark energy through its de Sitter vacuum interior. It is a gravitationally bound quantum system consisting of a nucleus represented by a regular primordial black hole (RPBH, its remnant or gravitational vacuum soliton G-lump, and a charged particle. We estimate probability of formation of RPBHs and G-lumps in the early Universe and evaluate energy spectrum and electromagnetic radiation of graviatom which can in principle bear information about a fundamental symmetry scale responsible for de Sitter interior and serve as its observational signatures.
Nishi, Masato
2016-07-01
We discuss the large mass hierarchy problem in a braneworld model which represents our acceleratively expanding universe. The Randall-Sundrum (RS) model with one extra warped dimension added to a flat four-dimensional space-time cannot describe our expanding universe. Here, we study instead the de Sitter thin brane model. This is described by the same action as that for the RS model, but the four-dimensional space-time on the branes is dS_4. We study the model for both the cases of positive five-dimensional cosmological constant Λ_5 and a negative one. In the positive Λ_5 case, the four-dimensional large hierarchy necessitates a five-dimensional large hierarchy, and we cannot get a natural explanation. On the other hand, in the negative Λ_5 case, the large hierarchy is naturally realized in the five-dimensional theory in the same manner as in the RS model. Moreover, another large hierarchy between the Hubble parameter and the Planck scale is realized by the O(10^2) hierarchy of the five-dimensional quantities. Finally, we find that the lightest mass of the massive Kaluza-Klein modes and the intervals of the mass spectrum are of order 10^2 GeV, which are the same as in the RS case and do not depend on the value of the Hubble parameter.
Super-gauge field in de Sitter universe
Energy Technology Data Exchange (ETDEWEB)
Parsamehr, S.; Takook, M.V. [Islamic Azad University, Department of Physics, Science and Research Branch, Tehran (Iran, Islamic Republic of); Enayati, M. [Razi University, Department of Physics, Kermanshah (Iran, Islamic Republic of)
2016-05-15
The Gupta-Bleuler triplet for a vector-spinor gauge field is presented in the de Sitter ambient space formalism. The invariant space of field equation solutions is obtained with respect to an indecomposable representation of the de Sitter group. By using the general solution of the massless spin-(3)/(2) field equation, the vector-spinor quantum field operator and its corresponding Fock space is constructed. The quantum field operator can be written in terms of the vector-spinor polarization states and a quantum conformally coupled massless scalar field, which is constructed on Bunch-Davies vacuum state. The two-point function is also presented, which is de Sitter covariant and analytic. (orig.)
''Massless'' vector field in de Sitter universe
International Nuclear Information System (INIS)
Garidi, T.; Gazeau, J.-P.; Rouhani, S.; Takook, M. V.
2008-01-01
We proceed to the quantization of the massless vector field in the de Sitter (dS) space. This work is the natural continuation of a previous article devoted to the quantization of the dS massive vector field [J. P. Gazeau and M. V. Takook, J. Math. Phys. 41, 5920 (2000); T. Garidi et al., ibid. 43, 6379 (2002).] The term ''massless'' is used by reference to conformal invariance and propagation on the dS lightcone whereas ''massive'' refers to those dS fields which unambiguously contract to Minkowskian massive fields at zero curvature. Due to the combined occurrences of gauge invariance and indefinite metric, the covariant quantization of the massless vector field requires an indecomposable representation of the de Sitter group. We work with the gauge fixing corresponding to the simplest Gupta-Bleuler structure. The field operator is defined with the help of coordinate-independent de Sitter waves (the modes). The latter are simple to manipulate and most adapted to group theoretical approaches. The physical states characterized by the divergencelessness condition are, for instance, easy to identify. The whole construction is based on analyticity requirements in the complexified pseudo-Riemannian manifold for the modes and the two-point function
``Massless'' vector field in de Sitter universe
Garidi, T.; Gazeau, J.-P.; Rouhani, S.; Takook, M. V.
2008-03-01
We proceed to the quantization of the massless vector field in the de Sitter (dS) space. This work is the natural continuation of a previous article devoted to the quantization of the dS massive vector field [J. P. Gazeau and M. V. Takook, J. Math. Phys. 41, 5920 (2000); T. Garidi et al., ibid. 43, 6379 (2002).] The term ``massless'' is used by reference to conformal invariance and propagation on the dS lightcone whereas ``massive'' refers to those dS fields which unambiguously contract to Minkowskian massive fields at zero curvature. Due to the combined occurrences of gauge invariance and indefinite metric, the covariant quantization of the massless vector field requires an indecomposable representation of the de Sitter group. We work with the gauge fixing corresponding to the simplest Gupta-Bleuler structure. The field operator is defined with the help of coordinate-independent de Sitter waves (the modes). The latter are simple to manipulate and most adapted to group theoretical approaches. The physical states characterized by the divergencelessness condition are, for instance, easy to identify. The whole construction is based on analyticity requirements in the complexified pseudo-Riemannian manifold for the modes and the two-point function.
Ringing in de Sitter spacetime
Directory of Open Access Journals (Sweden)
Alex Buchel
2018-03-01
Full Text Available Hydrodynamics is a universal effective theory describing relaxation of quantum field theories towards equilibrium. Massive QFTs in de Sitter spacetime are never at equilibrium. We use holographic gauge theory/gravity correspondence to describe relaxation of a QFT to its Bunch–Davies vacuum — an attractor of its late-time dynamics. Specifically, we compute the analogue of the quasinormal modes describing the relaxation of a holographic toy model QFT in de Sitter.
Open string fluctuations in AdS space with and without torsion
DEFF Research Database (Denmark)
Larsen, A.L.; Lomholt, Michael Andersen
2003-01-01
The equations of motion and boundary conditions for the fluctuations around a classical open string, in a curved space-time with torsion, are considered in compact and world-sheet covariant form. The rigidly rotating open strings in anti-de Sitter space with and without torsion are investigated...... dangerous than expected in these cases. The general formalism can be straightforwardly used also to study the (bosonic part of the) fluctuations around the closed strings, recently considered in connection with the AdS/conformal field theory duality, on AdS ×S and AdS ×S ×T ....
Booted domain wall and charged Kaigorodov space
International Nuclear Information System (INIS)
Cai Ronggen
2003-01-01
The Kaigorodov space is a homogeneous Einstein space and it describes a pp-wave propagating in anti-de Sitter space. It is conjectured in the literature that M-theory or string theory on the Kaigorodov space times a compact manifold is dual to a conformal field theory in an infinitely-boosted frame with constant momentum density. In this Letter we present a charged generalization of the Kaigorodov space by boosting a non-extremal charged domain wall to the ultrarelativity limit where the boost velocity approaches the speed of light. The finite boost of the domain wall solution gives the charged generalization of the Carter-Novotny-Horsky metric. We study the thermodynamics associated with the charged Carter-Novotny-Horsky space and discuss its relation to that of the static black domain walls and its implications in the domain wall/QFT (quantum field theory) correspondence
Tracking our universe to de Sitter by a Horndeski scalar
Germani, Cristiano; Martín-Moruno, Prado
2017-12-01
Assuming both that our Universe is evolving into a de Sitter space and a vanishing cosmological constant, leaves only the option that the observed acceleration is provided by a "kinetic" energy of a scalar field. From an effective field theory point of view, the absence of Ostrogradsky instabilities restricts the choice to shift-symmetric Horndeski theories. Within these theories, we find the conditions for the existence of a de Sitter critical point in a universe filled by matter, radiation and a Horndeski scalar. Moreover, we show that this point is a universal attractor and we provide the tracking trajectory. Therefore, if a de Sitter fixed point exists within these models, our Universe will eventually evolve into a de Sitter space. As an example, we have discussed the case of the combined Galileon-Slotheon system, in which the Galileon is kinetically non-minimal coupled to the Einstein tensor. Interestingly, we have also found that the tracker trajectory of this system does not follow previous literature assumptions.
Effective Lagrangian from higher-curvature terms: absence of a vDVZ discontinuity in AdS space
Neupane, I P
2002-01-01
We argue that the van Dam-Veltman-Zakharov discontinuity arising in the M sup 2 -> 0 limit of the massive graviton through an explicit Pauli-Fierz mass term could be absent in anti-de Sitter space. This is possible if the graviton can acquire mass spontaneously from the higher-curvature terms and/or the massless limit M sup 2 -> 0 is attained faster than the cosmological constant LAMBDA -> 0. We discuss the effects of higher-curvature couplings and an explicit cosmological term (LAMBDA) on the stability of such a continuity and of massive excitations.
Gyromagnetic ratio of charged Kerr-anti-de Sitter black holes
International Nuclear Information System (INIS)
Aliev, Alikram N
2007-01-01
We examine the gyromagnetic ratios of rotating and charged AdS black holes in four and higher spacetime dimensions. We compute the gyromagnetic ratio for Kerr-AdS black holes with an arbitrary electric charge in four dimensions and show that it corresponds to g = 2 irrespective of the AdS nature of the spacetime. We also compute the gyromagnetic ratio for Kerr-AdS black holes with a single angular momentum and with a test electric charge in all higher dimensions. The gyromagnetic ratio crucially depends on the dimensionless ratio of the rotation parameter to the curvature radius of the AdS background. At the critical limit, when the boundary Einstein universe is rotating at the speed of light, it exhibits a striking feature leading to g 2 regardless of the spacetime dimension. Next, we extend our consideration to include the exact metric for five-dimensional rotating charged black holes in minimal gauged supergravity. We show that the value of the gyromagnetic ratio found in the 'test-charge' approach remains unchanged for these black holes
Characterizing asymptotically anti-de Sitter black holes with abundant stable gauge field hair
International Nuclear Information System (INIS)
Shepherd, Ben L; Winstanley, Elizabeth
2012-01-01
In the light of the 'no-hair' conjecture, we revisit stable black holes in su(N) Einstein-Yang-Mills theory with a negative cosmological constant Λ. These black holes are endowed with copious amounts of gauge field hair, and we address the question of whether these black holes can be uniquely characterized by their mass and a set of global non-Abelian charges defined far from the black hole. For the su(3) case, we present numerical evidence that stable black hole configurations are fixed by their mass and two non-Abelian charges. For general N, we argue that the mass and N - 1 non-Abelian charges are sufficient to characterize large stable black holes, in keeping with the spirit of the 'no-hair' conjecture, at least in the limit of very large |Λ| and for a subspace containing stable black holes (and possibly some unstable ones as well). (paper)
Asymptotically spacelike warped anti-de Sitter spacetimes in generalized minimal massive gravity
Setare, M. R.; Adami, H.
2017-06-01
In this paper we show that warped AdS3 black hole spacetime is a solution of the generalized minimal massive gravity (GMMG) and introduce suitable boundary conditions for asymptotically warped AdS3 spacetimes. Then we find the Killing vector fields such that transformations generated by them preserve the considered boundary conditions. We calculate the conserved charges which correspond to the obtained Killing vector fields and show that the algebra of the asymptotic conserved charges is given as the semi direct product of the Virasoro algebra with U(1) current algebra. We use a particular Sugawara construction to reconstruct the conformal algebra. Thus, we are allowed to use the Cardy formula to calculate the entropy of the warped black hole. We demonstrate that the gravitational entropy of the warped black hole exactly coincides with what we obtain via Cardy’s formula. As we expect, the warped Cardy formula also gives us exactly the same result as we obtain from the usual Cardy’s formula. We calculate mass and angular momentum of the warped black hole and then check that obtained mass, angular momentum and entropy to satisfy the first law of the black hole mechanics. According to the results of this paper we believe that the dual theory of the warped AdS3 black hole solution of GMMG is a warped CFT.
Asymptotically spacelike warped anti-de Sitter spacetimes in generalized minimal massive gravity
International Nuclear Information System (INIS)
Setare, M R; Adami, H
2017-01-01
In this paper we show that warped AdS 3 black hole spacetime is a solution of the generalized minimal massive gravity (GMMG) and introduce suitable boundary conditions for asymptotically warped AdS 3 spacetimes. Then we find the Killing vector fields such that transformations generated by them preserve the considered boundary conditions. We calculate the conserved charges which correspond to the obtained Killing vector fields and show that the algebra of the asymptotic conserved charges is given as the semi direct product of the Virasoro algebra with U (1) current algebra. We use a particular Sugawara construction to reconstruct the conformal algebra. Thus, we are allowed to use the Cardy formula to calculate the entropy of the warped black hole. We demonstrate that the gravitational entropy of the warped black hole exactly coincides with what we obtain via Cardy’s formula. As we expect, the warped Cardy formula also gives us exactly the same result as we obtain from the usual Cardy’s formula. We calculate mass and angular momentum of the warped black hole and then check that obtained mass, angular momentum and entropy to satisfy the first law of the black hole mechanics. According to the results of this paper we believe that the dual theory of the warped AdS 3 black hole solution of GMMG is a warped CFT. (paper)
Building an explicit de Sitter
Energy Technology Data Exchange (ETDEWEB)
Louis, Jan [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Hamburg Univ. (Germany). Zentrum fuer Mathematische Physik; Rummel, Markus; Valandro, Roberto [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie
2012-11-15
We construct an explicit example of a de Sitter vacuum in type IIB string theory that realizes the proposal of Kaehler uplifting. As the large volume limit in this method depends on the rank of the largest condensing gauge group we carry out a scan of gauge group ranks over the Kreuzer-Skarke set of toric Calabi-Yau threefolds. We find large numbers of models with the largest gauge group factor easily exceeding a rank of one hundred. We construct a global model with Kaehler uplifting on a two-parameter model on CP{sup 4}{sub 11169}, by an explicit analysis from both the type IIB and F-theory point of view. The explicitness of the construction lies in the realization of a D7 brane configuration, gauge flux and RR and NS flux choices, such that all known consistency conditions are met and the geometric moduli are stabilized in a metastable de Sitter vacuum with spontaneous GUT scale supersymmetry breaking driven by an F-term of the Kaehler moduli.
On classical de Sitter and Minkowski solutions with intersecting branes
Andriot, David
2018-03-01
Motivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersecting D p -branes and orientifold O p -planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination of D 3/ O 3 and D 7/ O 7, while we derive interesting constraints for intersecting D 5/ O 5 or D 6/ O 6, or combinations of D 4/ O 4 and D 8/ O 8. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersecting D p / O p overlap each other, a point we focus on.
Quantum corrections for spinning particles in de Sitter
Fröb, Markus B.; Verdaguer, Enric
2017-04-01
We compute the one-loop quantum corrections to the gravitational potentials of a spinning point particle in a de Sitter background, due to the vacuum polarisation induced by conformal fields in an effective field theory approach. We consider arbitrary conformal field theories, assuming only that the theory contains a large number N of fields in order to separate their contribution from the one induced by virtual gravitons. The corrections are described in a gauge-invariant way, classifying the induced metric perturbations around the de Sitter background according to their behaviour under transformations on equal-time hypersurfaces. There are six gauge-invariant modes: two scalar Bardeen potentials, one transverse vector and one transverse traceless tensor, of which one scalar and the vector couple to the spinning particle. The quantum corrections consist of three different parts: a generalisation of the flat-space correction, which is only significant at distances of the order of the Planck length; a constant correction depending on the undetermined parameters of the renormalised effective action; and a term which grows logarithmically with the distance from the particle. This last term is the most interesting, and when resummed gives a modified power law, enhancing the gravitational force at large distances. As a check on the accuracy of our calculation, we recover the linearised Kerr-de Sitter metric in the classical limit and the flat-space quantum correction in the limit of vanishing Hubble constant.
CFT description of three-dimensional Kerr-de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Fjelstad, Jens E-mail: jens.fjelstad@kau.se; Hwang, Stephen E-mail: stephen.hwang@kau.se; Maansson, Teresia E-mail: teresia@physto.se
2002-10-07
We describe three-dimensional Kerr-de Sitter space using similar methods as recently applied to the BTZ black hole. A rigorous form of the classical connection between gravity in three dimensions and two-dimensional conformal field theory is employed, where the fundamental degrees of freedom are described in terms of two dependent SL(2,C) currents. In contrast to the BTZ case, however, quantization does not give the Bekenstein-Hawking entropy connected to the cosmological horizon of Kerr-de Sitter space.
CFT description of three-dimensional Kerr-de Sitter spacetime
International Nuclear Information System (INIS)
Fjelstad, Jens; Hwang, Stephen; Maansson, Teresia
2002-01-01
We describe three-dimensional Kerr-de Sitter space using similar methods as recently applied to the BTZ black hole. A rigorous form of the classical connection between gravity in three dimensions and two-dimensional conformal field theory is employed, where the fundamental degrees of freedom are described in terms of two dependent SL(2,C) currents. In contrast to the BTZ case, however, quantization does not give the Bekenstein-Hawking entropy connected to the cosmological horizon of Kerr-de Sitter space
Mechanics and Newton-Cartan-like gravity on the Newton-Hooke space-time
International Nuclear Information System (INIS)
Tian Yu; Guo Hanying; Huang Chaoguang; Xu Zhan; Zhou Bin
2005-01-01
We focus on the dynamical aspects on Newton-Hooke space-time NH + mainly from the viewpoint of geometric contraction of the de Sitter spacetime with Beltrami metric. (The term spacetime is used to denote a space with non-degenerate metric, while the term space-time is used to denote a space with degenerate metric.) We first discuss the Newton-Hooke classical mechanics, especially the continuous medium mechanics, in this framework. Then, we establish a consistent theory of gravity on the Newton-Hooke space-time as a kind of Newton-Cartan-like theory, parallel to the Newton's gravity in the Galilei space-time. Finally, we give the Newton-Hooke invariant Schroedinger equation from the geometric contraction, where we can relate the conservative probability in some sense to the mass density in the Newton-Hooke continuous medium mechanics. Similar consideration may apply to the Newton-Hooke space-time NH - contracted from anti-de Sitter spacetime
Inflation as de Sitter instability
Energy Technology Data Exchange (ETDEWEB)
Cadoni, Mariano; Franzin, Edgardo [Universita di Cagliari, Cittadella Universitaria, Dipartimento di Fisica, Monserrato (Italy); INFN, Sezione di Cagliari, Monserrato (Italy); Mignemi, Salvatore [INFN, Sezione di Cagliari, Monserrato (Italy); Universita di Cagliari, Dipartimento di Matematica e Informatica, Cagliari (Italy)
2016-09-15
We consider cosmological inflation generated by a scalar field slowly rolling off from a de Sitter maximum of its potential. The models belong to the class of hilltop models and represent the most general model of this kind in which the scalar potential can be written as the sum of two exponentials. The minimally coupled Einstein-scalar gravity theory obtained in this way is the cosmological version of a two-scale generalization of known holographic models, allowing for solitonic solutions interpolating between an AdS spacetime in the infrared and scaling solutions in the ultraviolet. We then investigate cosmological inflation in the slow-roll approximation. Our model reproduces correctly, for a wide range of its parameters, the most recent experimental data for the power spectrum of primordial perturbations. Moreover, it predicts inflation at energy scales of four to five orders of magnitude below the Planck scale. At the onset of inflation, the mass of the tachyonic excitation, i.e. of the inflaton, turns out to be seven to eight orders of magnitude smaller than the Planck mass. (orig.)
Inflation in de Sitter spacetime and CMB large scale anomaly
Zhao, Dong; Li, Ming-Hua; Wang, Ping; Chang, Zhe
2015-09-01
The influence of cosmological constant-type dark energy in the early universe is investigated. This is accommodated by a new dispersion relation in de Sitter spacetime. We perform a global fit to explore the cosmological parameter space by using the CosmoMC package with the recently released Planck TT and WMAP polarization datasets. Using the results from the global fit, we compute a new CMB temperature-temperature (TT) spectrum. The obtained TT spectrum has lower power compared with that based on the ACDM model at large scales. Supported by National Natural Science Foundation of China (11375203)
Towards a quantization of gauge fields on de Sitter group by functional integral method
International Nuclear Information System (INIS)
Chiritoiu, Viorel; Zet, Gheorghe
2008-01-01
A formulation of the de Sitter symmetry as a purely inner symmetry defined on a fixed Minkowski space-time is presented. We define the generators of the de Sitter group and write the structure equations using a constant deformation parameter λ. The conserved gauge currents are calculated, and their physical meaning is given. Local gauge transformations and the corresponding covariant derivative depending on the gauge fields are also obtained. We study the behavior of gauge fields, the torsion and curvature tensors and give a regularization technique in terms of the ζ function. (orig.)
Gravitationally induced adiabatic particle production: from big bang to de Sitter
de Haro, Jaume; Pan, Supriya
2016-08-01
In the background of a flat homogeneous and isotropic space-time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology.
Higher order corrections to asymptotic-de Sitter inflation
Mohsenzadeh, M.; Yusofi, E.
2017-08-01
Since trans-Planckian considerations can be associated with the re-definition of the initial vacuum, we investigate further the influence of trans-Planckian physics on the spectra produced by the initial quasi-de Sitter (dS) state during inflation. We use the asymptotic-dS mode to study the trans-Planckian correction of the power spectrum to the quasi-dS inflation. The obtained spectra consist of higher order corrections associated with the type of geometry and harmonic terms sensitive to the fluctuations of space-time (or gravitational waves) during inflation. As an important result, the amplitude of the power spectrum is dependent on the choice of c, i.e. the type of space-time in the period of inflation. Also, the results are always valid for any asymptotic dS space-time and particularly coincide with the conventional results for dS and flat space-time.
International Nuclear Information System (INIS)
Moritz, Jakob; Retaloza, Ander; Westphal, Alexander
2017-07-01
Using a 10D lift of non-perturbative volume stabilization in type IIB string theory we study the limitations for obtaining de Sitter vacua. Based on this we find that the simplest KKLT vacua with a single Kahler modulus stabilized by a gaugino condensate cannot be uplifted to de Sitter. Rather, the uplift flattens out due to stronger backreaction on the volume modulus than has previously been anticipated, resulting in vacua which are meta-stable and SUSY breaking, but that are always AdS. However, we also show that setups such as racetrack stabilization can avoid this issue. In these models it is possible to obtain supersymmetric AdS vacua with a cosmological constant that can be tuned to zero while retaining finite moduli stabilization. In this regime, it seems that de Sitter uplifts are possible with negligible backreaction on the internal volume. We exhibit this behavior also from the 10D perspective.
A Spacetime Foam Approach to the Schwarzschild-de Sitter Entropy
Directory of Open Access Journals (Sweden)
Remo Garattini
2000-03-01
Full Text Available The entropy for a black hole in a de Sitter space is approached within the framework of spacetime foam. A simple model made by N wormholes in a semiclassical approximation, is taken under examination to compute the entropy for such a case. An extension to the extreme case when the black hole and cosmological horizons are equal is discussed.
Quasinormal modes in pure de Sitter spacetimes
International Nuclear Information System (INIS)
Du Daping; Wang Bin; Su Ruheng
2004-01-01
We have studied scalar perturbations as well as fermion perturbations in pure de Sitter spacetimes. For scalar perturbations we have shown that well-defined quasinormal modes in d-dimensions can exist provided that the mass of scalar field m>(d-1/2l). The quasinormal modes of fermion perturbations in three and four dimensional cases have also been investigated. We found that different from other dimensional cases, in the three dimensional pure de Sitter spacetime there is no quasinormal mode for the s-wave. This interesting difference caused by the spacial dimensions is true for both scalar and fermion perturbations
Collapse and Nonlinear Instability of AdS Space with Angular Momentum
Choptuik, Matthew W.; Dias, Óscar J. C.; Santos, Jorge E.; Way, Benson
2017-11-01
We present a numerical study of rotational dynamics in AdS5 with equal angular momenta in the presence of a complex doublet scalar field. We determine that the endpoint of gravitational collapse is a Myers-Perry black hole for high energies and a hairy black hole for low energies. We investigate the time scale for collapse at low energies E , keeping the angular momenta J ∝E in anti-de Sitter (AdS) length units. We find that the inclusion of angular momenta delays the collapse time, but retains a t ˜1 /E scaling. We perturb and evolve rotating boson stars, and find that boson stars near AdS space appear stable, but those sufficiently far from AdS space are unstable. We find that the dynamics of the boson star instability depend on the perturbation, resulting either in collapse to a Myers-Perry black hole, or development towards a stable oscillating solution.
Zero modes in de Sitter background
Energy Technology Data Exchange (ETDEWEB)
Einhorn, Martin B. [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States); Jones, D.R. Timothy [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States); Dept. of Mathematical Sciences, University of Liverpool,Liverpool L69 3BX (United Kingdom)
2017-03-28
There are five well-known zero modes among the fluctuations of the metric of de Sitter (dS) spacetime. For Euclidean signature, they can be associated with certain spherical harmonics on the S{sup 4} sphere, viz., the vector representation 5 of the global SO(5) isometry. They appear, for example, in the perturbative calculation of the on-shell effective action of dS space, as well as in models containing matter fields. These modes are shown to be associated with collective modes of S{sup 4} corresponding to certain coherent fluctuations. When dS space is embedded in flat five dimensions E{sup 5}, they may be seen as a legacy of translation of the center of the S{sup 4} sphere. Rigid translations of the S{sup 4}-sphere on E{sup 5} leave the classical action invariant but are unobservable displacements from the point of view of gravitational dynamics on S{sup 4}. Thus, unlike similar moduli, the center of the sphere is not promoted to a dynamical degree of freedom. As a result, these zero modes do not signify the possibility of physically realizable fluctuations or flat directions for the metric of dS space. They are not associated with Killing vectors on S{sup 4} but can be identified with certain non-isometric, conformal Killing forms that locally correspond to a rescaling of the volume element dV{sub 4}. We frame much of our discussion in the context of renormalizable gravity, but, to the extent that they only depend upon the global symmetry of the background, the conclusions should apply equally to the corresponding zero modes found in Einstein gravity. Although their existence has only been demonstrated at one-loop, we expect that these zero modes will be present to all orders in perturbation theory. They will occur for Lorentzian signature as well, so long as the hyperboloid H{sup 4} is locally stable, but there remain certain infrared issues that need to be clarified. We conjecture that they will appear in any gravitational theory having dS background as a
Flux compactifications, gauge algebras and De Sitter
Dibitetto, Giuseppe; Linares, Roman; Roest, Diederik
2010-01-01
The introduction of (non-)geometric fluxes allows for N = 1 moduli stabilisation in a De Sitter vacuum. The aim of this Letter is to assess to what extent this is true in N = 4 compactifications. First we identify the correct gauge algebra in terms of gauge and (non-)geometric fluxes. We then show
Transforming to Lorentz gauge on de Sitter
Miao, S. P.; Tsamis, N.C.; Woodard, R.P.
2009-01-01
We demonstrate that certain gauge fixing functionals cannot be added to the action on backgrounds such as de Sitter, in which a linearization instability is present. We also construct the field-dependent gauge transformation that carries the electromagnetic vector potential from a convenient, non-de
Cosmic curvature from de Sitter equilibrium cosmology.
Albrecht, Andreas
2011-10-07
I show that the de Sitter equilibrium cosmology generically predicts observable levels of curvature in the Universe today. The predicted value of the curvature, Ω(k), depends only on the ratio of the density of nonrelativistic matter to cosmological constant density ρ(m)(0)/ρ(Λ) and the value of the curvature from the initial bubble that starts the inflation, Ω(k)(B). The result is independent of the scale of inflation, the shape of the potential during inflation, and many other details of the cosmology. Future cosmological measurements of ρ(m)(0)/ρ(Λ) and Ω(k) will open up a window on the very beginning of our Universe and offer an opportunity to support or falsify the de Sitter equilibrium cosmology.
Representing the vacuum polarization on de Sitter
Energy Technology Data Exchange (ETDEWEB)
Leonard, Katie E.; Woodard, Richard P. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Prokopec, Tomislav [Institute of Theoretical Physics (ITP) and Spinoza Institute, Utrecht University, Postbus 80195, 3508 TD Utrecht (Netherlands)
2013-03-15
Previous studies of the vacuum polarization on de Sitter have demonstrated that there is a simple, noncovariant representation of it in which the physics is transparent. There is also a cumbersome, covariant representation in which the physics is obscure. Despite being unwieldy, the latter form has a powerful appeal for those who are concerned about de Sitter invariance. We show that nothing is lost by employing the simple, noncovariant representation because there is a closed form procedure for converting its structure functions to those of the covariant representation. We also present a vastly improved technique for reading off the noncovariant structure functions from the primitive diagrams. And we discuss the issue of representing the vacuum polarization for a general metric background.
Nonexistence of extremal de Sitter black rings
Khuri, Marcus; Woolgar, Eric
2017-11-01
We show that near-horizon geometries in the presence of a positive cosmological constant cannot exist with ring topology. In particular, de Sitter black rings with vanishing surface gravity do not exist. Our result relies on a known mathematical theorem which is a straightforward consequence of a type of energy condition for a modified Ricci tensor, similar to the curvature-dimension conditions for the m-Bakry-Émery-Ricci tensor.
QCD condensates and holographic Wilson loops for asymptotically AdS spaces
Quevedo, R. Carcasses; Goity, J. L.; Trinchero, R. C.
2014-02-01
The minimization of the Nambu-Goto action for a surface whose contour defines a circular Wilson loop of radius a placed at a finite value of the coordinate orthogonal to the boundary is considered. This is done for asymptotically anti-de Sitter (AdS) spaces. The condensates of even dimension n =2 through 10 are calculated in terms of the coefficient of an in the expansion of the on-shell subtracted Nambu-Goto action for small a. The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the condensates is universal in the sense that they only depend on the first coefficients of the difference with the AdS case.
Quantum loop corrections of a charged de Sitter black hole
Naji, J.
2018-03-01
A charged black hole in de Sitter (dS) space is considered and logarithmic corrected entropy used to study its thermodynamics. Logarithmic corrections of entropy come from thermal fluctuations, which play a role of quantum loop correction. In that case we are able to study the effect of quantum loop on black hole thermodynamics and statistics. As a black hole is a gravitational object, it helps to obtain some information about the quantum gravity. The first and second laws of thermodynamics are investigated for the logarithmic corrected case and we find that it is only valid for the charged dS black hole. We show that the black hole phase transition disappears in the presence of logarithmic correction.
Energy Technology Data Exchange (ETDEWEB)
Anabalón, Andrés, E-mail: andres.anabalon-at@uai.cl [Departamento de Ciencias, Facultad de Artes Liberales y Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar (Chile); Astefanesei, Dumitru [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile)
2015-03-26
We review the existence of exact hairy black holes in asymptotically flat, anti-de Sitter and de Sitter space-times. We briefly discuss the issue of stability and the charging of the black holes with a Maxwell field.
Emergent gravity in spaces of constant curvature
Energy Technology Data Exchange (ETDEWEB)
Alvarez, Orlando; Haddad, Matthew [Department of Physics, University of Miami,1320 Campo Sano Ave, Coral Gables, FL 33146 (United States)
2017-03-07
In physical theories where the energy (action) is localized near a submanifold of a constant curvature space, there is a universal expression for the energy (or the action). We derive a multipole expansion for the energy that has a finite number of terms, and depends on intrinsic geometric invariants of the submanifold and extrinsic invariants of the embedding of the submanifold. This is the second of a pair of articles in which we try to develop a theory of emergent gravity arising from the embedding of a submanifold into an ambient space equipped with a quantum field theory. Our theoretical method requires a generalization of a formula due to by Hermann Weyl. While the first paper discussed the framework in Euclidean (Minkowski) space, here we discuss how this framework generalizes to spaces of constant sectional curvature. We focus primarily on anti de Sitter space. We then discuss how such a theory can give rise to a cosmological constant and Planck mass that are within reasonable bounds of the experimental values.
Emergent gravity in spaces of constant curvature
Alvarez, Orlando; Haddad, Matthew
2017-03-01
In physical theories where the energy (action) is localized near a submanifold of a constant curvature space, there is a universal expression for the energy (or the action). We derive a multipole expansion for the energy that has a finite number of terms, and depends on intrinsic geometric invariants of the submanifold and extrinsic invariants of the embedding of the submanifold. This is the second of a pair of articles in which we try to develop a theory of emergent gravity arising from the embedding of a submanifold into an ambient space equipped with a quantum field theory. Our theoretical method requires a generalization of a formula due to by Hermann Weyl. While the first paper discussed the framework in Euclidean (Minkowski) space, here we discuss how this framework generalizes to spaces of constant sectional curvature. We focus primarily on anti de Sitter space. We then discuss how such a theory can give rise to a cosmological constant and Planck mass that are within reasonable bounds of the experimental values.
De Sitter universes and the emerging landscape in string theory
Indian Academy of Sciences (India)
gravity coupled to a positive cosmological constant gives rise to an exponentially expanding solution, called the de Sitter ... Thus thinking of this question brings us to the frontiers of our understanding of string ... calculated, and those with a positive value give rise to de Sitter universes. In the rest of this article I will describe a ...
Analytic extension of the Schwarzschild-de Sitter metric
International Nuclear Information System (INIS)
Bazanski, S.L.; Ferrari, V.
1986-01-01
In this paper, co-ordinates are derived that are regular, respectively, in the neighbourhood of the two horizons which exist in the so-called Schwarzschild-de Sitter solution known in general relativity, and it is constructed a manifold that is the analytic extension of the manifold being the domain of classical Schwarzschild-de Sitter co-ordinates
Pair of accelerated black holes in a de Sitter background: The dS C metric
International Nuclear Information System (INIS)
Dias, Oscar J.C.; Lemos, Jose P.S.
2003-01-01
Following the work of Kinnersley and Walker for flat spacetimes, we analyzed the anti-de Sitter C metric in a previous paper. In this paper we study the de Sitter C metric (dS C metric). The C metric with a generic cosmological constant and other extra parameters was introduced by Plebanski and Demianski. When one then sets to zero some of the extra parameters, and works with a positive cosmological constant, one has the dS C metric which has been analyzed and physically interpreted by Podolsky and Griffiths. It describes a pair of accelerated black holes in the dS background with the acceleration being provided (in addition to the cosmological constant) by a strut that pushes away the two black holes or, alternatively, by a string that pulls them. We extend their analysis mainly in four directions. First, we draw the Carter-Penrose diagrams of the massless uncharged dS C metric, of the massive uncharged dS C metric and of the massive charged dS C metric. These diagrams allow us to clearly identify the presence of two dS black holes and to conclude that they cannot interact gravitationally. Second, we reexamine the embedding of the dS C metric in the 5D Minkowski spacetime and we represent the motion of the dS C metric origin in the dS 4-hyperboloid as well as the localization of the strut. Third, we comment on the physical properties of the strut that connects the two black holes. Finally, we find the range of parameters that correspond to nonextreme black holes, extreme black holes, and naked particles
arXiv On classical de Sitter and Minkowski solutions with intersecting branes
Andriot, David
2018-03-09
Motivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersecting D$_{p}$ -branes and orientifold O$_{p}$ -planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination of D$_{3}$/O$_{3}$ and D$_{7}$/O$_{7}$, while we derive interesting constraints for intersecting D$_{5}$/O$_{5}$ or D$_{6}$/O$_{6}$, or combinations of D$_{4}$/O$_{4}$ and D$_{8}$/O$_{8}$. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersecting D$_{p}$ /O$_{p}$ overlap each other, a point we focus on.
Vacuum polarization on black hole space times
International Nuclear Information System (INIS)
Jensen, B.P.
1985-01-01
The effects of vacuum polarization in black hole space times are examined. Particular attention is given to the vacuum physics inside the event horizon. The analytic properties of the solutions to the radial wave equation in Schwarzs child space time as functions of argument, frequency, and angular momentum are given. These functions are employed to define the Feynmann Green function (G/sub F/(x,x') for a scalar field subject to the Hartle-Hawking boundary conditions. An examination of the Schwarzschild mode functions near r = 0 is provided. This work is necessary background for a future calculation of 2 > and the quantum stress-energy tensor for small r. Some opinions are given on how this calculation might be performed. A solution of the one-loop Einstein equations for Schwarzs child Anti-deSitter (SAdS) space time is presented, using Page's approximation to the quantum stress tensor. The resulting perturbed metric is shown to be unphysical, as it leads to a system of fields with infinite total energy. This problem is believed to be due to a failure of Page's method in SAdS. Suggestions are given on how one might correct the method
Ghost inflation and de Sitter entropy
Jazayeri, Sadra; Mukohyama, Shinji; Saitou, Rio; Watanabe, Yota
2016-08-01
In the setup of ghost condensation model the generalized second law of black hole thermodynamics can be respected under a radiatively stable assumption that couplings between the field responsible for ghost condensate and matter fields such as those in the Standard Model are suppressed by the Planck scale. Since not only black holes but also cosmology are expected to play important roles towards our better understanding of gravity, we consider a cosmological setup to test the theory of ghost condensation. In particular we shall show that the de Sitter entropy bound proposed by Arkani-Hamed, et al. is satisfied if ghost inflation happened in the early epoch of our universe and if there remains a tiny positive cosmological constant in the future infinity. We then propose a notion of cosmological Page time after inflation.
A de Sitter tachyon thick braneworld
Energy Technology Data Exchange (ETDEWEB)
Germán, Gabriel; Herrera-Aguilar, Alfredo; Malagón-Morejón, Dagoberto [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apdo. Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Mora-Luna, Refugio Rigel [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, C.P. 58040, Morelia, Michoacán (Mexico); Rocha, Roldão da, E-mail: gabriel@fis.unam.mx, E-mail: aha@fis.unam.mx, E-mail: malagon@ifm.umich.mx, E-mail: rigel@ifm.umich.mx, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Rua Santa Adélia, 166 09210-170, Santo André, SP (Brazil)
2013-02-01
Among the multiple 5D thick braneworld models that have been proposed in the last years, in order to address several open problems in modern physics, there is a specific one involving a tachyonic bulk scalar field. Delving into this framework, a thick braneworld with a cosmological background induced on the brane is here investigated. The respective field equations — derived from the model with a warped 5D geometry — are highly non-linear equations, admitting a non-trivial solution for the warp factor and the tachyon scalar field as well, in a de Sitter 4D cosmological background. Moreover, the non-linear tachyonic scalar field, that generates the brane in complicity with warped gravity, has the form of a kink-like configuration. Notwithstanding, the non-linear field equations restricting character does not allow one to easily find thick brane solutions with a decaying warp factor which leads to the localization of 4D gravity and other matter fields. We derive such a thick brane configuration altogether in this tachyon-gravity setup. When analyzing the spectrum of gravity fluctuations in the transverse traceless sector, the 4D gravity is shown to be localized due to the presence of a single zero mode bound state, separated by a continuum of massive Kaluza-Klein (KK) modes by a mass gap. It contrasts with previous results, where there is a KK massive bound excitation providing no clear physical interpretation. The mass gap is determined by the scale of the metric parameter H. Finally, the corrections to Newton's law in this model are computed and shown to decay exponentially. It is in full compliance to corrections reported in previous results (up to a constant factor) within similar braneworlds with induced 4D de Sitter metric, despite the fact that the warp factor and the massive modes have a different form.
Inflation including collapse of the wave function: the quasi-de Sitter case
Energy Technology Data Exchange (ETDEWEB)
Leon, Gabriel [Universidad de Buenos Aires, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Landau, Susana J. [Universidad de Buenos Aires y IFIBA, CONICET, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Piccirilli, Maria Pia [Universidad Nacional de La Plata, Grupo de Astrofisica, Relatividad y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, Pcia de Buenos Aires (Argentina)
2015-08-15
The precise physical mechanism describing the emergence of the seeds of cosmic structure from a perfect isotropic and homogeneous universe has not been fully explained by the standard version of inflationary models. To handle this shortcoming, D. Sudarsky and collaborators have developed a proposal: the self-induced collapse hypothesis. In this scheme, the objective collapse of the inflaton wave function is responsible for the emergence of inhomogeneity and anisotropy at all scales. In previous papers, the proposal was developed with an almost exact de Sitter space-time approximation for the background that led to a perfect scale-invariant power spectrum. In the present article, we consider a full quasi-de Sitter expansion and calculate the primordial power spectrum for three different choices of the self-induced collapse. The consideration of a quasi-de Sitter background allows us to distinguish departures from an exact scale-invariant power spectrum that are due to the inclusion of the collapse hypothesis. These deviations are also different from the prediction of standard inflationary models with a running spectral index. A comparison with the primordial power spectrum and the CMB temperature fluctuation spectrum preferred by the latest observational data is also discussed. From the analysis performed in this work, it follows that most of the collapse schemes analyzed in this paper are viable candidates to explain the present observations of the CMB fluctuation spectrum. (orig.)
Inflation including collapse of the wave function: the quasi-de Sitter case
International Nuclear Information System (INIS)
Leon, Gabriel; Landau, Susana J.; Piccirilli, Maria Pia
2015-01-01
The precise physical mechanism describing the emergence of the seeds of cosmic structure from a perfect isotropic and homogeneous universe has not been fully explained by the standard version of inflationary models. To handle this shortcoming, D. Sudarsky and collaborators have developed a proposal: the self-induced collapse hypothesis. In this scheme, the objective collapse of the inflaton wave function is responsible for the emergence of inhomogeneity and anisotropy at all scales. In previous papers, the proposal was developed with an almost exact de Sitter space-time approximation for the background that led to a perfect scale-invariant power spectrum. In the present article, we consider a full quasi-de Sitter expansion and calculate the primordial power spectrum for three different choices of the self-induced collapse. The consideration of a quasi-de Sitter background allows us to distinguish departures from an exact scale-invariant power spectrum that are due to the inclusion of the collapse hypothesis. These deviations are also different from the prediction of standard inflationary models with a running spectral index. A comparison with the primordial power spectrum and the CMB temperature fluctuation spectrum preferred by the latest observational data is also discussed. From the analysis performed in this work, it follows that most of the collapse schemes analyzed in this paper are viable candidates to explain the present observations of the CMB fluctuation spectrum. (orig.)
Three-dimensional black hole from a stringy anti endash de Sitter background
International Nuclear Information System (INIS)
Hjelmeland, S.E.
1997-01-01
A new black hole solution in 2+1 dimensions is found by taking cosmic strings as part of the vacuum structure of the anti endash de Sitter space-time. The solution has a structure that in many ways is similar to that of the Reissner-Nordstroem solution. With a vanishing cosmological constant, a space-time with a black hole of infinite extension appears with the inner horizon playing the role of a cosmological event horizon. The timelike and null geodesics are discussed. In particular it is shown that photons may follow conic sections. copyright 1997 The American Physical Society
Exact Solution of Klein-Gordon and Dirac Equations with Snyder-de Sitter Algebra
Merad, M.; Hadj Moussa, M.
2018-01-01
In this paper, we present the exact solution of the (1+1)-dimensional relativistic Klein-Gordon and Dirac equations with linear vector and scalar potentials in the framework of deformed Snyder-de Sitter model. We introduce some changes of variables, we show that a one-dimensional linear potential for the relativistic system in a space deformed can be equivalent to the trigonometric Rosen-Morse potential in a regular space. In both cases, we determine explicitly the energy eigenvalues and their corresponding eigenfunctions expressed in terms of Romonovski polynomials. The limiting cases are analyzed for α 1 and α 2 → 0 and are compared with those of literature.
Area spectrum of the D-dimensional de Sitter spacetime
International Nuclear Information System (INIS)
Lopez-Ortega, A.
2009-01-01
The determination of the quantum area spectrum of a black hole horizon by means of its asymptotic quasinormal frequencies has been explored recently. We believe that for D-dimensional de Sitter horizon we must study if the idea works. Thus taking into account the local description of the thermodynamics of horizons proposed by Padmanabhan and the results of Hod, Kunstatter, and Maggiore we study the area spectrum of the D-dimensional de Sitter horizon.
High overtones of Schwarzschild-de-Sitter quasinormal spectrum
International Nuclear Information System (INIS)
Konoplya, R.A.; Zhidenko, A.
2004-01-01
We find the high overtones of gravitational and electromagnetic quasinormal spectrum of the Schwarzschild-de Sitter black hole. The calculations show that the real parts of the electromagnetic modes asymptotically approach zero. The gravitational modes show more peculiar behavior at large n: the real part oscillates as a function of imaginary even for very high overtones and these oscillations settles to some 'profile' which just repeats itself with further increasing of the overtone number n. This lets us judge that Reω is not a constant as n →∞ but rather some oscillating function. The spacing for imaginary part Imω n+1 -Imω n for electromagnetic perturbations at high n slowly approach k e as n→∞, where k e is the surface gravity. In addition we find the lower QN modes for which the values obtained with numerical methods are in a very good agreement with those obtained through the 6th order WKB technique. (author)
International Nuclear Information System (INIS)
Stuchlik, Zdenek; Hledik, Stanislav; Soltes, Jiri; Ostgaard, Erlend
2001-01-01
Null geodesics and embedding diagrams of central planes in the ordinary space geometry and the optical reference geometry of the interior Schwarzschild--de Sitter spacetimes with uniform density are studied. For completeness, both positive and negative values of the cosmological constant are considered. The null geodesics are restricted to the central planes of these spacetimes, and their properties can be reflected by an 'effective potential.' If the interior spacetime is extremely compact, the effective potential has a local maximum corresponding to a stable circular null geodesic around which bound null geodesics are concentrated. The upper limit on the size of the interior spacetimes containing bound null geodesics is R=3M, independently of the value of the cosmological constant. The embedding diagrams of the central planes of the ordinary geometry into three-dimensional Euclidean space are well defined for the complete interior of all spacetimes with a repulsive cosmological constant, but the planes cannot be embedded into the Euclidean space in the case of spacetimes with subcritical values of an attractive cosmological constant. On the other hand, the embedding diagrams of the optical geometry are well defined for all of the spacetimes, and the turning points of these diagrams correspond to the radii of the circular null geodesics. All the embedding diagrams, for both the ordinary and optical geometry, are smoothly matched to the corresponding embedding diagrams of the external vacuum Schwarzschild--de Sitter spacetimes
A de Sitter tachyonic braneworld revisited
Barbosa-Cendejas, Nandinii; Cartas-Fuentevilla, Roberto; Herrera-Aguilar, Alfredo; Rigel Mora-Luna, Refugio; da Rocha, Roldão
2018-01-01
Within the framework of braneworlds, several interesting physical effects can be described in a wide range of energy scales, starting from high-energy physics to cosmology and low-energy physics. An usual way to generate a thick braneworld model relies in coupling a bulk scalar field to higher dimensional warped gravity. Quite recently, a novel braneworld was generated with the aid of a tachyonic bulk scalar field, having several remarkable properties. It comprises a regular and stable solution that contains a relevant 3-brane with de Sitter induced metric, arising as an exact solution to the 5D field equations, describing the inflationary eras of our Universe. Besides, it is asymptotically flat, despite of the presence of a negative 5D cosmological constant, which is an interesting feature that contrasts with most of the known, asymptotically either dS or AdS models. Moreover, it encompasses a graviton spectrum with a single massless bound state, accounting for 4D gravity localized on the brane, separated from the continuum of Kaluza-Klein massive graviton modes by a mass gap that makes the 5D corrections to Newton's law to decay exponentially. Finally, gauge, scalar and fermion fields are also shown to be localized on this braneworld. In this work, we show that this tachyonic braneworld allows for a nontrivial solution with a vanishing 5D cosmological constant that preserves all the above mentioned remarkable properties with a less amount of parameters, constituting an important contribution to the construction of a realistic cosmological braneworld model.
An alternative path to the boundary: The CFT as the Fourier space of AdS
Tolfree, Ian M.
2009-12-01
In this thesis we shed new light on the conjectured duality between an n + 1 dimensional theory of gravity in anti de Sitter space (AdS) and an n dimensional conformal field theory (CFT) by showing that the CFT can be interpreted as the Fourier space of AdS. We then make use of this to gain insight into the nature of black hole entropy. In the first part of this thesis, we give an introduction to the ideas of and review the basics of the AdS/CFT. In the next section we make use of well known integral geometry techniques to derive the Fourier transformation of a function on AdS and see it is a function with compact support on the boundary. Comparing this to the literature, we find that the Green's functions from the literature are actually the Fourier weights of the transformation and that the boundary values of fields appearing in the correspondence are the Fourier coefficients of the transformation. One is thus left to interpret the CFT as the quantized version of a classical theory in AdS and the dual operator as the Fourier coefficients. Group theoretic considerations are discussed in relation to the transformation and its potential use in constructing QCD like theories. In the last section, we then build upon this to study the BTZ black hole. Named after its authors, Banados, Teitelboim and Zanelli, the BTZ black hole is a three dimensional (two space plus one time dimension) black hole in anti de Sitter space. Following standard procedures for modifying Fourier Transformations to accommodate quotient spaces we arrive at a mapping in a black hole background consistent with known results that yields the exact micro-states of a scalar field in a black hole background. We find that the micro-states are the Fourier coefficients on the boundary, which transform under the principal series representation of SL(2, R). Using the knowledge of how to represent a bulk scalar field in the CFT, and knowing how a black hole interacts with a scalar field, we deduce the
de Sitter geodesics: reappraising the notion of motion
Pereira, J. G.; Sampson, A. C.
2012-05-01
The de Sitter spacetime is transitive under a combination of translations and proper conformal transformations. Its usual family of geodesics, however, does not take into account this property. As a consequence, there are points in de Sitter spacetime which cannot be joined to each other by any one of these geodesics. By taking into account the appropriate transitivity properties in the variational principle, a new family of maximizing trajectories is obtained, whose members are able to connect any two points of the de Sitter spacetime. These geodesics introduce a new notion of motion, given by a combination of translations and proper conformal transformations, which may possibly become important at very-high energies, where conformal symmetry plays a significant role.
IR finite graviton propagators in de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Faizal, Mir [University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Upadhyay, Sudhaker; Mandal, Bhabani Prasad [Banaras Hindu University, Department of Physics, Varanasi (India)
2016-04-15
The graviton propagator diverges in certain gauges in de Sitter spacetime. We address this problem in this work by generalizing the infinitesimal BRST transformations in de Sitter spacetime to finite field-dependent BRST (FFBRST) transformations. These FFBRST transformations are a symmetry of the classical action, but they do not leave the path integral measure invariant for the graviton theory in de Sitter spacetime. Due to the non-trivial Jacobian of such a finite transformation the path integral measure changes and hence the FFBRST transformation is capable of relating theories in two different gauges. We explicitly construct the FFBRST transformation which relates the theory with a diverging graviton two-point function to a theory with an infrared finite graviton. The FFBRST transformation thus establishes that the divergence in a graviton two-point function may be only a gauge artifact. (orig.)
Rest frames and relativistic effects on de Sitter spacetimes
Energy Technology Data Exchange (ETDEWEB)
Cotaescu, Ion I. [West University of Timisoara, Timisoara (Romania)
2017-07-15
It is shown that the Nachtmann boosting method of introducing coordinates on de Sitter manifolds can be completed with suitable gauge transformations able to keep under control the transformation under isometries of the conserved quantities. With this method, the rest local charts (or natural frames) are defined pointing out the role of the conserved quantities in investigating the relative geodesic motion. The advantages of this approach can be seen from the applications presented here. For the first time, the simple kinematic effects, the electromagnetic field of a free falling charge and the binary fission are solved in terms of conserved quantities on the expanding portion of the de Sitter spacetime. (orig.)
Entropy of Kerr-de Sitter black hole
Li, Huai-Fan; Ma, Meng-Sen; Zhang, Li-Chun; Zhao, Ren
2017-07-01
Based on the consideration that the black hole horizon and the cosmological horizon of Kerr-de Sitter black hole are not independent of each other, we conjecture the total entropy of the system should have an extra term contributed from the correlations between the two horizons, except for the sum of the two horizon entropies. By employing globally effective first law and effective thermodynamic quantities, we obtain the corrected total entropy and find that the region of stable state for Kerr-de Sitter is related to the angular velocity parameter a, i.e., the region of stable state becomes bigger as the rotating parameters a is increases.
D-particle Recoil Space Times and "Glueball" Masses
Mavromatos, Nikolaos E; Mavromatos, Nick E.; Winstanley, Elizabeth
2001-01-01
We discuss the properties of matter in a D-dimensional anti-de-Sitter-type space time induced dynamically by the recoil of a very heavy D(irichlet)-particle defect embedded in it. The particular form of the recoil geometry, which from a world-sheet view point follows from logarithmic conformal field theory deformations of the pertinent sigma-models, results in the presence of both infrared and ultraviolet (spatial) cut-offs. These are crucial in ensuring the presence of mass gaps in scalar matter propagating in the D-particle recoil space time. The analogy of this problem with the Liouville-string approach to QCD, suggested earlier by John Ellis and one of the present authors, prompts us to identify the resulting scalar masses with those obtained in the supergravity approach based on the Maldacena's conjecture, but without the imposition of any supersymmetry in our case. Within reasonable numerical uncertainties, we observe that agreement is obtained between the two approaches for a particular value of the ra...
Snyder-de Sitter model from two-time physics
International Nuclear Information System (INIS)
Carrisi, M. C.; Mignemi, S.
2010-01-01
We show that the symplectic structure of the Snyder model on a de Sitter background can be derived from two-time physics in seven dimensions and propose a Hamiltonian for a free particle consistent with the symmetries of the model.
Equatorial circular orbits in the Kerr-de Sitter spacetimes
International Nuclear Information System (INIS)
Stuchlik, Zdenek; Slany, Petr
2004-01-01
Equatorial motion of test particles in Kerr-de Sitter spacetimes is considered. Circular orbits are determined, their properties are discussed for both black-hole and naked-singularity spacetimes, and their relevance for thin accretion disks is established. The circular orbits constitute two families that coalesce at the so-called static radius. The orientation of the motion along the circular orbits is, in accordance with case of asymptotically flat Kerr spacetimes, defined by relating the motion to the locally nonrotating frames. The minus-family orbits are all counterrotating, while the plus-family orbits are usually corotating relative to these frames. However, the plus-family orbits become counterrotating in the vicinity of the static radius in all Kerr-de Sitter spacetimes, and they become counterrotating in the vicinity of the ring singularity in Kerr-de Sitter naked-singularity spacetimes with a low enough rotational parameter. In such spacetimes, the efficiency of the conversion of the rest energy into heat energy in the geometrically thin plus-family accretion disks can reach extremely high values exceeding the efficiency of the annihilation process. The transformation of a Kerr-de Sitter naked singularity into an extreme black hole due to accretion in the thin disks is briefly discussed for both the plus-family and minus-family disks. It is shown that such a conversion leads to an abrupt instability of the innermost parts of the plus-family accretion disks that can have strong observational consequences
De Sitter universes and the emerging landscape in string theory
Indian Academy of Sciences (India)
We discuss a recent proposal to construct de Sitter vacua in string theory. It is based on flux compactifications in string theory where all the moduli are stabilised and supersymmetry is broken with control. The resulting picture is that of a complicated landscape with many vacua of widely varying values for the cosmological ...
de Sitter limit of inflation and nonlinear perturbation theory
DEFF Research Database (Denmark)
R. Jarnhus, Philip; Sloth, Martin Snoager
2007-01-01
We study the fourth order action of the comoving curvature perturbation in an inflationary universe in order to understand more systematically the de Sitter limit in nonlinear cosmological perturbation theory. We derive the action of the curvature perturbation to fourth order in the comoving gaug...
Entangled de Sitter from stringy axionic Bell pair I: an analysis using Bunch-Davies vacuum
Choudhury, Sayantan; Panda, Sudhakar
2018-01-01
In this work, we study the quantum entanglement and compute entanglement entropy in de Sitter space for a bipartite quantum field theory driven by an axion originating from Type IIB string compactification on a Calabi-Yau three fold (CY^3) and in the presence of an NS5 brane. For this computation, we consider a spherical surface S^2, which divides the spatial slice of de Sitter (dS_4) into exterior and interior sub-regions. We also consider the initial choice of vacuum to be Bunch-Davies state. First we derive the solution of the wave function of the axion in a hyperbolic open chart by constructing a suitable basis for Bunch-Davies vacuum state using Bogoliubov transformation. We then derive the expression for density matrix by tracing over the exterior region. This allows us to compute the entanglement entropy and Rényi entropy in 3+1 dimension. Furthermore, we quantify the UV-finite contribution of the entanglement entropy which contain the physics of long range quantum correlations of our expanding universe. Finally, our analysis complements the necessary condition for generating non-vanishing entanglement entropy in primordial cosmology due to the axion.
U(N) instantons on N=(1/2) superspace: Exact solution and geometry of moduli space
International Nuclear Information System (INIS)
Britto, Ruth; Feng Bo; Lunin, Oleg; Rey, Soo-Jong
2004-01-01
We construct the exact solution of one (anti-)instanton in N=(1/2) super Yang-Mills theory defined on non(anti-)commutative superspace. We first identify N=(1/2) superconformal invariance as maximal spacetime symmetry. For the gauge group U(2), the SU(2) part of the solution is given by the standard (anti-)instanton, but the U(1) field strength also turns out to be nonzero. The solution is SO(4) rotationally symmetric. For the gauge group U(N), in contrast with the U(2) case, we show that the entire U(N) part of the solution is deformed by non(anti-)commutativity and fermion zero modes. The solution is no longer rotationally symmetric; it is polarized into an axially symmetric configuration because of the underlying non(anti-)commutativity. We compute the 'information metric' of one (anti-)instanton. We find that the moduli space geometry is deformed from the hyperbolic space H 5 (Euclidean anti-de Sitter space) in a way anticipated from reduced spacetime symmetry. Remarkably, the volume measure of the moduli space turns out to be independent of the non(anti-)commutativity. Implications for D branes in the Ramond-Ramond flux background and the gauge-gravity correspondence are discussed
Instanton transition in thermal and moduli deformed de Sitter cosmology
International Nuclear Information System (INIS)
Kounnas, Costas; Partouche, Herve
2008-01-01
We consider the de Sitter cosmology deformed by the presence of a thermal bath of radiation and/or time-dependent moduli fields. Depending on the parameters, either a first or second-order phase transition can occur. In the first case, an instanton allows a double analytic continuation. It induces a probability to enter the inflationary evolution by tunnel effect from another cosmological solution. The latter starts with a big bang and, in the case the transition does not occur, ends with a big crunch. A temperature duality exchanges the two cosmological branches. In the limit where the pure de Sitter universe is recovered, the tunnel effect reduces to a 'creation from nothing', due to the vanishing of the big bang branch. However, the latter may be viable in some range of the deformation parameter. In the second case, there is a smooth evolution from a big bang to the inflationary phase
Semiclassical fermion pair creation in de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Stahl, Clément, E-mail: clement.stahl@icranet.org; Eckhard, Strobel, E-mail: eckhard.strobel@irap-phd.eu [ICRANet, Piazzale della Repubblica 10, 65122 Pescara (Italy); Dipartimento di Fisica, Università di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome (Italy); Université de Nice Sophia Antipolis, 28 Avenue de Valrose, 06103 Nice Cedex 2 (France)
2015-12-17
We present a method to semiclassically compute the pair creation rate of bosons and fermions in de Sitter spacetime. The results in the bosonic case agree with the ones in the literature. We find that for the constant electric field the fermionic and bosonic pair creation rate are the same. This analogy of bosons and fermions in the semiclassical limit is known from several flat spacetime examples.
Non-minimal Particle Creation from Asymptotic-de Sitter Inflation
Yusofi, E.; Mohsenzadeh, M.
2018-03-01
A general form of quasi-de Sitter(dS) modes is used to study the creation of particle during the inflation. Actually, by considering the general form of inflaton field equation as a function of the Hankel function index and by using the Planck 2015 constraint on spectral index, we obtain the possible new constraints for the values of coupling constant in the era with asymptotic-dS space-time. Then, we explicitly calculate the general form of expectation value of the created particles in terms of the Hankel function index and the conformal time. The correction terms in the number of created particles are very tiny in the early time but can have the significant effects in the later universe. Our result is general and at the early time limit confirm the conventional special results for the Minkowski and dS background.
International Nuclear Information System (INIS)
Burdík, C; Reshetnyak, A
2012-01-01
We derive non-linear commutator HS symmetry algebra, which encode unitary irreducible representations of AdS group subject to Young tableaux Y(s 1 ,..., s k ) with κ ≥ 2 rows on d-dimensional anti-de-Sitter space. Auxiliary representations for specially deformed non-linear HS symmetry algebra in terms of generalized Verma module in order to additively convert a subsystem of second-class constraints in the HS symmetry algebra into one with first-class constraints are found explicitly for the case of HS fields for κ = 2 Young tableaux. The oscillator realization over Heisenberg algebra for obtained Verma module is constructed. The results generalize the method of auxiliary representations construction for symplectic sp(2κ) algebra used for mixed-symmetry HS fields on a flat spaces and can be extended on a case of arbitrary HS fields in AdS-space. Gauge-invariant unconstrained reducible Lagrangian formulation for free bosonic HS fields with generalized spin (s 1 , s 2 ) is derived.
Deng, Gao-Ming; Huang, Yong-Chang
2018-03-01
The geodesics of tunneling particles were derived unnaturally and awkwardly in previous works. For one thing, the previous derivation was inconsistent with the variational principle of action. Moreover, the definition of geodesic equations for massive particles was quite different from that of massless case. Even worse, the relativistic and nonrelativistic foundations were mixed with each other during the past derivation of geodesics. As a highlight, remedying the urgent shortcomings, we improve treatment to derive the geodesic equations of massive and massless particles in a unified and self-consistent way. Besides, we extend to investigate the Hawking radiation via tunneling from Reissner-Nordström black holes in the context of AdS spacetime. Of special interest, the trick of utilizing the first law of black hole thermodynamics manifestly simplifies the calculation of tunneling integration.
Sequestered de Sitter string scenarios: soft-terms
Aparicio, Luis; Cicoli, Michele; Krippendorf, Sven; Maharana, Anshuman; Muia, Francesco; Quevedo, Fernando
2014-11-01
We analyse soft supersymmetry breaking in type IIB de Sitter string vacua after moduli stabilisation, focussing on models in which the Standard Model is sequestered from the supersymmetry breaking sources and the spectrum of soft-terms is hierarchically smaller than the gravitino mass m 3/2. Due to this feature, these models are compatible with gauge coupling unification and TeV scale supersymmetry with no cosmological moduli problem. We determine the influence on soft-terms of concrete realisations of de Sitter vacua constructed from supersymmetric effective actions. One of these scenarios provides the first study of soft-terms for consistent string models embedded in a compact Calabi-Yau manifold with all moduli stabilised. Depending on the moduli dependence of the Kähler metric for matter fields and on the mechanism responsible to obtain a de Sitter vacuum, we find two scenarios for phenomenology: (i) a split-supersymmetry scenario where gaugino masses are suppressed with respect to scalar masses: M 1/2 ˜ m 3/2 ɛ ≪ m 0 ˜ m 3/2 ≪ m 3/2 for ɛ ˜ m 3/2 /M P ≪ 1; (ii) a typical MSSM scenario where all soft-terms are of the same order: M 1/2 ˜ m 0 ˜ m 3/2 ɛ ≪ m 3/2. Background fluxes determine the numerical coefficients of the soft-terms allowing for small variations of parameters as is necessary to confront data and to interpolate between different scenarios. We comment on different stringy origins of the μ-term and potential sources of desequestering.
Achterbergh, J.M.I.M.; Vriens, D.J.
2011-01-01
- Purpose – The purpose of this paper is to show how the viable system model (VSM) and de Sitter's design theory can complement each other in the context of the diagnosis and design of viable organizations. - Design/methodology/approach – Key concepts from Beer's model and de Sitter's design theory
Novel pole-sitter mission concepts for continuous polar remote sensing
Ceriotti, Matteo; Heiligers, Jeannette; McInnes, Colin R.
2012-09-01
The pole-sitter concept is a solution to the poor temporal resolution of polar observations from highly inclined, low Earth orbits and the poor high latitude coverage from geostationary orbit. It considers a spacecraft that is continuously above either the North or South Pole and, as such, can provide real-time, continuous and hemispheric coverage of the polar regions. Despite the significant distance from the Earth, the utility of this platform for Earth observation and telecommunications is clear, and applications include polar weather forecasting and atmospheric science, glaciology and ice pack monitoring, ultraviolet imaging for aurora studies, continuous telecommunication links with polar regions, arctic ship routing and support for future high latitude oil and gas exploration. The paper presents a full mission design, including launch (Ariane 5 and Soyuz vehicles), for two propulsion options (a near-term solar electric propulsion (SEP) system and a more advanced combination of a solar sail with an SEP system). An optional transfer from the North Pole to South Pole and vice-versa allows viewing of both poles in summer. The paper furthermore focuses on payloads that could be used in such a mission concept. In particular, by using instruments designed for past deep space missions (DSCOVR), it is estimated that resolutions up to about 20 km/pixel in the visible wavelengths can be obtained. The mass of these instruments is well within the capabilities of the pole-sitter design, allowing an SEP-only mission lifetime of about 4 years, while the SEP/sail propulsion technology enables missions of up to 7 years.
Schwinger mechanism in electromagnetic field in de Sitter spacetime
Directory of Open Access Journals (Sweden)
Bavarsad Ehsan
2018-01-01
Full Text Available We investigate Schwinger scalar pair production in a constant electromagnetic field in de Sitter (dS spacetime. We obtain the pair production rate, which agrees with the Hawking radiation in the limit of zero electric field in dS. The result describes how a cosmic magnetic field affects the pair production rate. In addition, using a numerical method we study the effect of the magnetic field on the induced current. We find that in the strong electromagnetic field the current has a linear response to the electric and magnetic fields, while in the infrared regime, is inversely proportional to the electric field and leads to infrared hyperconductivity.
Schwinger mechanism in electromagnetic field in de Sitter spacetime
Bavarsad, Ehsan; Pyo Kim, Sang; Stahl, Clément; Xue, She-Sheng
2018-01-01
We investigate Schwinger scalar pair production in a constant electromagnetic field in de Sitter (dS) spacetime. We obtain the pair production rate, which agrees with the Hawking radiation in the limit of zero electric field in dS. The result describes how a cosmic magnetic field affects the pair production rate. In addition, using a numerical method we study the effect of the magnetic field on the induced current. We find that in the strong electromagnetic field the current has a linear response to the electric and magnetic fields, while in the infrared regime, is inversely proportional to the electric field and leads to infrared hyperconductivity.
Attracted to de Sitter: cosmology of the linear Horndeski models
Energy Technology Data Exchange (ETDEWEB)
Martín-Moruno, Prado; Nunes, Nelson J.; Lobo, Francisco S.N., E-mail: pmmoruno@fc.ul.pt, E-mail: njnunes@fc.ul.pt, E-mail: fslobo@fc.ul.pt [Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, PT1749-016 Lisboa (Portugal)
2015-05-01
We consider Horndeski cosmological models, with a minisuperspace Lagrangian linear in the field derivative, that are able to screen any vacuum energy and material content leading to a spatially flat de Sitter vacuum fixed by the theory itself. Furthermore, we investigate particular models with a cosmic evolution independent of the material content and use them to understand the general characteristics of this framework. We also consider more realistic models, which we denote the ''term-by-term'' and ''tripod'' models, focusing attention on cases in which the critical point is indeed an attractor solution and the cosmological history is of particular interest.
The deflationary universe: An instability of the de Sitter universe
International Nuclear Information System (INIS)
Barrow, J.D.
1986-01-01
The relevance is discussed of the initial value structure of the cosmological problem for inflationary explanations of its present structure. Existing proofs of the cosmic ''no hair'' conjecture are found to make use of an unrealistic strong energy condition on the stress tensor of the matter fields not driving the inflation. It is shown by explicit example that the no hair conjecture fails even in isotropic cosmological models if the strong energy condition is relaxed. A class of exact cosmological models are given which begin in a de Sitter state but subsequently deflate towards the flat Friedman model. Various implications of these examples are discussed. (orig.)
On de Sitter-like and Minkowski-like spacetimes
International Nuclear Information System (INIS)
Luebbe, Christian; Kroon, Juan Antonio Valiente
2009-01-01
Friedrich's proofs for the global existence results of de Sitter-like spacetimes and of semi-global existence of Minkowski-like spacetimes (Friedrich 1986 Commun. Math. Phys. 107 587) are re-examined and discussed, making use of the extended conformal field equations and a gauge based on conformal geodesics. In this gauge, the location of the conformal boundary of the spacetimes is known a priori once the initial data have been prescribed. Thus, it provides an analysis which is conceptually and calculationally simpler.
Gravitational radiation reaction in the NUT-de Sitter spacetime
International Nuclear Information System (INIS)
Ahmed, M.
1988-07-01
The equations for gravitational perturbation in the NUT-de Sitter spacetime are obtained. Using these equations, some preliminary calculations have been made with a view to constructing the retarded Green functions. Then with the help of the retarded Green functions, the radiative Green functions have been constructed. With the aid of these radiative Green functions, the reaction force on a particle is computed and this reaction force is then shown to account correctly for the energy and the angular momentum carried away by gravitational radiation to infinity and to the horizon. (author). 9 refs
Superintegrability on N-dimensional spaces of constant curvature from so(N + 1) and its contractions
International Nuclear Information System (INIS)
Herranz, F. J.; Ballesteros, A.
2008-01-01
The Lie-Poisson algebra so(N + 1) and some of its contractions are used to construct a family of superintegrable Hamiltonians on the N-dimensional spherical, Euclidean, hyperbolic, Minkowskian, and (anti-)de Sitter spaces. We firstly present a Hamiltonian which is a superposition of an arbitrary central potential with N arbitrary centrifugal terms. Such a system is quasi-maximally superintegrable since this is endowed with 2N - 3 functionally independent constants of motion (plus the Hamiltonian). Secondly, we identify two maximally superintegrable Hamiltonians by choosing a specific central potential and finding at the same time the remaining integral. The former is the generalization of the Smorodinsky-Winternitz system to the above six spaces, while the latter is a generalization of the Kepler-Coulomb potential, for which the Laplace-Runge-Lenz N vector is also given. All the systems and constants of motion are explicitly expressed in a unified form in terms of ambient and polar coordinates as they are parametrized by two contraction parameters (curvature and signature of the metric).
Holographic curvature perturbations in a cosmology with a space-like singularity
Energy Technology Data Exchange (ETDEWEB)
Ferreira, Elisa G.M. [Department of Physics, McGill University,3600 University St., Montréal, QC, H3A 2T8 (Canada); Brandenberger, Robert [Department of Physics, McGill University,3600 University St., Montréal, QC, H3A 2T8 (Canada); Institute for Theoretical Studies, ETH Zürich,Clausiusstr. 47, Zürich, CH-8092 (Switzerland)
2016-07-19
We study the evolution of cosmological perturbations in an anti-de-Sitter (AdS) bulk through a cosmological singularity by mapping the dynamics onto the boundary conformal fields theory by means of the AdS/CFT correspondence. We consider a deformed AdS space-time obtained by considering a time-dependent dilaton which induces a curvature singularity in the bulk at a time which we call t=0, and which asymptotically approaches AdS both for large positive and negative times. The boundary field theory becomes free when the bulk curvature goes to infinity. Hence, the evolution of the fluctuations is under better controle on the boundary than in the bulk. To avoid unbounded particle production across the bounce it is necessary to smooth out the curvature singularity at very high curvatures. We show how the bulk cosmological perturbations can be mapped onto boundary gauge field fluctuations. We evolve the latter and compare the spectrum of fluctuations on the infrared scales relevant for cosmological observations before and after the bounce point. We find that the index of the power spectrum of fluctuations is the same before and after the bounce.
Quasinormal modes of Kerr-de Sitter black holes
International Nuclear Information System (INIS)
Yoshida, Shijun; Uchikata, Nami; Futamase, Toshifumi
2010-01-01
We calculate the fundamental quasinormal modes of the Kerr-de Sitter black hole for the first time. In order to calculate the quasinormal modes, we employ the master equations derived by Suzuki, Takasugi, and Umetsu, who transform the Teukolsky equations for the Kerr-de Sitter black hole into the standard form of the Heun's equation. The transformed functions are expanded around the outer horizon of the black hole or the symmetric axis in the Froebenius series whose coefficients satisfy a three-term recurrence relation. These three-term recurrence relations allow us to use Leaver's continued fraction method to calculate the angular separation constant and the quasinormal mode frequency. Any unstable fundamental quasinormal mode is not found in this paper. It is also observed that for some black holes characterized by a large mass parameter, some retrograde modes in the slow rotation limit become prograde as the black hole spin increases. This phenomenon does not occur for the fundamental modes of the Kerr black hole.
Gauge Fields as Composite Boundary Excitations
Ferrara, Sergio; Ferrara, Sergio; Fronsdal, Christian
1998-01-01
We investigate representations of the conformal group that describe "massless" particles in the interior and at the boundary of anti-de Sitter space. It turns out that massless gauge excitations in anti-de Sitter are gauge "current" operators at the boundary. Conversely, massless excitations at the boundary are topological singletons in the interior. These representations lie at the threshold of two "unitary bounds" that apply to any conformally invariant field theory. Gravity and Yang-Mills gauge symmetry in anti-De Sitter is translated to global translational symmetry and continuous R-symmetry of the boundary superconformal field theory.
De Sitter en Einstein. ‘Het lijkt mij dat Einstein hier een vergissing begaan heeft’
Directory of Open Access Journals (Sweden)
Jan Guichelaar
2016-10-01
Full Text Available De Sitter and EinsteinWillem de Sitter’s interest in gravity was based on his work on celestial mechanics, in particular on the four big moons of Jupiter. His work on cosmology was based on the general theory of relativity of Albert Einstein. De Sitter published in 1917, on request of Arthur Eddington to inform the English astronomers, a series of four articles in The Observatory and the Monthly Notices of the Royal Astronomical Society. Einstein developed his own cosmological models, containing mass. De Sitter found a different solution and described a universe without mass. Einstein could not accept De Sitter’s model and they ‘fought out’ two controversies in their correspondence. In theend Einstein had to confess De Sitter was mainly right in his criticisms. In 1932 Einstein and De Sitter published an article on a new model, the so-called Einstein-De Sitter Model of the universe. So, De Sitter was able to do fundamental work in classical celestial mechanics as well as in the new cosmological theories.
Energy, momentum and angular momentum conservations in de Sitter gravity
International Nuclear Information System (INIS)
Lu, Jia-An
2016-01-01
In de Sitter (dS) gravity, where gravity is a gauge field introduced to realize the local dS invariance of the matter field, two kinds of conservation laws are derived. The first kind is a differential equation for a dS-covariant current, which unites the canonical energy-momentum (EM) and angular momentum (AM) tensors. The second kind presents a dS-invariant current which is conserved in the sense that its torsion-free divergence vanishes. The dS-invariant current unites the total (matter plus gravity) EM and AM currents. It is well known that the AM current contains an inherent part, called the spin current. Here it is shown that the EM tensor also contains an inherent part, which might be observed by its contribution to the deviation of the dust particle’s world line from a geodesic. All the results are compared to the ordinary Lorentz gravity. (paper)
Kam, Chon-Fai; Liu, Ren-Bao
2017-08-29
Berry phases and gauge structures are fundamental quantum phenomena. In linear quantum mechanics the gauge field in parameter space presents monopole singularities where the energy levels become degenerate. In nonlinear quantum mechanics, which is an effective theory of interacting quantum systems, there can be phase transitions and hence critical surfaces in the parameter space. We find that these critical surfaces result in a new type of gauge field singularity, namely, a conic singularity that resembles the big bang of a 2 + 1 dimensional de Sitter universe, with the fundamental frequency of Bogoliubov excitations acting as the cosmic scale, and mode softening at the critical surface, where the fundamental frequency vanishes, causing a causal singularity. Such conic singularity may be observed in various systems such as Bose-Einstein condensates and molecular magnets. This finding offers a new approach to quantum simulation of fundamental physics.
International Nuclear Information System (INIS)
Bellini, Mauricio
2005-01-01
We develop a nonperturbative quantum scalar field formalism from a noncompact Kaluza-Klein (KK) theory using the induced-matter theory of gravity during inflation. We study the particular case of a de Sitter expansion for the universe
Power radiated by a binary system in a de Sitter universe
Bonga, Béatrice; Hazboun, Jeffrey S.
2017-09-01
Gravitational waves emitted by high redshift sources propagate through various epochs of the Universe including the current era of measurable, accelerated expansion. Historically, the calculation of gravitational wave power on cosmological backgrounds is based on various simplifications, including a 1 /r -expansion and the use of an algebraic projection to retrieve the radiative degrees of freedom. On a de Sitter spacetime, recent work has demonstrated that many of these calculational techniques and approximations do not apply. Here we calculate the power emitted by a binary system on a de Sitter background using techniques tailored to de Sitter spacetime. The common expression for the power radiated by this source in an Friedmann-Lemaître-Robertson-Walker spacetime, calculated using far wave-zone techniques, gives the same expression as the late time expansion specialized to the de Sitter background in the high-frequency approximation.
Dynamics of quantum entanglement in de Sitter spacetime and thermal Minkowski spacetime
Directory of Open Access Journals (Sweden)
Zhiming Huang
2017-10-01
Full Text Available We investigate the dynamics of entanglement between two atoms in de Sitter spacetime and in thermal Minkowski spacetime. We treat the two-atom system as an open quantum system which is coupled to a conformally coupled massless scalar field in the de Sitter invariant vacuum or to a thermal bath in the Minkowski spacetime, and derive the master equation that governs its evolution. We compare the phenomena of entanglement creation, degradation, revival and enhancement for the de Sitter spacetime case with that for the thermal Minkowski spacetime case. We find that the entanglement dynamics of two atoms for these two spacetime cases behave quite differently. In particular, the two atoms interacting with the field in the thermal Minkowski spacetime (with the field in the de Sitter-invariant vacuum, under certain conditions, could be entangled, while they would not become entangled in the corresponding de Sitter case (in the corresponding thermal Minkowski case. Thus, although a single static atom in the de Sitter-invariant vacuum responds as if it were bathed in thermal radiation in a Minkowski universe, with the help of the different dynamic evolution behaviors of entanglement for two atoms one can in principle distinguish these two universes.
MONOPOLES AND DYONS IN THE PURE EINSTEIN YANG MILLS THEORY
International Nuclear Information System (INIS)
HOSOTANI, Y.; BJORAKER, J.
1999-01-01
In the pure Einstein-Yang-Mills theory in four dimensions there exist monopole and dyon solutions. The spectrum of the solutions is discrete in asymptotically flat or de Sitter space, whereas it is continuous in asymptotically anti-de Sitter space. The solutions are regular everywhere and specified with their mass, and non-Abelian electric and magnetic charges. In asymptotically anti-de Sitter space a class of monopole solutions have no node in non-Abelian magnetic fields, and are stable against spherically symmetric perturbations
Mobile app for human-interaction with sitter robots
Das, Sumit Kumar; Sahu, Ankita; Popa, Dan O.
2017-05-01
Human environments are often unstructured and unpredictable, thus making the autonomous operation of robots in such environments is very difficult. Despite many remaining challenges in perception, learning, and manipulation, more and more studies involving assistive robots have been carried out in recent years. In hospital environments, and in particular in patient rooms, there are well-established practices with respect to the type of furniture, patient services, and schedule of interventions. As a result, adding a robot into semi-structured hospital environments is an easier problem to tackle, with results that could have positive benefits to the quality of patient care and the help that robots can offer to nursing staff. When working in a healthcare facility, robots need to interact with patients and nurses through Human-Machine Interfaces (HMIs) that are intuitive to use, they should maintain awareness of surroundings, and offer safety guarantees for humans. While fully autonomous operation for robots is not yet technically feasible, direct teleoperation control of the robot would also be extremely cumbersome, as it requires expert user skills, and levels of concentration not available to many patients. Therefore, in our current study we present a traded control scheme, in which the robot and human both perform expert tasks. The human-robot communication and control scheme is realized through a mobile tablet app that can be customized for robot sitters in hospital environments. The role of the mobile app is to augment the verbal commands given to a robot through natural speech, camera and other native interfaces, while providing failure mode recovery options for users. Our app can access video feed and sensor data from robots, assist the user with decision making during pick and place operations, monitor the user health over time, and provides conversational dialogue during sitting sessions. In this paper, we present the software and hardware framework that
Photon motion in Kerr-de Sitter spacetimes
Energy Technology Data Exchange (ETDEWEB)
Charbulak, Daniel; Stuchlik, Zdenek [Silesian University in Opava, Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Opava (Czech Republic)
2017-12-15
We study the general motion of photons in the Kerr-de Sitter black-hole and naked singularity spacetimes. The motion is governed by the impact parameters X, related to the axial symmetry of the spacetime, and q, related to its hidden symmetry. Appropriate 'effective potentials' governing the latitudinal and radial motion are introduced and their behavior is examined by the 'Chinese boxes' technique giving regions allowed for the motion in terms of the impact parameters. Restrictions on the impact parameters X and q are established in dependence on the spacetime parameters M, Λ, a. The motion can be of orbital type (crossing the equatorial plane, q > 0) and vortical type (tied above or below the equatorial plane, q < 0). It is shown that for negative values of q, the reality conditions imposed on the latitudinal motion yield stronger constraints on the parameter X than that following from the reality condition of the radial motion, excluding the existence of vortical motion of constant radius. The properties of the spherical photon orbits of the orbital type are determined and used along with the properties of the effective potentials as criteria of classification of the KdS spacetimes according to the properties of the motion of the photon. (orig.)
International Nuclear Information System (INIS)
Paudel, Eak Raj
2007-01-01
Gravitational field of Schwarzschild and Schwarzschild de-sitter Black hole with a straight string passing through it. In such space analytical and numerical solutions of null and time like geodesics are investigated. The string parameter a + is found to affect both the angle of deflection in null geodesics and the precession of perihelion on time like geodesics .It is seen that the deflection of null and time like geodesics near the gravitating mass of de-sitter space time increases with t he gravitational field of a straight string in flat space time has the property that the Newtonian potential vanishes yet there are non trivial gravitational effects. A test particle is neither attracted nor repelled by a string, yet the conical nature of space outside of string produces observable effects such as light deflection . Schwarzschild Black hole is a mathematical solution to the Einstein's field equations and corresponds to the gravitational field of massive compact spherically symmetric ob normal. References 1. Aryal, M.M, A. Vilenkin and L.H Ford, 1986, Phys.Rev. D32 ,2262 2. Moriyasu ,K ., 1980 , An introduction to gauge Invariance 3. Vilenkin A., 1985 , Physical reports , cosmic strings and Domain walls 4. Berry, M. , 1976 , Principle of cosmology and Gravitation 5. Mishner , C.W ., K.S .Throne , J.A wheeler , 1973. (Author)
Huang, Chao-Guang; Guo, Han-Ying; Tian, Yu; Xu, Zhan; Zhou, Bin
2004-01-01
Based on the Beltrami-de Sitter spacetime, we present the Newton-Hooke model under the Newton-Hooke contraction of the $BdS$ spacetime with respect to the transformation group, algebra and geometry. It is shown that in Newton-Hooke space-time, there are inertial-type coordinate systems and inertial-type observers, which move along straight lines with uniform velocity. And they are invariant under the Newton-Hooke group. In order to determine uniquely the Newton-Hooke limit, we propose the Gal...
Schwarzschild-de Sitter spacetimes, McVittie coordinates, and trumpet geometries
Dennison, Kenneth A.; Baumgarte, Thomas W.
2017-12-01
Trumpet geometries play an important role in numerical simulations of black hole spacetimes, which are usually performed under the assumption of asymptotic flatness. Our Universe is not asymptotically flat, however, which has motivated numerical studies of black holes in asymptotically de Sitter spacetimes. We derive analytical expressions for trumpet geometries in Schwarzschild-de Sitter spacetimes by first generalizing the static maximal trumpet slicing of the Schwarzschild spacetime to static constant mean curvature trumpet slicings of Schwarzschild-de Sitter spacetimes. We then switch to a comoving isotropic radial coordinate which results in a coordinate system analogous to McVittie coordinates. At large distances from the black hole the resulting metric asymptotes to a Friedmann-Lemaître-Robertson-Walker metric with an exponentially-expanding scale factor. While McVittie coordinates have another asymptotically de Sitter end as the radial coordinate goes to zero, so that they generalize the notion of a "wormhole" geometry, our new coordinates approach a horizon-penetrating trumpet geometry in the same limit. Our analytical expressions clarify the role of time-dependence, boundary conditions and coordinate conditions for trumpet slices in a cosmological context, and provide a useful test for black hole simulations in asymptotically de Sitter spacetimes.
Euclidean action for vacuum decay in a de Sitter universe
International Nuclear Information System (INIS)
Balek, V.; Demetrian, M.
2005-01-01
The behavior of the action of the instantons describing vacuum decay in a de Sitter is investigated. For a near-to-limit instanton (a Coleman-de Luccia instanton close to some Hawking-Moss instanton) we find approximate formulas for the Euclidean action by expanding the scalar field and the metric of the instanton in the powers of the scalar field amplitude. The order of the magnitude of the correction to the Hawking-Moss action depends on the order of the instanton (the number of crossings of the barrier by the scalar field): for instantons of odd and even orders the correction is of the fourth and third order in the scalar field amplitude, respectively. If a near-to-limit instanton of the first order exists in a potential with the curvature at the top of the barrier greater than 4x(Hubble constant) 2 , which is the case if the fourth derivative of the potential at the top of the barrier is greater than some negative limit value, the action of the instanton is less than the Hawking-Moss action and, consequently, the instanton determines the outcome of the vacuum decay if no other Coleman-de Luccia instanton is admitted by the potential. A numerical study shows that for the quartic potential the physical mode of the vacuum decay is given by the Coleman-de Luccia instanton of the first order also in the region of parameters in which the potential admits two instantons of the second order
Quasi-normal modes for Dirac fields in Kerr-Newman-de Sitter black holes
Iantchenko, Alexei
2015-01-01
We provide the full asymptotic description of the quasi-normal modes (resonances) in any strip of fixed width for Dirac fields in slowly rotating Kerr-Newman-de Sitter black holes. The resonances split in a way similar to the Zeeman effect. The method is based on the extension to Dirac operators of techniques applied by Dyatlov 2011, 2012 to the (uncharged) Kerr-de Sitter black holes. We show that the mass of the Dirac field does not have effect on the two leading terms in the expansions of r...
On inflation and de Sitter in non-geometric string backgrounds
Energy Technology Data Exchange (ETDEWEB)
Hassler, Falk; Massai, Stefano [Arnold-Sommerfeld-Center for Theoretical Physics, Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen (Germany); Luest, Dieter [Arnold-Sommerfeld-Center for Theoretical Physics, Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen (Germany); Max-Planck-Institut fuer Physik, Muenchen (Germany)
2017-10-15
We study the problem of obtaining de Sitter and inflationary vacua from dimensional reduction of double field theory (DFT) on nongeometric string backgrounds. In this context, we consider a new class of effective potentials that admit Minkowski and de Sitter minima. We then construct a simple model of chaotic inflation arising from T-fold backgrounds and we discuss the possibility of trans-Planckian field range from nongeometric monodromies as well as the conditions required to get slow roll. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Dirac equation in a de Sitter expansion for massive neutrinos from modern Kaluza-Klein theory
International Nuclear Information System (INIS)
Sánchez, Pablo Alejandro; Anabitarte, Mariano; Bellini, Mauricio
2012-01-01
Using the modern Kaluza-Klein theory of gravity (or the Induced Matter theory), we study the Dirac equation for massive neutrinos on a de Sitter background metric from a 5D Riemann-flat (and hence Ricci-flat) extended de Sitter metric, on which is defined the vacuum for test massless 1/2-spin neutral fields minimally coupled to gravity and free of any other interactions. We obtain that the effective 4D masses of the neutrinos can only take three possible values, which are related to the (static) foliation of the fifth and noncompact extra dimension.
Gravitationally induced adiabatic particle production: from big bang to de Sitter
International Nuclear Information System (INIS)
Haro, Jaume de; Pan, Supriya
2016-01-01
In the background of a flat homogeneous and isotropic space–time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology. (paper)
A sufficient condition for de Sitter vacua in type IIB string theory
Energy Technology Data Exchange (ETDEWEB)
Rummel, Markus [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2011-07-15
We derive a sufficient condition for realizing meta-stable de Sitter vacua with small positive cosmological constant within type IIB string theory flux compactifications with spontaneously broken supersymmetry. There are a number of 'lamp post' constructions of de Sitter vacua in type IIB string theory and supergravity. We show that one of them - the method of 'Kaehler uplifting' by F-terms from an interplay between non-perturbative effects and the leading {alpha}'-correction - allows for a more general parametric understanding of the existence of de Sitter vacua. The result is a condition on the values of the flux induced superpotential and the topological data of the Calabi-Yau compactification, which guarantees the existence of a meta-stable de Sitter vacuum if met. Our analysis explicitly includes the stabilization of all moduli, i.e. the Kaehler, dilaton and complex structure moduli, by the interplay of the leading perturbative and non-perturbative effects at parametrically large volume. (orig.)
Continuous Planetary Polar Observation from Hybrid Pole-Sitters at Venus, Earth, and Mars
Heiligers, M.J.; van den Oever (student TUDelft), Tom; Ceriotti, M.; Mulligan, P.; McInnes, CR
2017-01-01
A pole-sitter is a satellite that is stationed along the polar axis of the Earth, or any other planet, to generate a continuous, hemispherical view of the planet’s polar regions. In order to maintain such a vantage point, a low-thrust propulsion system is required to counterbalance the gravitational
On the de Sitter and Nariai spacetimes in a generalized theory of gravitation
International Nuclear Information System (INIS)
Nariai, Hidekazu.
1985-07-01
A possibility of obtaining the de Sitter and Nariai spacetimes in a generalized theory of gravitation (which was in succession proposed by Utiyama-DeWitt, Parker-Fulling-Hu and Gurovich-Starobinski) is examined. It is shown that the generalized theory with a suitable fixation of three parameters admit both spacetimes, just like the general theory of relativity. (author)
Gauge-invariant metric fluctuations from NKK theory of gravity: de Sitter expansion
International Nuclear Information System (INIS)
Aguilar, Jose Edgar Madriz; Anabitarte, Mariano; Bellini, Mauricio
2006-01-01
In this Letter we study gauge-invariant metric fluctuations from a noncompact Kaluza-Klein (NKK) theory of gravity in de Sitter expansion. We recover the well-known result δρ/ρ∼2Φ, obtained from the standard 4D semiclassical approach to inflation. The spectrum for these fluctuations should be dependent of the fifth (spatial-like) coordinate
Quantum Scalar Corrections to the Gravitational Potentials on de Sitter Background
Park, Sohyun; Prokopec, Tomislav; Woodard, R. P.
We employ the graviton self-energy induced by a massless, minimally coupled (MMC) scalar on de Sitter background to compute the quantum corrections to the gravitational potentials of a static point particle with a mass $M$. The Schwinger-Keldysh formalism is used to derive real and causal effective
The de Sitter spacetime as an attractor solution in fourth-order gravity
International Nuclear Information System (INIS)
Schmidt, H.-J.
1988-01-01
We investigate the general vacuum solution of fourth-order gravity, and include the Bach tensor. For L 2 = 1.3μR 2 + 1/2αC 2 the expanding de Sitter spacetime is an attractor in the set of axially symmetric Bianchi type-I models if and only if αμ ≤ 0 or α > 4μ holds. It will be argued that this result holds true for a large class of inhomogeneous models. As a byproduct, a new closed-form cosmological solution, is obtained. It is also shown that the de Sitter spacetime is an attractor for the Bach-Einstein gravity with a minimally coupled scalar field φ. Specialised to Einstein gravity (i.e. α = 0 above) this conformal equivalence remains a non-trivial one. (author)
Edholm, James
2018-03-01
General Relativity is known to produce singularities in the potential generated by a point source. Our universe can be modeled as a de Sitter (dS) metric and we show that ghost-free infinite derivative gravity (IDG) produces a nonsingular potential around a dS background, while returning to the GR prediction at large distances. We also show that although there are an apparently infinite number of coefficients in the theory, only a finite number actually affect the predictions. By writing the linearized equations of motion in a simplified form, we find that at distances below the Hubble length scale, the difference between the IDG potential around a flat background and around a de Sitter background is negligible.
Restoration of the covariant gauge α in the initial field of gravity in de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Cheong, Lee Yen; Yan, Chew Xiao [Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Bandar Seri Iskandar, Tronoh 31750, Perak (Malaysia)
2014-03-05
The gravitational field generated by a mass term and the initial surface through covariant retarded Green's function for linearized gravity in de Sitter spacetime was studied recently [4, 5] with the covariant gauges set to β = 2/3 and α = 5/3. In this paper we extend the work to restore the gauge parameter α in the field coming from the initial data using the method of shifting the parameter. The α terms in the initial field cancels exactly with the one coming from the source term. Consequently, the correct field configuration, with two equal mass points moving in its geodesic, one located at the North pole and another one located at the South pole, is reproduced in the whole manifold of de Sitter spacetime.
Design of attitude solution algorithm for tail-sitter VTOL UAV
Directory of Open Access Journals (Sweden)
Donghui LIU
2016-02-01
Full Text Available The tail-sitter Vertical Takeoff and Landing (VTOL Unmanned Aerial Vehicle(UAV, flying in a fixed-wing model, overcomes many shortcomings of traditional fixed-wing UAVs, and inherits the advantage of high overall efficiency, which means it has great development potential and very broad application prospects. The attitude of tail-sitter VTOL UAV shows a wide change range in its takeoff and landing stages, and when the attitude sensor changes more than 90 degrees in pitch direction, the Euler angles converted by the Quaternions will have singular points, which means gimbal deadlock appears. From the solution algorithm, this paper provides a method of changing the order of rotation to avoid the appearance of singular points. The results show that this method can be well applied to the attitude solution of the VTOL UAV.
de Sitter-invariant special relativity and the dark energy problem
Araujo, A.; López, D. F.; Pereira, J. G.
2017-06-01
The replacement of the Poincaré-invariant Einstein special relativity by a de Sitter-invariant special relativity produces concomitant changes in all relativistic theories, including general relativity. A crucial change in the latter is that both the background de Sitter curvature and the gravitational dynamical curvature turns out to be included in a single curvature tensor. This means that the cosmological term Λ no longer explicitly appears in Einstein equation, and is consequently not restricted to be constant. In this paper, the Newtonian limit of such theory is obtained, and the ensuing Newtonian Friedmann equations are shown to provide a good account of the dark energy content of the present-day universe.
Classification of Kerr-de Sitter-like spacetimes with conformally flat \\mathscr{I}
Mars, Marc; Paetz, Tim-Torben; Senovilla, José M. M.
2017-05-01
We provide a classification of Λ >0 -vacuum spacetimes which admit a Killing vector field with respect to which the associated ‘Mars-Simon tensor’ (MST) vanishes and have a conformally flat {{\\mathscr{I}}-} (or {{\\mathscr{I}}+} ). To that end, we also give a complete classification of conformal Killing vector fields on the 3-sphere {{{S}}3} up to Möbius transformations shedding light on the two fundamental constants that characterize the family of Kerr-de Sitter-like spacetimes, which turn out to be well-defined geometrical invariants. The topology of \\mathscr{I} is determined in every case, and a characterization result at \\mathscr{I} of the Kerr-de Sitter family presented. Preprint UWThPh-2016-20.
Thermodynamics of the Schwarzschild-de Sitter black hole: Thermal stability of the Nariai black hole
International Nuclear Information System (INIS)
Myung, Yun Soo
2008-01-01
We study the thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalizations. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization and does not favor the Bousso-Hawking normalization
On the covariant gauge {alpha} of the linearized gravity in de Sitter spacetime
Energy Technology Data Exchange (ETDEWEB)
Cheong, Lee Yen [Department of Fundamental and Applied Science Universiti Teknologi Petronas, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)
2012-09-26
In previous work, we studied the linearized gravity with covariant gauge {beta}= 2/3 and {alpha}= 5/3. It was found that the sum of the source and initial contributions reproduces the correct field configuration over the whole de Sitter spacetime. In this paper, we extend this work to generalizing the linearized gravitational field in an arbitrary value of the gauge parameter {alpha} but the gauge parameter {beta} remains the same.
Phase transitions and critical behaviour for charged black holes
International Nuclear Information System (INIS)
Carlip, S; Vaidya, S
2003-01-01
We investigate the thermodynamics of a four-dimensional charged black hole in a finite cavity in asymptotically flat and asymptotically de Sitter spaces. In each case, we find a Hawking-Page-like phase transition between a black hole and a thermal gas very much like the known transition in asymptotically anti-de Sitter space. For a 'supercooled' black hole - a thermodynamically unstable black hole below the critical temperature for the Hawking-Page phase transition - the phase diagram has a line of first-order phase transitions that terminates in a second-order point. For the asymptotically flat case, we calculate the critical exponents at the second-order phase transition and find that they exactly match the known results for a charged black hole in anti-de Sitter space. We find strong evidence for similar phase transitions for the de Sitter black hole as well. Thus many of the thermodynamic features of charged anti-de Sitter black holes do not really depend on asymptotically anti-de Sitter boundary conditions; the thermodynamics of charged black holes is surprisingly universal
Separability and Killing tensors in Kerr-Taub-NUT-de Sitter metrics in higher dimensions
International Nuclear Information System (INIS)
Chong, Z.-W.; Gibbons, G.W.; Lue, H.; Pope, C.N.
2005-01-01
A generalisation of the four-dimensional Kerr-de Sitter metrics to include a NUT charge is well known, and is included within a class of metrics obtained by Plebanski. In this Letter, we study a related class of Kerr-Taub-NUT-de Sitter metrics in arbitrary dimensions D>=6, which contain three non-trivial continuous parameters, namely the mass, the NUT charge, and a (single) angular momentum. We demonstrate the separability of the Hamilton-Jacobi and wave equations, we construct a closely-related rank-2 Stackel-Killing tensor, and we show how the metrics can be written in a double Kerr-Schild form. Our results encompass the case of the Kerr-de Sitter metrics in arbitrary dimension, with all but one rotation parameter vanishing. Finally, we consider the real Euclidean-signature continuations of the metrics, and show how in a limit they give rise to certain recently-obtained complete non-singular compact Einstein manifolds
Hydrogen-like spectrum of spontaneously created brane universes with de-Sitter ground state
Davidson, Aharon
2018-05-01
Unification of Randall-Sundrum and Regge-Teitelboim brane cosmologies gives birth to a serendipitous Higgs-deSitter interplay. A localized Dvali-Gabadadze-Porrati scalar field, governed by a particular (analytically derived) double-well quartic potential, becomes a mandatory ingredient for supporting a deSitter brane universe. When upgraded to a general Higgs potential, the brane surface tension gets quantized, resembling a Hydrogen atom spectrum, with deSitter universe serving as the ground state. This reflects the local/global structure of the Euclidean manifold: From finite energy density no-boundary initial conditions, via a novel acceleration divide filter, to exact matching conditions at the exclusive nucleation point. Imaginary time periodicity comes as a bonus, with the associated Hawking temperature vanishing at the continuum limit. Upon spontaneous creation, while a finite number of levels describe universes dominated by a residual dark energy combined with damped matter oscillations, an infinite tower of excited levels undergo a Big Crunch.
Detecting the Curvature of de Sitter Universe with Two Entangled Atoms.
Tian, Zehua; Wang, Jieci; Jing, Jiliang; Dragan, Andrzej
2016-10-12
Casimir-Polder interaction arises from the vacuum fluctuations of quantum field that depend on spacetime curvature and thus is spacetime-dependent. Here we show how to use the resonance Casimir-Polder interaction (RCPI) between two entangled atoms to detect spacetime curvature. We find that the RCPI of two static entangled atoms in the de Sitter-invariant vacuum depends on the de Sitter spacetime curvature relevant to the temperature felt by the static observer. It is characterized by a 1/L 2 power law decay when beyond a characteristic length scale associated to the breakdown of a local inertial description of the two-atom system. However, the RCPI of the same setup embedded in a thermal bath in the Minkowski universe is temperature-independent and is always characterized by a 1/L power law decay. Therefore, although a single static atom in the de Sitter-invariant vacuum responds as if it were bathed in thermal radiation in a Minkowski universe, using the distinct difference between RCPI of two entangled atoms one can in principle distinguish these two universes.
Dingle and de Sitter Against the Metaphysicians, or Two Ways to Keep Modern Cosmology Physical
Gale, George
It would be hard to find two more radically different personalities than the irascible Herbert Dingle and the courtly Willem de Sitter. Yet, when it came to their philosophy of science, these two otherwise-so-different men were united against a common enemy, those they both called the "metaphysicians." Right from 1917, de Sitter attempted always to keep cosmology tightly bound to real observations made upon a real world. In Kosmos, written near the end of his life, he re-affirms most strongly his principle that "there is nothing an orthodox physicist abhors more than metaphysics." Dingle, for his part, accepts early on the positivist use of the verifiability principle to eliminate metaphysics from science, and continuously wields the principle as a weapon against those errant cosmologists who would sacrifice science for a sort of mysticism. Both men reject the strict and literal use of the term "universe," and for the same reasons: there is no observation, no verification, of statements containing that term. Both men reject the "cosmological principle" as Milne and others use it, on the grounds, as de Sitter puts it, that "we have . . . no means of communicating with other observers, situated on faraway stars." Eddington, although always closely associated with de Sitter personally, comes in for his own fine share of criticism. After de Sitter's death, Dingle carried on the battle alone, always on the bases that he and de Sitter had earlier established. The two peaks in Dingle's long struggle were the notorious 1937 controversy in the pages of Nature, a nasty dogfight which managed to involve almost every single important physicist in Britain; thirteen years later, the long war with the metaphysicians ended with the pyrrhic victory of Dingle's Royal Astronomical Society Presidential Address' invective against the latest and greatest metaphysical creation, Bondi's steady state universe theory. In the end, however, it would be a mistake to believe that the campaign
On the large subgroups of O(n-1,1) and a result by Kowalsky and Witte
Patrangenaru, Vic
2013-02-01
One shows that the maximal Lie subgroups of the Lorentz group O(n-1,1) of first and second largest possible dimensions are the groups of Lorentz transformations that leave invariant a vector hyperplane in the Minkowski space. One also shows that the only Lorentz manifolds that admit an almost simple transitive group of isometries with a noncompact stabilizer are the de-Sitter and the anti de-Sitter spaces.
Gauss-Bonnet black holes in dS spaces
International Nuclear Information System (INIS)
Cai Ronggen; Guo Qi
2004-01-01
We study the thermodynamic properties associated with the black hole horizon and cosmological horizon for the Gauss-Bonnet solution in de Sitter space. When the Gauss-Bonnet coefficient is positive, a locally stable small black hole appears in the case of spacetime dimension d=5, the stable small black hole disappears, and the Gauss-Bonnet black hole is always unstable quantum mechanically when d≥6. On the other hand, the cosmological horizon is found to be always locally stable independent of the spacetime dimension. But the solution is not globally preferred; instead, the pure de Sitter space is globally preferred. When the Gauss-Bonnet coefficient is negative, there is a constraint on the value of the coefficient, beyond which the gravity theory is not well defined. As a result, there is not only an upper bound on the size of black hole horizon radius at which the black hole horizon and cosmological horizon coincide with each other, but also a lower bound depending on the Gauss-Bonnet coefficient and spacetime dimension. Within the physical phase space, the black hole horizon is always thermodynamically unstable and the cosmological horizon is always stable; furthermore, as in the case of the positive coefficient, the pure de Sitter space is still globally preferred. This result is consistent with the argument that the pure de Sitter space corresponds to an UV fixed point of dual field theory
On the stabilization of modulus in Randall–Sundrum model by R2 ...
Indian Academy of Sciences (India)
these attempts, Randall–Sundrum I [1], explains this hierarchy in terms of a small extra dimension. This proposal involves a 'Planck brane' and a 'TeV brane' and the space bet- ween the branes is a slice of anti-de Sitter space. By solving the five-dimensional Einstein equations, one obtains the metric for this space as.
Dimensional degression in AdSd
International Nuclear Information System (INIS)
Artsukevich, A. Yu.; Vasiliev, M. A.
2009-01-01
We analyze the pattern of fields in (d+1)-dimensional anti-de Sitter space in terms of those in d-dimensional anti-de Sitter space. The procedure, which is neither dimensional reduction nor dimensional compactification, is called dimensional degression. The analysis is performed group theoretically for all totally symmetric bosonic and fermionic representations of the anti-de Sitter algebra. The field-theoretical analysis is done for a massive scalar field in AdS d+d ' and massless spin-one-half, spin-one, and spin-two fields in AdS d+1 . The mass spectra of the resulting towers of fields in AdS d are found. For the scalar field case, the obtained results extend to the shadow sector those obtained by Metsaev [Nucl. Phys. B, Proc. Suppl. 102, 100 (2001)] by a different method.
Noneuclidean momentum space and the two-body problem
International Nuclear Information System (INIS)
Donkov, A.D.; Kadyshevskij, V.G.; Mateev, M.D.
1980-01-01
In the framework of quantum field theory with De Sitter momentum space a quasipotential equation for the two-particle system is obtained. The equation is solved in quasiclassical approximation. The large angle scattering, similarly to the usual approach, is considered as scattering on a smooth quasipotential in the region of the classically forbidden angles
Noneuclidean momentum space and the two-body problem
International Nuclear Information System (INIS)
Donkov, A.D.; Kadyshevskij, V.G.; Mateev, M.D.
1980-01-01
In the framework of a quantum field theory with De Sitter momentum space a quasipotential equation for the two-particle system is obtained. The equation is solved in the quasiclassical approximation. The large angle scattering, similarly to the usual approach, is considered as scattering on a smooth quasipotential in the region of the classically forbidden angles
Black holes in su(N) Einstein-Yang-Mills theory: hair, fur and superconducting horizons
Energy Technology Data Exchange (ETDEWEB)
Winstanley, Elizabeth [School of Mathematics and Statistics, University of Sheffield (United Kingdom)
2012-07-01
Black hole solutions of general relativity coupled to an su(N) Yang-Mills gauge field have been studied for over 20 years. In this talk we focus on black holes in Einstein-Yang-Mills theory in four-dimensional, asymptotically anti-de Sitter space, with a negative cosmological constant. We emphasize three aspects of these black holes: (a) the existence of stable black holes in anti-de Sitter space with abundant Yang-Mills hair; (b) how these hairy black holes may be characterized by non-Abelian charges at infinity; (c) planar black holes with superconducting horizons.
1+1 dimensional compactifications of string theory.
Goheer, Naureen; Kleban, Matthew; Susskind, Leonard
2004-05-14
We argue that stable, maximally symmetric compactifications of string theory to 1+1 dimensions are in conflict with holography. In particular, the finite horizon entropies of the Rindler wedge in 1+1 dimensional Minkowski and anti-de Sitter space, and of the de Sitter horizon in any dimension, are inconsistent with the symmetries of these spaces. The argument parallels one made recently by the same authors, in which we demonstrated the incompatibility of the finiteness of the entropy and the symmetries of de Sitter space in any dimension. If the horizon entropy is either infinite or zero, the conflict is resolved.
1+1 dimensional compactifications of string theory
International Nuclear Information System (INIS)
Goheer, Naureen; Kleban, Matthew; Susskind, Leonard
2004-01-01
We argue that stable, maximally symmetric compactifications of string theory to 1+1 dimensions are in conflict with holography. In particular, the finite horizon entropies of the Rindler wedge in 1+1 dimensional Minkowski and anti-de Sitter space, and of the de Sitter horizon in any dimension, are inconsistent with the symmetries of these spaces. The argument parallels one made recently by the same authors, in which we demonstrated the incompatibility of the finiteness of the entropy and the symmetries of de Sitter space in any dimension. If the horizon entropy is either infinite or zero, the conflict is resolved
1+1 Dimensional Compactifications of String Theory
Goheer, Naureen; Kleban, Matthew; Susskind, Leonard
2004-05-01
We argue that stable, maximally symmetric compactifications of string theory to 1+1 dimensions are in conflict with holography. In particular, the finite horizon entropies of the Rindler wedge in 1+1 dimensional Minkowski and anti de Sitter space, and of the de Sitter horizon in any dimension, are inconsistent with the symmetries of these spaces. The argument parallels one made recently by the same authors, in which we demonstrated the incompatibility of the finiteness of the entropy and the symmetries of de Sitter space in any dimension. If the horizon entropy is either infinite or zero, the conflict is resolved.
Greybody factors for a spherically symmetric Einstein-Gauss-Bonnet-de Sitter black hole
Zhang, Cheng-Yong; Li, Peng-Cheng; Chen, Bin
2018-02-01
We study the greybody factors of the scalar fields in spherically symmetric Einstein-Gauss-Bonnet-de Sitter black holes in higher dimensions. We derive the greybody factors analytically for both minimally and nonminimally coupled scalar fields. Moreover, we discuss the dependence of the greybody factor on various parameters including the angular momentum number, the nonminimally coupling constant, the spacetime dimension, the cosmological constant, and the Gauss-Bonnet coefficient in detail. We find that the nonminimal coupling may suppress the greybody factor and the Gauss-Bonnet coupling could enhance it, but they both suppress the energy emission rate of Hawking radiation.
The flux-scaling scenario. De Sitter uplift and axion inflation
Energy Technology Data Exchange (ETDEWEB)
Blumenhagen, Ralph; Damian, Cesar; Herschmann, Daniela; Sun, Rui [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Font, Anamaria [Departamento de Fisica, Centro de Fisica Teorica y Computacional, Facultad de Ciencias, Universidad Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of)
2016-06-15
Non-geometric flux-scaling vacua provide promising starting points to realize axion monodromy inflation via the F-term scalar potential. We show that these vacua can be uplifted to Minkowski and de Sitter by adding an D3-brane or a D-term containing geometric and non-geometric fluxes. These uplifted non-supersymmetric models are analyzed with respect to their potential to realize axion monodromy inflation self-consistently. Admitting rational values of the fluxes, we construct examples with the required hierarchy of mass scales. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
The flux-scaling scenario. De Sitter uplift and axion inflation
International Nuclear Information System (INIS)
Blumenhagen, Ralph; Damian, Cesar; Herschmann, Daniela; Sun, Rui; Font, Anamaria
2016-01-01
Non-geometric flux-scaling vacua provide promising starting points to realize axion monodromy inflation via the F-term scalar potential. We show that these vacua can be uplifted to Minkowski and de Sitter by adding an D3-brane or a D-term containing geometric and non-geometric fluxes. These uplifted non-supersymmetric models are analyzed with respect to their potential to realize axion monodromy inflation self-consistently. Admitting rational values of the fluxes, we construct examples with the required hierarchy of mass scales. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Indications of de Sitter spacetime from classical sequential growth dynamics of causal sets
International Nuclear Information System (INIS)
Ahmed, Maqbool; Rideout, David
2010-01-01
A large class of the dynamical laws for causal sets described by a classical process of sequential growth yields a cyclic universe, whose cycles of expansion and contraction are punctuated by single 'origin elements' of the causal set. We present evidence that the effective dynamics of the immediate future of one of these origin elements, within the context of the sequential growth dynamics, yields an initial period of de Sitter-like exponential expansion, and argue that the resulting picture has many attractive features as a model of the early universe, with the potential to solve some of the standard model puzzles without any fine-tuning.
A Review on the Cosmology of the de Sitter Horndeski Models
Directory of Open Access Journals (Sweden)
Nelson J. Nunes
2017-03-01
Full Text Available We review the most general scalar-tensor cosmological models with up to second-order derivatives in the field equations that have a fixed spatially flat de Sitter critical point independent of the material content or vacuum energy. This subclass of the Horndeski Lagrangian is capable of dynamically adjusting any value of the vacuum energy of the matter fields at the critical point. We present the cosmological evolution of the linear models and the non-linear models with shift symmetry. We come to the conclusion that the shift symmetric non-linear models can deliver a viable background compatible with current observations.
Holographic Thermalization in Gauss-Bonnet Gravity with de Sitter Boundary
Zhang, Shao-Jun; Abdalla, Elcio; Papantonopoulos, Eleftherios
2015-01-01
We introduce higher-derivative Gauss-Bonnet correction terms in the gravity sector and we relate the modified gravity theory in the bulk to the strongly coupled quantum field theory on a de Sitter boundary. We study the process of holographic thermalization by examining three non-local observables, the two-point function, the Wilson loop and the holographic entanglement entropy. We study the time evolution of these three observables and we find that the modification of the gravity side with the Gauss-Bonnet correction terms influences the saturation time to reach thermal equilibrium with the dominant effect given by the holographic entanglement entropy since it contains more bulk information.
Quantum scalar corrections to the gravitational potentials on de Sitter background
Energy Technology Data Exchange (ETDEWEB)
Park, Sohyun [Korea Astronomy and Space Science Institute,Daejeon, 305-348 (Korea, Republic of); Prokopec, Tomislav [Institute of Theoretical Physics, Spinoza Instituteand the Center for Extreme Matter and Emergent Phenomena (EMME),Utrecht University, Leuvenlaan 4, 3584 CE Utrecht (Netherlands); Woodard, R.P. [Department of Physics, University of Florida,Gainesville, FL 32611 (United States)
2016-01-13
We employ the graviton self-energy induced by a massless, minimally coupled (MMC) scalar on de Sitter background to compute the quantum corrections to the gravitational potentials of a static point particle with a mass M. The Schwinger-Keldysh formalism is used to derive real and causal effective field equations. When evaluated at the one-loop order, the gravitational potentials exhibit a secular decrease in the observed gravitational coupling G. This can also be interpreted as a (time dependent) anti-screening of the mass M.
Lake, Kayll
2010-12-01
The title immediately brings to mind a standard reference of almost the same title [1]. The authors are quick to point out the relationship between these two works: they are complementary. The purpose of this work is to explain what is known about a selection of exact solutions. As the authors state, it is often much easier to find a new solution of Einstein's equations than it is to understand it. Even at first glance it is very clear that great effort went into the production of this reference. The book is replete with beautifully detailed diagrams that reflect deep geometric intuition. In many parts of the text there are detailed calculations that are not readily available elsewhere. The book begins with a review of basic tools that allows the authors to set the notation. Then follows a discussion of Minkowski space with an emphasis on the conformal structure and applications such as simple cosmic strings. The next two chapters give an in-depth review of de Sitter space and then anti-de Sitter space. Both chapters contain a remarkable collection of useful diagrams. The standard model in cosmology these days is the ICDM model and whereas the chapter on the Friedmann-Lemaître-Robertson-Walker space-times contains much useful information, I found the discussion of the currently popular a representation rather too brief. After a brief but interesting excursion into electrovacuum, the authors consider the Schwarzschild space-time. This chapter does mention the Swiss cheese model but the discussion is too brief and certainly dated. Space-times related to Schwarzschild are covered in some detail and include not only the addition of charge and the cosmological constant but also the addition of radiation (the Vaidya solution). Just prior to a discussion of the Kerr space-time, static axially symmetric space-times are reviewed. Here one can find a very interesting discussion of the Curzon-Chazy space-time. The chapter on rotating black holes is rather brief and, for
Indian Academy of Sciences (India)
Parthasarathi Majumdar defined with the periodicity of time (i.e., the temperature) determined by the black hole. The temperatures are set to be equal at the boundary of space (which is taken to infinity). Hawking and Page [1] considered the competition in free energy or action between the black hole and anti-de Sitter space.
Horizons in 2+1-dimensional collapse of particles
Indian Academy of Sciences (India)
front that will be smooth ... Anti-de Sitter space, like Minkowski space, can be represented in static coordinates, eq. (1), as a time sequence of ... masses of the particles, containing a contribution from the kinetic energy. Thus the total mass M of the ...
AdS/QCD and Applications of Light-Front Holography
DEFF Research Database (Denmark)
Brodsky, S. J.; Cao, F. G.; de Teramond, G. F.
2012-01-01
Light-front holography leads to a rigorous connection between hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space and frame-independent light-front wavefunctions of hadrons in (3+1)-dimensional physical space-time, thus providing a compelling physical interpretation of the Ad...
Stringy stability of charged dilaton black holes with flat event horizon
Energy Technology Data Exchange (ETDEWEB)
Ong, Yen Chin [National Taiwan Univ., Taipei (Taiwan); Chen, Pisin [National Taiwan Univ., Taipei (Taiwan); SLAC National Accelerator Lab., Menlo Park, CA (United States)
2015-01-15
Electrically charged black holes with flat event horizon in anti-de Sitter space have received much attention due to various applications in Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, from modeling the behavior of quark-gluon plasma to superconductor. Critical to the physics on the dual field theory is the fact that when embedded in string theory, black holes in the bulk may become vulnerable to instability caused by brane pair-production. Since dilation arises naturally in the context of string theory, we study the effect of coupling dilation to Maxwell field on the stability of flat charged AdS black holes.
Energy Technology Data Exchange (ETDEWEB)
Braun, Andreas P. [Rudolph Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford, OX1 3NP (United Kingdom); Mathematical Institute, University of Oxford, Woodstock Road,Oxford, OX2 6GG (United Kingdom); Rummel, Markus [Rudolph Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford, OX1 3NP (United Kingdom); Sumitomo, Yoske [High Energy Accelerator Research Organization, KEK,1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Valandro, Roberto [Dipartimento di Fisica dell’Università di Trieste,Strada Costiera 11, 34151 Trieste (Italy); INFN - Sezione di Trieste,Via Valerio 2, 34127 Trieste (Italy); ICTP,Strada Costiera 11, 34151 Trieste (Italy)
2015-12-04
In http://dx.doi.org/10.1007/JHEP01(2015)015 a mechanism to fix the closed string moduli in a de Sitter minimum was proposed: a D-term potential generates a linear relation between the volumes of two rigid divisors which in turn produces at lower energies a race-track potential with de Sitter minima at exponentially large volume. In this paper, we systematically search for implementations of this mechanism among all toric Calabi-Yau hypersurfaces with h{sup 1,1}≤4 from the Kreuzer-Skarke list. For these, topological data can be computed explicitly allowing us to find the subset of three-folds which have two rigid toric divisors that do not intersect each other and that are orthogonal to h{sup 1,1}−2 independent four-cycles. These manifolds allow to find D7-brane configurations compatible with the de Sitter uplift mechanism and we find an abundance of consistent choices of D7-brane fluxes inducing D-terms leading to a de Sitter minimum. Finally, we work out a couple of models in detail, checking the global consistency conditions and computing the value of the potential at the minimum.
Charged de Sitter-like black holes: quintessence-dependent enthalpy and new extreme solutions
Energy Technology Data Exchange (ETDEWEB)
Azreg-Ainou, Mustapha [Baskent University, Faculty of Engineering, Ankara (Turkey)
2015-01-01
We consider Reissner-Nordstroem black holes surrounded by quintessence where both a non-extremal event horizon and a cosmological horizon exist besides an inner horizon (-1 ≤ ω < -1/3). We determine new extreme black hole solutions that generalize the Nariai horizon to asymptotically de Sitter-like solutions for any order relation between the squares of the charge q{sup 2} and the mass parameter M{sup 2} provided q{sup 2} remains smaller than some limit, which is larger than M{sup 2}. In the limit case q{sup 2} = 9ω{sup 2}M{sup 2}/(9ω{sup 2}-1), we derive the general expression of the extreme cosmo-blackhole, where the three horizons merge, and we discuss some of its properties.We also show that the endpoint of the evaporation process is independent of any order relation between q{sup 2} and M{sup 2}. The Teitelboim energy and the Padmanabhan energy are related by a nonlinear expression and are shown to correspond to different ensembles. We also determine the enthalpy H of the event horizon, as well as the effective thermodynamic volume which is the conjugate variable of the negative quintessential pressure, and show that in general the mass parameter and the Teitelboim energy are different from the enthalpy and internal energy; only in the cosmological case, that is, for Reissner-Nordstroem-de Sitter black hole we have H = M. Generalized Smarr formulas are also derived. It is concluded that the internal energy has a universal expression for all static charged black holes, with possibly a variable mass parameter, but it is not a suitable thermodynamic potential for static-black-hole thermodynamics if M is constant. It is also shown that the reverse isoperimetric inequality holds. We generalize the results to the case of the Reissner-Nordstroem-de Sitter black hole surrounded by quintessence with two physical constants yielding two thermodynamic volumes. (orig.)
Schwarzschild-de Sitter spacetime: The role of temperature in the emission of Hawking radiation
Pappas, Thomas; Kanti, Panagiota
2017-12-01
We consider a Schwarzschild-de Sitter (SdS) black hole, and focus on the emission of massless scalar fields either minimally or non-minimally coupled to gravity. We use six different temperatures, two black-hole and four effective ones for the SdS spacetime, as the question of the proper temperature for such a background is still debated in the literature. We study their profiles under the variation of the cosmological constant, and derive the corresponding Hawking radiation spectra. We demonstrate that only few of these temperatures may support significant emission of radiation. We finally compute the total emissivities for each temperature, and show that the non-minimal coupling constant of the scalar field to gravity also affects the relative magnitudes of the energy emission rates.
Effect of a magnetic field on Schwinger mechanism in de Sitter spacetime
Bavarsad, Ehsan; Kim, Sang Pyo; Stahl, Clément; Xue, She-Sheng
2018-01-01
We investigate the effect of a uniform magnetic field background on scalar QED pair production in a four-dimensional de Sitter spacetime (dS4 ). We obtain a pair production rate which agrees with the known Schwinger result in the limit of Minkowski spacetime and with Hawking radiation in dS spacetime in the zero electric field limit. Our results describe how the cosmic magnetic field affects the pair production rate in cosmological setups. In addition, using the zeta function regularization scheme we calculate the induced current and examine the effect of a magnetic field on the vacuum expectation value of the current operator. We find that, in the case of a strong electromagnetic background the current responds as E .B , while in the infrared regime, it responds as B /E , which leads to a phenomenon of infrared hyperconductivity. These results for the induced current have important applications for the cosmic magnetic field evolution.
Scalar potential from de Sitter brane in 5D and effective cosmological constant
International Nuclear Information System (INIS)
Ito, Masato
2004-01-01
We derive the scalar potential in zero mode effective action arising from a de Sitter brane embedded in five dimensions with bulk cosmological constant Λ. The scalar potential for a scalar field canonically normalized is given by the sum of exponential potentials. In the case of Λ = 0 and Λ > 0, we point out that the scalar potential has an unstable maximum at the origin and exponentially vanishes for large positive scalar field. In the case of Λ < 0, the scalar potential has an unstable maximum at the origin and a local minimum. It is shown that the positive cosmological constant in dS brane is reduced by negative potential energy of scalar at minimum and that effective cosmological constant depends on a dimensionless quantity. Furthermore, we discuss the fate of our universe including the potential energy of the scalar. (author)
Nonsingular black holes, wormholes, and de Sitter cores from anisotropic fluids
Menchon, Cintia C.; Olmo, Gonzalo J.; Rubiera-Garcia, Diego
2017-11-01
We study Born-Infeld gravity coupled to an anisotropic fluid in a static, spherically symmetric background. The free function characterizing the fluid is selected on the following grounds: i) recovery of the Reissner-Nordström solution of General Relativity at large distances, ii) fulfillment of classical energy conditions, and iii) inclusion of models of nonlinear electrodynamics as particular examples. Four branches of solutions are obtained, depending on the signs of two parameters on the gravity and matter sectors. On each branch, we discuss in detail the modifications on the innermost region of the corresponding solutions, which provides a plethora of configurations, including nonsingular black holes and naked objects, wormholes, and de Sitter cores. The regular character of these configurations is discussed according to the completeness of geodesics and the behavior of curvature scalars.
Reply to "Comment on `Fermion production in a magnetic field in a de Sitter universe"'
Crucean, Cosmin; Bǎloi, Mihaela-Andreea
2017-02-01
In this paper, we study the problem of gauge invariance of the first order transition amplitudes in de Sitter QED in the Coulomb gauge. We consider the gauge transformations which preserve the Coulomb gauge, that contain the gradient of the gauge function. The final results prove that the first order transition amplitudes do not change at a gradient transformation of the vector potential because the only allowed transformation is Λ =0 . Our results suggest that the remarks made in the comment by Nicolaevici and Farkas [this issue, Phys. Rev. D 95, 048501 (2017), 10.1103/PhysRevD.95.048501] are not directly applicable to the results in our paper since their proposed gauge transformations do not preserve the Coulomb gauge.
Quantum radiation of Maxwell’s electromagnetic field in nonstationary Kerr-de Sitter black hole
Ibungochouba Singh, T.; Ablu Meitei, I.; Yugindro Singh, K.
2016-03-01
Quantum radiation properties of nonstationary Kerr-de Sitter (KdS) black hole is investigated using the method of generalized tortoise coordinate transformation. The locations of horizons and the temperature of the thermal radiation as well as the maximum energy of the nonthermal radiation are derived. It is found that the surface gravity and the Hawking temperature depend on both time and different angles. An extra coupling effect is obtained in the thermal radiation spectrum of Maxwell’s electromagnetic field equations which is absent in the thermal radiation spectrum of scalar particles. Further, the chemical potential derived from the thermal radiation spectrum of scalar particle has been found to be equal to the highest energy of the negative energy state of the scalar particle in the nonthermal radiation for KdS black hole. It is also shown that the generalized tortoise coordinate transformation produces a constant term in the expression of the surface gravity and Hawking temperature.
De Sitter and scaling solutions in a higher-order modified teleparallel theory
Energy Technology Data Exchange (ETDEWEB)
Paliathanasis, Andronikos, E-mail: anpaliat@phys.uoa.gr [Instituto de Ciencias Físicas y Matemáticas, Universidad Austral de Chile, Valdivia (Chile)
2017-08-01
The existence and the stability conditions for some exact relativistic solutions of special interest are studied in a higher-order modified teleparallel gravitational theory. The theory with the use of a Lagrange multiplier is equivalent with that of General Relativity with a minimally coupled noncanonical field. The conditions for the existence of de Sitter solutions and ideal gas solutions in the case of vacuum are studied as also the stability criteria. Furthermore, in the presence of matter the behaviour of scaling solutions is given. Finally, we discuss the degrees of freedom of the field equations and we reduce the field equations in an algebraic equation, where in order to demonstrate our result we show how this noncanonical scalar field can reproduce the Hubble function of Λ-cosmology.
De Sitter vacua and inflation in no-scale string models
International Nuclear Information System (INIS)
Gross, Christian
2009-09-01
This thesis studies the question of how de Sitter vacua and slow-roll inflation may be realized in string-motivated models. More specifically, we consider 4d N = 1 supergravity theories (without vector multiplets) with Kaehler potentials which are 'no-scale' at leading order. Such theories frequently arise in the moduli sector of string compactifications. We discuss a condition on the scalar geometry (defined by the Kaehler potential) and on the direction of supersymmetry breaking in the scalar manifold, which has to be met in order for the average of the masses of the sGoldstinos to be positive, and hence for metastable vacua to be possible. This condition also turns out to be necessary for the existence of trajectories admitting slow-roll inflation. Its implications for certain scalar manifolds which arise from Calabi-Yau string compactifications are discussed. In particular, for two-moduli models arising from compactifications of heterotic- and type IIB string theory, a simple criterion on the intersection numbers needs to be satisfied for possible de Sitter phases to exist. In addition, we show that subleading corrections breaking the no-scale property may allow the condition on the scalar geometry to be fulfilled, even when it is violated at leading order. Finally, we develop a procedure to construct superpotentials for a given viable Kaehler potential, such that the scalar potential has a realistic local minimum. We propose two-moduli models, with superpotentials which could arise from flux backgrounds and non-perturbative effects, which have a viable vacuum without employing subleading corrections or an uplifting sector. (orig.)
De Sitter vacua and inflation in no-scale string models
Energy Technology Data Exchange (ETDEWEB)
Gross, Christian
2009-09-15
This thesis studies the question of how de Sitter vacua and slow-roll inflation may be realized in string-motivated models. More specifically, we consider 4d N = 1 supergravity theories (without vector multiplets) with Kaehler potentials which are 'no-scale' at leading order. Such theories frequently arise in the moduli sector of string compactifications. We discuss a condition on the scalar geometry (defined by the Kaehler potential) and on the direction of supersymmetry breaking in the scalar manifold, which has to be met in order for the average of the masses of the sGoldstinos to be positive, and hence for metastable vacua to be possible. This condition also turns out to be necessary for the existence of trajectories admitting slow-roll inflation. Its implications for certain scalar manifolds which arise from Calabi-Yau string compactifications are discussed. In particular, for two-moduli models arising from compactifications of heterotic- and type IIB string theory, a simple criterion on the intersection numbers needs to be satisfied for possible de Sitter phases to exist. In addition, we show that subleading corrections breaking the no-scale property may allow the condition on the scalar geometry to be fulfilled, even when it is violated at leading order. Finally, we develop a procedure to construct superpotentials for a given viable Kaehler potential, such that the scalar potential has a realistic local minimum. We propose two-moduli models, with superpotentials which could arise from flux backgrounds and non-perturbative effects, which have a viable vacuum without employing subleading corrections or an uplifting sector. (orig.)
Quantum theory of spinor field in four-dimensional Riemannian space-time
International Nuclear Information System (INIS)
Shavokhina, N.S.
1996-01-01
The review deals with the spinor field in the four-dimensional Riemannian space-time. The field beys the Dirac-Fock-Ivanenko equation. Principles of quantization of the spinor field in the Riemannian space-time are formulated which in a particular case of the plane space-time are equivalent to the canonical rules of quantization. The formulated principles are exemplified by the De Sitter space-time. The study of quantum field theory in the De Sitter space-time is interesting because it itself leads to a method of an invariant well for plane space-time. However, the study of the quantum spinor field theory in an arbitrary Riemannian space-time allows one to take into account the influence of the external gravitational field on the quantized spinor field. 60 refs
AdS collapse of a scalar field in higher dimensions
International Nuclear Information System (INIS)
Jalmuzna, Joanna; Rostworowski, Andrzej; Bizon, Piotr
2011-01-01
We show that the weakly turbulent instability of anti-de Sitter space, recently found in P. Bizon and A. Rostworowski, Phys. Rev. Lett. 107, 031102 (2011) for 3+1-dimensional spherically symmetric Einstein-massless-scalar field equations with negative cosmological constant, is present in all dimensions d+1 for d≥3.
A comment on AdS collapse of a scalar field in higher dimensions
Jałmużna, Joanna; Rostworowski, Andrzej; Bizoń, Piotr
2011-01-01
We point out that the weakly turbulent instability of anti-de Sitter space, recently found in arXiv:1104.3702 for four dimensional spherically symmetric Einstein-massless-scalar field equations with negative cosmological constant, is present in all dimensions $d+1$ for $d\\geq 3$, contrary to a claim made in arXiv:1106.2339.
Noncommutative geometry-inspired rotating black hole in three ...
Indian Academy of Sciences (India)
Abstract. We find a new rotating black hole in three-dimensional anti-de Sitter space using an anisotropic perfect fluid inspired by the noncommutative black hole. We deduce the thermodynam- ical quantities of this black hole and compare them with those of a rotating BTZ solution and give corrections to the area law to get ...
Decay constants in soft wall AdS/QCD revisited
Directory of Open Access Journals (Sweden)
Nelson R.F. Braga
2016-12-01
We show here that a modified framework of soft wall AdS/QCD involving an additional dimensionfull parameter, associated with an ultraviolet energy scale, provides decay constants decreasing with radial excitation level. In this version of the soft wall model the two point function of gauge theory operators is calculated at a finite position of the anti-de Sitter space radial coordinate.
Zeta Function Expression of Spin Partition Functions on Thermal AdS3
Directory of Open Access Journals (Sweden)
Floyd L.Williams
2015-07-01
Full Text Available We find a Selberg zeta function expression of certain one-loop spin partition functions on three-dimensional thermal anti-de Sitter space. Of particular interest is the partition function of higher spin fermionic particles. We also set up, in the presence of spin, a Patterson-type formula involving the logarithmic derivative of zeta.
Noncommutative geometry-inspired rotating black hole in three ...
Indian Academy of Sciences (India)
We ﬁnd a new rotating black hole in three-dimensional anti-de Sitter space using an anisotropic perfect ﬂuid inspired by the noncommutative black hole. We deduce the thermodynamical quantities of this black hole and compare them with those of a rotating BTZ solution and give corrections to the area law to get the exact ...
Warped products and black holes
International Nuclear Information System (INIS)
Hong, Soon-Tae
2005-01-01
We apply the warped product space-time scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstroem-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horizons of these black holes
D-instantons and asymptotic geometries
Bergshoeff, E.; Behrndt, K.
1998-01-01
The large-N limit of D-3-branes is expected to correspond to a superconformal field theory living on the boundary of the anti-de Sitter space appearing in the near-horizon geometry. Dualizing the D-3-brane to a D-instanton, we show that this limit is equivalent to a type IIB S-duality. In both cases
Holographic applications of logarithmic conformal field theories
Grumiller, D.; Riedler, W.; Rosseel, J.; Zojer, T.
2013-01-01
We review the relations between Jordan cells in various branches of physics, ranging from quantum mechanics to massive gravity theories. Our main focus is on holographic correspondences between critically tuned gravity theories in anti-de Sitter space and logarithmic conformal field theories in
On Critical Massive (Super)Gravity in adS(3)
Bergshoeff, Eric A.; Hohm, Olaf; Rosseel, Jan; Sezgin, Ergin; Townsend, Paul K.; Aldaya,; Barcelo, C; Jaramillo, JL
2011-01-01
We review the status of three-dimensional "general massive gravity" (GMG) in its linearization about an anti-de Sitter (adS) vacuum, focusing on critical points in parameter space that yield generalizations of "chiral gravity". We then show how these results extend to,N = 1 super-GMG, expanded about
Three-dimensional tricritical gravity
Bergshoeff, Eric A.; de Haan, Sjoerd; Merbis, Wout; Rosseel, Jan; Zojer, Thomas
2012-01-01
We consider a class of parity-even, six-derivative gravity theories in three dimensions. After linearizing around anti-de Sitter space, the theories have one massless and two massive graviton solutions for generic values of the parameters. At a special, so-called tricritical, point in parameter
Bulk reconstruction in AdS and Gel'fand-Graev-Radon transform
Bhowmick, Samrat; Ray, Koushik; Sen, Siddhartha
2017-10-01
The bulk reconstruction formula for a Euclidean anti-de Sitter space is directly related to the inverse of the Gel'fand-Graev-Radon transform. Correlation functions of a conformal scalar field theory in the boundary are thereby related to correlation functions of a self-interacting scalar field theory in the bulk at different loop orders.
International Nuclear Information System (INIS)
Hasan, M. Khayrul; Ali, M. Hossain
2009-01-01
We formulate the general relativistic magnetohydrodynamic equations for isothermal plasma in spatially flat Reissner–Nordström–de Sitter metric by using 3+1 split of spacetime. Respective perturbed equations are linearized for rotating magnetized surroundings. These are then Fourier analyzed and the corresponding dispersion relations are obtained. These relations are discussed both analytically and numerically in order to investigate the nature of waves with positive angular frequency around the horizon
Tunneling probability for the birth of an asymptotically de Sitter universe
International Nuclear Information System (INIS)
Acacio de Barros, J.; Correa Silva, E. V.; Monerat, G. A.; Oliveira-Neto, G.; Ferreira Filho, L. G.; Romildo, P. Jr.
2007-01-01
In the present work, we quantize a closed Friedmann-Robertson-Walker model in the presence of a positive cosmological constant and radiation. It gives rise to a Wheeler-DeWitt equation for the scale factor which has the form of a Schroedinger equation for a potential with a barrier. We solve it numerically and determine the tunneling probability for the birth of a asymptotically DeSitter, inflationary universe, initially, as a function of the mean energy of the initial wave function. Then, we verify that the tunneling probability increases with the cosmological constant, for a fixed value of the mean energy of the initial wave function. Our treatment of the problem is more general than previous ones, based on the WKB approximation. That is the case because we take into account the fact that the scale factor (a) cannot be smaller than zero. It means that, one has to introduce an infinity potential wall at a=0, which forces any wave packet to be zero there. That condition introduces new results, in comparison with previous works
Stability, tunneling and flux changing de Sitter transitions in the large volume string scenario
de Alwis, S.; Gupta, R.; Hatefi, E.; Quevedo, F.
2013-11-01
We study the non-perturbative stability of the Large Volume Scenario (LVS) of IIB string compactifications, by analysing transitions mediated by the Brown-Teitelboim (BT) brane nucleations and by Coleman De Luccia tunneling (CDL). We find that, as long as the effective field theory description holds, the LVS AdS minima are stable despite being non-supersymmetric. This opens the possibility of having a CFT dual. Metastable de Sitter vacua behave differently depending on the uplifting mechanism. We find explicit expressions for the different decay rates in terms of exponentials of the volume. Among the transitions of dS to dS those with increasing volume and decreasing vacuum energy are preferred, though dS decays to AdS (big-crunch sinks) have higher probability. Transitions via the CDL mechanism to decompactification are exponentially suppressed compared to these. The BT decays correspond to flux/D3 brane transitions mediated by the nucleation of D5/NS5 branes. We compare our results with previous analysis for KKLT, type IIA, and 6D Einstein-Maxwell studies. In particular we find no indication for a bubble of nothing decay.
Localization of gauge fields in a tachyonic de Sitter thick braneworld
Energy Technology Data Exchange (ETDEWEB)
Herrera-Aguilar, Alfredo [Universidad Autonoma de Chiapas, Ciudad Universitaria, Mesoamerican Centre for Theoretical Physics, Kilometro 4, Carretera Emiliano Zapata, Colonia Real del Bosque (Teran), Tuxtla Gutierrez, Chiapas (Mexico); Universidad Autonoma Metropolitana Iztapalapa, Departamento de Fisica, Mexico, D.F. (Mexico); Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Fisica y Matematicas, Morelia, Michoacan (Mexico); Rojas, Alma D. [Universidad Autonoma de Chiapas, Ciudad Universitaria, Mesoamerican Centre for Theoretical Physics, Kilometro 4, Carretera Emiliano Zapata, Colonia Real del Bosque (Teran), Tuxtla Gutierrez, Chiapas (Mexico); AHEP Group, Instituto de Fisica Corpuscular C.S.I.C./Universitat de Valencia, Paterna (Valencia) (Spain); Santos, Eli [Universidad Autonoma de Chiapas, Ciudad Universitaria, Mesoamerican Centre for Theoretical Physics, Kilometro 4, Carretera Emiliano Zapata, Colonia Real del Bosque (Teran), Tuxtla Gutierrez, Chiapas (Mexico)
2014-04-15
In this work we show that universal gauge vector fields can be localized on the recently proposed 5D thick tachyonic braneworld which involves a de Sitter cosmological background induced on the 3-brane. Namely, by performing a suitable decomposition of the vector field, the resulting 4D effective action corresponds to a massive gauge field, while the profile along the extra dimension obeys a Schroedinger-like equation with a Poeschl-Teller potential. It turns out that the massless zero mode of the gauge field is bound to the expanding 3-brane and allows us to recover the standard 4D electromagnetic phenomena of our world. Moreover, this zero mode is separated from the continuum of Kaluza-Klein (KK) modes by a mass gap determined by the scale of the expansion parameter. We also were able to analytically solve the corresponding Schroedinger-like equation for arbitrary mass, showing that KK massive modes asymptotically behave like plane waves, as expected. (orig.)
Directory of Open Access Journals (Sweden)
Amin Dehyadegari
2017-05-01
Full Text Available It has been argued that charged Anti-de Sitter (AdS black holes have similar thermodynamic behavior as the Van der Waals fluid system, provided one treats the cosmological constant as a thermodynamic variable (pressure in an extended phase space. In this paper, we disclose the deep connection between charged AdS black holes and Van der Waals fluid system from an alternative point of view. We consider the mass of an AdS black hole as a function of square of the charge Q2 instead of the standard Q, i.e. M=M(S,Q2,P. We first justify such a change of view mathematically and then ask if a phase transition can occur as a function of Q2 for fixed P. Therefore, we write the equation of state as Q2=Q2(T,Ψ where Ψ (conjugate of Q2 is the inverse of the specific volume, Ψ=1/v. This allows us to complete the analogy of charged AdS black holes with Van der Waals fluid system and derive the phase transition as well as critical exponents of the system. We identify a thermodynamic instability in this new picture with real analogy to Van der Waals fluid with physically relevant Maxwell construction. We therefore study the critical behavior of isotherms in Q2–Ψ diagram and deduce all the critical exponents of the system and determine that the system exhibits a small–large black hole phase transition at the critical point (Tc,Qc2,Ψc. This alternative view is important as one can imagine such a change for a given single black hole i.e. acquiring charge which induces the phase transition. Finally, we disclose the microscopic properties of charged AdS black holes by using thermodynamic geometry. Interestingly, we find that scalar curvature has a gap between small and large black holes, and this gap becomes exceedingly large as one moves away from the critical point along the transition line. Therefore, we are able to attribute the sudden enlargement of the black hole to the strong repulsive nature of the internal constituents at the phase transition.
Evidence for Galaxy Dynamics Tracing Background Cosmology Below the de Sitter Scale of Acceleration
Van Putten, Maurice H.
2018-01-01
Galaxy dynamics probes weak gravity at accelerations below the de Sitter scale of acceleration $a_{dS}=cH$, where $c$ is the velocity of light and $H$ is the Hubble parameter. Low and high redshift galaxies hereby offer a novel probe of weak gravity in an evolving cosmology, satisfying $H(z)=H_0\\sqrt{1+\\omega_m(6z+12z^2+12z^3+6z^4+(6/5)z^5)}/(1+z)$ with baryonic matter content $\\omega_m=0.2808\\pm0.028$ sans tension to $H_0$ in surveys of the Local Universe. Galaxy rotation curves show anomalous galaxy dynamics in weak gravity $a_Ninertia from entanglement entropy, that introduces a $C^0$ onset across $a_N=a_{dS}$ with asymptotic behavior described by a Milgrom parameter satisfying $a_0=\\omega_0/2\\pi$, where $\\omega_0=\\sqrt{1-q}H$ is a fundamental eigenfrequency of the cosmological horizon. Extending an earlier confrontation with data covering $0.003\\lesssim a_N/a_{dS}\\lesssim1$ at redshift $z\\sim0$ in Lellie et al. (2016), the modest anomalous behavior in the Genzel et al. sample at redshifts $0.854\\le z\\le 2.282$ is found to be mostly due to clustering $0.36\\lesssim a_N/a_{dS}\\lesssim1$ close to the $C^0$ onset to weak gravity and an increase of up to 65\\% in $a_0$.
Trembach, Vera
2014-01-01
Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.
Bulk and brane decay of a (4+n)-dimensional Schwarzschild-de Sitter black hole: Scalar radiation
International Nuclear Information System (INIS)
Kanti, P.; Grain, J.; Barrau, A.
2005-01-01
In this paper, we extend the idea that the spectrum of Hawking radiation can reveal valuable information on a number of parameters that characterize a particular black hole background--such as the dimensionality of spacetime and the value of coupling constants--to gain information on another important aspect: the curvature of spacetime. We investigate the emission of Hawking radiation from a D-dimensional Schwarzschild-de Sitter black hole emitted in the form of scalar fields, and employ both analytical and numerical techniques to calculate greybody factors and differential energy emission rates on the brane and in the bulk. The energy emission rate of the black hole is significantly enhanced in the high-energy regime with the number of spacelike dimensions. On the other hand, in the low-energy part of the spectrum, it is the cosmological constant that leaves a clear footprint, through a characteristic, constant emission rate of ultrasoft quanta determined by the values of black hole and cosmological horizons. Our results are applicable to 'small' black holes arising in theories with an arbitrary number and size of extra dimensions, as well as to pure 4-dimensional primordial black holes, embedded in a de Sitter spacetime
Directory of Open Access Journals (Sweden)
Wang Hongyu
2018-01-01
Full Text Available This paper presents the design of a symmetrical quad-rotor biplane tail-sitter VTOL UAV (Vertical Take-off and Landing Unmanned Aerial Vehicle which is composed of four rotors and two symmetrically mounted fixed wings. This aircraft achieves high accuracy in the attitude control and smooth flight mode transition with four rotors rather than the conventional VTOL UAVs using control surfaces. The proposal of angled rotor mounting is adopted to address the issue of insufficient yaw control authority. The layout of symmetrically mounted fixed wings makes the aircraft have capability of rapid bidirectional flight mode transition to improve maneuverability. To validate the performance of the aircraft, simulation and flight experiments are both implemented. These results show that the aircraft has a rapid yaw response under condition of the stable attitude control. In comparative experiment, it is shown that the aircraft is more flexible than other similar configuration of aircrafts. This symmetrical quad-rotor biplane tail-sitter VTOL UAV will have a wide range of potential applications in the military and civilian areas due to its superior performance..
Directory of Open Access Journals (Sweden)
R. da Rocha
2017-12-01
Full Text Available Sound waves on a fluid stream, in a de Laval nozzle, are shown to correspond to quasinormal modes emitted by black holes that are physical solutions in a quadratic curvature gravity with cosmological constant. Sound waves patterns in transsonic regimes at a laboratory are employed here to provide experimental data regarding generalized theories of gravity, comprised by the exact de Sitter-like solution and a perturbative solution around the Schwarzschildâde Sitter standard solution as well. Using the classical tests of General Relativity to bound free parameters in these solutions, acoustic perturbations on fluid flows in nozzles are then regarded, to study quasinormal modes of these black holes solutions, providing deviations of the de Laval nozzle cross-sectional area, when compared to the Schwarzschild solution. The fluid sonic point in the nozzle, for sound waves in the fluid, is shown to implement the acoustic event horizon corresponding to quasinormal modes. Keywords: Black holes, Fluid branes, Fluid dynamics, Quadratic curvature gravity, de Laval nozzle
Coulomb’s law corrections and fermion field localization in a tachyonic de Sitter thick braneworld
Energy Technology Data Exchange (ETDEWEB)
Cartas-Fuentevilla, Roberto; Escalante, Alberto [Instituto de Física, Benemérita Universidad Autónoma de Puebla,Apdo. postal J-48, 72570 Puebla, Pue. (Mexico); Germán, Gabriel [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apdo. Postal 48-3, 62251 Cuernavaca, Morelos (Mexico); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road,Oxford, OX1 3NP (United Kingdom); Herrera-Aguilar, Alfredo [Instituto de Física, Benemérita Universidad Autónoma de Puebla,Apdo. postal J-48, 72570 Puebla, Pue. (Mexico); Institutode Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo,Edificio C-3, Ciudad Universitaria, CP 58040, Morelia, Michoacán (Mexico); Mora-Luna, Refugio Rigel [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apdo. Postal 48-3, 62251 Cuernavaca, Morelos (Mexico)
2016-05-11
Following recent studies which show that it is possible to localize gravity as well as scalar and gauge vector fields in a tachyonic de Sitter thick braneworld, we investigate the solution of the gauge hierarchy problem, the localization of fermion fields in this model, the recovering of the Coulomb law on the non-relativistic limit of the Yukawa interaction between bulk fermions and gauge bosons localized in the brane, and confront the predicted 5D corrections to the photon mass with its upper experimental/observational bounds, finding the model physically viable since it passes these tests. In order to achieve the latter aims we first consider the Yukawa interaction term between the fermionic and the tachyonic scalar fields MF(T)ΨΨ-bar in the action and analyze four distinct tachyonic functions F(T) that lead to four different structures of the respective fermionic mass spectra with different physics. In particular, localization of the massless left-chiral fermion zero mode is possible for three of these cases. We further analyze the phenomenology of these Yukawa interactions among fermion fields and gauge bosons localized on the brane and obtain the crucial and necessary information to compute the corrections to Coulomb’s law coming from massive KK vector modes in the non-relativistic limit. These corrections are exponentially suppressed due to the presence of the mass gap in the mass spectrum of the bulk gauge vector field. From our results we conclude that corrections to Coulomb’s law in the thin brane limit have the same form (up to a numerical factor) as far as the left-chiral massless fermion field is localized on the brane. Finally we compute the corrections to the Coulomb’s law for an arbitrarily thick brane scenario which can be interpreted as 5D corrections to the photon mass. By performing consistent estimations with brane phenomenology, we found that the predicted corrections to the photon mass, which are well bounded by the experimentally
Chern-Simons gravity in four dimensions
Energy Technology Data Exchange (ETDEWEB)
Morales, Ivan; Neves, Bruno; Piguet, Olivier [Universidade Federal de Vicosa (UFV), Departamento de Fisica, Vicosa, MG (Brazil); Oporto, Zui [Universidade Federal de Vicosa (UFV), Departamento de Fisica, Vicosa, MG (Brazil); Universidad Mayor de San Andres, Carrera de Fisica, La Paz (Bolivia, Plurinational State of)
2017-02-15
Five-dimensional Chern-Simons theory with (anti-)de Sitter SO(1,5) or SO(2,4) gauge invariance presents an alternative to general relativity with cosmological constant. We consider the zero modes of its Kaluza-Klein compactification to four dimensions. Solutions with vanishing torsion are obtained in the cases of a spherically symmetric 3-space and of a homogeneous and isotropic 3-space, which reproduce the Schwarzshild-de Sitter and ΛCDM cosmological solutions of general relativity. We also check that vanishing torsion is a stable feature of the solutions. (orig.)
International Nuclear Information System (INIS)
Alishahiha, M.; Karch, A.; Silverstein, E.; Tong, D.
2004-07-01
We present a holographic duality for the de Sitter static patch which consolidates basic features of its geometry and the behavior of gravity and brane probes, valid on timescales short compared to the decay or Poincare recurrence times. Namely de Sitter spacetime dS d (R) in d dimensions with curvature radius R is holographically dual to two conformal field theories on dS d-l (R), cut off at an energy scale 1/R where they couple to each other and to d-1 dimensional gravity. As part of our analysis, we study brane probes in de Sitter and thermal Anti de Sitter spaces, and interpret the terms in the corresponding DBI action via strongly coupled thermal field theory. This provides a dual field theoretic interpretation of the fact that probes take forever to reach a horizon in general relativity. (author)
Holographic description of curved-space quantum field theory and gravity
Energy Technology Data Exchange (ETDEWEB)
Uhlemann, Christoph Frank
2012-12-12
The celebrated AdS/CFT dualities provide a window to strongly-coupled quantum field theories (QFTs), which are realized in nature at the most fundamental level on the one hand, but are hardly accessible for the standard mathematical tools on the other hand. The prototype examples of AdS/CFT relate classical supergravity theories on (d+1)-dimensional anti-de Sitter space (AdS) to strongly-coupled d-dimensional conformal field theories (CFTs). The AdS spacetimes admit a timelike conformal boundary, on which the dual CFT is defined. In that sense the AdS/CFT dualities are holographic, and this new approach has led to remarkable progress in understanding strongly-coupled QFTs defined on Minkowski space and on the Einstein cylinder. On the other hand, the study of QFT on more generic curved spacetimes is of fundamental interest and non-trivial already for free theories. Moreover, understanding the properties of gravity as a quantum theory remains among the hardest problems to solve in physics. Both of these issues can be studied holographically and we investigate here generalizations of AdS/CFT involving on the lower-dimensional side QFTs on curved backgrounds and as a further generalization gravity. In the first part we expand on the holographic description of QFT on fixed curved backgrounds, which involves gravity on an asymptotically-AdS space with that prescribed boundary structure. We discuss geometries with de Sitter and AdS as conformal boundary to holographically describe CFTs on these spacetimes. After setting up the procedure of holographic renormalization we study the reflection of CFT unitarity properties in the dual bulk description. The geometry with AdS on the boundary exhibits a number of interesting features, mainly due to the fact that the boundary itself has a boundary. We study both cases and resolve potential tensions between the unitarity properties of the bulk and boundary theories, which would be incompatible with a duality. The origin of these
Einstein's cosmology review of 1933: a new perspective on the Einstein-de Sitter model of the cosmos
O'Raifeartaigh, Cormac; O'Keeffe, Michael; Nahm, Werner; Mitton, Simon
2015-09-01
We present a first English translation and analysis of a little-known review of relativistic cosmology written by Albert Einstein in late 1932. The article, which was published in 1933 in a book of Einstein papers translated into French, contains a substantial review of static and dynamic relativistic models of the cosmos, culminating in a discussion of the Einstein-de Sitter model. The article offers a valuable contemporaneous insight into Einstein's cosmology in the early 1930s and confirms that his interest lay in the development of the simplest model of the cosmos that could account for observation. The article also confirms that Einstein did not believe that simplified relativistic models could give an accurate description of the early universe.
Schwarzschildâde Sitter spacetime: The role of temperature in the emission of Hawking radiation
Directory of Open Access Journals (Sweden)
Thomas Pappas
2017-12-01
Full Text Available We consider a Schwarzschildâde Sitter (SdS black hole, and focus on the emission of massless scalar fields either minimally or non-minimally coupled to gravity. We use six different temperatures, two black-hole and four effective ones for the SdS spacetime, as the question of the proper temperature for such a background is still debated in the literature. We study their profiles under the variation of the cosmological constant, and derive the corresponding Hawking radiation spectra. We demonstrate that only few of these temperatures may support significant emission of radiation. We finally compute the total emissivities for each temperature, and show that the non-minimal coupling constant of the scalar field to gravity also affects the relative magnitudes of the energy emission rates.
On the Gauss Map of Surfaces of Revolution with Lightlike Axis in Minkowski 3-Space
Directory of Open Access Journals (Sweden)
Minghao Jin
2013-01-01
Full Text Available By studying the Gauss map G and Laplace operator Δh of the second fundamental form h, we will classify surfaces of revolution with a lightlike axis in 3-dimensional Minkowski space and also obtain the surface of Enneper of the 2nd kind, the surface of Enneper of the 3rd kind, the de Sitter pseudosphere, and the hyperbolic pseudosphere that satisfy condition ΔhG=ΛG, Λ being a 3×3 real matrix.
AdS and dS black hole solutions in analogue gravity: The relativistic and nonrelativistic cases
Dey, Ramit; Liberati, Stefano; Turcati, Rodrigo
2016-11-01
We show that Schwarzschild black hole solutions in asymptotically anti-de Sitter (AdS) and de Sitter spaces may, up to a conformal factor, be reproduced in the framework of analogue gravity. The aforementioned derivation is performed using relativistic and nonrelativistic Bose-Einstein condensates. In addition, we demonstrate that the (2 +1 ) planar AdS black hole can be mapped into the nonrelativistic acoustic metric. Given that AdS black holes are extensively employed in the gauge/gravity duality, we then comment on the possibility of studying the AdS/CFT correspondence and gravity/fluid duality from an analogue gravity perspective.
AdS and dS black hole solutions in analogue gravity: The relativistic and non-relativistic cases
Dey, Ramit; Liberati, Stefano; Turcati, Rodrigo
2016-01-01
We show that Schwarzschild black hole solutions in asymptotically Anti-de Sitter (AdS) and de Sitter (dS) spaces may, up to a conformal factor, be reproduced in the framework of analogue gravity. The aforementioned derivation is performed using relativistic and non-relativistic Bose-Einstein condensates. In addition, we demonstrate that the (2+1) planar AdS black hole can be mapped into the non-relativistic acoustic metric. Given that AdS black holes are extensively employed in the gauge/grav...
Constant curvature black holes in Einstein AdS gravity: Euclidean action and thermodynamics
Guilleminot, Pablo; Olea, Rodrigo; Petrov, Alexander N.
2018-03-01
We compute the Euclidean action for constant curvature black holes (CCBHs), as an attempt to associate thermodynamic quantities to these solutions of Einstein anti-de Sitter (AdS) gravity. CCBHs are gravitational configurations obtained by identifications along isometries of a D -dimensional globally AdS space, such that the Riemann tensor remains constant. Here, these solutions are interpreted as extended objects, which contain a (D -2 )-dimensional de-Sitter brane as a subspace. Nevertheless, the computation of the free energy for these solutions shows that they do not obey standard thermodynamic relations.
Curvature, zero modes and quantum statistics
Energy Technology Data Exchange (ETDEWEB)
Calixto, M [Departamento de Matematica Aplicada y EstadIstica, Universidad Politecnica de Cartagena, Paseo Alfonso XIII 56, 30203 Cartagena (Spain); Aldaya, V [Instituto de AstrofIsica de AndalucIa, Apartado Postal 3004, 18080 Granada (Spain)
2006-08-18
We explore an intriguing connection between the Fermi-Dirac and Bose-Einstein statistics and the thermal baths obtained from a vacuum radiation of coherent states of zero modes in a second quantized (many-particle) theory on the compact O(3) and noncompact O(2, 1) isometry subgroups of the de Sitter and anti-de Sitter spaces, respectively. The high frequency limit is retrieved as a (zero-curvature) group contraction to the Newton-Hooke (harmonic oscillator) group. We also make some comments on the vacuum energy density and the cosmological constant problem. (letter to the editor)
Rényi entropy and the thermodynamic stability of black holes
Energy Technology Data Exchange (ETDEWEB)
Czinner, Viktor G., E-mail: czinner.viktor@wigner.mta.hu [Laboratory of Physics, College of Science and Technology, Nihon University, 274-8501 Narashinodai, Funabashi, Chiba (Japan); HAS Wigner Research Centre for Physics, H-1525 Budapest, P.O. Box 49 (Hungary); Centro de Matemática, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Iguchi, Hideo, E-mail: iguchi.h@phys.ge.cst.nihon-u.ac.jp [Laboratory of Physics, College of Science and Technology, Nihon University, 274-8501 Narashinodai, Funabashi, Chiba (Japan)
2016-01-10
Thermodynamic stability of black holes, described by the Rényi formula as equilibrium compatible entropy function, is investigated. It is shown that within this approach, asymptotically flat, Schwarzschild black holes can be in stable equilibrium with thermal radiation at a fixed temperature. This implies that the canonical ensemble exists just like in anti-de Sitter space, and nonextensive effects can stabilize the black holes in a very similar way as it is done by the gravitational potential of an anti-de Sitter space. Furthermore, it is also shown that a Hawking–Page-like black hole phase transition occurs at a critical temperature which depends on the q-parameter of the Rényi formula.
Relativistic particles with rigidity and torsion in D = 3 spacetimes
International Nuclear Information System (INIS)
Barros, Manuel; Ferrandez, Angel; Javaloyes, Miguel Angel; Lucas, Pascual
2005-01-01
Models describing relativistic particles, where Lagrangian densities depend linearly on both the curvature and the torsion of the trajectories, are revisited in D = 3 Lorentzian spacetimes with constant curvature. The moduli spaces of trajectories are completely and explicitly determined. Trajectories are Lancret curves including ordinary helices. To get the geometric integration of the solutions, we design algorithms that essentially involve the Lancret program as well as the notions of scrolls and Hopf tubes. The most interesting and consistent models appear in anti-de Sitter spaces, where the Hopf mappings, both the standard and the Lorentzian ones, play an important role. The moduli subspaces of closed solitons in anti-de Sitter settings are also obtained. Our main tool is the isoperimetric inequality in the hyperbolic plane. The mass spectra of these models are also obtained. The main characteristic of the anti-de Sitter space comes from the presence of real gravity, which becomes essential to find some system with only massive states. This fact, on one hand, has no equivalent in flat spaces, where spectra necessarily present tachyonic sectors and, on the other hand, solves an early stated problem
Daudé, Thierry
2017-01-01
In this paper, the authors study the direct and inverse scattering theory at fixed energy for massless charged Dirac fields evolving in the exterior region of a Kerr-Newman-de Sitter black hole. In the first part, they establish the existence and asymptotic completeness of time-dependent wave operators associated to our Dirac fields. This leads to the definition of the time-dependent scattering operator that encodes the far-field behavior (with respect to a stationary observer) in the asymptotic regions of the black hole: the event and cosmological horizons. The authors also use the miraculous property (quoting Chandrasekhar)-that the Dirac equation can be separated into radial and angular ordinary differential equations-to make the link between the time-dependent scattering operator and its stationary counterpart. This leads to a nice expression of the scattering matrix at fixed energy in terms of stationary solutions of the system of separated equations. In a second part, the authors use this expression of ...
The Effect of de-Sitter Like Background on Increasing the Zero Point Budget of Dark Energy
International Nuclear Information System (INIS)
Aghamohammadi, Ali; Saaidi, Khaled; Sheikhahmadi, Haidar
2016-01-01
During this work, using subtraction renormalization mechanism, zero point quantum fluctuations for bosonic scalar fields in a de-Sitter like background are investigated. By virtue of the observed value for spectral index, n s (k), for massive scalar field the best value for the first slow roll parameter, ϵ, is achieved. In addition, the energy density of vacuum quantum fluctuations for massless scalar field is obtained. The effects of these fluctuations on other components of the universe are studied. By solving the conservation equation, for some different examples, the energy density for different components of the universe is obtained. In the case which all components of the universe are in an interaction, the different dissipation functions, Q-tilde i , are considered. The time evolution of ρ DE (z)/ρ cri (z) shows that Q-tilde=3γH(t)ρ m has the best agreement in comparison to observational data including CMB, BAO, and SNeIa data set.
Stability of the Schwarzschild–de Sitter black hole in the dRGT massive gravity theory
International Nuclear Information System (INIS)
Kodama, Hideo; Arraut, Ivan
2014-01-01
The Schwarzschild–de Sitter solution in the Einstein theory with a positive cosmological constant Λ=m 2 /α becomes an exact solution to the de Rham–Gabadadze–Tolley (dRGT) nonlinear massive gravity theory with the mass parameter m when the theory parameters α and β satisfy the relation β=α 2 . We study the perturbative behavior of this black hole solution in the nonlinear dRGT theory with β=α 2 . We find that the linear perturbation equations become identical to those for the vacuum Einstein theory when they are expressed in terms of gauge-invariant variables. This implies that this black hole is stable in the dRGT theory as far as the spacetime structure is concerned, in contrast to the case of the bi-Schwarzschild solution in the bi-metric theory. However, we have also found a pathological feature that the general solution to the perturbation equations contain a single arbitrary function of spacetime coordinates. This implies a degeneracy of dynamics in the Stückelberg field sector at the linear perturbation level in this background. The physical significance of this degeneracy depends on how the Stückelberg fields couple observable fields
Regular black hole in three dimensions
Myung, Yun Soo; Yoon, Myungseok
2008-01-01
We find a new black hole in three dimensional anti-de Sitter space by introducing an anisotropic perfect fluid inspired by the noncommutative black hole. This is a regular black hole with two horizons. We compare thermodynamics of this black hole with that of non-rotating BTZ black hole. The first-law of thermodynamics is not compatible with the Bekenstein-Hawking entropy.
CERN. Geneva
2014-01-01
The conjectured relation between higher spin theories on anti de-Sitter (AdS) spaces and weakly coupled conformal field theories is reviewed. I shall then outline the evidence in favour of a concrete duality of this kind, relating a specific higher spin theory on AdS3 to a family of 2d minimal model CFTs. Finally, I shall explain how this relation fits into the framework of the familiar stringy AdS/CFT correspondence.
Black Holes in Higher Dimensions
Directory of Open Access Journals (Sweden)
Reall Harvey S.
2008-09-01
Full Text Available We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.
Effective actions for high energy scattering in QCD and in gravity
Lipatov, L. N.
2017-12-01
The scattering amplitudes in QCD and gravity at high energies are described in terms of reggeized gluons and gravitons, respectively. In particular, the BFKL Pomeron in N = 4 SUSY is dual to the reggeized graviton living in the 10-dimensional anti-de-Sitter space. The effective actions for the reggeized gluons and gravitons are local in their rapidities. The Euler-Lagrange equations for these effective theories are constructed and their solutions are used for calculations of corresponding Reggeon vertices and trajectories.
Conformal Maxwell Theory as a Singleton Field Theory on $ADS_{5}$, IIB Three Branes and Duality
Ferrara, Sergio
1998-01-01
We examine the boundary conditions associated with extended supersymmetric Maxwell theory in 5-dimensional anti-De Sitter space. Excitations on the boundary are identical to those of ordinary 4-dimensional conformal invariant super electrodynammics. Extrapolations of these excitations give rise to a 5-dimensional topological gauge theory of the singleton type. The possibility of a connection of this phenomenon to the world volume theory of 3-branes in IIB string theory is discussed.
Hawking radiation from AdS black holes
Hemming, Samuli; Keski-Vakkuri, Esko
2001-08-01
We investigate Hawking radiation from black holes in (d+1)-dimensional anti-de Sitter space. We focus on s waves, make use of the geometrical optics approximation, and follow three approaches to analyze the radiation. First, we compute a Bogoliubov transformation between Kruskal and asymptotic coordinates and compare the different vacua. Second, following a method due to Kraus, Parikh, and Wilczek, we view Hawking radiation as a tunneling process across the horizon and compute the tunneling probability. This approach uses an anti-de Sitter version of a metric originally introduced by Painlevé for Schwarzschild black holes. From the tunneling probability one also finds a leading correction to the semiclassical emission rate arising from back reaction to the background geometry. Finally, we consider a spherically symmetric collapse geometry and the Bogoliubov transformation between the initial vacuum state and the vacuum of an asymptotic observer.
Quantum Dynamics of Test Particle in Curved Space-Time
International Nuclear Information System (INIS)
Piechocki, W.
2002-01-01
To reveal the nature of space-time singularities of removable type we examine classical and quantum dynamics of a free particle in the Sitter type spacetimes. Consider space-times have different topologies otherwise are isometric. Our systems are integrable and we present analytic solutions of the classical dynamics. We quantize the systems by making use of the group theoretical method: we find an essentially self-adjoint representation of the algebra of observables integrable to the irreducible unitarity representation of the symmetry group of each consider gravitational system. The massless particle dynamics is obtained in the zero-mass limit of the massive case. Global properties of considered gravitational systems are of primary importance for the quantization procedure. Systems of a particle in space-times with removable singularities appear to be quantizable. We give specific proposal for extension of our analysis to space-times with essential type singularities. (author)
Fermions in compactified d=11 supergravity
International Nuclear Information System (INIS)
Kogan, Ya.; Morozov, A.
1984-01-01
Miraculous simplifications are observed in the gravitino equations of motion in the Englert background. Though the problem of getting rid of anti-de-Sitter geometry has not been solved yet, it is clear that the anti-de-Sitter geometry is absent in the correct solution and the four-dimensional world has flat metric
de Sitter vacua in no-scale supergravities and Calabi-Yau string models
International Nuclear Information System (INIS)
Covi, L.; Gross, C.; Scrucca, C.A.
2008-04-01
We perform a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N = 1 supersymmetry and non-negative cosmological constant in the moduli sector of string models. More specifically, we study the condition under which the scalar partners of the Goldstino are non-tachyonic, which depends only on the Kaehler potential. This condition is not only necessary but also sufficient, in the sense that all of the other scalar fields can be given arbitrarily large positive square masses if the superpotential is suitably tuned. We consider both heterotic and orientifold string compactifications in the large-volume limit and show that the no-scale property shared by these models severely restricts the allowed values for the 'sGoldstino' masses in the superpotential parameter space. We find that a positive mass term may be achieved only for certain types of compactifications and specific Goldstino directions. Additionally, we show how subleading corrections to the Kaehler potential which break the no-scale property may allow to lift these masses. (orig.)
International Nuclear Information System (INIS)
Starobinskij, A.A.
1983-01-01
Spectrum of primary adiabatic perturbations and gravitational waves formed in the proposed earlier by the author nonsingular cosmological model with the initial quantum de Sitter stage generated by gravitational vacuum polarization is calculated. The spectrum of gravitational waves appears to be flat, the spectrum of adiabatic perturbations is close to the flat one. The large-scale anisotropy of the temperature T of the relic electromagnetic radiation due to these fluctuations is found. It is shown that the most promising way to detect the anisotropy in the case of a flat perturbation spectrum is the investigation of correlations of ΔT/T at the angles of 5 deg - 10 deg
Feng, Zhong-wen; Li, Guo-ping; Zhang, Yan; Zu, Xiao-tao
2015-02-01
In this paper, we combine the Hamilton-Jacobi equation with a new general tortoise coordinate transformation to study quantum tunneling of scalar particles and fermions from the non-stationary higher dimensional Vaidya-de Sitter black hole. The results show that Hamilton-Jacobi equation is a semi-classical foundation equation which can easily derived from the particles' dynamic equations, it can helps us understand the origin of Hawking radiation. Besides, based on the dimensional analysis, we believed that the new general tortoise coordinate transformation is more reasonable than old ones.
Notes on teleportation in an expanding space
Energy Technology Data Exchange (ETDEWEB)
Feng, Jun, E-mail: tsunfeng@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Wen-Li [Institute of Modern Physics, Northwest University, Xian 710069 (China); Zhang, Yao-Zhong [School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072 (Australia); Fan, Heng, E-mail: hfan@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2013-02-26
We investigate the quantum teleportation between a conformal detector Alice and an inertial detector Bob in de Sitter space in two schemes, (i) one uses free scalar modes and (ii) one utilizes cavity to store qubit. We show that the fidelity of the teleportation is degraded for Bob in both cases. While the fidelity-loss is due to the Gibbons–Hawking effect associated with his cosmological horizon in the scheme (i), the entanglement decreases in the scheme (ii) because the ability to entangle the cavities is reduced by the spacetime curvature. With a cutoff at Planck-scale, comparing with the standard Bunch–Davies choice, we also show that the possible Planckian physics cause extra modifications to the fidelity of the teleportation protocol in both schemes.
Exact Solutions of the Field Equations for Empty Space in the Nash Gravitational Theory
Directory of Open Access Journals (Sweden)
Matthew T. Aadne
2017-02-01
Full Text Available John Nash has proposed a new theory of gravity. We define a Nash-tensor equal to the curvature tensor appearing in the Nash field equations for empty space, and calculate its components for two cases: 1. A static, spherically symmetric space; and 2. The expanding, homogeneous and isotropic space of the Friedmann-Lemaitre-Robertson-Walker (FLRW universe models. We find the general, exact solution of Nash’s field equations for empty space in the static case. The line element turns out to represent the Schwarzschild-de Sitter spacetime. Also we find the simplest non-trivial solution of the field equations in the cosmological case, which gives the scale factor corresponding to the de Sitter spacetime. Hence empty space in the Nash theory corresponds to a space with Lorentz Invariant Vacuum Energy (LIVE in the Einstein theory. This suggests that dark energy may be superfluous according to the Nash theory. We also consider a radiation filled universe model in an effort to find out how energy and matter may be incorporated into the Nash theory. A tentative interpretation of the Nash theory as a unified theory of gravity and electromagnetism leads to a very simple form of the field equations in the presence of matter. It should be noted, however, that the Nash theory is still unfinished. A satisfying way of including energy momentum into the theory has yet to be found.
Equivalent equations of motion for gravity and entropy
International Nuclear Information System (INIS)
Czech, Bartłomiej; Lamprou, Lampros; McCandlish, Samuel; Mosk, Benjamin; Sully, James
2017-01-01
We demonstrate an equivalence between the wave equation obeyed by the entanglement entropy of CFT subregions and the linearized bulk Einstein equation in Anti-de Sitter space. In doing so, we make use of the formalism of kinematic space https://www.doi.org/10.1007/JHEP10(2015)175 and fields on this space, introduced in https://www.doi.org/10.1007/JHEP07(2016)129. We show that the gravitational dynamics are equivalent to a gauge invariant wave-equation on kinematic space and that this equation arises in natural correspondence to the conformal Casimir equation in the CFT.
Noncommutative spaces from matrix models
Lu, Lei
Noncommutative (NC) spaces commonly arise as solutions to matrix model equations of motion. They are natural generalizations of the ordinary commutative spacetime. Such spaces may provide insights into physics close to the Planck scale, where quantum gravity becomes relevant. Although there has been much research in the literature, aspects of these NC spaces need further investigation. In this dissertation, we focus on properties of NC spaces in several different contexts. In particular, we study exact NC spaces which result from solutions to matrix model equations of motion. These spaces are associated with finite-dimensional Lie-algebras. More specifically, they are two-dimensional fuzzy spaces that arise from a three-dimensional Yang-Mills type matrix model, four-dimensional tensor-product fuzzy spaces from a tensorial matrix model, and Snyder algebra from a five-dimensional tensorial matrix model. In the first part of this dissertation, we study two-dimensional NC solutions to matrix equations of motion of extended IKKT-type matrix models in three-space-time dimensions. Perturbations around the NC solutions lead to NC field theories living on a two-dimensional space-time. The commutative limit of the solutions are smooth manifolds which can be associated with closed, open and static two-dimensional cosmologies. One particular solution is a Lorentzian fuzzy sphere, which leads to essentially a fuzzy sphere in the Minkowski space-time. In the commutative limit, this solution leads to an induced metric that does not have a fixed signature, and have a non-constant negative scalar curvature, along with singularities at two fixed latitudes. The singularities are absent in the matrix solution which provides a toy model for resolving the singularities of General relativity. We also discussed the two-dimensional fuzzy de Sitter space-time, which has irreducible representations of su(1,1) Lie-algebra in terms of principal, complementary and discrete series. Field
Nadjafikhah, Mehdi; Ahangari, Fatemeh
2012-06-01
This paper is devoted to the comprehensive analysis of the problem of symmetries and conservation laws for the geodesic equations of the Reissner-Nordström de Sitter (RNdS) black hole with a global monopole. For this purpose, the system of geodesic equations is determined and the corresponding classical Lie point symmetry operators are obtained. An optimal system of one dimensional subalgebras is constructed and a brief discussion about the algebraic structure of the Lie algebra of symmetries is presented. Also, the Noether symmetries of the geodesic Lagrangian is calculated. Finally, by applying two methods including Noether's theorem and direct method the conservation laws associated to the system of geodesic equations are obtained.
Wormholes and black universes communicated with extra dimensions
International Nuclear Information System (INIS)
Bronnikov, K A; Korolyov, P A; Skvortsova, M V; Makhmudov, A
2017-01-01
In 6D general relativity with a phantom scalar field as a source of gravity, we present solutions that implement a transition from an effective 4D geometry times small extra dimensions to an effectively 6D space-time where the physical laws are different from ours. We consider manifolds with the structure M 0 ×M 1 ×M 2 , where M 0 is 2D Lorentzian space-time while each of M 1,2 can be a 2-sphere or a 2-torus. Some solutions describe wormholes with spherical symmetry in our space-time and toroidal extra dimensions. Others are of black universe type: at one end there is a 6D asymptotically anti-de Sitter black hole while beyond the horizon the geometry tends to a 4D de Sitter cosmology times a small 2D spherical extra space. (paper)
Vacuum energy in asymptotically flat 2 + 1 gravity
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Miskovic, Olivera, E-mail: olivera.miskovic@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile); Olea, Rodrigo, E-mail: rodrigo.olea@unab.cl [Departamento de Ciencias Físicas, Universidad Andres Bello, Sazié 2212, Piso 7, Santiago (Chile); Roy, Debraj, E-mail: roy.debraj@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile)
2017-04-10
We compute the vacuum energy of three-dimensional asymptotically flat space based on a Chern–Simons formulation for the Poincaré group. The equivalent action is nothing but the Einstein–Hilbert term in the bulk plus half of the Gibbons–Hawking term at the boundary. The derivation is based on the evaluation of the Noether charges in the vacuum. We obtain that the vacuum energy of this space has the same value as the one of the asymptotically flat limit of three-dimensional anti-de Sitter space.
Vacuum energy in asymptotically flat 2+1 gravity
Directory of Open Access Journals (Sweden)
Olivera Miskovic
2017-04-01
Full Text Available We compute the vacuum energy of three-dimensional asymptotically flat space based on a Chern–Simons formulation for the Poincaré group. The equivalent action is nothing but the Einstein–Hilbert term in the bulk plus half of the Gibbons–Hawking term at the boundary. The derivation is based on the evaluation of the Noether charges in the vacuum. We obtain that the vacuum energy of this space has the same value as the one of the asymptotically flat limit of three-dimensional anti-de Sitter space.
Directory of Open Access Journals (Sweden)
Castro C.
2005-07-01
Full Text Available By recurring to Geometric Probability methods, it is shown that the coupling constants, αEM; αW; αC associated with Electromagnetism, Weak and the Strong (color force are given by the ratios of the ratios of the measures of the Shilov boundaries Q2=S1×RP1; Q3=S2×RP1; S5, respectively, with respect to the ratios of the measures μ[Q5]/μN[Q5] associated with the 5D conformally compactified real Minkowski spacetime ˉ M5 that has the same topology as the Shilov boundary Q5 of the 5 complex-dimensional poly-disc D5. The homogeneous symmetric complex domain D5=SO(5,2/SO(5×SO(2 corresponds to the conformal relativistic curved 10 real-dimensional phase space H10 associated with a particle moving in the 5D Anti de Sitter space AdS5. The geometric coupling constant associated to the gravitational force can also be obtained from the ratios of the measures involving Shilov boundaries. We also review our derivation of the observed vacuum energy density based on the geometry of de Sitter (Anti de Sitter spaces.
Stability properties of gravity theories
Deser, S
1982-01-01
Studies the stability properties of general relativity with a non- vanishing cosmological constant Lambda by means of the energy. First, it is shown that there exists a suitable definition of energy in these models, for all metrics tending asymptotically to any background solution which has a timelike Killing symmetry. It is conserved and has flux integral form. Stability is established for all systems tending asymptotically to anti-De Sitter space when Lambda >0, using supergravity techniques. Spinorial charges are defined which are also flux integrals and satisfy the global graded anti-De Sitter algebra. The latter then implies that the energy is always positive. For Lambda >0, it is shown that small excitations about De Sitter space are stable, provided they occur within the event horizon intrinsic to this space. Outside the horizon an instability arises which signals the onset of Hawking radiation: it is shown to be universal to all systems. Semi-classical stability is also discussed for Lambda >0.
Naka, S.; Toyoda, H.; Takanashi, T.; Umezawa, E.
2014-04-01
In kappa -Minkowski spacetime, the coordinates are Lie algebraic elements such that time and space coordinates do not commute, whereas space coordinates commute with each other. The noncommutativity is proportional to a Planck-length-scale constant kappa ^{-1}, which is a universal constant other than the velocity of light, under the kappa -Poincaré transformation. In this sense, the spacetime has a structure called "doubly special relativity." Such a noncommutative structure is known to be realized by SO(1,4) generators in 4-dimensional de Sitter space. In this paper, we try to construct a noncommutative spacetime having a commutative n-dimensional Minkowski spacetime based on AdS_{n+1} space with SO(2,n) symmetry. We also study an invariant wave equation corresponding to the first Casimir invariant of this symmetry as a nonlocal field equation expected to yield finite loop amplitudes.
Three-dimensional gravity and Drinfel'd doubles: Spacetimes and symmetries from quantum deformations
International Nuclear Information System (INIS)
Ballesteros, Angel; Herranz, Francisco J.; Meusburger, Catherine
2010-01-01
We show how the constant curvature spacetimes of 3d gravity and the associated symmetry algebras can be derived from a single quantum deformation of the 3d Lorentz algebra sl(2,R). We investigate the classical Drinfel'd double of a 'hybrid' deformation of sl(2,R) that depends on two parameters (η,z). With an appropriate choice of basis and real structure, this Drinfel'd double agrees with the 3d anti-de Sitter algebra. The deformation parameter η is related to the cosmological constant, while z is identified with the inverse of the speed of light and defines the signature of the metric. We generalise this result to de Sitter space, the three-sphere and 3d hyperbolic space through analytic continuation in η and z; we also investigate the limits of vanishing η and z, which yield the flat spacetimes (Minkowski and Euclidean spaces) and Newtonian models, respectively.
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Gudnason, Sven Bjarke [Institute of Modern Physics, Chinese Academy of Sciences,Lanzhou 730000 (China); Nitta, Muneto [Department of Physics, and Research and Education Center for Natural Sciences, Keio University,Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521 (Japan); Sawado, Nobuyuki [Department of Physics, Tokyo University of Science,Noda, Chiba 278-8510 (Japan)
2015-12-02
The BPS Skyrme model has many exact analytic solutions in flat space. We generalize the model to a curved space or spacetime and find that the solutions can only be BPS for a constant time-time component of the metric tensor. We find exact solutions on the curved spaces: a 3-sphere and a 3-hyperboloid; and we further find an analytic gravitating Skyrmion on the 3-sphere. For the case of a nontrivial time-time component of the metric, we suggest a potential for which we find analytic solutions on anti-de Sitter and de Sitter spacetimes in the limit of no gravitational backreaction. We take the gravitational coupling into account in numerical solutions and show that they are well approximated by the analytic solutions for weak gravitational coupling.
S1 x S2 as a bag membrane and its Einstein-Weyl geometry
International Nuclear Information System (INIS)
Rosu, H.
1992-10-01
In the hybrid skyrmion in which an anti-de Sitter bag is embedded into the skyrmion configuration a S 1 x S 2 membrane is lying on the compactified spatial infinity of the bag. The connection between the quark degrees of freedom and the mesonic ones is made through the membrane. This 3-dimensional manifold is at the same time Weyl-Einstein space. We present what is known until the present time to people working in the differential geometry of these spaces. (author). 11 refs
Analog Systems for Gravity Duals
Hossenfelder, S.
2014-01-01
We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog gravity therefore ...
Researching on Hawking Effect in a Kerr Space Time via Open Quantum System Approach
International Nuclear Information System (INIS)
Liu, Wen-Biao; Liu, Xian-Ming
2014-01-01
It has been proposed that Hawking radiation from a Schwarzschild or a de Sitter spacetime can be understood as the manifestation of thermalization phenomena in the framework of an open quantum system. Through examining the time evolution of a detector interacting with vacuum massless scalar fields, it is found that the detector would spontaneously excite with a probability the same as the thermal radiation at Hawking temperature. Following the proposals, the Hawking effect in a Kerr space time is investigated in the framework of an open quantum systems. It is shown that Hawking effect of the Kerr space time can also be understood as the the manifestation of thermalization phenomena via open quantum system approach. Furthermore, it is found that near horizon local conformal symmetry plays the key role in the quantum effect of the Kerr space time
Holography for a non-inflationary early universe
International Nuclear Information System (INIS)
Hinterbichler, Kurt; Stokes, James; Trodden, Mark
2015-01-01
We construct a gravitational dual of the pseudo-conformal universe, a proposed alternative to inflation in which a conformal field theory in nearly flat space develops a time dependent vacuum expectation value. Constructing this dual amounts to finding five-dimensional domain-wall spacetimes with anti-de Sitter asymptotics, for which the wall has the symmetries of four-dimensional de Sitter space. This holographically realizes the characteristic symmetry breaking pattern so(2,4)→so(1,4) of the pseudo-conformal universe. We present an explicit example with a massless scalar field, using holographic renormalization to obtain general expressions for the renormalized scalar and stress-tensor one-point functions. We discuss the relationship between these solutions and those of four-dimensional holographic defect conformal field theories which break so(2,4)→so(2,3).
The entropy function for the black holes of Nariai class
International Nuclear Information System (INIS)
Cho, Jin-Ho; Nam, Soonkeon
2008-01-01
Based on the fact that the near horizon geometry of the extremal Schwarzschild-de Sitter black holes is Nariai geometry, we define the black holes of Nariai class as the configuration whose near-horizon geometry is factorized as two dimensional de Sitter space-time and some compact topology, that is Nariai geometry. We extend the entropy function formalism to the case of the black holes of Nariai class. The conventional entropy function (for the extremal black holes) is defined as Legendre transformation of Lagrangian density, thus the 'Routhian density', over two dimensional anti-de Sitter. As for the black holes of Nariai class, it is defined as minus 'Routhian density' over two dimensional de Sitter space-time. We found an exact agreement of the result with Bekenstein-Hawking entropy. The higher order corrections are nontrivial only when the space-time dimension is over four, that is, d>4. There is a subtlety as regards the temperature of the black holes of Nariai class. We show that in order to be consistent with the near horizon geometry, the temperature should be non-vanishing despite the extremality of the black holes
Holography and Colliding gravitational shock waves in asymptotically AdS5 spacetime.
Chesler, Paul M; Yaffe, Laurence G
2011-01-14
Using holography, we study the collision of planar shock waves in strongly coupled N=4 supersymmetric Yang-Mills theory. This requires the numerical solution of a dual gravitational initial value problem in asymptotically anti-de Sitter spacetime.
International Nuclear Information System (INIS)
Urano, Miho; Tomimatsu, Akira; Saida, Hiromi
2009-01-01
The mechanical first law (MFL) of black hole spacetimes is a geometrical relation which relates variations of the mass parameter and horizon area. While it is well known that the MFL of an asymptotic flat black hole is equivalent to its thermodynamical first law, however we do not know the detail of the MFL of black hole spacetimes with a cosmological constant which possess a black hole and cosmological event horizons. This paper aims to formulate an MFL of the two-horizon spacetimes. For this purpose, we try to include the effects of two horizons in the MFL. To do so, we make use of the Iyer-Wald formalism and extend it to regard the mass parameter and the cosmological constant as two independent variables which make it possible to treat the two horizons on the same footing. Our extended Iyer-Wald formalism preserves the existence of the conserved Noether current and its associated Noether charge, and gives an abstract form of the MFL of black hole spacetimes with a cosmological constant. Then, as a representative application of this formalism, we derive the MFL of the Schwarzschild-de Sitter (SdS) spacetime. Our MFL of the SdS spacetime relates the variations of three quantities: the mass parameter, the total area of the two horizons and the volume enclosed by the two horizons. If our MFL is regarded as a thermodynamical first law of the SdS spacetime, it offers a thermodynamically consistent description of the SdS black hole evaporation process: the mass decreases while the volume and the entropy increase. In our suggestion, a generalized second law is not needed to ensure the second law of SdS thermodynamics for its evaporation process.
Acceleration-enlarged symmetries in nonrelativistic space-time with a cosmological constant TH1"-->
Lukierski, J.; Stichel, P. C.; Zakrzewski, W. J.
2008-05-01
By considering the nonrelativistic limit of de Sitter geometry one obtains the nonrelativistic space-time with a cosmological constant and Newton Hooke (NH) symmetries. We show that the NH symmetry algebra can be enlarged by the addition of the constant acceleration generators and endowed with central extensions (one in any dimension (D) and three in D=(2+1)). We present a classical Lagrangian and Hamiltonian framework for constructing models quasi-invariant under enlarged NH symmetries that depend on three parameters described by three nonvanishing central charges. The Hamiltonian dynamics then splits into external and internal sectors with new noncommutative structures of external and internal phase spaces. We show that in the limit of vanishing cosmological constant the system reduces to the one, which possesses acceleration-enlarged Galilean symmetries.
Spinning geodesic Witten diagrams
International Nuclear Information System (INIS)
Dyer, Ethan; Freedman, Daniel Z.; Massachusetts Institute of Technology; Massachusetts Institute of Technology; Sully, James; McGill University, Montreal, QC
2017-01-01
We present an expression for the four-point conformal blocks of symmetric traceless operators of arbitrary spin as an integral over a pair of geodesics in Anti-de Sitter space, generalizing the geodesic Witten diagram formalism of Hijano et al. to arbitrary spin. As an intermediate step in the derivation, we identify a convenient basis of bulk threepoint interaction vertices which give rise to all possible boundary three point structures. Lastly, we highlight a direct connection between the representation of the conformal block as geodesic Witten diagram and the shadow operator formalism.
Decoding the hologram: Scalar fields interacting with gravity
Kabat, Daniel; Lifschytz, Gilad
2014-03-01
We construct smeared conformal field theory (CFT) operators which represent a scalar field in anti-de Sitter (AdS) space interacting with gravity. The guiding principle is microcausality: scalar fields should commute with themselves at spacelike separation. To O(1/N) we show that a correct and convenient criterion for constructing the appropriate CFT operators is to demand microcausality in a three-point function with a boundary Weyl tensor and another boundary scalar. The resulting bulk observables transform in the correct way under AdS isometries and commute with boundary scalar operators at spacelike separation, even in the presence of metric perturbations.
G2-structures for N = 1 supersymmetric AdS4 solutions of M-theory
Grigorian, Sergey
2018-04-01
We study the N = 1 supersymmetric solutions of D = 11 supergravity obtained as a warped product of four-dimensional anti-de Sitter space with a seven-dimensional Riemannian manifold M. Using the octonion bundle structure on M we reformulate the Killing spinor equations in terms of sections of the octonion bundle on M. The solutions then define a single complexified G 2-structure on M or equivalently two real G 2-structures. We then study the torsion of these G 2-structures and the relationships between them.
Twistor description of spinning particles in AdS
Arvanitakis, Alex S.; Barns-Graham, Alec E.; Townsend, Paul K.
2018-01-01
The two-twistor formulation of particle mechanics in D-dimensional anti-de Sitter space for D = 4 , 5 , 7, which linearises invariance under the AdS isometry group Sp(4; K ) for K=R,C,H, is generalized to the massless N -extended "spinning particle". The twistor variables are gauge invariant with respect to the initial N local worldline supersymmetries; this simplifies aspects of the quantum theory such as implications of global gauge anomalies. We also give details of the two-supertwistor form of the superparticle, in particular the massive superparticle on AdS5.
Entropy Inequality Violations from Ultraspinning Black Holes.
Hennigar, Robie A; Mann, Robert B; Kubizňák, David
2015-07-17
We construct a new class of rotating anti-de Sitter (AdS) black hole solutions with noncompact event horizons of finite area in any dimension and study their thermodynamics. In four dimensions these black holes are solutions to gauged supergravity. We find that their entropy exceeds the maximum implied from the conjectured reverse isoperimetric inequality, which states that for a given thermodynamic volume, the black hole entropy is maximized for Schwarzschild-AdS space. We use this result to suggest more stringent conditions under which this conjecture may hold.
Semiclassical strings in AdS5 × S5 and automorphic functions.
Pawellek, Michael
2011-06-17
Using anti-de Sitter-space/conformal-field-theory correspondence we derive from the folded spinning string ordinary differential equations for the anomalous dimension of the dual N=4 super Yang-Mills theory twist-two operators at strong coupling. We show that for large spin the asymptotic solutions have the Gribov-Lipatov reciprocity property. To obtain this result we use a hidden modular invariance of the energy-spin relation of the folded spinning string. Furthermore, we identify the Moch-Vermaseren-Vogt relations, which were first recognized in plain QCD calculations, as the recurrence relations of the asymptotic series ansatz.
Reentrant phase transitions of higher-dimensional AdS black holes in dRGT massive gravity
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Zou, De-Cheng; Yue, Ruihong [Yangzhou University, College of Physical Science and Technology, Yangzhou (China); Zhang, Ming [Xi' an Aeronautical University, Faculty of Science, Xi' an (China)
2017-04-15
We study the P-V criticality and phase transition in the extended phase space of anti-de Sitter (AdS) black holes in higher-dimensional de Rham, Gabadadze and Tolley (dRGT) massive gravity, treating the cosmological constant as pressure and the corresponding conjugate quantity is interpreted as thermodynamic volume. Besides the usual small/large black hole phase transitions, the interesting thermodynamic phenomena of reentrant phase transitions (RPTs) are observed for black holes in all d ≥ 6-dimensional spacetime when the coupling coefficients c{sub i}m{sup 2} of massive potential satisfy some certain conditions. (orig.)
Constructing an explicit AdS/CFT correspondence with Cartan geometry
Hazboun, Jeffrey S.
2018-04-01
An explicit AdS/CFT correspondence is shown for the Lie group SO (4 , 2). The Lie symmetry structures allow for the construction of two physical theories through the tools of Cartan geometry. One is a gravitational theory that has anti-de Sitter symmetry. The other is also a gravitational theory but is conformally symmetric and lives on 8-dimensional biconformal space. These "extra" four dimensions have the degrees of freedom used to construct a Yang-Mills theory. The two theories, based on AdS or conformal symmetry, have a natural correspondence in the context of their Lie algebras alone where neither SUSY, nor holography, is necessary.
In-Out Formalism for One-Loop Effective Actions in QED and Gravity
Kim, S. P.
2017-03-01
The in-out formalism is a systematic and powerful method for finding the effective actions in an electromagnetic field and a curved spacetime provided that the field equation has explicitly known solutions. The effective action becomes complex when pairs of charged particles are produced due to an electric field and curved spacetime. This may lead to a conjecture of one-to-one correspondence between the vacuum polarization (real part) and the vacuum persistence (imaginary part). We illustrate the one-loop effective action in a constant electric field in a Minkowski spacetime and in a uniform electric field in a two-dimensional (anti-) de Sitter space.
Representations of superconformal algebras in the $AdS_{7/4}/CFT_{6/3}$ correspondence
Ferrara, Sergio; Ferrara, Sergio; Sokatchev, Emery
2001-01-01
We perform a general analysis of representations of the superconformal algebras OSp(8/4,R) and OSp(8*/2N) in harmonic superspace. We present a construction of their highest-weight UIR's by multiplication of the different types of massless conformal superfields ("supersingletons"). In particular, all "short multiplets" are classified. Representations undergoing shortening have "protected dimension" and may correspond to BPS states in the dual supergravity theory in anti-de Sitter space. These results are relevant for the classification of multitrace operators in boundary conformally invariant theories as well as for the classification of AdS black holes preserving different fractions of supersymmetry.
Generalized Recursion Relations for Correlators in the Gauge-Gravity Correspondence
Raju, Suvrat
2011-03-01
We show that a generalization of the Britto-Cachazo-Feng-Witten recursion relations gives a new and efficient method of computing correlation functions of the stress tensor or conserved currents in conformal field theories with an (d+1)-dimensional anti-de Sitter space dual, for d≥4, in the limit where the bulk theory is approximated by tree-level Yang-Mills theory or gravity. In supersymmetric theories, additional correlators of operators that live in the same multiplet as a conserved current or stress tensor can be computed by these means.
Generalized recursion relations for correlators in the gauge-gravity correspondence.
Raju, Suvrat
2011-03-04
We show that a generalization of the Britto-Cachazo-Feng-Witten recursion relations gives a new and efficient method of computing correlation functions of the stress tensor or conserved currents in conformal field theories with an (d+1)-dimensional anti-de Sitter space dual, for d≥4, in the limit where the bulk theory is approximated by tree-level Yang-Mills theory or gravity. In supersymmetric theories, additional correlators of operators that live in the same multiplet as a conserved current or stress tensor can be computed by these means.
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Engquist, J. [Institute for Theoretical Physics and Spinoza Institute, Utrecht University (Netherlands); Sundell, P. [INFN, Pisa (Italy); Scuola Normale Superiore, Pisa (Italy); Tamassia, L. [Instituut voor Theoretische Fysica, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium)
2007-05-15
The group theoretical structure underlying physics in anti de Sitter (AdS) spacetime is intrinsically different with respect to the flat case, due to the presence of special ultra-short representations, named singletons, that do not admit a flat space limit. The purpose of this collaboration is to exploit this feature in the study of string and brane dynamics in AdS spacetime, in particular while trying to establish a connection between String Theory in AdS backgrounds (in the tensionless limit) and Higher-Spin Gauge Theory. (orig.)
Viscosity in strongly interacting quantum field theories from black hole physics.
Kovtun, P K; Son, D T; Starinets, A O
2005-03-25
The ratio of shear viscosity to volume density of entropy can be used to characterize how close a given fluid is to being perfect. Using string theory methods, we show that this ratio is equal to a universal value of variant Planck's over 2pi/4pik(B) for a large class of strongly interacting quantum field theories whose dual description involves black holes in anti-de Sitter space. We provide evidence that this value may serve as a lower bound for a wide class of systems, thus suggesting that black hole horizons are dual to the most ideal fluids.
Effective actions for high energy scattering in QCD and in gravity
Directory of Open Access Journals (Sweden)
Lipatov L. N.
2017-01-01
Full Text Available The scattering amplitudes in QCD and gravity at high energies are described in terms of reggeized gluons and gravitons, respectively. In particular, the BFKL Pomeron in N = 4 SUSY is dual to the reggeized graviton living in the 10-dimensional anti-de-Sitter space. The effective actions for the reggeized gluons and gravitons are local in their rapidities. The Euler-Lagrange equations for these effective theories are constructed and their solutions are used for calculations of corresponding Reggeon vertices and trajectories.
Partition functions for supersymmetric black holes
Manschot, Jan
2008-01-01
This dissertation presents recent discoveries on partition functions for four-dimensional supersymmetric black holes. These partition functions are important tools to explain the entropy of black holes from a microscopic point of view within string theory and M-theory. The results are applied to two central research topics in modern theoretical physics, namely (1) the correspondence between the physics (including gravity) within an Anti-de Sitter space and conformal field theory, and (2) the relation between black holes and topological strings.
Einstein Equations from Varying Complexity
Czech, Bartłomiej
2018-01-01
A recent proposal equates the circuit complexity of a quantum gravity state with the gravitational action of a certain patch of spacetime. Since Einstein's equations follow from varying the action, it should be possible to derive them by varying complexity. I present such a derivation for vacuum solutions of pure Einstein gravity in three-dimensional asymptotically anti-de Sitter space. The argument relies on known facts about holography and on properties of tensor network renormalization, an algorithm for coarse-graining (and optimizing) tensor networks.
Euler-Lagrange equations for high energy actions in QCD and in gravity*
Directory of Open Access Journals (Sweden)
Lipatov L.N.
2016-01-01
Full Text Available The high energy scattering in QCD and gravity can be described in terms of reggeized gluons and gravitons, respectively. At N = 4 SUSY the BFKL Pomeron is dual to the reggeized graviton living in the 10-dimensional anti-de-Sitter space. We discuss the corresponding effective actions for reggeized gluon and graviton interactions. The Euler-Lagrange equations for these effective theories are constructed with a variational approach and by using an invariance under the gauge and general coordinate transformations. We discuss their solutions and applications to the calculation of effective Reggeon vertices and trajectories.
Geometrothermodynamics of phantom AdS black holes
Energy Technology Data Exchange (ETDEWEB)
Quevedo, Hernando [Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Mexico (Mexico); Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica ed ICRANet, Rome (Italy); Quevedo, Maria N. [Facultad de Ciencias Basicas, Universidad Militar Nueva Granada, Departamento de Matematicas, Bogota (Colombia); Sanchez, Alberto [CIIDET, Departamento de Posgrado, Queretaro (Mexico)
2016-03-15
We show that to investigate the thermodynamic properties of charged phantom spherically symmetric anti-de Sitter black holes, it is necessary to consider the cosmological constant as a thermodynamic variable so that the corresponding fundamental equation is a homogeneous function defined on an extended equilibrium space. We explore all the thermodynamic properties of this class of black holes by using the classical physical approach, based upon the analysis of the fundamental equation, and the alternative mathematical approach as proposed in geometrothermodynamics. We show that both approaches are compatible and lead to equivalent results. (orig.)
Les Houches lectures on large N field theories and gravity
International Nuclear Information System (INIS)
Maldacena, J.
2002-01-01
We describe the holographic correspondence between field theories and string/M theory, focusing on the relation between compactifications of string/M theory on Anti-de Sitter spaces and conformal field theories. We review the background for this correspondence and discuss its motivations and the evidence for its correctness. We describe the main results that have been derived from the correspondence in the regime that the field theory is approximated by classical or semiclassical gravity. We focus on the case of the N = 4 supersymmetric gauge theory in four dimensions. (authors)
Kink-antikink, trapping bags and five-dimensional Gauss-Bonnet gravity
Giovannini, Massimo
2006-01-01
Five-dimensional Gauss-Bonnet gravity, with one warped extra-dimension, allows classes of solutions where two scalar fields combine either in a kink-antikink system or in a trapping bag configuration. While the kink-antikink system can be interpreted as a pair of gravitating domain walls with opposite topological charges, the trapping bag solution consists of a domain wall supplemented by a non-topological defect. In both classes of solutions, for large absolute values of the bulk coordinate (i.e. far from the core of the defects), the geometry is given by five-dimensional anti-de Sitter space.
On a curvature-statistics theorem
Energy Technology Data Exchange (ETDEWEB)
Calixto, M [Departamento de Matematica Aplicada y Estadistica, Universidad Politecnica de Cartagena, Paseo Alfonso XIII 56, 30203 Cartagena (Spain); Aldaya, V [Instituto de Astrofisica de Andalucia, Apartado Postal 3004, 18080 Granada (Spain)], E-mail: Manuel.Calixto@upct.es
2008-08-15
The spin-statistics theorem in quantum field theory relates the spin of a particle to the statistics obeyed by that particle. Here we investigate an interesting correspondence or connection between curvature ({kappa} = {+-}1) and quantum statistics (Fermi-Dirac and Bose-Einstein, respectively). The interrelation between both concepts is established through vacuum coherent configurations of zero modes in quantum field theory on the compact O(3) and noncompact O(2; 1) (spatial) isometry subgroups of de Sitter and Anti de Sitter spaces, respectively. The high frequency limit, is retrieved as a (zero curvature) group contraction to the Newton-Hooke (harmonic oscillator) group. We also make some comments on the physical significance of the vacuum energy density and the cosmological constant problem.
Extremal limits of the C metric: Nariai, Bertotti-Robinson, and anti-Nariai C metrics
International Nuclear Information System (INIS)
Dias, Oscar J.C.; Lemos, Jose P.S.
2003-01-01
In two previous papers we have analyzed the C metric in a background with a cosmological constant Λ, namely, the de-Sitter (dS) C metric (Λ>0), and the anti-de Sitter (AdS) C metric (Λ 0, Λ=0, and Λ 2 xS-tilde 2 ) to each point in the deformed two-sphere S-tilde 2 corresponds a dS 2 spacetime, except for one point which corresponds to a dS 2 spacetime with an infinite straight strut or string. There are other important new features that appear. One expects that the solutions found in this paper are unstable and decay into a slightly nonextreme black hole pair accelerated by a strut or by strings. Moreover, the Euclidean version of these solutions mediate the quantum process of black hole pair creation that accompanies the decay of the dS and AdS spaces
Etesi, Gábor
2013-03-01
In this paper we present a proof of a mathematical version of the strong cosmic censor conjecture attributed to Geroch-Horowitz and Penrose but formulated explicitly by Wald. The proof is based on the existence of future-inextendible causal curves in causal pasts of events on the future Cauchy horizon in a non-globally hyperbolic space-time. By examining explicit non-globally hyperbolic space-times we find that in case of several physically relevant solutions these future-inextendible curves have in fact infinite length. This way we recognize a close relationship between asymptotically flat or anti-de Sitter, physically relevant extendible space-times and the so-called Malament-Hogarth space-times which play a central role in recent investigations in the theory of "gravitational computers". This motivates us to exhibit a more sharp, more geometric formulation of the strong cosmic censor conjecture, namely "all physically relevant, asymptotically flat or anti-de Sitter but non-globally hyperbolic space-times are Malament-Hogarth ones". Our observations may indicate a natural but hidden connection between the strong cosmic censorship scenario and the Church-Turing thesis revealing an unexpected conceptual depth beneath both conjectures.
Adams, Robert A
2003-01-01
Sobolev Spaces presents an introduction to the theory of Sobolev Spaces and other related spaces of function, also to the imbedding characteristics of these spaces. This theory is widely used in pure and Applied Mathematics and in the Physical Sciences.This second edition of Adam''s ''classic'' reference text contains many additions and much modernizing and refining of material. The basic premise of the book remains unchanged: Sobolev Spaces is intended to provide a solid foundation in these spaces for graduate students and researchers alike.* Self-contained and accessible for readers in other disciplines.* Written at elementary level making it accessible to graduate students.
Adelstein, Pamela
2018-01-01
A space can be sacred, providing those who inhabit a particular space with sense of transcendence-being connected to something greater than oneself. The sacredness may be inherent in the space, as for a religious institution or a serene place outdoors. Alternatively, a space may be made sacred by the people within it and events that occur there. As medical providers, we have the opportunity to create sacred space in our examination rooms and with our patient interactions. This sacred space can be healing to our patients and can bring us providers opportunities for increased connection, joy, and gratitude in our daily work.
CMC Hypersurfaces on Riemannian and Semi-Riemannian Manifolds
International Nuclear Information System (INIS)
Perdomo, Oscar M.
2012-01-01
In this paper we generalize the explicit formulas for constant mean curvature (CMC) immersion of hypersurfaces of Euclidean spaces, spheres and hyperbolic spaces given in Perdomo (Asian J Math 14(1):73–108, 2010; Rev Colomb Mat 45(1):81–96, 2011) to provide explicit examples of several families of immersions with constant mean curvature and non constant principal curvatures, in semi-Riemannian manifolds with constant sectional curvature. In particular, we prove that every h is an element of [-1,-(2√n-1/n can be realized as the constant curvature of a complete immersion of S 1 n-1 x R in the (n + 1)-dimensional de Sitter space S 1 n+1 . We provide 3 types of immersions with CMC in the Minkowski space, 5 types of immersion with CMC in the de Sitter space and 5 types of immersion with CMC in the anti de Sitter space. At the end of the paper we analyze the families of examples that can be extended to closed hypersurfaces.
As well as authorizing NASA's funding for FY 1998 and 1999, the Civilian Space Authorization Act (H.R. 1275) would affect U.S.-Russia interactions in space. Regarding the International Space Station, the bill: prohibits transferring funds to Russia to pay for work on elements that are Russia's responsibility;
Worthington, Scott; Worthington, Scott
2015-01-01
My dissertation consists of two parts. The larger portion is an hour-long piece for double bass, electronics, and projected text called Space Administration. The second portion, this essay, discusses my musical background leading up to Space Administration, details of the composition itself, and what new directions I see in my work that in part stem from creating the piece Space Administration
The Fefferman-Graham ambiguity and /AdS black holes
Bautier, K.; Englert, F.; Rooman, M.; Spindel, P.
2000-04-01
Asymptotically anti-de Sitter space-times in pure gravity with negative cosmological constant are described, in all space-time dimensions greater than two, by classical degrees of freedom on the conformal boundary at space-like infinity. Their effective boundary action has a conformal anomaly for even dimensions and is conformally invariant for odd ones. These degrees of freedom are encoded in traceless tensor fields in the Fefferman-Graham asymptotic metric for any choice of conformally flat boundary and generate all Schwarzschild and Kerr black holes in anti-de Sitter space-time. We argue that these fields describe components of an energy-momentum tensor of a boundary theory and show explicitly how this is realized in 2+1 dimensions. There, the Fefferman-Graham fields reduce to the generators of the Virasoro algebra and give the mass and the angular momentum of the BTZ black holes. Their local expression is the Liouville field in a general curved background.
Impulsive gravitational waves in general massive 3D gravity
Baykal, Ahmet; Dereli, Tekin
2017-10-01
Impulsive, nondiverging, Petrov-Segre type-N gravitational wave solutions to a general massive three-dimensional gravity in the de Sitter, anti-de Sitter, and flat Minkowski backgrounds are constructed in a unified manner by using the exterior algebra of differential forms.
Directory of Open Access Journals (Sweden)
José M. Hernández Hernández
2004-12-01
Full Text Available Se realizó estudio descriptivo prospectivo en mujeres cuidadoras de niños en el área de salud de Cabezas, provincia Matanzas, en el período octubre 2002 - marzo 2003, con el objetivo de valorar aspectos vinculados a la cultura sanitaria en relación con la salud infantil. Se aplicó una encuesta para evaluar el cuidado de la enfermedad diarreica aguda, la enfermedad respiratoria aguda, la conducta ante cuadros febriles, uso de antibióticos y otros temas. Se apreció que sólo el 30,86 % de las cuidadoras obtuvo una valoración adecuada respecto al tratamiento de estas afecciones y problemas. En la atención a la enfermedad diarreica aguda y la enfermedad respiratoria aguda se encontró un mayor nivel de conocimientos con respecto a los otros temas. La identificación de síntomas y signos de alarma ante la fiebre, la aplicación de medidas higiénicas para la prevención de la sepsis urinaria en las hembras, la ingestión de agua hervida y la atención adecuada de la fiebre, fueron las temáticas con menor dominio.A descriptive and prospective study was conducted among baby sitters in the health area of Cabezas, province of Matanzas, from October 2002 to March 2003, to assess aspects connected with the health culture in the field of children's health. A survey was done to evaluate the care of acute diarrheal disease, acute respiratory disease, the conduct followed in febrile pictures, use of antibiotics and other topics. It was found that only 30.86 % of these women had an adequate assessment concernign these affections and problems. It was observed a higher level of knowledge in the acute diarrheal disease and in the acute respiratory disease compared with other topics. The identification of symptoms and signs of alarm in the case of fever, the application of health measures for preventing urinary sepsis in the females, the ingestion of boiled water and the appropiate attention to fever were the topics with less control.
DEFF Research Database (Denmark)
2005-01-01
of digital technology with space poses new challenges that call for new approaches. Creative alternatives to traditional systems methodologies are called for when designers use digital media to create new possibilities for action in space. Design Spaces explores how design and media art can provide creative......Digital technologies and media are becoming increasingly embodied and entangled in the spaces and places at work and at home. However, our material environment is more than a geometric abstractions of space: it contains familiar places, social arenas for human action. For designers, the integration...... alternatives for integrating digital technology with space. Connecting practical design work with conceptual development and theorizing, art with technology, and usesr-centered methods with social sciences, Design Spaces provides a useful research paradigm for designing ubiquitous computing. This book...
DEFF Research Database (Denmark)
2005-01-01
Digital technologies and media are becoming increasingly embodied and entangled in the spaces and places at work and at home. However, our material environment is more than a geometric abstractions of space: it contains familiar places, social arenas for human action. For designers, the integration...... of digital technology with space poses new challenges that call for new approaches. Creative alternatives to traditional systems methodologies are called for when designers use digital media to create new possibilities for action in space. Design Spaces explores how design and media art can provide creative...... alternatives for integrating digital technology with space. Connecting practical design work with conceptual development and theorizing, art with technology, and usesr-centered methods with social sciences, Design Spaces provides a useful research paradigm for designing ubiquitous computing. This book...
Martin, Gary L.
2011-01-01
A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.
Canonical energy is quantum Fisher information
International Nuclear Information System (INIS)
Lashkari, Nima; Raamsdonk, Mark Van
2016-01-01
In quantum information theory, Fisher Information is a natural metric on the space of perturbations to a density matrix, defined by calculating the relative entropy with the unperturbed state at quadratic order in perturbations. In gravitational physics, Canonical Energy defines a natural metric on the space of perturbations to spacetimes with a Killing horizon. In this paper, we show that the Fisher information metric for perturbations to the vacuum density matrix of a ball-shaped region B in a holographic CFT is dual to the canonical energy metric for perturbations to a corresponding Rindler wedge R B of Anti-de-Sitter space. Positivity of relative entropy at second order implies that the Fisher information metric is positive definite. Thus, for physical perturbations to anti-de-Sitter spacetime, the canonical energy associated to any Rindler wedge must be positive. This second-order constraint on the metric extends the first order result from relative entropy positivity that physical perturbations must satisfy the linearized Einstein’s equations.
Berberian, S K
2002-01-01
A detailed exposition of G.W. Mackey's theory of Borel spaces (standard, substandard, analytic), based on results in Chapter 9 of Bourbaki's General Topology. Appended are five informal lectures on the subject (given at the CIMPA/ICPAM Summer School, Nice, 1986), sketching the connection between Borel spaces and representations of operator algebras.
Parin, V. V.; Gorbov, F. D.; Kosmolinskiy, F. P.
1974-01-01
Psychological selection of astronauts considers mental responses and adaptation to the following space flight stress factors: (1) confinement in a small space; (2) changes in three dimensional orientation; (3) effects of altered gravity and weightlessness; (4) decrease in afferent nerve pulses; (5) a sensation of novelty and danger; and (6) a sense of separation from earth.
DEFF Research Database (Denmark)
Svaneklink, Annette
2009-01-01
that can be related to traditional architectural concepts in terms of dealing with space, body, time and movement. The paper considers this performativity and dual spatiality as being a processual architecture, constantly reconfiguring new hybrids between space, image and user. This dual spatiality raises...
Horneck, Gerda; Klaus, David M.; Mancinelli, Rocco L.
2010-01-01
Summary: The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis. PMID:20197502
Directory of Open Access Journals (Sweden)
Alex Ellery
2004-09-01
Full Text Available In this second of three short papers, I introduce some of the basic concepts of space robotics with an emphasis on some specific challenging areas of research that are peculiar to the application of robotics to space infrastructure development. The style of these short papers is pedagogical and the concepts in this paper are developed from fundamental manipulator robotics. This second paper considers the application of space manipulators to on-orbit servicing (OOS, an application which has considerable commercial application. I provide some background to the notion of robotic on-orbit servicing and explore how manipulator control algorithms may be modified to accommodate space manipulators which operate in the micro-gravity of space.
Kellett, B. J.; Griffin, D. K.; Bingham, R.; Campbell, R. N.; Forbes, A.; Michaelis, M. M.
2008-05-01
Hybrid space propulsion has been a feature of most space missions. Only the very early rocket propulsion experiments like the V2, employed a single form of propulsion. By the late fifties multi-staging was routine and the Space Shuttle employs three different kinds of fuel and rocket engines. During the development of chemical rockets, other forms of propulsion were being slowly tested, both theoretically and, relatively slowly, in practice. Rail and gas guns, ion engines, "slingshot" gravity assist, nuclear and solar power, tethers, solar sails have all seen some real applications. Yet the earliest type of non-chemical space propulsion to be thought of has never been attempted in space: laser and photon propulsion. The ideas of Eugen Saenger, Georgii Marx, Arthur Kantrowitz, Leik Myrabo, Claude Phipps and Robert Forward remain Earth-bound. In this paper we summarize the various forms of nonchemical propulsion and their results. We point out that missions beyond Saturn would benefit from a change of attitude to laser-propulsion as well as consideration of hybrid "polypropulsion" - which is to say using all the rocket "tools" available rather than possibly not the most appropriate. We conclude with three practical examples, two for the next decades and one for the next century; disposal of nuclear waste in space; a grand tour of the Jovian and Saturnian moons - with Huygens or Lunoxod type, landers; and eventually mankind's greatest space dream: robotic exploration of neighbouring planetary systems.
Doignon, Jean-Paul
1999-01-01
Knowledge spaces offer a rigorous mathematical foundation for various practical systems of knowledge assessment. An example is offered by the ALEKS system (Assessment and LEarning in Knowledge Spaces), a software for the assessment of mathematical knowledge. From a mathematical standpoint, knowledge spaces generalize partially ordered sets. They are investigated both from a combinatorial and a stochastic viewpoint. The results are applied to real and simulated data. The book gives a systematic presentation of research and extends the results to new situations. It is of interest to mathematically oriented readers in education, computer science and combinatorics at research and graduate levels. The text contains numerous examples and exercises and an extensive bibliography.
DEFF Research Database (Denmark)
Birke, Alexander; Schoenau-Fog, Henrik; Reng, Lars
2012-01-01
This paper presents Space Bugz! - a novel crowd game for large venues or cinemas that utilises the audience's smartphones as controllers for the game. This paper explains what crowd gaming is and describes how the approach used in Space Bugz! enables more advanced gameplay concepts and individual...... player control than current technologies allow. The gameplay of Space Bugz! is then explained along with the technical architecture of the game. After this, the iterative design process used to create the game is described together with future perspectives. The article concludes with links to a video...
Mapping superintegrable quantum mechanics to resonant spacetimes
Evnin, Oleg; Demirchian, Hovhannes; Nersessian, Armen
2018-01-01
We describe a procedure naturally associating relativistic Klein-Gordon equations in static curved spacetimes to nonrelativistic quantum motion on curved spaces in the presence of a potential. Our procedure is particularly attractive in application to (typically, superintegrable) problems whose energy spectrum is given by a quadratic function of the energy level number, since for such systems the spacetimes one obtains possess evenly spaced, resonant spectra of frequencies for scalar fields of a certain mass. This construction emerges as a generalization of the previously studied correspondence between the Higgs oscillator and anti-de Sitter spacetime, which has been useful for both understanding weakly nonlinear dynamics in anti-de Sitter spacetime and algebras of conserved quantities of the Higgs oscillator. Our conversion procedure ("Klein-Gordonization") reduces to a nonlinear elliptic equation closely reminiscent of the one emerging in relation to the celebrated Yamabe problem of differential geometry. As an illustration, we explicitly demonstrate how to apply this procedure to superintegrable Rosochatius systems, resulting in a large family of spacetimes with resonant spectra for massless wave equations.
Energy Technology Data Exchange (ETDEWEB)
Burikham, Piyabut; Cheamsawat, Krai [Chulalongkorn University, High Energy Physics Theory Group, Department of Physics, Faculty of Science, Bangkok (Thailand); Harko, Tiberiu [University College London, Department of Mathematics, London (United Kingdom); Lake, Matthew J. [Naresuan University, The Institute for Fundamental Study, ' ' The Tah Poe Academia Institute' ' , Phitsanulok (Thailand); Ministry of Education, Thailand Center of Excellence in Physics, Bangkok (Thailand)
2015-09-15
The existence of both a minimum mass and a minimum density in nature, in the presence of a positive cosmological constant, is one of the most intriguing results in classical general relativity. These results follow rigorously from the Buchdahl inequalities in four-dimensional de Sitter space. In this work, we obtain the generalized Buchdahl inequalities in arbitrary space-time dimensions with Λ ≠ 0 and consider both the de Sitter and the anti-de Sitter cases. The dependence on D, the number of space-time dimensions, of the minimum and maximum masses for stable spherical objects is explicitly obtained. The analysis is then extended to the case of dark energy satisfying an arbitrary linear barotropic equation of state. The Jeans instability of barotropic dark energy is also investigated, for arbitrary D, in the framework of a simple Newtonian model with and without viscous dissipation, and we determine the dispersion relation describing the dark energy-matter condensation process, along with estimates of the corresponding Jeans mass (and radius). Finally, the quantum mechanical implications of the mass limits are investigated, and we show that the existence of a minimum mass scale naturally leads to a model in which dark energy is composed of a 'sea' of quantum particles, each with an effective mass proportional to Λ{sup 1/4}. (orig.)
Zaanen, A C
1983-01-01
While Volume I (by W.A.J. Luxemburg and A.C. Zaanen, NHML Volume 1, 1971) is devoted to the algebraic aspects of the theory, this volume emphasizes the analytical theory of Riesz spaces and operators between these spaces. Though the numbering of chapters continues on from the first volume, this does not imply that everything covered in Volume I is required for this volume, however the two volumes are to some extent complementary.
International Nuclear Information System (INIS)
Doke, Tadayoshi
1988-01-01
Japan will take part in the LML-1 (International Microgravity Laboratory 1) program that is scheduled to be carried out with space shuttles to be launched in 1991. The program will be followed by the LS-J (Space Laboratory-Japan) and IML-2 programs. A reliable dosimetry system is currently required to be established to evaluate the radiations in space. The present article reviews major features of different types of space radiations and requirements of dosimeters for these radiations. The radiations in the space environment consist of: 1) electrons and protons that have been trapped by the terrestrial magnetism, 2) corpuscular, gamma-and X-rays released from the sun, and 3) galactic cosmic rays (corpuscular, gamma-and X-rays). The effects of the trapped radiations will be low if a spacecraft can get through the zone of such radiations in a short period of time. The effects of galactic cosmic rays are much smaller than those of the trapped radiations. A solar flare can give significant contributions to the total radiations received by a spacecraft. An extremely large flare can release a fatal amount of radiations to the crew of a spacecraft. Prediction of such a large flare is of great important for a long trip through the space. Significant improvements should be made on existing dosimeters. (Nogami, K.)
Directory of Open Access Journals (Sweden)
Elena Grigoryeva
2013-01-01
Full Text Available The topic of this issue is PUBLIC SPACES. It is familiar and clear to every citizen. The streets and courtyards as childhood experiences remain with us forever. And these are the places where we come with our parents at weekends, where we meet friends, where we have dates and where we already come for a walk with our children.The history of public spaces is long and captivating. It was the main city squares where the most important events took place in history. The Agoras of Ancient Greece and the Roman Forums, the squares of Vatican, Paris and London, Moscow and Saint Petersburg… Greve, Trafalgar, Senate, Palace, Red, Bolotnaya – behind every name there is life of capitals, countries and nations.Public spaces, their shapes, image and development greatly influence the perception of the city as a whole. Both visitors and inhabitants can see in public spaces not only the visage but the heart, the soul and the mind of the city.Unfortunately, sometimes we have to prove the value of public spaces and defend them from those who consider them nothing but a blank space, nobody’s land destined for barbarous development.What should happen to make citizens perceive public spaces as their own and to make authorities consider development and maintenance of squares and parks their priority task against the background of increasing competition between cities and the fight for human capital? Lately they more often say about “a high-quality human capital”. And now, when they say “the city should be liveable” they add “for all groups of citizens, including the creative class”.
Underground spaces/cybernetic spaces
Directory of Open Access Journals (Sweden)
Tomaž Novljan
2000-01-01
Full Text Available A modern city space is a space where in the vertical and horizontal direction dynamic, non-linear processes exist, similar as in nature. Alongside the “common” city surface, cities have underground spaces as well that are increasingly affecting the functioning of the former. It is the space of material and cybernetic communication/transport. The psychophysical specifics of using underground places have an important role in their conceptualisation. The most evident facts being their limited volume and often limited connections to the surface and increased level of potential dangers of all kinds. An efficient mode for alleviating the effects of these specific features are artistic interventions, such as: shape, colour, lighting, all applications of the basic principles of fractal theory.
New classes of bi-axially symmetric solutions to four-dimensional Vasiliev higher spin gravity
Energy Technology Data Exchange (ETDEWEB)
Sundell, Per; Yin, Yihao [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago de Chile (Chile)
2017-01-11
We present new infinite-dimensional spaces of bi-axially symmetric asymptotically anti-de Sitter solutions to four-dimensional Vasiliev higher spin gravity, obtained by modifications of the Ansatz used in https://arxiv.org/abs/1107.1217, which gave rise to a Type-D solution space. The current Ansatz is based on internal semigroup algebras (without identity) generated by exponentials formed out of the bi-axial symmetry generators. After having switched on the vacuum gauge function, the resulting generalized Weyl tensor is given by a sum of generalized Petrov type-D tensors that are Kerr-like or 2-brane-like in the asymptotic AdS{sub 4} region, and the twistor space connection is smooth in twistor space over finite regions of spacetime. We provide evidence for that the linearized twistor space connection can be brought to Vasiliev gauge.
Gravity with a cosmological constant from rational curves
Energy Technology Data Exchange (ETDEWEB)
Adamo, Tim [Department of Applied Mathematics & Theoretical Physics,University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2015-11-16
We give a new formula for all tree-level correlators of boundary field insertions in gauged N=8 supergravity in AdS{sub 4}; this is an analogue of the tree-level S-matrix in anti-de Sitter space. The formula is written in terms of rational maps from the Riemann sphere to twistor space, with no reference to bulk perturbation theory. It is polynomial in the cosmological constant, and equal to the classical scattering amplitudes of supergravity in the flat space limit. The formula is manifestly supersymmetric, independent of gauge choices on twistor space, and equivalent to expressions computed via perturbation theory at 3-point (MHV)-bar and n-point MHV. We also show that the formula factorizes and obeys BCFW recursion in twistor space.
DEFF Research Database (Denmark)
Larsen, Henrik Gutzon
Using the development of intergovernmental environmental cooperation in the Baltic Sea area as a concrete example, the aim of this study is to explore how the 'environment' in situations of environmental interdependence is identified and institutionalised as political-geographical objects....... 'Environmental interdependence' is to this end conceptualised as a tension between 'political spaces' of discrete state territories and 'environmental spaces' of spatially nested ecosystems. This tension between geographies of political separateness and environmental wholeness is the implicit or explicit basis...... for a large and varied literature. But in both its critical and problemsolving manifestations, this literature tends to naturalise the spatiality of environmental concerns: environmental spaces are generally taken for granted. On the suggestion that there is a subtle politics to the specification...
Casazza, Peter G
1989-01-01
This monograph provides a structure theory for the increasingly important Banach space discovered by B.S. Tsirelson. The basic construction should be accessible to graduate students of functional analysis with a knowledge of the theory of Schauder bases, while topics of a more advanced nature are presented for the specialist. Bounded linear operators are studied through the use of finite-dimensional decompositions, and complemented subspaces are studied at length. A myriad of variant constructions are presented and explored, while open questions are broached in almost every chapter. Two appendices are attached: one dealing with a computer program which computes norms of finitely-supported vectors, while the other surveys recent work on weak Hilbert spaces (where a Tsirelson-type space provides an example).
Rega, Joseph Mark
2003-01-01
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Inglês e Literatura Correspondente. The recent surge in cyberspace science fiction follows previous trends within the genre, i.e. those connected with future city-space and outer space, and is an inevitable result of economic forces. There has always been a close relationship between capitalism and spatial expansion, compelled by technological innovations that ha...
Petrov, Aleksej Z
1969-01-01
Einstein Spaces presents the mathematical basis of the theory of gravitation and discusses the various spaces that form the basis of the theory of relativity. This book examines the contemporary development of the theory of relativity, leading to the study of such problems as gravitational radiation, the interaction of fields, and the behavior of elementary particles in a gravitational field. Organized into nine chapters, this book starts with an overview of the principles of the special theory of relativity, with emphasis on the mathematical aspects. This text then discusses the need for a ge
Zubrin, Robert
The authors is giving a classification of civilisations depending on the degree of colonisation of the Earth, Solar System and Our Galaxy. The problems of: History of geographic discoveries (The great geographical discoveries during the Middle Age, the concurence of Chinnese and Europeans in this Area); The Astrophysics, such as: Asteroids, Water and Atmosphere on outer planets, Planet Mars Planet, Agriculture on outer planets, Minerals on outer planets; Cosmic flights: Fuels, Robotics, Moon (as an intermediary basis for interplanetary flights), Mars colonisation; Interstellar flights, Space research costs, strategy and tactics of the space colonisation; Policy: War and Peace, International Collaboration are discussed.
DEFF Research Database (Denmark)
Raahauge, Kirsten Marie
2008-01-01
This article deals with representations of one specific city, Århus, Denmark, especially its central district. The analysis is based on anthropological fieldwork conducted in Skåde Bakker and Fedet, two well-off neighborhoods. The overall purpose of the project is to study perceptions of space...... and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...
Emergent Gravity and the Dark Universe
Directory of Open Access Journals (Sweden)
Erik P. Verlinde
2017-05-01
Full Text Available Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional 'dark' gravitational force describing the 'elastic' response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton's constant and the Hubble acceleration scale a_0 =cH_0, and provide evidence for the fact that this additional `dark gravity~force' explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
Yu, Hao; Gu, Bao-Min; Huang, Fa Peng; Wang, Yong-Qiang; Meng, Xin-He; Liu, Yu-Xiao
2017-02-01
The future gravitational wave (GW) observations of compact binaries and their possible electromagnetic counterparts may be used to probe the nature of the extra dimension. It is widely accepted that gravitons and photons are the only two completely confirmed objects that can travel along null geodesics in our four-dimensional space-time. However, if there exist extra dimensions and only GWs can propagate freely in the bulk, the causal propagations of GWs and electromagnetic waves (EMWs) are in general different. In this paper, we study null geodesics of GWs and EMWs in a five-dimensional anti-de Sitter space-time in the presence of the curvature of the universe. We show that for general cases the horizon radius of GW is longer than EMW within equal time. Taking the GW150914 event detected by the Advanced Laser Interferometer Gravitational-Wave Observatory and the X-ray event detected by the Fermi Gamma-ray Burst Monitor as an example, we study how the curvature k and the constant curvature radius l affect the horizon radii of GW and EMW in the de Sitter and Einstein-de Sitter models of the universe. This provides an alternative method for probing extra dimension through future GW observations of compact binaries and their electromagnetic counterparts.
Weinstein, Margery
2010-01-01
Creating a balanced learning space for employees is about more than trying different types of seating. It is a challenge that an affect how well employees absorb the lessons and whether they will be able to product better results for the company. The possible solutions are as diverse as the learners. This article describes how three companies…
2005-01-01
An old water tank from the time of the ISR is being converted into a temporary store for ATLAS muon chambers. This is the last chapter in the big programme by the PH Department to make better use of space at CERN.
DEFF Research Database (Denmark)
Raahauge, Kirsten Marie
2008-01-01
and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...
Miquel, J. (Editor); Economos, A. C. (Editor)
1982-01-01
Presentations are given which address the effects of space flght on the older person, the parallels between the physiological responses to weightlessness and the aging process, and experimental possibilities afforded by the weightless environment to fundamental research in gerontology and geriatrics.
Directory of Open Access Journals (Sweden)
David N. Keck
2003-01-01
Full Text Available We investigate a class of abstract functional integro-differential stochastic evolution equations in a real separable Hilbert space. Global existence results concerning mild and periodic solutions are formulated under various growth and compactness conditions. Also, related convergence results are established and an example arising in the mathematical modeling of heat conduction is discussed to illustrate the abstract theory.
Cort, Cliff
2006-01-01
Education administrators face the dual dilemma of crowded, aging facilities and tightening capital budgets. The challenge is to build the necessary classroom, laboratory and activity space while minimizing the length and expense of the construction process. One solution that offers an affordable alternative is modular construction, a method that…
DEFF Research Database (Denmark)
Fajstrup, Lisbeth; Goubault, Eric; Haucourt, Emmanuel
2012-01-01
State-space reduction techniques, used primarily in model-checkers, all rely on the idea that some actions are independent, hence could be taken in any (respective) order while put in parallel, without changing the semantics. It is thus not necessary to consider all execution paths...
Thermodynamics and jet-quenching in the quark-gluon plasma from an AdS/QCD model
Lilleskov, Elias; Bartz, Sean
2015-10-01
The Anti-de Sitter Space/Conformal Field Theory Correspondence (AdS/CFT) has been used to study both hadronic dynamics and the thermodynamics and jet quenching behavior of the quark-gluon plasma created in heavy ion collisions. We attempt to connect the two regimes by adapting an AdS/QCD model previously used to study meson spectra to apply to the quark-gluon plasma. The model includes three fields: a dilaton to introduce confinement, and chiral and glueball condensates to reflect the zero-temperature dynamics. We dynamically solve the Einstein field equations to numerically determine the metric, which asymptotically describes an anti-de Sitter-Schwarzschild black hole solution. We then numerically calculate the temperature as a function of the black hole horizon location. Next, we determine the behavior of the entropy density, the speed of sound, and the jet quenching parameter as functions of the temperature. These quantities approach the behavior of a conformal plasma in the high temperature limit. The minimum of the temperature-horizon plot is interpreted as the plasma's deconfinement temperature, found to be 104 MeV.
Black holes with su(N) gauge field hair and superconducting horizons
International Nuclear Information System (INIS)
Shepherd, Ben L.; Winstanley, Elizabeth
2017-01-01
We present new planar dyonic black hole solutions of the su(N) Einstein-Yang-Mills equations in asymptotically anti-de Sitter space-time, focussing on su(2) and su(3) gauge groups. The magnetic part of the gauge field forms a condensate close to the planar event horizon. We compare the free energy of a non-Abelian hairy black hole with that of an embedded Reissner-Nordström-anti-de Sitter (RN-AdS) black hole having the same Hawking temperature and electric charge. We find that the hairy black holes have lower free energy. We present evidence that there is a phase transition at a critical temperature, above which the only solutions are embedded RN-AdS black holes. At the critical temperature, an RN-AdS black hole can decay into a hairy black hole, and it is thermodynamically favourable to do so. Working in the probe limit, we compute the frequency-dependent conductivity, and find that enlarging the gauge group from su(2) to su(3) eliminates a divergence in the conductivity at nonzero frequency.
Exceptional F(4) higher-spin theory in AdS{sub 6} at one-loop and other tests of duality
Energy Technology Data Exchange (ETDEWEB)
Günaydin, Murat [Institute for Gravitation and the Cosmos Physics Department, Pennsylvania State University, University Park, PA 16802 (United States); Skvortsov, Evgeny [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians University Munich, Theresienstr. 37, D-80333 Munich (Germany); Lebedev Institute of Physics, Leninsky ave. 53, 119991 Moscow (Russian Federation); Tran, Tung [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States)
2016-11-28
We study the higher-spin gauge theory in six-dimensional anti-de Sitter space AdS{sub 6} that is based on the exceptional Lie superalgebra F(4). The relevant higher-spin algebra was constructed in http://arxiv.org/abs/1409.2185. We determine the spectrum of the theory and show that it contains the physical fields of the Romans F(4) gauged supergravity. The full spectrum consists of an infinite tower of unitary supermultiplets of F(4) which extend the Romans multiplet to higher spins plus a single short supermultiplet. Motivated by applications to this novel supersymmetric higher-spin theory as well as to other theories, we extend the known one-loop tests of AdS/CFT duality in various directions. The spectral zeta-function is derived for the most general case of fermionic and mixed-symmetry fields, which allows one to test the Type-A and B theories and supersymmetric extensions thereof in any dimension. We also study higher-spin doubletons and partially-massless fields. While most of the tests are successfully passed, the Type-B theory in all even dimensional anti-de Sitter spacetimes presents an interesting puzzle: the free energy as computed from the bulk is not equal to that of the free fermion on the CFT side, though there is some systematics to the discrepancy.
Stability analysis of lower dimensional gravastars in noncommutative geometry
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Ayan [Jadavpur University, Department of Mathematics, Kolkata (India); Hansraj, Sudan [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)
2016-11-15
The Banados et al. (Phys. Rev. Lett 69:1849, 1992), black hole solution is revamped from the Einstein field equations in (2 + 1)-dimensional anti-de Sitter spacetime, in a context of noncommutative geometry (Phys. Rev. D 87:084014, 2013). In this article, we explore the exact gravastar solutions in three-dimensional anti-de Sitter space given in the same geometry. As a first step we derive BTZ solution assuming the source of energy density as point-like structures in favor of smeared objects, where the particle mass M, is diffused throughout a region of linear size √(α) and is described by a Gaussian function of finite width rather than a Dirac delta function. We matched our interior solution to an exterior BTZ spacetime at a junction interface situated outside the event horizon. Furthermore, a stability analysis is carried out for the specific case when χ < 0.214 under radial perturbations about the static equilibrium solutions. To give theoretical support we are also trying to explore their physical properties and characteristics. (orig.)
Black holes with su(N) gauge field hair and superconducting horizons
Energy Technology Data Exchange (ETDEWEB)
Shepherd, Ben L.; Winstanley, Elizabeth [Consortium for Fundamental Physics, School of Mathematics and Statistics,The University of Sheffield,Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)
2017-01-16
We present new planar dyonic black hole solutions of the su(N) Einstein-Yang-Mills equations in asymptotically anti-de Sitter space-time, focussing on su(2) and su(3) gauge groups. The magnetic part of the gauge field forms a condensate close to the planar event horizon. We compare the free energy of a non-Abelian hairy black hole with that of an embedded Reissner-Nordström-anti-de Sitter (RN-AdS) black hole having the same Hawking temperature and electric charge. We find that the hairy black holes have lower free energy. We present evidence that there is a phase transition at a critical temperature, above which the only solutions are embedded RN-AdS black holes. At the critical temperature, an RN-AdS black hole can decay into a hairy black hole, and it is thermodynamically favourable to do so. Working in the probe limit, we compute the frequency-dependent conductivity, and find that enlarging the gauge group from su(2) to su(3) eliminates a divergence in the conductivity at nonzero frequency.
Quantum criticality and black holes.
Sachdev, Subir; Müller, Markus
2009-04-22
Many condensed matter experiments explore the finite temperature dynamics of systems near quantum critical points. Often, there are no well-defined quasiparticle excitations, and so quantum kinetic equations do not describe the transport properties completely. The theory shows that the transport coefficients are not proportional to a mean free scattering time (as is the case in the Boltzmann theory of quasiparticles), but are completely determined by the absolute temperature and by equilibrium thermodynamic observables. Recently, explicit solutions of this quantum critical dynamics have become possible via the anti-de Sitter/conformal field theory duality discovered in string theory. This shows that the quantum critical theory provides a holographic description of the quantum theory of black holes in a negatively curved anti-de Sitter space, and relates its transport coefficients to properties of the Hawking radiation from the black hole. We review how insights from this connection have led to new results for experimental systems: (i) the vicinity of the superfluid-insulator transition in the presence of an applied magnetic field, and its possible application to measurements of the Nernst effect in the cuprates, (ii) the magnetohydrodynamics of the plasma of Dirac electrons in graphene and the prediction of a hydrodynamic cyclotron resonance.
Broken bridges: a counter-example of the ER=EPR conjecture
Energy Technology Data Exchange (ETDEWEB)
Chen, Pisin; Wu, Chih-Hung; Yeom, Dong-han, E-mail: pisinchen@phys.ntu.edu.tw, E-mail: b02202007@ntu.edu.tw, E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)
2017-06-01
In this paper, we provide a counter-example to the ER=EPR conjecture. In an anti-de Sitter space, we construct a pair of maximally entangled but separated black holes. Due to the vacuum decay of the anti-de Sitter background toward a deeper vacuum, these two parts can be trapped by bubbles. If these bubbles are reasonably large, then within the scrambling time, there should appear an Einstein-Rosen bridge between the two black holes. Now by tracing more details on the bubble dynamics, one can identify parameters such that one of the two bubbles either monotonically shrinks or expands. Because of the change of vacuum energy, one side of the black hole would evaporate completely. Due to the shrinking of the apparent horizon, a signal of one side of the Einstein-Rosen bridge can be viewed from the opposite side. We analytically and numerically demonstrate that within a reasonable semi-classical parameter regime, such process can happen. Bubbles are a non-perturbative effect, which is the crucial reason that allows the transmission of information between the two black holes through the Einstein-Rosen bridge, even though the probability is highly suppressed. Therefore, the ER=EPR conjecture cannot be generic in its present form and its validity maybe restricted.
Soft Connected Spaces and Soft Paracompact Spaces
Fucai Lin
2013-01-01
Soft topological spaces are considered as mathematical tools for dealing with uncertainties, and a fuzzy topological space is a special case of the soft topological space. The purpose of this paper is to study soft topological spaces. We introduce some new concepts in soft topological spaces such as soft closed mapping, soft open mappings, soft connected spaces and soft paracompact spaces. We also redefine the concept of soft points such that it is reasonable in soft topological spaces. Mo...
Twistor methods for AdS{sub 5}
Energy Technology Data Exchange (ETDEWEB)
Adamo, Tim; Skinner, David; Williams, Jack [Department of Applied Mathematics & Theoretical Physics, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA United Kingdom (United Kingdom)
2016-08-30
We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS{sub 5} is the same as the ambitwistor space of the four-dimensional conformal boundary; the geometry of this correspondence is reviewed for both the bulk and boundary. A Penrose transform allows us to describe free bulk fields, with or without mass, in terms of data on twistor space. Explicit representatives for the bulk-to-boundary propagators of scalars and spinors are constructed, along with twistor action functionals for the free theories. Evaluating these twistor actions on bulk-to-boundary propagators is shown to produce the correct two-point functions.
Mynard, Frédéric; Seal, Gavin J
2010-02-01
The topological viewpoint on spaces of phenotypes presented in Stadler et al. (J Theor Biol 213:241-274, 2001) is revisited, and a quantified version is proposed. While necessary probabilistic information can be encoded in a topological- like fashion, it turns out that it is not reflected adequately by the concept of continuity. We propose alternative models, but the behavior of maps make these models non-topological in fundamental ways.
Coiera, Enrico
2014-01-01
Annotations to physical workspaces such as signs and notes are ubiquitous. When densely annotated, work areas become communication spaces. This study aims to characterize the types and purpose of such annotations. A qualitative observational study was undertaken in two wards and the radiology department of a 440-bed metropolitan teaching hospital. Images were purposefully sampled; 39 were analyzed after excluding inferior images. Annotation functions included signaling identity, location, capability, status, availability, and operation. They encoded data, rules or procedural descriptions. Most aggregated into groups that either created a workflow by referencing each other, supported a common workflow without reference to each other, or were heterogeneous, referring to many workflows. Higher-level assemblies of such groupings were also observed. Annotations make visible the gap between work done and the capability of a space to support work. Annotations are repairs of an environment, improving fitness for purpose, fixing inadequacy in design, or meeting emergent needs. Annotations thus record the missing information needed to undertake tasks, typically added post-implemented. Measuring annotation levels post-implementation could help assess the fit of technology to task. Physical and digital spaces could meet broader user needs by formally supporting user customization, 'programming through annotation'. Augmented reality systems could also directly support annotation, addressing existing information gaps, and enhancing work with context sensitive annotation. Communication spaces offer a model of how work unfolds. Annotations make visible local adaptation that makes technology fit for purpose post-implementation and suggest an important role for annotatable information systems and digital augmentation of the physical environment.
Energy Technology Data Exchange (ETDEWEB)
Corliss, William R.
1968-01-01
This booklet discusses three kinds of space radiation, cosmic rays, Van Allen Belts, and solar plasma. Cosmic rays are penetrating particles that we cannot see, hear or feel, which come from distant stars. Van Allen Belts, named after their discoverer are great belts of protons and electrons that the earth has captured in its magnetic trap. Solar plasma is a gaseous, electrically neutral mixture of positive and negative ions that the sun spews out from convulsed regions on its surface.
2013-05-29
attack Laser attack Jamming Indications and warning Cyber attack Environmental monitoring System status Re-entry Detect and track Cataloging...vulnerable to interference or attack. Space segments are vulnerable to attacks or interference such as direct-ascent anti- satellite interceptors, laser ...blinding, and dazzling . Additionally, ground-to-satellite link segments are susceptible to jamming and other forms of interference, and ground
Smith, Scott M.
2009-01-01
Optimal nutrition will be critical for crew members who embark on space exploration missions. Nutritional assessment provides an opportunity to ensure that crewmembers begin their missions in optimal nutritional status, to document changes during a mission and, if necessary, to provide intervention to maintain that status throughout the mission, and to assesses changes after landing in order to facilitate the return to their normal status as soon as possible after landing. We report here the findings from our nutritional assessment of astronauts who participated in the International Space Station (ISS) missions, along with flight and ground-based research findings. We also present ongoing and planned nutrition research activities. These studies provide evidence that bone loss, compromised vitamin status, and oxidative damage are the critical nutritional concerns for space travelers. Other nutrient issues exist, including concerns about the stability of nutrients in the food system, which are exposed to longterm storage and radiation during flight. Defining nutrient requirements, and being able to provide and maintain those nutrients on exploration missions, will be critical for maintaining crew member health.
DEFF Research Database (Denmark)
Kristiansen, Erik
2015-01-01
, called “pervasive games.” These are games that are based on computer technology, but use a physical space as the game space as opposed to video games. Coupling spatial configuration with performance theory of rituals as liminal phenomena, I put forward a model and a new understanding of the magic circle......When we play games of any kind, from tennis to board games, it is easy to notice that games seem to be configured in space, often using stripes or a kind of map on a board. Some games are clearly performed within this marked border, while it may be difficult to pinpoint such a border in games like...... hide-and-seek, but even these games are still spatially configured. The border (visible or not) both seem to separate and uphold the game that it is meant for. This chapter sets out to analyse the possible border that separates a game from the surrounding world. Johan Huizinga noted this “separateness...
Tyszka, Steph; Saraiva, Jose; Doran, Rosa
2017-04-01
NUCLIO is a Portuguese non-profit organization with a strong record of investing in science education and outreach. We have developed and implemented many activities mostly directed to a young audience, in a bid to awaken and reinforce the interest that young people devote to Astronomy and all things spatial. In this framework, we have created a week-long program called Space Detectives, supported by the Municipality of Cascais, based on a story-line that provided a number of challenges and opportunities for learning matters as diverse as the electro-magnetic spectrum, means of communication, space travel, the martian environment, coding and robotics. We report on the first session that took place in December 2016. We had as participants several kids aged 9 to 12, with a mixed background in terms of interest in the sciences. Their response varied from enthusiastic to somewhat less interested, depending on the nature of the subject and the way it was presented - a reaction not necessarily related to its complexity. This week was taken as something of a trial run, in preparation for the European Commission- funded project "Stories of Tomorrow", to be implemented in schools. The individual activities and the way they were related to the story-line, as well as the smooth transition from one to the next, were subject to an analysis that will allow for improvements in the next installments of this program. We believe this is an excellent approach to the goals of using Space and Astronomy as an anchor for generating and keeping interest in the scientific areas, and of finding new and richer ways of learning.
2009-01-01
Space Exploration, is one book in the Britannica Illustrated Science Library Series that is correlated to the science curriculum in grades 5-8. The Britannica Illustrated Science Library is a visually compelling set that covers earth science, life science, and physical science in 16 volumes. Created for ages 10 and up, each volume provides an overview on a subject and thoroughly explains it through detailed and powerful graphics-more than 1,000 per volume-that turn complex subjects into information that students can grasp. Each volume contains a glossary with full definitions for vocabulary help and an index.
Wotring, Virginia E
2012-01-01
“Space Pharmacology” is a review of the current knowledge regarding the use of pharmaceuticals during spaceflights. It is a comprehensive review of the literature, addressing each area of pharmacokinetics and each major physiological system in turn. Every section begins with a topic overview, and is followed by a discussion of published data from spaceflight, and from ground experiments meant to model the spaceflight situation. Includes a discussion looking forward to the new medical challenges we are likely to face on longer duration exploration missions. This book is a snapshot of our current knowledge that also highlights areas of unknown.
A noncompact Weyl-Einstein-Yang-Mills model: A semiclassical quantum gravity
Dengiz, Suat
2017-08-01
We construct and study perturbative unitarity (i.e., ghost and tachyon analysis) of a 3 + 1-dimensional noncompact Weyl-Einstein-Yang-Mills model. The model describes a local noncompact Weyl's scale plus SU(N) phase invariant Higgs-like field,conformally coupled to a generic Weyl-invariant dynamical background. Here, the Higgs-like sector generates the Weyl's conformal invariance of system. The action does not admit any dimensionful parameter and genuine presence of de Sitter vacuum spontaneously breaks the noncompact gauge symmetry in an analogous manner to the Standard Model Higgs mechanism. As to flat spacetime, the dimensionful parameter is generated within the dimensional transmutation in quantum field theories, and thus the symmetry is radiatively broken through the one-loop Effective Coleman-Weinberg potential. We show that the mere expectation of reducing to Einstein's gravity in the broken phases forbids anti-de Sitter space to be its stable vacua. The model is unitary in de Sitter and flat vacua around which a massless graviton, N2 - 1 massless scalar bosons, N massless Dirac fermions, N2 - 1 Proca-type massive Abelian and non-Abelian vector bosons are generically propagated.
Supersymmetry across the Hadronic Spectrum
Directory of Open Access Journals (Sweden)
Hans Günter Dosch
2017-01-01
Full Text Available Semiclassical light-front bound-state equations for hadrons are presented and compared with experiment. The essential dynamical feature is the holographic approach; that is, the hadronic equations in four-dimensional Minkowski space are derived as holograms of classical equations in a 5-dimensional anti-de Sitter space. The form of the equations is constrained by the imposed superconformal algebra, which fixes the form of the light-front potential. If conformal symmetry is strongly broken by heavy quark masses, the combination of supersymmetry and the classical action in the 5-dimensional space still fixes the form of the potential. By heavy quark symmetry, the strength of the potential is related to the heavy quark mass. The contribution is based on several recent papers in collaboration with Stan Brodsky and Guy de Téramond.
International Nuclear Information System (INIS)
Khoury, Justin; Parikh, Maulik
2009-01-01
Mach's principle is the proposition that inertial frames are determined by matter. We put forth and implement a precise correspondence between matter and geometry that realizes Mach's principle. Einstein's equations are not modified and no selection principle is applied to their solutions; Mach's principle is realized wholly within Einstein's general theory of relativity. The key insight is the observation that, in addition to bulk matter, one can also add boundary matter. Given a space-time, and thus the inertial frames, we can read off both boundary and bulk stress tensors, thereby relating matter and geometry. We consider some global conditions that are necessary for the space-time to be reconstructible, in principle, from bulk and boundary matter. Our framework is similar to that of the black hole membrane paradigm and, in asymptotically anti-de Sitter space-times, is consistent with holographic duality.
International Nuclear Information System (INIS)
Kay, Bernard S.; Larkin, Peter
2008-01-01
We construct a symplectic isomorphism h from classical Klein Gordon solutions of mass m on (d+1)-dimensional Lorentzian anti-de Sitter space (equipped with the usual symplectic form) to a certain symplectic space of functions on its conformal boundary (only) for all integer and half-integer Δ (=(d/2)+(1/2)(d 2 +4m 2 ) 1/2 ). h induces a large family of new examples of Rehren's algebraic holography in which the net of local quantum Klein Gordon algebras in AdS is seen to map to a suitably defined net of local algebras for the (generalized free) scalar conformal field with anomalous dimension Δ on d-dimensional Minkowski space (the AdS boundary). Relatedly, we show for these models that Bertola et al.'s boundary-limit holography becomes a quantum duality (only) if the test functions for boundary Wightman distributions are restricted in a particular way
DEFF Research Database (Denmark)
Johannessen, Runa
The thesis is concerned with spatial practices of resistance employed in Palestinian struggles against Israel’s violent dispossession of Palestinian land through half a century of occupation. In the political configuration of the built space of the West Bank, architecture appears as a tactically...... deployed weapon of territorial control and a dialectical resistance to displacement. Standing in the position of being both a means to achieve an objective and the objective in itself, the elementary gestures of architecture —to control and inhabit a place —are employed in a conflict that concerns......, fundamentally, who has the right to a future in this land. By viewing architecture in its dual dimension of praxis and object, built structures are investigated as agents that induce and manifest territorial struggles. The spatial instrumentalisation of architecture is effected by Israel through commonplace...
Space weather and space anomalies
Directory of Open Access Journals (Sweden)
L. I. Dorman
2005-11-01
Full Text Available A large database of anomalies, registered by 220 satellites in different orbits over the period 1971-1994 has been compiled. For the first time, data from 49 Russian Kosmos satellites have been included in a statistical analysis. The database also contains a large set of daily and hourly space weather parameters. A series of statistical analyses made it possible to quantify, for different satellite orbits, space weather conditions on the days characterized by anomaly occurrences. In particular, very intense fluxes (>1000 pfu at energy >10 MeV of solar protons are linked to anomalies registered by satellites in high-altitude (>15000 km, near-polar (inclination >55° orbits typical for navigation satellites, such as those used in the GPS network, NAVSTAR, etc. (the rate of anomalies increases by a factor ~20, and to a much smaller extent to anomalies in geostationary orbits, (they increase by a factor ~4. Direct and indirect connections between anomaly occurrence and geomagnetic perturbations are also discussed.
AdS/QCD and Light Front Holography: A New Approximation to QCD
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J.; de Teramond, Guy
2010-02-15
The combination of Anti-de Sitter space (AdS) methods with light-front holography leads to a semi-classical first approximation to the spectrum and wavefunctions of meson and baryon light-quark bound states. Starting from the bound-state Hamiltonian equation of motion in QCD, we derive relativistic light-front wave equations in terms of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. These equations of motion in physical space-time are equivalent to the equations of motion which describe the propagation of spin-J modes in anti-de Sitter (AdS) space. Its eigenvalues give the hadronic spectrum, and its eigenmodes represent the probability distribution of the hadronic constituents at a given scale. Applications to the light meson and baryon spectra are presented. The predicted meson spectrum has a string-theory Regge form M{sup 2} = 4{kappa}{sup 2}(n+L+S/2); i.e., the square of the eigenmass is linear in both L and n, where n counts the number of nodes of the wavefunction in the radial variable {zeta}. The space-like pion form factor is also well reproduced. One thus obtains a remarkable connection between the description of hadronic modes in AdS space and the Hamiltonian formulation of QCD in physical space-time quantized on the light-front at fixed light-front time {tau}. The model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method in order to systematically include the QCD interaction terms.
Space Science in Action: Space Exploration [Videotape].
1999
In this videotape recording, students learn about the human quest to discover what is out in space. Students see the challenges and benefits of space exploration including the development of rocket science, a look back at the space race, and a history of manned space travel. A special section on the Saturn V rocket gives students insight into the…
Sachs, Ivo; Solodukhin, Sergey N.
2001-12-01
A holographic correspondence between horizon data and space-time physics is investigated. We find similarities with the AdS-CFT correspondence, based on the observation that the optical metric near the horizon describes a Euclidean, asymptotically anti-de Sitter space. This picture emerges for a wide class of static space-times with a nondegenerate horizon, including Schwarzschild black holes as well as de Sitter space-time. We reveal an asymptotic conformal symmetry at the horizon. We compute the conformal weights and 2-point functions for a scalar perturbation and discuss possible connections with a conformal field theory located on the horizon. We then reconstruct the scalar field and the metric from the data given on the horizon. We show that the solution for the metric in the bulk is completely determined in terms of a specified metric on the horizon. From the general relativity point of view our solutions present a new class of space-time metrics with nonspherical horizons. The horizon entropy associated with these solutions is also discussed.
Curved twistor spaces and H-space
International Nuclear Information System (INIS)
Tod, K.P.
1980-01-01
The curved twistor space construction of Penrose for anti-self-dual solutions to the Einstein vacuum equations is described. Curved twistor spaces are defined and it is shown with the aid of an example how to obtain them by deforming the complex structure of regions of flat twistor space. The connection of this procedure with Newman's H-space construction via asymptotic twistor space is outlined. (Auth.)
Ozturk, Taha Yasin; Bayramov, Sadi
2014-01-01
Various soft topologies are being introduced on a given function space soft topological spaces. In this paper, soft compact-open topology is defined in functional spaces of soft topological spaces. Further, these functional spaces are studied and interrelations between various functional spaces with soft compact-open topology are established.
Shortcuts in cosmological branes
Abdalla, Elcio; Casali, Adenauer G.; Cuadros-Melgar, Bertha
2004-02-01
We consider a dynamical membrane world in a space-time with scalar bulk matter described by domain walls, as well as a dynamical membrane world in empty Anti de Sitter space-time. Using the solutions to Einstein equations and boundary conditions we investigate the possibility of having shortcuts for gravitons leaving the membrane and returning subsequently. In comparison with photons following a geodesic inside the brane we verify that shortcuts exist. For some Universes they are small, but sometimes are quite effective. In the case of matter branes, we argue that at times just before nucleosynthesis the effect is sufficiently large to provide corrections to the inflationary scenario, especially as concerning the horizon problem. This work has been supported by Fundca~o de Amparo à Pesquisa do Estado de Sa~o Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil.
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S
2003-10-24
The effective QCD charge extracted from {tau} decay is remarkably constant at small momenta, implying the near-conformal behavior of hadronic interactions at small momentum transfer. The correspondence of large-N{sub c} supergravity theory in higher-dimensional anti-de Sitter spaces with gauge theory in physical space-time also has interesting implications for hadron phenomenology in the conformal limit, such as constituent counting rules for hard exclusive processes. The utility of light-front quantization and lightfront Fock wavefunctions for analyzing such phenomena and representing the dynamics of QCD bound states is reviewed. I also discuss the novel effects of initial- and final-state interactions in hard QCD inclusive processes, including Bjorken-scaling single-spin asymmetries and the leading-twist diffractive and shadowing contributions to deep inelastic lepton-proton scattering.
Geometric actions for three-dimensional gravity
Barnich, G.; González, H. A.; Salgado-Rebolledo, P.
2018-01-01
The solution space of three-dimensional asymptotically anti-de Sitter or flat Einstein gravity is given by the coadjoint representation of two copies of the Virasoro group in the former and the centrally extended BMS3 group in the latter case. Dynamical actions that control these solution spaces are usually constructed by starting from the Chern–Simons formulation and imposing all boundary conditions. In this note, an alternative route is followed. We study in detail how to derive these actions from a group-theoretical viewpoint by constructing geometric actions for each of the coadjoint orbits, including the appropriate Hamiltonians. We briefly sketch relevant generalizations and potential applications beyond three-dimensional gravity.
Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena
DEFF Research Database (Denmark)
Brodsky, S. J.; de Teramond, G. F.
2012-01-01
-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryons. The model predicts a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number n. The hadron eigensolutions......Light-front holography is one of the most remarkable features of the AdS/CFT correspondence. In spite of its present limitations, it provides important physical insights into the non-perturbative regime of QCD and its transition to the perturbative domain. This novel framework allows hadronic...... amplitudes in a higher dimensional anti-de Sitter (AdS) space to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The model leads to an effective confining light-front QCD Hamiltonian and a single-variable light-front Schrodinger equation which determines...
Threefold Complementary Approach to Holographic QCD
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); de Teramond, Guy F. [Univ. of Costa Rica, San Jose (Costa Rica); Dosch, Hans Gunter [Inst. for Theoretical Physics, Heidelberg (Germany)
2013-12-27
A complementary approach, derived from (a) higher-dimensional anti-de Sitter (AdS) space, (b) light-front quantization and (c) the invariance properties of the full conformal group in one dimension leads to a nonperturbative relativistic light-front wave equation which incorporates essential spectroscopic and dynamical features of hadron physics. The fundamental conformal symmetry of the classical QCD Lagrangian in the limit of massless quarks is encoded in the resulting effective theory. The mass scale for confinement emerges from the isomorphism between the conformal group andSO(2,1). This scale appears in the light-front Hamiltonian by mapping to the evolution operator in the formalism of de Alfaro, Fubini and Furlan, which retains the conformal invariance of the action. Remarkably, the specific form of the confinement interaction and the corresponding modification of AdS space are uniquely determined in this procedure.
A defect in holographic interpretations of tensor networks
Energy Technology Data Exchange (ETDEWEB)
Czech, Bartłomiej [Institute for Advanced Study,Princeton, NJ 08540 (United States); Nguyen, Phuc H.; Swaminathan, Sivaramakrishnan [Theory Group, Department of Physics and Texas Cosmology Center,The University of Texas at Austin,Austin, TX 78712 (United States)
2017-03-16
We initiate the study of how tensor networks reproduce properties of static holographic space-times, which are not locally pure anti-de Sitter. We consider geometries that are holographically dual to ground states of defect, interface and boundary CFTs and compare them to the structure of the requisite MERA networks predicted by the theory of minimal updates. When the CFT is deformed, certain tensors require updating. On the other hand, even identical tensors can contribute differently to estimates of entanglement entropies. We interpret these facts holographically by associating tensor updates to turning on non-normalizable modes in the bulk. In passing, we also clarify and complement existing arguments in support of the theory of minimal updates, propose a novel ansatz called rayed MERA that applies to a class of generalized interface CFTs, and analyze the kinematic spaces of the thin wall and AdS{sub 3}-Janus geometries.
Throat quantization of the Schwarzschild–Tangherlini(-AdS) black hole
International Nuclear Information System (INIS)
Kunstatter, Gabor; Maeda, Hideki
2014-01-01
Adopting the throat quantization pioneered by Louko and Mäkelä, we derive the mass and area spectra for the Schwarzschild–Tangherlini black hole and its anti-de Sitter (AdS) generalization in arbitrary dimensions. We find that the system can be quantized exactly in three special cases: the three-dimensional BTZ black hole, toroidal black holes in any dimension, and five-dimensional Schwarzshild–Tangherlini(-AdS) black holes. For the remaining cases the spectra are obtained for large mass using the WKB approximation. For asymptotically flat black holes, the area/entropy has an equally spaced spectrum, as expected from previous work. In the asymptotically AdS case on the other hand, it is the mass spectrum that is equally spaced. Our exact results for the BTZ black hole mass with Dirichlet boundary conditions are consistent with the spectra of the corresponding operators in the dual CFT. (paper)