Labyrinthus creditorum concurrentium ad litem per debitorem communem inter illos causatum
Salgado de Somoza, Francisco
2013-01-01
2 v. ([26], 540, [2]; 322, [88]; 112, [28]; 48, [10] p. ) ; Fol. maior [Editio novissima Antuerpiensi, Veneta, & Francofurtensi, multoÌ auctior & emendatior, cui accesserunt Decisionum S.R.R. centuriae duae ad materiam ejusdem tractatus collectae, prior aÌ ... Andrea Censalio ... posterior veroÌ aÌ D. Nicolao Antonio …] Exemp. falto de port. no T. I Ed. probable de 1672 Data tomada da licencia Ex-Libris ms. : Soy del Licdo. Dn. Angel Vázquez Cao. Ils. e capitulares xil. P...
2001-01-01
20. mai. Segakoor Ad Libitum laulis Niguliste Muuseum-kontserdisaalis. Dirigendid Alice Pehk ja Kaie Viigipuu. Kaastegev Tiit Kiik (orel). Esitati koorimuusikat renessansist tänapäevani ning prantsuse orelimuusikat : [täistekst
Powers, Shelley
2007-01-01
Ajax can bring many advantages to an existing web application without forcing you to redo the whole thing. This book explains how you can add Ajax to enhance, rather than replace, the way your application works. For instance, if you have a traditional web application based on submitting a form to update a table, you can enhance it by adding the capability to update the table with changes to the form fields, without actually having to submit the form. That's just one example.Adding Ajax is for those of you more interested in extending existing applications than in creating Rich Internet Applica
de Boer, J.
2000-01-01
In these notes we discuss various aspects of string theory in AdS spaces. We briefly review the formulation in terms of Green-Schwarz, NSR, and Berkovits variables, as well as the construction of exact conformal field theories with AdS backgrounds. Based on lectures given at the Kyoto YITP Workshop
Online Ad Assignment with an Ad Exchange
Dvořák, Wolfgang; Henzinger, Monika
2016-01-01
Ad exchanges are becoming an increasingly popular way to sell advertisement slots on the internet. An ad exchange is basically a spot market for ad impressions. A publisher who has already signed contracts reserving advertisement impressions on his pages can choose between assigning a new ad impression for a new page view to a contracted advertiser or to sell it at an ad exchange. This leads to an online revenue maximization problem for the publisher. Given a new impression to sell decide whe...
Callebaut, Nele; Samberg, Andreas; Toldo, Chiara
2015-01-01
We study segmented strings in flat space and in $AdS_3$. In flat space, these well known classical motions describe strings which at any instant of time are piecewise linear. In $AdS_3$, the worldsheet is composed of faces each of which is a region bounded by null geodesics in an $AdS_2$ subspace of $AdS_3$. The time evolution can be described by specifying the null geodesic motion of kinks in the string at which two segments are joined. The outcome of collisions of kinks on the worldsheet can be worked out essentially using considerations of causality. We study several examples of closed segmented strings in $AdS_3$ and find an unexpected quasi-periodic behavior. We also work out a WKB analysis of quantum states of yo-yo strings in $AdS_3$ and find a logarithmic term reminiscent of the logarithmic twist of string states on the leading Regge trajectory.
Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.
2016-06-01
We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.
Costa, Miguel S.; Oliveira, Miguel; Penedones, João; Santos, Jorge E.
2016-01-01
We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global $AdS_{4}$ with conformal boundary $S^{2}\\times\\mathbb{R}_{t}$. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic $AdS$ behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an $AdS$ soliton that includes the full backreaction of the electric field on the $AdS$ geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both $AdS$ soliton and black hole phases. The corresponding phase diagram generalizes the Hawkin...
Constructing Lifshitz solutions from AdS
Cassani, Davide
2011-01-01
Under general assumptions, we show that a gravitational theory in d+1 dimensions admitting an AdS solution can be reduced to a d-dimensional theory containing a Lifshitz solution with dynamical exponent z=2. Working in a d=4, N=2 supergravity setup, we prove that if the AdS background is N=2 supersymmetric, then the Lifshitz geometry preserves 1/4 of the supercharges, and we construct the corresponding Killing spinors. We illustrate these results in examples from supersymmetric consistent truncations of type IIB supergravity, enhancing the class of known 4-dimensional Lifshitz solutions of string theory. As a byproduct, we find a new AdS4 x S1 x T(1,1) solution of type IIB.
Institute of Scientific and Technical Information of China (English)
王海涛
2005-01-01
首先介绍了Ad Hoc网络的基本概念、技术特点以及关键技术等,然后较为全面地归纳了Ad Hoc网络的典型应用,最后讨论了Ad Hoc网络的发展趋势和有待解决的问题.
AdS orbifolds and Penrose limits
Energy Technology Data Exchange (ETDEWEB)
Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu
2002-12-09
In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.
Superradiant instability in AdS
Ganchev, Bogdan
2016-01-01
The phenomenon of superradiance in the context of asymptotically global AdS spacetimes is investigated with particular accent on its effect on the stability of the systems under consideration. To this end, the concept of an asymptotically AdS spacetime is explained, together with its implications on the boundary conditions at $\\mathcal{I}$, as well as the Newman-Penrose-Teukolsky formalism, whereby the Teukolsky master equation in a most general form for Kerr-AdS is given. Furthermore, work done in the cases of RN-AdS and Kerr-AdS is laid out in a concise manner, putting emphasis on the important steps taken in determining the endpoint of the superradiant instability in the two configurations. For the former this turns out to be a black hole with reduced charge and a static charged scalar condensate around it, whereas for the latter two of the more probable outcomes are presented, both of which imply a violation of one of the cosmic censorships.
Lorentzian AdS, Wormholes and Holography
Arias, Raul E; Silva, Guillermo A
2011-01-01
We investigate the structure of two point functions for the QFT dual to an asymptotically Lorentzian AdS-wormhole. The bulk geometry is a solution of 5-dimensional second order Einstein Gauss Bonnet gravity and causally connects two asymptotically AdS space times. We revisit the GKPW prescription for computing two-point correlation functions for dual QFT operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values phi_0^\\pm at each of the two asymptotic AdS regions, along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O^\\pm and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom leaving at each boundary. The AdS_(1+1) geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a ...
Buchel, Alex; Lehner, Luis
2013-01-01
We construct boson stars in global Anti de Sitter (AdS) space and study their stability. Linear perturbation results suggest that the ground state along with the first three excited state boson stars are stable. We evolve some of these solutions and study their nonlinear stability in light of recent work \\cite{Bizon:2011gg} arguing that a weakly turbulent instability drives scalar perturbations of AdS to black hole formation. However evolutions suggest that boson stars are nonlinearly stable and immune to the instability for sufficiently small perturbation. Furthermore, these studies find other families of initial data which similarly avoid the instability for sufficiently weak parameters. Heuristically, we argue that initial data families with widely distributed mass-energy distort the spacetime sufficiently to oppose the coherent amplification favored by the instability. From the dual CFT perspective our findings suggest that there exist families of rather generic initial conditions in strongly coupled CFT ...
AdS solutions through transgression
Energy Technology Data Exchange (ETDEWEB)
Donos, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Gauntlett, J.P. [Imperial College, London (United Kingdom). Blackett Lab.]|[Imperial College, London (United Kingdom). The Institute for Mathematical Sciences; Kim, Nakwoo [Kyung Hee Univ., Seoul (Korea). Dept. of Physics and Research Inst. of Basic Science
2008-07-15
We present new classes of explicit supersymmetric AdS{sub 3} solutions of type IIB supergravity with non-vanishing five-form flux and AdS{sub 2} solutions of D=11 supergravity with electric four-form flux. The former are dual to two-dimensional SCFTs with (0,2) supersymmetry and the latter to supersymmetric quantum mechanics with two supercharges. We also investigate more general classes of AdS{sub 3} solutions of type IIB supergravity and AdS{sub 2} solutions of D=11 supergravity which in addition have non-vanishing three-form flux and magnetic four-form flux, respectively. The construction of these more general solutions makes essential use of the Chern-Simons or ''transgression'' terms in the Bianchi identity or the equation of motion of the field strengths in the supergravity theories. We construct infinite new classes of explicit examples and for some of the type IIB solutions determine the central charge of the dual SCFTs. The type IIB solutions with non-vanishing three-form flux that we construct include a two-torus, and after two T-dualities and an S-duality, we obtain new AdS3 solutions with only the NS fields being non-trivial. (orig.)
Refined Holographic Entanglement Entropy for the AdS Solitons and AdS black Holes
Ishihara, Masafumi; Ning, Bo
2012-01-01
We consider the refinement of the holographic entanglement entropy on a disk region for the holographic dual theories to the AdS solitons and AdS black holes, including the corrected ones by the Gauss-Bonnet term. The AdS soliton is dual to a gapped system with an IR fixed-point. The refinement is obtained by extracting the UV-independent piece of the holographic entanglement entropy. We then study the renormalization group (RG) flow of the refinement by tuning the linear size of the chosen disk region. Our main results are (i) the RG flow of the refinement decreases monotonically for most of the cases; (ii) there is no topological entanglement entropy for AdS$_5$ soliton even with Gauss-Bonnet correction; (iii) for the AdS black holes, the refinement obeys the volume law at IR regime, and the transition between UV and IR regimes is a smooth crossover; however, the crossover will turn into phase transition by the Gauss-Bonnet correction; (iv) for the AdS solitons, there are discontinuous phase transitions bet...
DEFF Research Database (Denmark)
Liu, Yawu; Mattila, Jussi; Ruiz, Miguel �ngel Mu�oz
2013-01-01
To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool) and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA) on MRI...
Hertog, Thomas
2004-12-01
We review some properties of N=8 gauged supergravity in four dimensions with modified, but AdS invariant boundary conditions on the m2 = -2 scalars. There is a one-parameter class of asymptotic conditions on these fields and the metric components, for which the full AdS symmetry group is preserved. The generators of the asymptotic symmetries are finite, but acquire a contribution from the scalar fields. For a large class of such boundary conditions, we find there exist black holes with scalar hair that are specified by a single conserved charge. Since Schwarschild-AdS is a solution too for all boundary conditions, this provides an example of black hole non-uniqueness. We also show there exist solutions where smooth initial data evolve to a big crunch singularity. This opens up the possibility of using the dual conformal field theory to obtain a fully quantum description of the cosmological singularity, and we report on a preliminary study of this.
Adding more value to added-value
DEFF Research Database (Denmark)
Marian, Livia
regulation. The results of a qualitative concept test reveal positive attitudes towards the proposed production process. The discussions about fewer standards being sufficient or about options “in-between” conventional and organic standards indicate that the difference in production processes is noticed, yet...... it is probably valued less than expected. The added attributes need to be thoroughly considered when developing and marketing “organic plus” products, as their effect on other product characteristics (e.g. high prices) can detract from their added value....
Probing crunching AdS cosmologies
Kumar, S. Prem; Vaganov, Vladislav
2016-02-01
Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of {N}=8 supergravity on AdS4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor ã max. Radial geodesics connecting antipodal points necessarily have de Sitter energy Ɛ ≲ ã max, while geodesics with Ɛ > ã max terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved "outward" in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green's function has a branch point determined by ã max which corresponds to the lowest quasinormal frequency.
Directory of Open Access Journals (Sweden)
Palma Peña-Jiménez, Ph.D.
2011-01-01
Full Text Available During election campaigns the political spot has a clear objective: to win votes. This message is communicated to the electorate through television and Internet, and usually presents a negative approach, which includes a direct critical message against the opponent, rather than an exposition of proposals. This article is focused on the analysis of the campaign attack video ad purposely created to encourage the disapproval of the political opponent among voters. These ads focus on discrediting the opponent, many times, through the transmission of ad hominem messages, instead of disseminating the potential of the political party and the virtues and manifesto of its candidate. The article reviews the development of the attack ad since its first appearance, which in Spain dates back to 1996, when the famous Doberman ad was broadcast, and examines the most memorable campaign attack ads.
Probing crunching AdS cosmologies
Kumar, S Prem
2015-01-01
Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of N=8 supergravity on AdS_4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor a_{max} . Radial geodesics connecting antipodal points necessarily have de Sitter energy E \\leq a_{max}, while geodesics with E > a_{max} terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved "outw...
Holography of AdS vacuum bubbles
Energy Technology Data Exchange (ETDEWEB)
Barbon, J.L.F. [Instituto de Fisica Teorica IFT UAM/CSIC, Cantoblanco, Madrid 28049 (Spain); Rabinovici, E. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)
2011-07-15
We consider the fate of AdS vacua connected by tunneling events. A precise holographic dual of thin-walled Coleman-de Luccia bounces is proposed in terms of Fubini instantons in an unstable CFT. This proposal is backed by several qualitative and quantitative checks, including the precise calculation of the instanton action appearing in evaluating the decay rate. Big crunches manifest themselves as time dependent processes which reach the boundary of field space in a finite time. The infinite energy difference involved is identified on the boundary and highlights the ill-defined nature of the bulk setup. We propose a qualitative scenario in which the crunch is resolved by stabilizing the CFT, so that all attempts at crunching always end up shielded from the boundary by the formation of black hole horizons. In all these well defined bulk processes the configurations have the same asymptotics and are finite energy excitations.
Adamo, Tim; Williams, Jack
2016-01-01
We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS$_5$ 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.
Cvetič, Mirjam; Papadimitriou, Ioannis
2016-12-01
We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger [1], in agreement with the results of Castro and Song [2]. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS2 × S 2 or conformally AdS2 × S 2 solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton solutions coincide with the so called `subtracted geometries', while those obtained
DEFF Research Database (Denmark)
Kaspersen, Peter
2007-01-01
På grundlag af evalueringer og forskning i gymnasiereformen 2005 foreslås det at skille problemerne ad i forskellige niveauer. Herved kan der arbejdes med niveaudelte løsninger.......På grundlag af evalueringer og forskning i gymnasiereformen 2005 foreslås det at skille problemerne ad i forskellige niveauer. Herved kan der arbejdes med niveaudelte løsninger....
Probing crunching AdS cosmologies
Energy Technology Data Exchange (ETDEWEB)
Kumar, S. Prem; Vaganov, Vladislav [Department of Physics, Swansea University,Singleton Park, Swansea SA2 8PP (United Kingdom)
2016-02-03
Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of N=8 supergravity on AdS{sub 4}, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor ã{sub max}. Radial geodesics connecting antipodal points necessarily have de Sitter energy E≲ã{sub max}, while geodesics with E>ã{sub max} terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved “outward” in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green’s function has a branch point determined by ã{sub max} which corresponds to the lowest quasinormal frequency.
John Wiley & Sons
2004-01-01
"Assimilating the most up-to-date information on research and development activities in this rapidly growing area, Mobile Ad Hoc Networking covers physical, data link, network, and transport layers, as well as application, security, simulation, and power management issues in sensor, local area, personal, and mobile ad hoc networks. Each of the book's sixteen chapters has been written by a top expert and discusses in-depth the most important topics in the field. Mobile Ad Hoc Networking is an excellent reference and guide for professionals seeking an in-depth examination of topics that also provides a comprehensive overview of the current state-of-the-art."--Jacket.
Laurent Guiraud
1998-01-01
When the Low-Energy Antiproton Ring (LEAR) was stopped in 1996, because of its costly operation, a cheaper way of continuing low-energy antiproton physics was sought. The Antiproton-Collector (AC), added in 1987 to the Antiproton Accumulator (AA) to provide a tenfold intensity increase, was converted into the Antiproton-Decelerator (AD). Antiprotons from the target at 3.5 GeV/c are decelerated to 100 MeV/c, and fast-ejected to the experiments. Major changes were necessary. Above all, the conversion from a constant-field machine to one with a magnetic cycle, modulating the field by an impressive factor 35. New systems for stochastic and electron cooling had to be added. Beam diagnostics at an intensity of only 2E7 antiprotons was a challenge. In 2000, the AD began delivery of antiprotons to the experiments.
DEFF Research Database (Denmark)
Jensen, Per Anker; Katchamart, Akarapong
2011-01-01
Purpose: To investigate how Facilities Management (FM) can add value and develop a management concept that can assist facilities managers in implementing value adding strategies and practices. Theory: The study is based on the management model for FM included in the European FM standards, recent...... theories on added value of FM and real estate and the related concept of Value Management from building projects. The study is related to the EuroFM research group on The Added Value of FM. Design/methodology/approach: The study outlines a preliminary theoretical based management concept, which...... is investigated, tested and discussed based on a case study of an international corporation. Findings: The study shows that the management model for FM creates a relevant starting point but also that stakeholder and relationship management is an essential aspect of Value Adding Management. The case study confirms...
Bena, Iosif; Puhm, Andrea
2015-01-01
It was argued in arXiv:1203.4227 that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically-AdS_3 x S^3/Z_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.
Rashvand, Habib
2013-01-01
Motivated by the exciting new application paradigm of using amalgamated technologies of the Internet and wireless, the next generation communication networks (also called 'ubiquitous', 'complex' and 'unstructured' networking) are changing the way we develop and apply our future systems and services at home and on local, national and global scales. Whatever the interconnection - a WiMAX enabled networked mobile vehicle, MEMS or nanotechnology enabled distributed sensor systems, Vehicular Ad hoc Networking (VANET) or Mobile Ad hoc Networking (MANET) - all can be classified under new networking s
Israel, D
2005-01-01
We study the exact construction of D-branes in Lorentzian AdS(3). We start by defining a family of conformal field theories that gives a natural Euclidean version of the SL(2,R) CFT and does not correspond to H(3)+, the analytic continuation of AdS(3). We argue that one can recuperate the exact CFT results of Lorentzian AdS(3), upon an analytic continuation in the moduli space of these conformal field theories. Then we construct exact boundary states for various symmetric and symmetry-breaking D-branes in AdS(3).
Localization on $AdS_2\\times S^1$
David, Justin R; Gupta, Rajesh Kumar; Narain, Kumar
2016-01-01
Conformal symmetry relates the metric on $AdS_2 \\times S^{1}$ to that of $S^3$. This implies that under a suitable choice of boundary conditions for fields on $AdS_2$ the partition function of conformal field theories on these spaces must agree which makes $AdS_2 \\times S^{1}$ a good testing ground to study localization on non-compact spaces. We study supersymmetry on $AdS_2\\times S^1$ and determine the localizing Lagrangian for ${\\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2\\times S^1$. We evaluate the partition function of ${\\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2 \\times S^1$ using localization, where the radius of $S^1$ is $q$ times that of $AdS_2$. With boundary conditions on $AdS_2\\times S^1$ which ensure that all the physical fields are normalizable and lie in the space of square integrable wave functions in $AdS_2$, the result for the partition function precisely agrees with that of the theory on the $q$-fold covering of $S^3$.
Directory of Open Access Journals (Sweden)
Wulan Roro Retno
2017-01-01
Full Text Available Cosmetics industry created the beauty myth for women through advertising. A cosmetic ad in Indonesia has spread a new concept of white skin: East Asia beauty myth. The white concept of Asia white skin basically derived from colonial legacy. The purpose of the research was analyzing the beauty myth in Indonesia ads using postcolonial perspective. The principal result brought the discourse analysis and postcolonial perspective a new insight in communication research. Particularly on media and cultural studies. Major conclusions showed that the beauty myth since the Dutch colonial period never been change. The main concept is always in colonialism’s idea: “white is better”. The West is better than the East.
Shelah, Saharon
2011-01-01
We address the following question: Can we expand an NIP theory by adding a linear order such that the expansion is still NIP? Easily, if acl(A)=A for all A, then this is true. Otherwise, we give counterexamples. More precisely, there is a totally categorical theory for which every expansion by a linear order has IP. There is also an \\omega-stable NDOP theory for which every expansion by a linear order interprets bounded arithmetic.
AdS 3-manifolds and Higgs bundles
DEFF Research Database (Denmark)
Alessandrini, Daniele; Li, Qiongling
2015-01-01
In this paper we investigate the relationships between closed AdS 3-manifolds and Higgs bundles. We have a new way to construct AdS structures that allows us to see many of their properties explicitly, for example we can recover the very recent formula by Tholozan for the volumes. We also find...
Pathologies in Lovelock AdS Black Branes and AdS/CFT
Takahashi, Tomohiro
2011-01-01
We study the pathologies in AdS black branes in Lovelock theory. More precisely, we examine the conditions that AdS black branes have the naked singularity, the ghost instability and the dynamical instability. From the point of view of the AdS/CFT correspondence, the pathologies in AdS black branes indicate the pathologies in the corresponding CFT. Hence, we need to be careful when we apply AdS/CFT in Lovelock theory to various phenomena such as the shear viscosity to entropy ratio in strongly coupled quantum filed theory.
Institute of Scientific and Technical Information of China (English)
李小艳
2010-01-01
There is the trend that now people appreciate those who are slim and regard slim even thin people beautiful. The thinner a person is, the more beautiful. Women, born to pursuit beauty, try various means to follow the trend. We all watch TV, and find a lot of advertisements on diet. The effect of them is tremendous. We all know the fact that it is not at all the better mouse trap will catch mouse. The sales methods are more important. If an advertisement is very interesting and seemingly effective, people will be lured by the ad and then try some of the products.
DEFF Research Database (Denmark)
2014-01-01
The article asks whether it is not the responsibility of corporations to address the issue of women being underrepresented in Danish management jobs. In other words, it is argued that corporations should be encouraged to engage more actively in the recruitment of both men and women for management...... that this agreement reflects a high degree of conservatism in the system where men enjoy a considerable advantage and where procedures that ensure male dominance are perpetuated even in the linguistic and discursive construction of job ads....
DEFF Research Database (Denmark)
Hillersdal, Line
ask what make up food stuff and eaters in the meal tests? More specifically I explore a scientific testing of changes in taste preferences before and after weight-loss surgery using an ad libitum buffet with a selection of different foods and another testing the effect of exercise on appetite also...... an eater who: ”shouldn't restrain herself”. Practices of food and eating in the test meal I suggest, will allow us to tackle reductionism by showing the complex cultural context shaping clinical intervention....
Rudolfs Bems; Robert C. Johnson
2012-01-01
This paper updates the conceptual foundations for measuring real effective exchange rates (REERs) to allow for vertical specialization in trade. We derive a value-added REER describing how demand for the value added that a country produces changes as the price of its value added changes relative to competitors. We then compute this index for 42 countries from 1970-2009 using trade measured in value added terms and GDP deflators. There are substantial differences between value-added and conven...
An $xp$ model on $AdS_2$ spacetime
Molina-Vilaplana, Javier
2013-01-01
In this paper we formulate the $xp$ model on the AdS$_2$ spacetime. We find that the spectrum of the Hamiltonian has positive and negative eigenvalues, equal in magnitude, given by a harmonic oscillator with a zero point energy parameterized by the AdS radius, measured in units of a fundamental length of the model. We also construct the generators of the isometry group SO(2,1) of the AdS$_2$ spacetime, and discuss the relation with conformal quantum mechanics.
Directory of Open Access Journals (Sweden)
Hong-Chuan Yang
2007-01-01
Full Text Available We study the energy-efficient configuration of multihop paths with automatic repeat request (ARQ mechanism in wireless ad hoc networks. We adopt a cross-layer design approach and take both the quality of each radio hop and the battery capacity of each transmitting node into consideration. Under certain constraints on the maximum tolerable transmission delay and the required packet delivery ratio, we solve optimization problems to jointly schedule the transmitting power of each transmitting node and the retransmission limit over each hop. Numerical results demonstrate that the path configuration methods can either significantly reduce the average energy consumption per packet delivery or considerably extend the average lifetime of the multihop route.
Borsato, Riccardo; Sfondrini, Alessandro; Stefanski, Bogdan; Torrielli, Alessandro
2013-01-01
We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3 x S3 x T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly-coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their sub-leading order and compare it with recent one-loop perturbative results, and co
Borsato, Riccardo; Ohlsson Sax, Olof; Sfondrini, Alessandro; Stefański, Bogdan, Jr.; Torrielli, Alessandro
2013-09-01
We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3×S3×T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their subleading order and compare it with recent one-loop perturbative results and comment on their weak-coupling expansion.
Quantum Field Theory and Unification in AdS5
Randall, Lisa; Randall, Lisa; Schwartz, Matthew D.
2001-01-01
We consider gauge bosons in the bulk of AdS5 in a two-brane theory that addresses the hierarchy problem. We show such a theory can be consistent with gauge coupling unification at a high scale. We discuss subtleties in this calculation and show how to regulate consistently in a bounded AdS5 background. Our regularization is guided by the holographic dual of the calculation.
Chaos and hydrodynamics near AdS$_2$
Jensen, Kristan
2016-01-01
We revisit AdS$_2$ holography with the Sachdev-Ye-Kitaev models in mind. Our main result is to rewrite a generic theory of gravity near an AdS$_2$ throat as a novel hydrodynamics coupled to the correlation functions of a conformal quantum mechanics. This gives a prescription for the computation of $n$-point functions in the dual quantum mechanics. We thereby find that the dual is maximally chaotic.
Supersymmetry of AdS and flat IIB backgrounds
Beck, S.; Gutowski, J.; Papadopoulos, G.
2015-02-01
We present a systematic description of all warped AdS n × w M 10- n and IIB backgrounds and identify the a priori number of supersymmetries N preserved by these solutions. In particular, we find that the AdS n backgrounds preserve for n ≤ 4 and for 4 < n ≤ 6 supersymmetries and for suitably restricted. In addition under some assumptions required for the applicability of the maximum principle, we demonstrate that the Killing spinors of AdS n backgrounds can be identified with the zero modes of Dirac-like operators on M 10- n establishing a new class of Lichnerowicz type theorems. Furthermore, we adapt some of these results to backgrounds with fluxes by taking the AdS radius to infinity. We find that these backgrounds preserve for 2 < n ≤ 4 and for 4 < n ≤ 7 supersymmetries. We also demonstrate that the Killing spinors of AdS n × w M 10- n do not factorize into Killing spinors on AdS n and Killing spinors on M 10- n .
Directory of Open Access Journals (Sweden)
Blanca Alicia Correa
2007-01-01
Full Text Available Los métodos de agrupamiento permiten que las MANET (redes móviles ad hoc presenten un mejor desempeño en cuanto a la rapidez de conexión, el enrutamiento y el manejo de la topología. En este trabajo se presenta una revisión sobre las técnicas de agrupamiento para MANET. Se introducen algunos temas preliminares que forman la base para el desarrollo de los algoritmos de agrupamiento, tales como: la topología de la red, el enrutamiento, la teoría de grafos y los algoritmos de movilidad. Adicionalmente, se describen algunas de las técnicas de agrupamiento más conocidas como Lowest-ID heuristic, Highest degree heuristic, DMAC (distributed mobility-adaptive clustering, WCA (weighted clustering algorithm, entre otros. El propósito central es ilustrar los conceptos principales respecto a las técnicas de agrupamiento en MANET.
Action growth for AdS black holes
Cai, Rong-Gen; Ruan, Shan-Ming; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui
2016-09-01
Recently a Complexity-Action (CA) duality conjecture has been proposed, which relates the quantum complexity of a holographic boundary state to the action of a Wheeler-DeWitt (WDW) patch in the anti-de Sitter (AdS) bulk. In this paper we further investigate the duality conjecture for stationary AdS black holes and derive some exact results for the growth rate of action within the Wheeler-DeWitt (WDW) patch at late time approximation, which is supposed to be dual to the growth rate of quantum complexity of holographic state. Based on the results from the general D-dimensional Reissner-Nordström (RN)-AdS black hole, rotating/charged Bañados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a universal formula for the action growth expressed in terms of some thermodynamical quantities associated with the outer and inner horizons of the AdS black holes. And we leave the conjecture unchanged that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.
AdS_5 Black Holes with Fermionic Hair
Burrington, B A; Sabra, W A; Burrington, Benjamin A.; Liu, James T.
2004-01-01
The study of new BPS objects in AdS_5 has led to a deeper understanding of AdS/CFT. To help complete this picture, and to fully explore the consequences of the supersymmetry algebra, it is also important to obtain new solutions with bulk fermions turned on. In this paper we construct superpartners of the 1/2 BPS black hole in AdS_5 using a natural set of fermion zero modes. We demonstrate that these superpartners, carrying fermionic hair, have conserved charges differing from the original bosonic counterpart. To do so, we find the R-charge and dipole moment of the new system, as well as the mass and angular momentum, defined through the boundary stress tensor. The complete set of superpartners fits nicely into a chiral representation of AdS_5 supersymmetry, and the spinning solutions have the expected gyromagnetic ratio, g=1.
Complexity Growth for AdS Black Holes
Cai, Rong-Gen; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui
2016-01-01
We further investigate the Complexity-Action (CA) duality conjecture for stationary anti de-Sitter (AdS) black holes and derive some exact results for the growth rate of action within Wheeler-DeWitt (WDW) patch at late time approximation, which is dual to the growth rate of quantum complexity of holographic state. Based on the results from the general $D$-dimensional Reissner-Nordstr\\"{o}m (RN)-AdS black hole, rotating/charged Ba\\~{n}ados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a new complexity bound but leave unchanged the conjecture that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.
Constructing the AdS dual of a Fermi liquid: AdS Black holes with Dirac hair
\\vCubrović, Mihailo; Schalm, Koenraad
2010-01-01
We provide new evidence that the holographic dual to a strongly coupled charged Fermi Liquid has a non-zero fermion density in the bulk. We show that the pole-strength of the stable quasiparticle characterizing the Fermi surface is encoded in the spatially averaged AdS probability density of a single normalizable fermion wavefunction in AdS. Recalling Migdal's theorem which relates the pole strength to the Fermi-Dirac characteristic discontinuity in the number density at $\\ome_F$, we conclude that the AdS dual of a Fermi liquid is described by occupied on-shell fermionic modes in AdS. Encoding the occupied levels in the total probability density of the fermion field directly, we show that an AdS Reissner-Nordstr\\"{o}m black hole in a theory with charged fermions has a critical temperature, at which the system undergoes a first-order transition to a black hole with a non-vanishing profile for the bulk fermion field. Thermodynamics and spectral analysis confirm that the solution with non-zero AdS fermion-profil...
Global geometric properties of AdS space and the AdS/CFT correspondence
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The Poisson kernels and relations between them for a massive scalar field in a unit ball Bn with Hua's metric and conformal flat metric are obtained by describing the Bn as a submanifold of an (n+1)-dimensional embedding space. Global geometric properties of the AdS space are discussed. We show that the(n+1)-dimensional AdS space AdSn+1 is isomorphic to RP1×Bn and boundary of the AdS is isomorphic to RP1×Sn-1. Bulk-boundary propagator and the AdS/CFT like correspondence are demonstrated based on these global geometric properties of the RP1×Bn.
Different views of AEGIS / AD-6 Experiment (AD facility) AD-6
Maximilien Brice
2012-01-01
Different views of AEGIS / AD-6 Experiment (AD facility) in July of 2012. The visible parts are the positron accumulator (blue structures on top of of the antiproton extraction line) and the 5T magnet which traps the antiprotons.
Clark, T E
2016-01-01
Coset methods are used to determine the action of a co-dimension one brane (domain wall) embedded in (d+1)-dimensional AdS space in the Carroll limit in which the speed of light goes to zero. The action is invariant under the non-linearly realized symmetries of the AdS-Carroll spacetime. The Nambu-Goldstone field exhibits a static spatial distribution for the brane with a time varying momentum density related to the brane's spatial shape as well as the AdS-C geometry. The AdS-C vector field dual theory is obtained.
Entanglement entropy for free scalar fields in AdS
Sugishita, Sotaro
2016-01-01
We compute entanglement entropy for free massive scalar fields in anti-de Sitter (AdS) space. The entangling surface is a minimal surface whose boundary is a sphere at the boundary of AdS. The entropy can be evaluated from the thermal free energy of the fields on a topological black hole by using the replica method. In odd-dimensional AdS, exact expressions of the Renyi entropy S_n are obtained for arbitrary n. We also evaluate 1-loop corrections coming from the scalar fields to holographic entanglement entropy. Applying the results, we compute the leading difference of entanglement entropy between two holographic CFTs related by a renormalization group flow triggered by a double trace deformation. The difference is proportional to the shift of a central charge under the flow.
Microstates at the boundary of AdS
Mathur, Samir D
2011-01-01
The bound states of the D1D5 brane system have a known gravitational description: flat asymptotics, an anti-de Sitter region, and a 'cap' ending the AdS region. We construct perturbations that correspond to the action of chiral algebra generators on Ramond ground states of D1D5 branes. Abstract arguments in the literature suggest that the perturbation should be pure gauge in the AdS region; our perturbation indeed has this structure, with the nontrivial deformation of the geometry occurring at the 'neck' between the AdS region and asymptotic infinity. This 'non-gauge' deformation is needed to provide the nonzero energy and momentum carried by the perturbation. We also suggest implications this structure may have for the majority of microstates which live at the cap.
Detailed ultraviolet asymptotics for AdS scalar field perturbations
Evnin, Oleg
2016-01-01
We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.
Detailed ultraviolet asymptotics for AdS scalar field perturbations
Energy Technology Data Exchange (ETDEWEB)
Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University,Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Jai-akson, Puttarak [Department of Physics, Faculty of Science, Chulalongkorn University,Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand)
2016-04-11
We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.
Asymptotically AdS spacetimes with a timelike Kasner singularity
Energy Technology Data Exchange (ETDEWEB)
Ren, Jie [Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel)
2016-07-21
Exact solutions to Einstein’s equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution’s appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.
Asymptotically AdS spacetimes with a timelike Kasner singularity
Ren, Jie
2016-07-01
Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.
Revisiting the thermodynamic relations in AdS /CMT models
Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon
2017-03-01
Motivated by the recent unified approach to the Smarr-like relation of anti-de Sitter (AdS) planar black holes in conjunction with the quasilocal formalism on conserved charges, we revisit the quantum statistical and thermodynamic relations of hairy AdS planar black holes. By extending the previous results, we identify the hairy contribution in the bulk and show that the holographic computation can be improved so that it is consistent with the bulk computation. We argue that the first law can be retained in its universal form and that the relation between the on-shell renormalized Euclidean action and its free energy interpretation in gravity may also be undeformed even with the hairy contribution in hairy AdS black holes.
Di Dato, Adriana
2014-01-01
We derive a map between Einstein spaces of positive and negative curvature. Starting from a space of positive curvature with some dimensions compactified on a sphere and analytically continuing the number of compact dimensions, we obtain a space of negative curvature with a compact hyperbolic subspace, and vice versa. Prime examples of such spaces are de Sitter and Anti-de Sitter space, as well as black hole spacetimes with (A)dS asymptotics and perturbed versions thereof, which play an important role in holography. This map extends work done by Caldarelli et.al., who map asymptotically AdS spaces to Ricci-flat ones. A remarkable result is that the boundary of asymptotically AdS spaces is mapped to a brane in the bulk of de Sitter, and perturbations near the AdS boundary are sourced by a stress tensor confined to this brane. We also calculate the Brown-York stress tensor for the perturbed AdS metric, which turns out to be the negative of the stress tensor on the de Sitter brane.
An $xp$ model on $AdS_2$ spacetime
2012-01-01
In this paper we formulate the $xp$ model on the AdS$_2$ spacetime. We find that the spectrum of the Hamiltonian has positive and negative eigenvalues, whose absolute values are given by a harmonic oscillator spectrum, which in turn coincides with that of a massive Dirac fermion in AdS$_2$. We extend this result to generic $xp$ models which are shown to be equivalent to a massive Dirac fermion on spacetimes whose metric depend of the $xp$ Hamiltonian. Finally, we construct the generators of t...
AdS5 magnetized solutions in minimal gauged supergravity
Directory of Open Access Journals (Sweden)
Jose Luis Blázquez-Salcedo
2017-08-01
Full Text Available We construct a generalization of the AdS charged rotating black holes with two equal magnitude angular momenta in five-dimensional minimal gauged supergravity. In addition to the mass, electric charge and angular momentum, the new solutions possess an extra-parameter associated with a non-zero magnitude of the magnetic potential at infinity. In contrast with the known cases, these new black holes possess a non-trivial zero-horizon size limit which describes a one parameter family of spinning charged solitons. All configurations reported in this work approach asymptotically an AdS5 spacetime in global coordinates and are free of pathologies.
Diffusion and Chaos from near AdS$_2$ horizons
Blake, Mike
2016-01-01
We calculate the thermal diffusivity $D = \\kappa/c_{\\rho}$ and butterfly velocity $v_B$ in holographic models that flow to AdS$_2 \\times R^{d}$ fixed points in the infra-red. We show that both these quantities are governed by the same irrelevant deformation of AdS$_2$ and hence establish a simple relationship between them. When this deformation corresponds to a universal dilaton mode of dimension $\\Delta = 2$ then this relationship is always given by $D = v_B^2/(2 \\pi T)$.
Penrose inequality for asymptotically AdS spaces
Energy Technology Data Exchange (ETDEWEB)
Itkin, Igor [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Oz, Yaron, E-mail: yaronoz@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)
2012-02-28
In general relativity, the Penrose inequality relates the mass and the entropy associated with a gravitational background. If the inequality is violated by an initial Cauchy data, it suggests a creation of a naked singularity, thus providing means to consider the cosmic censorship hypothesis. We propose a general form of Penrose inequality for asymptotically locally AdS spaces.
Internet Advertising. Google AdWords versus Facebook Ads
Directory of Open Access Journals (Sweden)
Paul PAŞCU
2014-05-01
Full Text Available This article describes how to use the applications for Internet advertising, Google AdWords and Facebook Ads. Our attempt is to present the advantages and disadvantages of each of them, the costs and benefits, a useful aspect for companies that plan to start advertising campaigns on the Internet.
Directory of Open Access Journals (Sweden)
Yawu Liu
Full Text Available To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA on MRI and CSF biomarkers.Altogether 391 MCI cases (158 AD converters were selected from the ADNI cohort. All the cases had baseline cognitive tests, MRI and/or CSF levels of Aβ1-42 and Tau. Using baseline data, the status of MCI patients (AD or MCI three years later was predicted using current diagnostic research guidelines and the PredictAD software tool designed for supporting clinical diagnostics. The data used were 1 clinical criteria for episodic memory loss of the hippocampal type, 2 visual MTA, 3 positive CSF markers, 4 their combinations, and 5 when the PredictAD tool was applied, automatically computed MRI measures were used instead of the visual MTA results. The accuracies of diagnosis were evaluated with the diagnosis made 3 years later.The PredictAD tool achieved the overall accuracy of 72% (sensitivity 73%, specificity 71% in predicting the AD diagnosis. The corresponding number for a clinician's prediction with the assistance of the PredictAD tool was 71% (sensitivity 75%, specificity 68%. Diagnosis with the PredictAD tool was significantly better than diagnosis by biomarkers alone or the combinations of clinical diagnosis of hippocampal pattern for the memory loss and biomarkers (p≤0.037.With the assistance of PredictAD tool, the clinician can predict AD conversion more accurately than the current diagnostic criteria.
AdS5 backgrounds with 24 supersymmetries
Beck, S.; Gutowski, J.; Papadopoulos, G.
2016-06-01
We prove a non-existence theorem for smooth AdS 5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D = 11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS 5 × S 5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if gravitational duals for strictly mathcal{N}=3 superconformal theories in 4-dimensions exist, they are either singular or their internal spaces are not compact.
Coset construction of AdS particle dynamics
Heinze, Martin; Megrelidze, Luka
2016-01-01
We analyze dynamics of the AdS$_{N+1}$ particle realized on the coset SO$(2,N)/$SO$(1,N)$. Hamiltonian reduction provides the physical phase space in terms of the coadjoint orbit obtained by boosting a timelike element of ${\\frak so}(2,N)$. We show equivalence of this approach to geometric quantization and to the SO$(N)$ covariant oscillator description, for which the boost generators entail a complicated operator ordering. As an alternative scheme, we introduce dual oscillator variables and derive their algebra at the classical and the quantum level. This simplifies the calculations of the commutators for the boost generators and leads to unitary irreducible representations of ${\\frak so}(2,N)$ for all admissible values of the mass parameter. We furthermore discuss a SO$(N)$ covariant supersymmetric extensions of the oscillator quantization, with its realization for superparticles in AdS$_2$ and AdS$_3$ given by recent works.
Sub-AdS Scale Locality in AdS$_3$/CFT$_2$
Belin, Alexandre; Jefferson, Robert A; Kabir, Laurens
2016-01-01
We investigate sub-AdS scale locality in a weakly coupled toy model of the AdS$_3$/CFT$_2$ correspondence. We find that this simple model has the correct density of states at low and high energies to be dual to Einstein gravity coupled to matter in AdS$_3$. Bulk correlation functions also have the correct behavior at leading order in the large $N$ expansion, but non-local effects emerge at order $1/N$. Our analysis leads to the conjecture that any large $N$ CFT$_2$ that is modular invariant and has the right low-energy density of states is dual to a gravitational theory with sub-AdS scale locality.
Ultraviolet asymptotics for quasiperiodic AdS_4 perturbations
Craps, Ben; Jai-akson, Puttarak; Vanhoof, Joris
2015-01-01
Spherically symmetric perturbations in AdS-scalar field systems of small amplitude epsilon approximately periodic on time scales of order 1/epsilon^2 (in the sense that no significant transfer of energy between the AdS normal modes occurs) have played an important role in considerations of AdS stability. They are seen as anchors of stability islands where collapse of small perturbations to black holes does not occur. (This collapse, if it happens, typically develops on time scales of the order 1/epsilon^2.) We construct an analytic treatment of the frequency spectra of such quasiperiodic perturbations, paying special attention to the large frequency asymptotics. For the case of a self-interacting phi^4 scalar field in a non-dynamical AdS background, we arrive at a fairly complete analytic picture involving quasiperiodic spectra with an exponential suppression modulated by a power law at large mode numbers. For the case of dynamical gravity, the structure of the large frequency asymptotics is more complicated....
AdS nonlinear instability: moving beyond spherical symmetry
Dias, Oscar J C
2016-01-01
Anti-de Sitter (AdS) is conjectured to be nonlinear unstable to a weakly turbulent mechanism that develops a cascade towards high frequencies, leading to black hole formation [1,2]. We give evidence that the gravitational sector of perturbations behaves differently from the scalar one studied in [2]. In contrast with [2], we find that not all gravitational normal modes of AdS can be nonlinearly extended into periodic horizonless smooth solutions of the Einstein equation. In particular, we show that even seeds with a single normal mode can develop secular resonances, unlike the spherically symmetric scalar field collapse studied in [2]. Moreover, if the seed has two normal modes, more than one resonance can be generated at third order, unlike the spherical collapse of [2]. We also show that weak turbulent perturbative theory predicts the existence of direct and inverse cascades, with the former dominating the latter for equal energy two-mode seeds.
Universal isolation in the AdS landscape
Danielsson, U. H.; Dibitetto, G.; Vargas, S. C.
2016-12-01
We study the universal conditions for quantum nonperturbative stability against bubble nucleation for pertubatively stable AdS vacua based on positive energy theorems. We also compare our analysis with the preexisting ones in the literature carried out within the thin-wall approximation. The aforementioned criterion is then tested in two explicit examples describing massive type IIA string theory compactified on S3 and S3×S3, respectively. The AdS landscape of both classes of compactifications is known to consist of a set of isolated points. The main result is that all critical points respecting the Breitenlohner-Freedman (BF) bound also turn out be stable at a nonperturbative level. Finally, we speculate on the possible universal features that may be extracted from the above specific examples.
The Mixed Phase of Charged AdS Black Holes
Directory of Open Access Journals (Sweden)
Piyabut Burikham
2016-01-01
Full Text Available We study the mixed phase of charged AdS black hole and radiation when the total energy is fixed below the threshold to produce a stable charged black hole branch. The coexistence conditions for the charged AdS black hole and radiation are derived for the generic case when radiation particles carry charge. The phase diagram of the mixed phase is demonstrated for both fixed potential and charge ensemble. In the dual gauge picture, they correspond to the mixed phase of quark-gluon plasma (QGP and hadron gas in the fixed chemical potential and density ensemble, respectively. In the nuclei and heavy-ion collisions at intermediate energies, the mixed phase of exotic QGP and hadron gas could be produced. The mixed phase will condense and evaporate into the hadron gas as the fireball expands.
Smoothed Transitions in Higher Spin AdS Gravity
Banerjee, Shamik; Hellerman, Simeon; Hijano, Eliot; Lepage-Jutier, Arnaud; Maloney, Alexander; Shenker, Stephen
2012-01-01
We consider CFTs conjectured to be dual to higher spin theories of gravity in AdS_3 and AdS_4. Two dimensional CFTs with W_N symmetry are considered in the lambda=0 (k --> infinity) limit, where they are conjectured to be described by continuous orbifolds. The torus partition function is computed, using reasonable assumptions, and equals that of a free field theory. We find no phase transition at temperatures of order one; the usual Hawking-Page phase transition is removed by the highly degenerate light states associated with conical defect states in the bulk. Three dimensional Chern-Simons-matter CFTs with vector-like matter are considered on T^3, where the dynamics is described by an effective theory for the eigenvalues of the holonomies. Likewise, we find no evidence for a Hawking-Page phase transition at large level k.
Perturbative entanglement thermodynamics for AdS spacetime: Renormalization
Mishra, Rohit
2015-01-01
We study the effect of charged excitations in the AdS spacetime on the first law of entanglement thermodynamics. It is found that `boosted' AdS black holes give rise to a more general form of first law which includes chemical potential and charge density. To obtain this result we have to resort to a second order perturbative calculation of entanglement entropy for small size subsystems. At first order the form of entanglement law remains unchanged even in the presence of charged excitations. But the thermodynamic quantities have to be appropriately `renormalized' at the second order due to the corrections. We work in the perturbative regime where $T_{thermal}\\ll T_E$.
Thermodynamics of Einstein-Proca AdS Black Holes
Liu, Hai-Shan; Pope, C N
2014-01-01
We study static spherically-symmetric solutions of the Einstein-Proca equations in the presence of a negative cosmological constant. We show that the theory admits solutions describing both black holes and also solitons in an asymptotically AdS background. Interesting subtleties can arise in the computation of the mass of the solutions and also in the derivation of the first law of thermodynamics. We make use of holographic renormalisation in order to calculate the mass, even in cases where the solutions have a rather slow approach to the asymptotic AdS geometry. By using the procedure developed by Wald, we derive the first law of thermodynamics for the black hole and soliton solutions. This includes a non-trivial contribution associated with the Proca "charge." The solutions cannot be found analytically, and so we make use of numerical integration techniques to demonstrate their existence.
Note on classical string dynamics on AdS3
Bañados, Máximo; Ritz, Adam
1999-12-01
We consider bosonic strings propagating on Euclidean anti-de Sitter space (AdS3), and study in particular the realization of various worldsheet symmetries. We give a proper definition for the Brown-Henneaux asymptotic target space symmetry, when acting on the string action, and derive the Giveon-Kutasov-Seiberg worldsheet contour integral representation simply by using Noether's theorem. We show that making identifications in the target space is equivalent to the insertion of an (exponentiated) graviton vertex operator carrying the corresponding charge. Finally, we point out an interesting relation between 3D gravity and the dynamics of the worldsheet on AdS3. Both theories are described by an SL(2,C)/SU(2) Wess-Zumino-Witten (WZW) model, and we prove that the reduction conditions determined on one hand by worldsheet diffeomorphism invariance, and on the other by the Brown-Henneaux boundary conditions, are the same.
Observing quantum gravity in asymptotically AdS space
Emelyanov, Slava
2015-12-01
The question is studied of whether an observer can discover quantum gravity in the semiclassical regime. It is shown that it is indeed possible to probe a certain quantum gravity effect by employing an appropriately designed detector. The effect is related to the possibility of having topologically inequivalent geometries in the path-integral approach at the same time. A conformal field theory (CFT) state which is expected to describe the eternal anti-de Sitter (AdS) black hole in the large-N limit is discussed. It is argued under certain assumptions that the black hole boundary should be merely a patch of the entire AdS boundary. This leads then to a conclusion that that CFT state is the ordinary CFT vacuum restricted to that patch. If existent, the bulk CFT operators can behave as the ordinary semiclassical quantum field theory in the large-N limit in the weak sense.
Semiclassical Virasoro Blocks from AdS$_3$ Gravity
Hijano, Eliot; Perlmutter, Eric; Snively, River
2015-01-01
We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in arXiv:1508.00501, evaluated in locally AdS$_3$ geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block -- in which two external operators become parametrically heavy -- as a certain scattering process involving higher spin gauge fields in AdS$_3$; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.
AdS plane waves, entanglement and mutual information
Mukherjee, Debangshu
2014-01-01
$AdS$ plane wave backgrounds are dual to CFT excited states with energy momentum density $T_{++}=Q$. Building on previous work on entanglement entropy in these and nonconformal brane plane wave backgrounds, we first describe a phenomenological scaling picture for entanglement in terms of "entangling partons". We then study aspects of holographic mutual information in these backgrounds for two strip shaped subsystems, aligned parallel or orthogonal to the flux. We focus on the wide ($Ql^d\\gg 1$) and narrow ($Ql^d\\ll 1$) strip regimes. In the wide strip regime, mutual information exhibits growth with the individual strip sizes and a disentangling transition as the separation between the strips increases, whose behaviour is distinct from the ground and thermal states. In the narrow strip case, our calculations have parallels with "entanglement thermodynamics" for these $AdS$ plane wave deformations. We also discuss some numerical analysis.
N=2 supersymmetric sigma-models in AdS
Butter, Daniel
2011-01-01
We construct the most general N=2 supersymmetric nonlinear sigma-model in four-dimensional anti-de Sitter (AdS) space in terms of N=1 chiral superfields. The target space is shown to be a non-compact hyperkahler manifold restricted to possess a special Killing vector field. A remarkable property of the sigma-model constructed is that the algebra of OSp(2|4) transformations is closed off the mass shell.
Generalised structures for N=1 AdS backgrounds
Energy Technology Data Exchange (ETDEWEB)
Coimbra, André [Institut für Theoretische Physik & Center for Quantum Engineering and Spacetime Research,Leibniz Universität Hannover,Appelstraße 2, 30167 Hannover (Germany); Strickland-Constable, Charles [Institut de physique théorique, Université Paris Saclay, CEA, CNRS, Orme des Merisiers, F-91191 Gif-sur-Yvette (France)
2016-11-16
We expand upon a claim made in a recent paper [http://arxiv.org/abs/1411.5721] that generic minimally supersymmetric AdS backgrounds of warped flux compactifications of Type II and M theory can be understood as satisfying a straightforward weak integrability condition in the language of E{sub d(d)}×ℝ{sup +} generalised geometry. Namely, they are spaces admitting a generalised G-structure set by the Killing spinor and with constant singlet generalised intrinsic torsion.
SUSY properties of warped AdS3
Jeong, Jaehoon; Colgáin, Eoin Ó.; Yoshida, Kentaroh
2014-06-01
We examine supersymmetric properties of null-warped AdS3, or alternatively Schrödinger geometries, dual to putative warped CFTs in two dimensions. We classify super Schrödinger subalgebras of the superalgebra psu(1, 1|2) ⊕ psu(1, 1|2), corresponding to the superconformal algebra of the AdS3 × S3 geometry. We comment on geometric realisations and provide a string theory description with enhanced supersymmetry in terms of intersecting D3-branes. For type IIB supergravity solutions based on T 1,1, we consider the relationship between five-dimensional Schrödinger solutions and their three-dimensional null-warped counterparts, corresponding to R symmetry twists. Finally, we study a family of null-warped AdS3 solutions in a setting where there is an ambiguity over the R symmetry and confirm that, for examples admitting a Kaluza-Klein (KK) reduction to three dimensions, the minimisation of a real superpotential of the three-dimensional gauged supergravity captures the central charge and R symmetry.
N=2 AdS supergravity and supercurrents
Butter, Daniel
2011-01-01
We consider the minimal off-shell formulation for four-dimensional N=2 supergravity with a cosmological term, in which the second compensator is an improved tensor multiplet. We use it to derive a linearized supergravity action (and its dual versions) around the anti-de Sitter (AdS) background in terms of three N=2 off-shell multiplets: an unconstrained scalar superfield, vector and tensor multiplets. This allows us to deduce the structure of the supercurrent multiplet associated with those supersymmetric theories which naturally couple to the supergravity formulation chosen, with or without a cosmological term. Finally, our linearized N=2 AdS supergravity action is reduced to N=1 superspace. The result is a sum of two N=1 linearized actions describing (i) old minimal supergravity; and (ii) an off-shell massless gravitino multiplet. We also derive dual formulations for the massless N=1 gravitino multiplet in AdS. As a by-product of our consideration, we derive the consistent supergravity extension of the N=1 ...
Intellectual mobile Ad Hoc networks
Sova, Oleg; Romanjuk, Valeriy; Bunin, Sergey; Zhuk, Pavlo
2012-01-01
In this article intellectualization of Mobile Ad Hoc Networks resources management is offered. It was proposed decomposition of the primary goal of MANET functioning into easy subgoals, and fragment of the MANET node target structure is presented.
Supergravity one-loop corrections on AdS7 and AdS3, higher spins and AdS/CFT
Directory of Open Access Journals (Sweden)
Matteo Beccaria
2015-03-01
Full Text Available As was shown earlier, the one-loop correction in 10d supergravity on AdS5×S5 corresponds to the contributions to the vacuum energy and 4d boundary conformal anomaly which are minus the values for one N=4 Maxwell supermultiplet, thus reproducing the subleading term in the N2−1 coefficient in the dual SU(N SYM theory. We perform similar one-loop computations in 11d supergravity on AdS7×S4 and 10d supergravity on AdS3×S3×T4. In the AdS7 case we find that the corrections to the 6d conformal anomaly a-coefficient and the vacuum energy are again minus the ones for one (2,0 tensor multiplet, suggesting that the total a-anomaly coefficient for the dual (2,0 theory is 4N3−9/4N−7/4 and thus vanishes for N=1. In the AdS3 case the one-loop correction to the vacuum energy or 2d central charge turns out to be equal to that of one free (4,4 scalar multiplet, i.e. is c=+6. This reproduces the subleading term in the central charge c=6(Q1Q5+1 of the dual 2d CFT describing decoupling limit of D5–D1 system. We also present the expressions for the 6d a-anomaly coefficient and vacuum energy contributions of general-symmetry higher spin field in AdS7 and consider their application to tests of vectorial AdS/CFT with the boundary conformal 6d theory represented by free scalars, spinors or rank-2 antisymmetric tensors.
Entanglement Temperature and Perturbed AdS$_3$ Geometry
Levine, Gregory
2015-01-01
In analogy to the first law of thermodynamics, the increase in entanglement entropy $\\delta S$ of a conformal field theory (CFT) is proportional to the increase in energy, $\\delta E$, of the subsystem divided by an effective entanglement temperature, $T_E$. Extending this analogy, we study entanglement entropy when the subsystem is perturbed by applying an external field, expressed as a coupling to a local marginal operator in the CFT. We show that the resulting entropy change is associated with a change in the entanglement temperature itself, leading to an equation analogous to the Clausius relation. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature, $\\delta T_E(x)$ of the CFT and the perturbation of the bulk AdS metric. Using the AdS$_3$ minimal surface as a probe, we can construct bulk metric perturbations from an exact numerical computation of the entanglement temperature in a two dimensional $c=1$ boundary theory deformed by a marginal perturbati...
Ultraviolet asymptotics and singular dynamics of AdS perturbations
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel, and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel, and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Vanhoof, Joris [Theoretische Natuurkunde, Vrije Universiteit Brussel, and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)
2015-10-12
Important insights into the dynamics of spherically symmetric AdS-scalar field perturbations can be obtained by considering a simplified time-averaged theory accurately describing perturbations of amplitude ε on time-scales of order 1/ε{sup 2}. The coefficients of the time-averaged equations are complicated expressions in terms of the AdS scalar field mode functions, which are in turn related to the Jacobi polynomials. We analyze the behavior of these coefficients for high frequency modes. The resulting asymptotics can be useful for understanding the properties of the finite-time singularity in solutions of the time-averaged theory recently reported in the literature. We highlight, in particular, the gauge dependence of this asymptotics, with respect to the two most commonly used gauges. The harsher growth of the coefficients at large frequencies in higher-dimensional AdS suggests strengthening of turbulent instabilities in higher dimensions. In the course of our derivations, we arrive at recursive relations for the coefficients of the time-averaged theory that are likely to be useful for evaluating them more efficiently in numerical simulations.
Coherent Cascade: Collapsing Solutions in Global AdS
Freivogel, Ben
2015-01-01
We analyze the gravitational dynamics of a classical scalar field that sometimes leads to blackhole formation in asymptotically AdS spacetime at the shortest nonlinear time scale. We present strong evidence that the dynamics is governed by a "coherent cascade", with all modes remaining in phase as the energy flows to higher frequencies into a power-law spectrum. Using a coherent phase ansatz, we analytically find these power-law solutions. We show how the particular power is determined by the scaling properties of the interaction coefficients. Our result agrees with existing numerical results in 4+1 dimensions, and makes predictions in higher dimensions.
Configurational entropy of charged AdS black holes
Lee, Chong Oh
2017-09-01
When we consider charged AdS black holes in higher dimensional spacetime and a molecule number density along coexistence curves is numerically extended to higher dimensional cases. It is found that a number density difference of a small and large black holes decrease as a total dimension grows up. In particular, we find that a configurational entropy is a concave function of a reduced temperature and reaches a maximum value at a critical (second-order phase transition) point. Furthermore, the bigger a total dimension becomes, the more concave function in a configurational entropy while the more convex function in a reduced pressure.
Internal Structure of Charged AdS Black Holes
Bhattacharjee, Srijit; Virmani, Amitabh
2016-01-01
When an electrically charged black hole is perturbed its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.
Duality invariance of s≥32 fermions in AdS
Directory of Open Access Journals (Sweden)
S. Deser
2014-11-01
Full Text Available We show that in D=4 AdS, s≥3/2 partially massless (PM fermions retain the duality invariances of their flat space massless counterparts. They have tuned ratios m2/M2≠0 that turn them into sums of effectively massless unconstrained helicity ±(s,⋯,32 excitations, shorn of the lowest (non-dual helicity ±12-rung and — more generally — of succeeding higher rung as well. Each helicity mode is separately duality invariant, like its flat space counterpart.
Reentrant Phase Transitions in Rotating AdS Black Holes
Altamirano, Natacha; Mann, Robert B
2013-01-01
We study the thermodynamics of higher-dimensional singly spinning asymptotically AdS black holes in the canonical (fixed J) ensemble of extended phase space, where the cosmological constant is treated as pressure and the corresponding conjugate quantity is interpreted as thermodynamic volume. Along with the usual small/large black hole phase transition, we find a new phenomenon of reentrant phase transitions for all d>5 dimensions, in which a monotonic variation of the temperature yields two phase transitions from large to small and back to large black holes. This situation is similar to that seen in multicomponent liquids.
Entanglement entropy and duality in AdS4
Directory of Open Access Journals (Sweden)
Ioannis Bakas
2015-07-01
Full Text Available Small variations of the entanglement entropy δS and the expectation value of the modular Hamiltonian δE are computed holographically for circular entangling curves in the boundary of AdS4, using gravitational perturbations with general boundary conditions in spherical coordinates. Agreement with the first law of thermodynamics, δS=δE, requires that the line element of the entangling curve remains constant. In this context, we also find a manifestation of electric–magnetic duality for the entanglement entropy and the corresponding modular Hamiltonian, following from the holographic energy–momentum/Cotton tensor duality.
Most general AdS_3 boundary conditions
Grumiller, Daniel
2016-01-01
We consider the most general asymptotically anti-de Sitter boundary conditions in three-dimensional Einstein gravity with negative cosmological constant. The metric contains in total twelve independent functions, six of which are interpreted as chemical potentials (or non-normalizable fluctuations) and the other half as canonical boundary charges (or normalizable fluctuations). Their presence modifies the usual Fefferman-Graham expansion. The asymptotic symmetry algebra consists of two sl(2)_k current algebras, the levels of which are given by k=l/(4G_N), where l is the AdS radius and G_N the three-dimensional Newton constant.
M-Theory solutions with AdS factors
Gauntlett, J P; Pakis, S; Waldram, D; Gauntlett, Jerome P.; Kim, Nakwoo; Pakis, Stathis; Waldram, Daniel
2002-01-01
Solutions of D=7 maximal gauged supergravity are constructed with metrics that are a product of a n-dimensional anti-de Sitter (AdS) space, with n=2,3,4,5, and certain Einstein manifolds. The gauge fields have the same form as in the recently constructed solutions describing the near-horizon limits of M5-branes wrapping supersymmetric cycles. The new solutions do not preserve any supersymmetry and can be uplifted to obtain new solutions of D=11 supergravity, which are warped and twisted products of the D=7 metric with a squashed four-sphere. Some aspects of the stability of the solutions are discussed.
M-theory solutions with AdS factors
Energy Technology Data Exchange (ETDEWEB)
Gauntlett, Jerome P [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Kim, Nakwoo [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, D-14476 Golm (Germany); Pakis, Stathis [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Waldram, Daniel [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)
2002-08-07
Solutions of D=7 maximal gauged supergravity are constructed with metrics that are a product of an n-dimensional anti-de Sitter (AdS) space, with n=2, 3, 4, 5, and certain Einstein manifolds. The gauge fields have the same form as in the recently constructed solutions describing the near-horizon limits of M5-branes wrapping supersymmetric cycles. The new solutions do not preserve any supersymmetry and can be uplifted to obtain new solutions of D=11 supergravity, which are warped and twisted products of the D=7 metric with a squashed four-sphere. Some aspects of the stability of the solutions are discussed.
Heavy quark potential from deformed AdS5 models
Zhang, Zi-qiang; Hou, De-fu; Chen, Gang
2017-04-01
In this paper, we investigate the heavy quark potential in some holographic QCD models. The calculation relies on a modified renormalization scheme mentioned in a previous work of Albacete et al. After studying the heavy quark potential in Pirner-Galow model and Andreev-Zakharov model, we extend the discussion to a general deformed AdS5 case. It is shown that the obtained potential is negative definite for all quark-antiquark separations, differs from that using the usual renormalization scheme.
AdS Chern-Simons Gravity induces Conformal Gravity
Aros, Rodrigo
2013-01-01
The leitmotif of this paper is the question of whether four- and higher even-dimensional Conformal Gravities do have a Chern-Simons pedigree. We show that Weyl gravity can be obtained as dimensional reduction of a five-dimensional Chern-Simons action for a suitable (gauged-fixed, tractor-like) five-dimensional AdS connection. The gauge-fixing and dimensional reduction program admits a readily generalization to higher dimensions for the case of certain conformal gravities obtained by contractions of the Weyl tensor.
Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.
2014-01-01
In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.
Parikh, Maulik
2012-01-01
In anti-de Sitter space a highly accelerating observer perceives a Rindler horizon. The two Rindler wedges in AdS_{d+1} are holographically dual to an entangled conformal field theory that lives on two boundaries with geometry R x H_{d-1}. For AdS_3, the holographic duality is especially tractable, allowing quantum-gravitational aspects of Rindler horizons to be probed. We recover the thermodynamics of Rindler-AdS space directly from the boundary conformal field theory. We derive the temperature from the two-point function and obtain the Rindler entropy density precisely, including numerical factors, using the Cardy formula. We also probe the causal structure of the spacetime, and find from the behavior of the one-point function that the CFT "knows" when a source has fallen across the Rindler horizon. This is so even though, from the bulk point of view, there are no local signifiers of the presence of the horizon. Finally, we discuss an alternate foliation of Rindler-AdS which is dual to a CFT living in de Si...
The CFT dual of AdS gravity with torsion
Klemm, Dietmar
2007-01-01
We consider the Mielke-Baekler model of three-dimensional AdS gravity with torsion, which has gravitational and translational Chern-Simons terms in addition to the usual Einstein-Hilbert action with cosmological constant. It is shown that the topological nature of the model leads to a finite Fefferman-Graham expansion. We derive the holographic stress tensor and the associated Ward identities and show that, due to the asymmetry of the left- and right-moving central charges, a Lorentz anomaly appears in the dual conformal field theory. Both the consistent and the covariant Weyl and Lorentz anomaly are determined, and the Wess-Zumino consistency conditions for the former are verified. Moreover we consider the most general solution with flat boundary geometry, which describes left-and right-moving gravitational waves on AdS_3 with torsion, and shew that in this case the holographic energy-momentum tensor is given by the wave profiles. The anomalous transformation laws of the wave profiles under diffeomorphisms p...
AdS nonlinear instability: moving beyond spherical symmetry
Dias, Óscar J. C.; Santos, Jorge E.
2016-12-01
Anti-de Sitter (AdS) is conjectured to be nonlinear unstable to a weakly turbulent mechanism that develops a cascade towards high frequencies, leading to black hole formation (Dafermos and Holzegel 2006 Seminar at DAMTP (University of Cambridge) available at https://dpmms.cam.ac.uk/~md384/ADSinstability.pdf, Bizon and Rostworowski 2011 Phys. Rev. Lett. 107 031102). We give evidence that the gravitational sector of perturbations behaves differently from the scalar one studied by Bizon and Rostworowski. In contrast with Bizon and Rostworowski, we find that not all gravitational normal modes of AdS can be nonlinearly extended into periodic horizonless smooth solutions of the Einstein equation. In particular, we show that even seeds with a single normal mode can develop secular resonances, unlike the spherically symmetric scalar field collapse studied by Bizon and Rostworowski. Moreover, if the seed has two normal modes, more than one resonance can be generated at third order, unlike the spherical collapse of Bizon and Rostworowski. We also show that weak turbulent perturbative theory predicts the existence of direct and inverse cascades, with the former dominating the latter for equal energy two-mode seeds.
AdS pure spinor superstring in constant backgrounds
Energy Technology Data Exchange (ETDEWEB)
Chandia, Osvaldo [Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Diagonal Las Torres 2640, Peñalolén, Santiago (Chile); Bevilaqua, L. Ibiapina [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte,Caixa Postal 1524, 59072-970, Natal, RN (Brazil); Vallilo, Brenno Carlini [Facultad de Ciencias Exactas, Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile)
2014-06-05
In this paper we study the pure spinor formulation of the superstring in AdS{sub 5}×S{sup 5} around point particle solutions of the classical equations of motion. As a particular example we quantize the pure spinor string in the BMN background.
Cassani, Davide; Marrani, Alessio; Morales, Jose F; Samtleben, Henning
2010-01-01
We apply the techniques of special Kaehler geometry to investigate AdS_4 vacua of general N=2 gauged supergravities underlying flux compactifications of type II theories. We formulate the scalar potential and its extremization conditions in terms of a triplet of prepotentials P_x and their special Kaehler covariant derivatives only, in a form that recalls the potential and the attractor equations of N=2 black holes. We propose a system of first order equations for the P_x which generalize the supersymmetry conditions and yield non-supersymmetric vacua. Special geometry allows us to recast these equations in algebraic form, and we find an infinite class of new N=0 and N=1 AdS_4 solutions, displaying a rich pattern of non-trivial charges associated with NSNS and RR fluxes. Finally, by explicit evaluation of the entropy function on the solutions, we derive a U-duality invariant expression for the cosmological constant and the central charges of the dual CFT's.
AdS twistors for higher spin theory
Cederwall, M
2004-01-01
We construct spectra of supersymmetric higher spin theories in D=4, 5 and 7 from twistors describing massless (super-)particles on AdS spaces. A massless twistor transform is derived in a geometric way from classical kinematics. Relaxing the spin-shell constraints on twistor space gives an infinite tower of massless states of a ``higher spin particle'', generalising previous work of Bandos et al. This can generically be done in a number of ways, each defining the states of a distinct higher spin theory, and the method provides a systematic way of finding these. We reproduce known results in D=4, minimal supersymmetric 5- and 7-dimensional models, as well as supersymmetrisations of Vasiliev's Sp-models as special cases. In the latter models a dimensional enhancement takes place, meaning that the theory lives on a space of higher dimension than the original AdS space, and becomes a theory of doubletons. This talk was presented at the XIXth Max Born Symposium ``Fundamental Interactions and Twistor-Like Methods''...
Enthalpy and the Mechanics of AdS Black Holes
Kastor, David; Traschen, Jennie
2009-01-01
We present geometric derivations of the Smarr formula for static AdS black holes and an expanded first law that includes variations in the cosmological constant. These two results are further related by a scaling argument based on Euler's theorem. The key new ingredient in the constructions is a two-form potential for the static Killing field. Surface integrals of the Killing potential determine the coefficient of the variation of the cosmological constant in the first law. This coefficient is proportional to a finite, effective volume for the region outside the AdS black hole horizon, which can also be interpreted as minus the volume excluded from a spatial slice by the black hole horizon. This effective volume also contributes to the Smarr formula. Since the cosmological constant is naturally thought of as a pressure, the new term in the first law has the form of effective volume times change in pressure that arises in the variation of the enthalpy in classical thermodynamics. This and related arguments sug...
Quantum cat map dynamics on AdS$_2$
Axenides, Minos; Nicolis, Stam
2016-01-01
We present a toy model for the chaotic unitary scattering of single particle wave packets on the radial AdS$_2$ geometry of extremal BH horizons. Based on our recent work for the discretization of the AdS$_2$ space-time, which describes a finite and random geometry, by modular arithmetic, we investigate the validity of the eigenstate thermalization hypothesis (ETH), as well as that of the fast scrambling time bound conjecture (STB), for an observer with time evolution operator the quantum Arnol'd cat map (QACM). We find that the QACM, while possessing a linear spectrum, has eigenstates, which can be expressed in closed form, are found to be random and to satisfy the assumptions of the ETH.The implications are that the dynamics is described by a chaotic, unitary, single particle S-matrix, which completely delocalizes and randomizes initial gaussian wave packets . Applying results obtained by Dyson and Falk for the periods of the Arnol'd Cat Map(ACM),which are related to its mixing time, we also find that the t...
Smooth Causal Patches for AdS Black Holes
Raju, Suvrat
2016-01-01
We review the paradox of low energy excitations about an AdS black hole. An appropriately chosen unitary operator in the boundary theory can create a locally strong excitation near the black hole horizon, whose global energy is small as a result of the gravitational redshift. The paradox is that this seems to violate a general rule of statistical mechanics, which states that an operator with energy parametrically smaller than $k T$ cannot create a significant excitation in a thermal system. When we carefully examine the position dependence of the boundary unitary operator that produces the excitation and the bulk observable necessary to detect the anomalously large effect, we find that they do not both fit in a single causal patch. This follows from a remarkable property of position space AdS correlators that we establish explicitly, and resolves the paradox in a generic state of the system, since no combination of observers can both create the excitation and observe its effect. As a special case of our analy...
AdCell: Ad Allocation in Cellular Networks
Alaei, Saeed; Liaghat, Vahid; Pei, Dan; Saha, Barna
2011-01-01
With more than four billion usage of cellular phones worldwide, mobile advertising has become an attractive alternative to online advertisements. In this paper, we propose a new targeted advertising policy for Wireless Service Providers (WSPs) via SMS or MMS- namely {\\em AdCell}. In our model, a WSP charges the advertisers for showing their ads. Each advertiser has a valuation for specific types of customers in various times and locations and has a limit on the maximum available budget. Each query is in the form of time and location and is associated with one individual customer. In order to achieve a non-intrusive delivery, only a limited number of ads can be sent to each customer. Recently, new services have been introduced that offer location-based advertising over cellular network that fit in our model (e.g., ShopAlerts by AT&T) . We consider both online and offline version of the AdCell problem and develop approximation algorithms with constant competitive ratio. For the online version, we assume tha...
Online Ad Slotting With Cancellations
Constantin, Florin; Muthukrishnan, S; Pal, Martin
2008-01-01
Many advertisers buy advertisements (ads) on the Internet or on traditional media and seek simple, online mechanisms to reserve ad slots in advance. Media publishers represent a vast and varying inventory, and they too seek automatic, online mechanisms for pricing and allocating such reservations. In this paper, we present and study a simple model for auctioning such ad slots in advance. Bidders arrive sequentially and report which slots they are interested in. The seller must decide immediately whether or not to grant a reservation. Our model allows a seller to accept reservations, but possibly cancel the allocations later and pay the bidder a cancellation compensation (bump payment). Our main result is an online mechanism to derive prices and bump payments that is efficient to implement. This mechanism has many desirable properties. It is individually rational; winners have an incentive to be honest and bidding one's true value dominates any lower bid. Our mechanism's efficiency is within a constant fractio...
Adding momentum to supersymmetric geometries
Energy Technology Data Exchange (ETDEWEB)
Lunin, Oleg, E-mail: olunin@albany.edu [Department of Physics, University at Albany (SUNY), Albany, NY 12222 (United States); Mathur, Samir D., E-mail: mathur.16@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States); Turton, David, E-mail: turton.7@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)
2013-03-11
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a traveling wave deformation involving the additional directions. The deformed solution is given in terms of a function which is harmonic in the background geometry. We also present a family of explicit examples describing microstates of the D1-D5 system on T{sup 4}. In the case where the background contains a large AdS region, the deformation is identified as corresponding to an action of a U(1) current of the D1-D5 orbifold CFT on a given state.
Adding momentum to supersymmetric geometries
Lunin, Oleg; Turton, David
2012-01-01
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a travelling-wave deformation involving the additional directions. The deformed solution is given in terms of a function which is harmonic in the background geometry. We also present a family of explicit examples describing microstates of the D1-D5 system on T^4. In the case where the background contains a large AdS region, the deformation is identified as corresponding to an action of a U(1) current of the D1-D5 orbifold CFT on a given state.
DEFF Research Database (Denmark)
Schröder, Philipp J.H.; Sørensen, Allan
2010-01-01
a general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit...
Added Value via SPI supplement
Supplement that indicates where to find the source data sets on the EPA system.This dataset is associated with the following publication:Bowden, J., K.D. Talgo, T. Spero , and C. Nolte. Assessing the Added Value of Dynamical Downscaling Using the Standardized Precipitation Index. ADVANCES IN METEOROLOGY. Hindawi Publishing Corporation, New York, NY, USA, 2016(8432064): 14 pages, (2016).
Holographic properties in three-dimensional AdS soliton using $AdS_3/CFT_2$
Peng, Yan
2016-01-01
We study the holographic description of a superconductor by the $AdS_{3}/CFT_{2}$ correspondence. The system is constructed with a Maxwell field and a charged scalar field coupled in the (2+1)-dimensional AdS soliton background. With analytical methods, we obtain the exact expression for the critical chemical potential as $\\mu_{c} = 1 + \\sqrt{1+m^2}$, which has also been generalized to higher dimensions as $\\mu_c \\thickapprox a + \\sqrt{m^2-m_{BF}^2}$ in this work. Around the phase transition points, we find a correspondence between the value of the scalar field at the tip and the scalar operator at infinity. We also arrive at the classical second order phase transition threshold exponent $\\beta=\\frac{1}{2}$ as the same as the mean field theory near the critical chemical potential. As the condensation becomes heavier, we show surprisingly that superconducting phases exist only in a certain range of the chemical potential, which is very different from higher-dimensional cases. And for the small enough negative ...
de Boer, J.; Hubeny, V.E.; Rangamani, M.; Shigemori, M.
2009-01-01
We study Brownian motion and the associated Langevin equation in AdS/CFT. The Brownian particle is realized in the bulk spacetime as a probe fundamental string in an asymptotically AdS black hole background, stretching between the AdS boundary and the horizon. The modes on the string are excited by
Colliding waves on a string in AdS$_3$
Vegh, David
2015-01-01
This paper is concerned with the classical motion of a string in global AdS$_3$. The initially static string stretches between two antipodal points on the boundary circle. Both endpoints are perturbed which creates cusps at a steady rate. The cusps propagate towards the interior where they collide. The behavior of the string depends on the strength of forcing. Three qualitatively different phases can be distinguished: transparent, gray, and black. The transparent region is analogous to a standing wave. In the black phase, there is a horizon on the worldsheet and cusps never reach the other endpoint. The string keeps folding and its length grows linearly over time. In the gray phase, the string still grows linearly. However, cusps do cross to the other side. The transparent and gray regions are separated by a transition point where a logarithmic accumulation of cusps is numerically observed. A simple model reproduces the qualitative behavior of the string in the three phases.
Bootstrapping Pure Quantum Gravity in AdS3
Bae, Jin-Beom; Lee, Sungjay
2016-01-01
The three-dimensional pure quantum gravity with negative cosmological constant is supposed to be dual to the extremal conformal field theory of central charge $c=24k$ in two dimensions. We employ the conformal bootstrap method to analyze the extremal CFTs, and find numerical evidence for the non-existence of the extremal CFTs for sufficiently large central charge ($k \\ge 20$). We also explore near-extremal CFTs, a small modification of extremal ones, and find similar evidence for their non-existence for large central charge. This indicates, under the assumption of holomorphic factorization, the pure gravity in the weakly curved AdS$_3$ do not exist as a consistent quantum theory.
On jordanian deformations of AdS5 and supergravity
Hoare, Ben; van Tongeren, Stijn J.
2016-10-01
We consider various homogeneous Yang-Baxter deformations of the {{AdS}}5× {{{S}}}5 superstring that can be obtained from the η-deformed superstring and related models by singular boosts. The jordanian deformations we obtain in this way behave similarly to the η-deformed model with regard to supergravity: T dualizing the classical sigma model it is possible to find corresponding solutions of supergravity, which, however, have dilatons that prevent T dualizing back. Hence the backgrounds of these jordanian deformations are not solutions of supergravity. Still, they do satisfy a set of recently found modified supergravity equations which implies that the corresponding sigma models are scale invariant. The abelian models that we obtain by singular boosts do directly correspond to solutions of supergravity. In addition to our main results we consider contraction limits of our main example, which do correspond to supergravity solutions.
On jordanian deformations of AdS_5 and supergravity
Hoare, Ben
2016-01-01
We consider various homogeneous Yang-Baxter deformations of the AdS_5 x S^5 superstring that can be obtained from the eta-deformed superstring and related models by singular boosts. The jordanian deformations we obtain in this way behave similarly to the eta-deformed model with regard to supergravity: T dualizing the classical sigma model it is possible to find corresponding solutions of supergravity, which, however, have dilatons that prevent T dualizing back. Hence the backgrounds of these jordanian deformations are not solutions of supergravity. Still, they do satisfy a set of recently found modified supergravity equations which should imply that the corresponding sigma models are scale invariant. The abelian models that we obtain by singular boosts do directly correspond to solutions of supergravity. In addition to our main results we consider contraction limits of our main example, which also do not correspond to supergravity solutions.
Higher spins on AdS3 from the worldsheet
Ferreira, Kevin; Gaberdiel, Matthias R.; Jottar, Juan I.
2017-07-01
It was recently shown that the CFT dual of string theory on AdS3 × S3 × T 4, the symmetric orbifold of T 4, contains a closed higher spin subsector. Via holography, this makes precise the sense in which tensionless string theory on this background contains a Vasiliev higher spin theory. In this paper we study this phenomenon directly from the worldsheet. Using the WZW description of the background with pure NS-NS flux, we identify the states that make up the leading Regge trajectory and show that they fit into the even spin N=4 Vasiliev higher spin theory. We also show that these higher spin states do not become massless, except for the somewhat singular case of level k = 1 where the theory contains a stringy tower of massless higher spin fields coming from the long string sector.
Thermodynamics of charged Lovelock: AdS black holes
Prasobh, C. B.; Suresh, Jishnu; Kuriakose, V. C.
2016-04-01
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.
Jet physics from static charges in AdS space
Chien, Yang-Ting; Schwartz, Matthew D.; Simmons-Duffin, David; Stewart, Iain W.
2012-02-01
Soft interactions with high-energy jets are explored in radial coordinates which exploit the approximately conformal behavior of perturbative gauge theories. In these coordinates, the jets, approximated by Wilson lines, become static charges in Euclidean AdS. The anomalous dimension of the corresponding Wilson line operator is then determined by the potential energy of the charges. To study these Wilson lines we introduce a “conformal gauge” which does not have kinetic mixing between radial and angular directions, and show that a number of properties of Wilson lines are reproduced through relatively simple calculations. For example, certain nonplanar graphs involving multiple Wilson lines automatically vanish. We also discuss the linear growth of the charges’ imaginary potential energy with separation, and a relationship between Wilson line diagrams and Witten diagrams.
Jet Physics from Static Charges in AdS
Chien, Yang-Ting; Simmons-Duffin, David; Stewart, Iain W
2011-01-01
Soft interactions with high-energy jets are explored in radial coordinates which exploit the approximately conformal behavior of perturbative gauge theories. In these coordinates, the jets, approximated by Wilson lines, become static charges in Euclidean AdS. The anomalous dimension of the corresponding Wilson line operator is then determined by the potential energy of the charges. To study these Wilson lines we introduce a "conformal gauge" which does not have kinetic mixing between radial and angular directions, and show that a number of properties of Wilson lines are reproduced through relatively simple calculations. For example, certain non-planar graphs involving multiple Wilson lines automatically vanish. We also discuss the linear growth of the charges' imaginary potential energy with separation, and a relationship between Wilson line diagrams and Witten diagrams.
An Investigation of AdS2 Backreaction and Holography
Engelsöy, Julius; Verlinde, Herman
2016-01-01
We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski and develop an 1D effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1D version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.
On Information Loss in AdS$_3$/CFT$_2$
Fitzpatrick, A Liam; Li, Daliang; Wang, Junpu
2016-01-01
We discuss information loss from black hole physics in AdS$_3$, focusing on two sharp signatures infecting CFT$_2$ correlators at large central charge $c$: 'forbidden singularities' arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite $c$, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior of correlators at times $t \\sim S_{BH}$, the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the $1/c$ expansion of exact examples, we explicitly identify 'information-restoring' effects from heavy states that should correspo...
Supersymmetry Properties of AdS Supergravity Backgrounds
Beck, Samuel; Gutowski, Jan; Papadopoulos, George
2017-01-01
Anti-de Sitter supergravity backgrounds are of particular interest in light of the AdS/CFT correspondence, which relates them to dual conformal field theories on the boundary of the anti-de Sitter space. We have investigated the forms of the supersymmetries these backgrounds preserve by solving the Killing spinor equations on the anti-de Sitter components of these spaces. We have found that a supersymmetric AdSn background necessarily preserves 2⌊n/2⌋ k supersymmetries for n 0 . Additionally, we have found that the Killing spinors of each background are exactly the zeroes of a Dirac-like operator constructed from the Killing spinor equations.
Thermodynamics of charged Lovelock: AdS black holes
Energy Technology Data Exchange (ETDEWEB)
Prasobh, C.B.; Suresh, Jishnu; Kuriakose, V.C. [Cochin University of Science and Technology, Department of Physics, Cochin (India)
2016-04-15
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime. (orig.)
Adiabatic pumping solutions in global AdS
Carracedo, Pablo; Mas, Javier; Musso, Daniele; Serantes, Alexandre
2017-05-01
We construct a family of very simple stationary solutions to gravity coupled to a massless scalar field in global AdS. They involve a constantly rising source for the scalar field at the boundary and thereby we name them pumping solutions. We construct them numerically in D = 4. They are regular and, generically, have negative mass. We perform a study of linear and nonlinear stability and find both stable and unstable branches. In the latter case, solutions belonging to different sub-branches can either decay to black holes or to limiting cycles. This observation motivates the search for non-stationary exactly timeperiodic solutions which we actually construct. We clarify the role of pumping solutions in the context of quasistatic adiabatic quenches. In D = 3 the pumping solutions can be related to other previously known solutions, like magnetic or translationally-breaking backgrounds. From this we derive an analytic expression.
Worldsheet dilatation operator for the AdS superstring
Energy Technology Data Exchange (ETDEWEB)
Ramírez, Israel [Departamento de Física, Universidad Técnica Federico Santa María,Casilla 110-V, Valparaíso (Chile); Institut für Mathematik und Institut für Physik, Humboldt-Universität zu Berlin,IRIS Haus, Zum Großen Windkanal 6, 12489 Berlin (Germany); Vallilo, Brenno Carlini [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile)
2016-05-23
In this work we propose a systematic way to compute the logarithmic divergences of composite operators in the pure spinor description of the AdS{sub 5}×S{sup 5} superstring. The computations of these divergences can be summarized in terms of a dilatation operator acting on the local operators. We check our results with some important composite operators of the formalism.
Islands of stability and recurrence times in AdS
Green, Stephen R; Lehner, Luis; Liebling, Steven L
2015-01-01
We study the stability of anti-de Sitter (AdS) spacetime to spherically symmetric perturbations of a real scalar field in general relativity. Further, we work within the context of the "two time framework" (TTF) approximation, which describes the leading nonlinear effects for small amplitude perturbations, and is therefore suitable for studying the weakly turbulent instability of AdS---including both collapsing and non-collapsing solutions. We have previously identified a class of quasi-periodic (QP) solutions to the TTF equations, and in this work we analyze their stability. We show that there exist several families of QP solutions that are stable to linear order, and we argue that these solutions represent islands of stability in TTF. We extract the eigenmodes of small oscillations about QP solutions, and we use them to predict approximate recurrence times for generic non-collapsing initial data in the full (non-TTF) system. Alternatively, when sufficient energy is driven to high-frequency modes, as occurs ...
Holographic reconstruction of AdS exchanges from crossing symmetry
Alday, Luis F.; Bissi, Agnese; Perlmutter, Eric
2017-08-01
Motivated by AdS/CFT, we address the following outstanding question in large N conformal field theory: given the appearance of a single-trace operator in the O× O OPE of a scalar primary O , what is its total contribution to the vacuum four-point function theories at leading order in 1/ N. Viewed holographically, this provides a field theory reconstruction of crossing-symmetric, four-point exchange amplitudes in AdS5. Our solution takes the form of a resummation of the large spin solution to the crossing equations, supplemented by corrections at finite spin, required by crossing. The method can be applied to the exchange of operators of arbitrary twist τ and spin s, although it vastly simplifies for even-integer twist, where we give explicit results. The output is the set of OPE data for the exchange of all double-trace operators {[OO]}_{n,ℓ } . We find that the double-trace anomalous dimensions γ n, ℓ are negative, monotonic and convex functions of ℓ, for all n and all ℓ > s. This constitutes a holographic signature of bulk causality and classical dynamics of even-spin fields. We also find that the "derivative relation" between double-trace anomalous dimensions and OPE coefficients does not hold in general, and derive the explicit form of the deviation in several cases. Finally, we study large n limits of γ n,ℓ, relevant for the Regge and bulk-point regimes.
Natsuume, Makoto
2014-01-01
This is the draft version of a textbook on "real-world" applications of the AdS/CFT duality for beginning graduate students in particle physics and for researchers in the other fields. The aim of this book is to provide background materials such as string theory, general relativity, nuclear physics, nonequilibrium physics, and condensed-matter physics as well as some key applications of the AdS/CFT duality in a single textbook. Contents: (1) Introduction, (2) General relativity and black holes, (3) Black holes and thermodynamics, (4) Strong interaction and gauge theories, (5) The road to AdS/CFT, (6) The AdS spacetime, (7) AdS/CFT - equilibrium, (8) AdS/CFT - adding probes, (9) Basics of nonequilibrium physics, (10) AdS/CFT - nonequilibrium, (11) Other AdS spacetimes, (12) Applications to quark-gluon plasma, (13) Basics of phase transition, (14) AdS/CFT - phase transition.
Facilities Management and Added Value
DEFF Research Database (Denmark)
Jensen, Per Anker
2010-01-01
Aim: This paper aims to present different models of the concept of the added value of Facilities Management (FM), including the FM Value Map, which forms the basis of research group in EuroFM, and to present some of the results of this research collaboration. Approach and methodology: The paper...... on the aimed output) and the internal resource based view (with a focus on the input from FM and RE). Good relationship management and building on trust shows to be equally important as delivering the agreed services. In order to measure the multi-dimensional components of adding value both qualitative...... is based on literature reviews of the most influential journals within the academic fields of FM, Corporate Real Estate Management and Business to Business Marketing and discussions between participants of the research group working on a further exploration and testing of the FM Value Map. Conclusions...
DEFF Research Database (Denmark)
Antila, Kari; Lötjönen, Jyrki; Thurfjell, Lennart;
2013-01-01
can be managed. Today the significance of early and precise diagnosis of AD is emphasized in order to minimize its irreversible effects on the nervous system. When new drugs and therapies enter the market it is also vital to effectively identify the right candidates to benefit from these. The main...... candidates and implement the framework in software. The results are currently used in several research projects, licensed to commercial use and being tested for clinical use in several trials....
Energy Technology Data Exchange (ETDEWEB)
Fitzpatrick, A.Liam; /Boston U.; Kaplan, Jared; /SLAC
2012-02-14
We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.
Holography in 3D AdS gravity with torsion
Blagojević, Milutin; Miskovic, Olivera; Olea, Rodrigo
2013-01-01
Basic aspects of the AdS/CFT correspondence are studied in the framework of 3-dimensional gravity with torsion. After choosing a consistent holographic ansatz, we formulate an improved approach to the Noether--Ward identities for the boundary theory. The method is applied first to the topological Mielke--Baekler model, and then to the more interesting (parity-preserving) 3-dimensional gravity with propagating torsion. In both cases, we find the finite holographic energy-momentum and spin currents and obtain the associated (anomalous) Noether--Ward identities.
Towards Timelike Singularity via AdS Dual
Bhowmick, Samrat
2016-01-01
It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore one can study field theory on this Kasner space via its gravity dual. In this paper, we show that there exists a Kasner-like geometry with timelike singularity for which one can construct a dual gravity description. We then study various minimal surfaces including spacelike geodesics. Finally, we compute correlators of highly massive operators in the boundary field theory with a geodesic approximation.
Canonical energy and hairy AdS black holes
Hyun, Seungjoon; Yi, Sang-Heon
2016-01-01
We propose the modified version of the canonical energy which was introduced originally by Hollands and Wald. Our construction depends only on the Euler-Lagrange expression of the system and thus is independent of the ambiguity in the Lagrangian. After some comments on our construction, we briefly mention on the relevance of our construction to the boundary information metric in the context of the AdS/CFT correspondence. We also study the stability of three-dimensional hairy extremal black holes by using our construction.
Stability of Charged Global AdS$_4$ Spacetimes
Arias, Raúl; Serantes, Alexandre
2016-01-01
We study linear and nonlinear stability of asymptotically AdS$_4$ solutions in Einstein-Maxwell-scalar theory. After summarizing the set of static solutions we first examine thermodynamical stability in the grand canonical ensemble and the phase transitions that occur among them. In the second part of the paper we focus on nonlinear stability in the microcanonical ensemble by evolving radial perturbations numerically. We find hints of an instability corner for vanishingly small perturbations of the same kind as the ones present in the uncharged case. Collapses are avoided, instead, if the charge and mass of the perturbations come to close the line of solitons. Finally we examine the soliton solutions. The linear spectrum of normal modes is not resonant and instability turns on at extrema of the mass curve. Linear stability extends to nonlinear stability up to some threshold for the amplitude of the perturbation. Beyond that, the soliton is destroyed and collapses to a hairy black hole. The relative width of t...
AdS crunches, CFT falls, and cosmological complexity
Barbón, José Luis
2015-01-01
This chapter discusses the holographic description of crunching AdS cosmologies. Crunching FRW models with hyperbolic spatial sections are dual to semiclassical condensates in deformed de Sitter (dS) CFTs. dS-invariant condensates with a sharply defined energy scale are induced by effective negative-definite relevant or marginal operators, which may or may not destabilize the CFT. This result is obtained by explicitly constructing a “complementarity map” for this model, given by a conformal transformation of the dS CFT into a static time-frame, which reveals the crunch as an infinite potential-energy fall in finite time. Quite generically, the crunch is associated with a finite-mass black hole if the dS O(d, 1) invariance is an accidental IR symmetry, broken to U(1) × O(d) in the UV. Any such regularization cuts off the eternity of dS spacetime. Equivalently, the dimension of the Hilbert space propagating into the crunch is finite only when dS is not eternal.
Couzens, Christopher; Lawrie, Craig; Martelli, Dario; Schäfer-Nameki, Sakura; Wong, Jin-Mann
2017-08-01
We construct supersymmetric AdS3 solutions in F-theory, that is Type IIB supergravity with varying axio-dilaton, which are holographically dual to 2d N=(0,4) superconformal field theories with small superconformal algebra. In F-theory these arise from D3-branes wrapped on curves in the base of an elliptically fibered Calabi-Yau threefold Y 3 and correspond to self-dual strings in the 6d N=(1,0) theory obtained from F-theory on Y 3. The non-trivial fibration over the wrapped curves implies a varying coupling of the N=4 Super-Yang-Mills theory on the D3-branes. We compute the holographic central charges and show that these agree with the field theory and with the anomalies of self-dual strings in 6d. We complement our analysis with a discussion of the dual M-theory solutions and a comparison of the central charges.
On modular properties of the AdS3 CFT
Baron, Walter
2010-01-01
We study modular properties of the AdS3 WZNW model. Although the Euclidean partition function is modular invariant, the characters on the Euclidean torus are ill-defined and their modular transformations are unknown. We reconsider the characters defined on the Lorentzian torus, focusing on their structure as distributions. We find a generalized S matrix, depending on the sign of the real modular parameters, which has two diagonal blocks and one off-diagonal block, mixing discrete and continuous representations, that we fully determine. We then explore the relations among the modular transformations, the fusion algebra and the boundary states. We explicitly construct Ishibashi states for the maximally symmetric D-branes and show that the generalized S matrix defines the one-point functions associated to point-like and H2 branes as well as the fusion rules of the degenerate representations of SL(2,R) appearing in the open string spectrum of the point-like D-branes, through a generalized Verlinde theorem.
Goodman, Alyssa
We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where
Noncommutative AdS2/CFT1 duality: The case of massless scalar fields
Pinzul, A.; Stern, A.
2017-09-01
We show how to construct correlators for the CFT1 which is dual to noncommutative AdS2 (n c AdS2). We do it explicitly for the example of the massless scalar field on Euclidean n c AdS2. n c AdS2 is the quantization of AdS2 that preserves all the isometries. It is described in terms of the unitary irreducible representations, more specifically discrete series representations, of s o (2 ,1 ). We write down symmetric differential representations for the discrete series and then map them to functions on the Moyal-Weyl plane. The Moyal-Weyl plane has a large distance limit which can be identified with the boundary of n c AdS2. Killing vectors can be constructed on n c AdS2 which reduce to the AdS2 Killing vectors near the boundary. We, therefore, conclude that n c AdS2 is asymptotically AdS2, and so the AdS /CFT correspondence should apply. For the example of the massless scalar field on Euclidean n c AdS2, the on-shell action, and resulting two-point function for the boundary theory, are computed to leading order in the noncommutativity parameter. The computation is nontrivial because nonlocal interactions appear in the Moyal-Weyl description. Nevertheless, the result is remarkably simple and agrees with that of the commutative scalar field theory, up to a rescaling.
Entanglement Entropy of AdS Black Holes
Directory of Open Access Journals (Sweden)
Maurizio Melis
2010-11-01
Full Text Available We review recent progress in understanding the entanglement entropy of gravitational configurations for anti-de Sitter gravity in two and three spacetime dimensions using the AdS/CFT correspondence. We derive simple expressions for the entanglement entropy of two- and three-dimensional black holes. In both cases, the leading term of the entanglement entropy in the large black hole mass expansion reproduces exactly the Bekenstein-Hawking entropy, whereas the subleading term behaves logarithmically. In particular, for the BTZ black hole the leading term of the entanglement entropy can be obtained from the large temperature expansion of the partition function of a broad class of 2D CFTs on the torus.
MUSICAL ARRANGEMENT OF MEDIA ADS
Directory of Open Access Journals (Sweden)
Chernyshov Alexander V.
2015-01-01
Full Text Available The music-compositional principles of commercial and political advertising and also the self-promotion of electronic media (radio, television, Internet are considered in this mediatext: from the elementary beeps, symbolic functions, emblems/logos and musical brands to the sound engineering technology to underscore the product's name and the complex synthesis between music and intra movements and color-light design of frames. Simultaneously examines, how the musical arrangement of ethereal advertising is involved in creation the emotional drama or bravado which reach the level of explicit or associative counterpoint 'music with the advertised object or subject' and which extend to expression of cultural image of all the broadcast channel. The article explores the works of the next genres like infomercial, teleshopping, film-ad, and autonomous commercials that have been produced in European countries or USA.
DEFF Research Database (Denmark)
Schröder, Philipp J.H.; Sørensen, Allan
2010-01-01
Real-world industries are composed from heterogeneous firms and substantial intra-industry reallocations take place, i.e. high productivity firms squeeze out low productivity firms. Previous tax-tool comparisons have not included these central forces of industry structure. This paper examines...... a general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit...... taxes distort relative prices, which in turn reduces average industry productivity through reallocations (the survival and increased market share of lower productivity firms). Importantly, numerical solutions of the model reveal that the relative welfare loss from using the unit tax increases...
Mitreska, Biljana
2017-01-01
The LHCb experiment is designed to perform high precision measurements of matter-antimatter asymmetries and searches for rare and forbidden decays, with the aim of discovering new and unexpected particles and forces. In 2030 the LHC beam intensity will increase by a factor of 50 compared to current operations. This means increased samples of the particles we need to study, but it also presents experimental challenges. In particular, with current technology it becomes impossible to differentiate the many (>50) separate proton-proton collisions which occur for each bunch crossing.\\\\ In this project a Monte Carlo simulation was developed to model the operation of a silicon pixel vertex detector surrounding the collision region at LHCb, under the conditions expected after 2030, after the second upgrade of the Vertex Locator(VELO).The main goal was studying the effect of adding '4D' detectors which save high-precision timing information, in addition to the usual three spatial coordinates, as charged particles pas...
Axenides, Minos; Linardopoulos, Georgios
2013-01-01
We study membrane configurations in AdS_{7/4}xS^{4/7}. The membranes are wrapped around the compact manifold S^{4/7} and are dynamically equivalent to bosonic strings in AdS_5. We thus conveniently identify them as "stringy membranes". For the case of AdS_7xS^4, their construction is carried out by embedding the Polyakov action for classical bosonic strings in AdS_5, into the corresponding membrane action. Therefore, every string configuration in AdS_5 can be realized by an appropriately chosen stringy membrane in AdS_7xS^4. We discuss the possibility of this being also the case for stringy membranes in AdS_4xS^7/Z^k (k > 1 or k = 1). By performing a stability analysis to the constructed solutions, we find that the (membrane) fluctuations along their transverse directions are organized in multiple Lam\\'{e} stability bands and gaps in the space of parameters of the configurations. In this membrane picture, strings exhibit a single band/gap structure. Since the spectrum of quadratic fluctuations is important fo...
Spiky strings in AdS_3 x S^1 and their AdS-pp-wave limits
Ishizeki, R; Tirziu, A; Tseytlin, A A
2008-01-01
We study a class of classical solutions for closed strings moving in AdS_3 x S^1 part of AdS_5 x S^5 with energy E and spin S in AdS_3 and angular momentum J and winding m in S^1. They have rigid shape with n spikes in AdS_3. We find that when J or m are non-zero, the spikes do not end in cusps. We consider in detail a special large n limit in which S ~ n^2, J ~ n, i.e. S >> J >> 1, with (E+S)/ n^2, (E-S)/ n, J/n, m/n staying finite. In that limit the spiky spinning string approaches the boundary of AdS_5. We show that the corresponding solution can be interpreted as describing a periodic-spike string moving in AdS_3 --pp-wave x S^1 background. The resulting expression for the string energy should represent a strong-coupling prediction for anomalous dimension of a class of dual gauge theory states in a particular thermodynamic limit of the SL(2) spin chain.
Recurring Anomaly Detection System (ReADS)
National Aeronautics and Space Administration — Overview: ReADS can analyze text reports, such as aviation reports and problem or maintenance records. ReADS uses text clustering algorithms to group loosely related...
TV Snack Ads Make Preschoolers Snack More
... Sesame Street" interrupted by TV ads for a salty snack food ended up eating more of that ... watched the show with commercials for a popular salty snack. The ads depicted kids happily playing and ...
The AdS/CFT/Unparticle Correspondence
Cacciapaglia, Giacomo; Terning, John
2009-01-01
We examine the correspondence between the anti-de Sitter (AdS) description of conformal field theories (CFTs) and the unparticle description of CFTs. We show how unparticle actions are equivalent to holographic boundary actions for fields in AdS, and how massive unparticles provide a new type of infrared cutoff that can be simply implemented in AdS by a soft breaking of conformal symmetry. We also show that processes involving scalar unparticles with dimensions d_s<2 or fermion unparticles with dimensions d_f<5/2 are insensitive to ultraviolet cutoff effects. Finally we show that gauge interactions for unparticles can be described by bulk gauge interactions in AdS and that they correspond to minimal gauging of the non-local effective action, and we compute the fermion unparticle production cross-section.
Penedones, Joao
2017-01-01
We introduce the AdS/CFT correspondence as a natural extension of QFT in a fixed AdS background. We start by reviewing some general concepts of CFT, including the embedding space formalism. We then consider QFT in a fixed AdS background and show that one can define boundary operators that enjoy very similar properties as in a CFT, except for the lack of a stress tensor. Including a dynamical metric in AdS generates a boundary stress tensor and completes the CFT axioms. We also discuss some applications of the bulk geometric intuition to strongly coupled QFT. Finally, we end with a review of the main properties of Mellin amplitudes for CFT correlation functions and their uses in the context of AdS/CFT.
Condom ads promote illicit sex.
Kippley, J F
1994-01-01
Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads.
Directory of Open Access Journals (Sweden)
Manasvi Kalra,
2016-02-01
Full Text Available The apps consist of advertisements to promote their products. Not all of them are appropriate to resume. Therefore various algorithms have been used in order to block those apps from existence but none of them is completely successful. In our app we are using an antivirus which can by default block those spy apps and remove them from the web page. The algorithm which has been used makes use of various ant viruses in the background which detect irrelevant and intimate apps and then our algorithm will demolish them. Certain apps are non-trustworthy where one click can spy all the mobile data. They block those apps and works on security. We are working on secure ads for mobile apps. It can also work as a basic antivirus where it detects the viruses like malwares in any of your installed apps or downloads. It will create a popup of discarding or keeping it. Mobile applications can be downloaded from anywhere like amazon, googleplay, apps store etc. There is no rigorous verification of an application when it is uploaded to the market. One can easily develop a malicious application and upload it to the app market. The user itself is responsible for accepting the risk of an app available from secondary markets. Therefore, we have decided to develop this app to make the market more secure and bounded. In future, It will take the mobile market while consuming minimal additional resources and preserving user privacy.
Material Developing for ADS Beam Window
Institute of Scientific and Technical Information of China (English)
XUYong-li; XUYuan-chao; LIHua-qing; NINGGuang-sheng; WANFa-rong; ZHAOFei
2003-01-01
The irradiation damage and the chemical interaction with the coolant for the ADS target and the structure materials are the key issues in ADS engineering. The developing of the materials that are irradiation and corrosion resistance is the important topic in ADS program in many countries. In this case,a topic of the material developing for the beam window has been proposed in our ADS program.
Myths & Facts about Value-Added Analysis
TNTP, 2011
2011-01-01
This paper presents myths as well as facts about value-added analysis. These myths include: (1) "Value-added isn't fair to teachers who work in high-need schools, where students tend to lag far behind academically"; (2) "Value-added scores are too volatile from year-to-year to be trusted"; (3) "There's no research behind value-added"; (4) "Using…
Automated Experiments on Ad Privacy Settings
Directory of Open Access Journals (Sweden)
Datta Amit
2015-04-01
Full Text Available To partly address people’s concerns over web tracking, Google has created the Ad Settings webpage to provide information about and some choice over the profiles Google creates on users. We present AdFisher, an automated tool that explores how user behaviors, Google’s ads, and Ad Settings interact. AdFisher can run browser-based experiments and analyze data using machine learning and significance tests. Our tool uses a rigorous experimental design and statistical analysis to ensure the statistical soundness of our results. We use AdFisher to find that the Ad Settings was opaque about some features of a user’s profile, that it does provide some choice on ads, and that these choices can lead to seemingly discriminatory ads. In particular, we found that visiting webpages associated with substance abuse changed the ads shown but not the settings page. We also found that setting the gender to female resulted in getting fewer instances of an ad related to high paying jobs than setting it to male. We cannot determine who caused these findings due to our limited visibility into the ad ecosystem, which includes Google, advertisers, websites, and users. Nevertheless, these results can form the starting point for deeper investigations by either the companies themselves or by regulatory bodies.
16 CFR 460.18 - Insulation ads.
2010-01-01
... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Insulation ads. 460.18 Section 460.18 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation...
Ad-Coop Positioning System (ACPS)
DEFF Research Database (Denmark)
Frattasi, Simone; Monti, Marco
2008-01-01
In this paper, we propose an innovative solution for positioning determination in 4G wireless networks by introducing the Ad-Coop Positioning System (ACPS). The ACPS is supported by a hybrid cellular ad-hoc architecture, where the cellular network has a centralized control over the ad...
Supergravity on $AdS_{5/4}$ x Hopf Fibrations and Conformal Field Theories
Halyo, E
2000-01-01
We obtain three and four dimensional conformal field theories with less than maximal supersymmetry by using their supergravity duals. These supergravity theories are type II on $AdS_5 \\times CP^2$, IIA on $AdS_4 \\times CP^3$, IIB on $AdS_5 \\times S^5/Z_k$ and D=11 supergravity on $AdS_4 \\times S^7/Z_k$. They are obtained from the spherically compactified ten and eleven dimensional theories by either Hopf reduction or by winding the U(1) fiber over the base.
Supergravity on $AdS_{5/4} \\times$ Hopf Fibrations and Conformal Field Theories
1998-01-01
We obtain three and four dimensional conformal field theories with less than maximal supersymmetry by using their supergravity duals. These supergravity theories are type II on $AdS_5 \\times CP^2$, IIA on $AdS_4 \\times CP^3$, IIB on $AdS_5 \\times S^5/Z_k$ and D=11 supergravity on $AdS_4 \\times S^7/Z_k$. They are obtained from the spherically compactified ten and eleven dimensional theories by either Hopf reduction or by winding the U(1) fiber over the base.
Protein domain organisation: adding order
Directory of Open Access Journals (Sweden)
Kummerfeld Sarah K
2009-01-01
Full Text Available Abstract Background Domains are the building blocks of proteins. During evolution, they have been duplicated, fused and recombined, to produce proteins with novel structures and functions. Structural and genome-scale studies have shown that pairs or groups of domains observed together in a protein are almost always found in only one N to C terminal order and are the result of a single recombination event that has been propagated by duplication of the multi-domain unit. Previous studies of domain organisation have used graph theory to represent the co-occurrence of domains within proteins. We build on this approach by adding directionality to the graphs and connecting nodes based on their relative order in the protein. Most of the time, the linear order of domains is conserved. However, using the directed graph representation we have identified non-linear features of domain organization that are over-represented in genomes. Recognising these patterns and unravelling how they have arisen may allow us to understand the functional relationships between domains and understand how the protein repertoire has evolved. Results We identify groups of domains that are not linearly conserved, but instead have been shuffled during evolution so that they occur in multiple different orders. We consider 192 genomes across all three kingdoms of life and use domain and protein annotation to understand their functional significance. To identify these features and assess their statistical significance, we represent the linear order of domains in proteins as a directed graph and apply graph theoretical methods. We describe two higher-order patterns of domain organisation: clusters and bi-directionally associated domain pairs and explore their functional importance and phylogenetic conservation. Conclusion Taking into account the order of domains, we have derived a novel picture of global protein organization. We found that all genomes have a higher than expected
Flat Currents of Green-Schwarz Superstring in AdS2 × S2 Background
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
From the κ symmetric action of ⅡB string in AdS2 × S2 background given by Zhou, we derive the equations of motion. By using the twisted dual transformation which was introduced by Hou, we construct the flat currents, conserving non-local charge with one free parameter, for the superstring in AdS2 × S2.
Joule-Thomson expansion of the charged AdS black holes
Ökcü, Özgür; Aydıner, Ekrem
2017-01-01
In this paper, we study Joule-Thomson effects for charged AdS black holes. We obtain inversion temperatures and curves. We investigate similarities and differences between van der Waals fluids and charged AdS black holes for the expansion. We obtain isenthalpic curves for both systems in the T- P plane and determine the cooling-heating regions.
Joule-Thomson Expansion of Charged AdS Black Holes
Ökcü, Özgür
2016-01-01
In this paper, we study Joule-Thomson effects for charged AdS black holes. We obtain inversion temperatures and curves. We investigate similarities and differences between van der Waals fluids and charged AdS black holes for the expansion. We obtain isenthalpic curves for both systems in $T-P$ plane and determine the cooling-heating regions.
Static Einstein-Maxwell Black Holes with No Spatial Isometries in AdS Space.
Herdeiro, Carlos A R; Radu, Eugen
2016-11-25
We explicitly construct static black hole solutions to the fully nonlinear, D=4, Einstein-Maxwell-anti-de Sitter (AdS) equations that have no continuous spatial symmetries. These black holes have a smooth, topologically spherical horizon (section), but without isometries, and approach, asymptotically, global AdS spacetime. They are interpreted as bound states of a horizon with the Einstein-Maxwell-AdS solitons recently discovered, for appropriate boundary data. In sharp contrast to the uniqueness results for a Minkowski electrovacuum, the existence of these black holes shows that single, equilibrium, black hole solutions in an AdS electrovacuum admit an arbitrary multipole structure.
Static Einstein-Maxwell Black Holes with No Spatial Isometries in AdS Space
Herdeiro, Carlos A. R.; Radu, Eugen
2016-11-01
We explicitly construct static black hole solutions to the fully nonlinear, D =4 , Einstein-Maxwell-anti-de Sitter (AdS) equations that have no continuous spatial symmetries. These black holes have a smooth, topologically spherical horizon (section), but without isometries, and approach, asymptotically, global AdS spacetime. They are interpreted as bound states of a horizon with the Einstein-Maxwell-AdS solitons recently discovered, for appropriate boundary data. In sharp contrast to the uniqueness results for a Minkowski electrovacuum, the existence of these black holes shows that single, equilibrium, black hole solutions in an AdS electrovacuum admit an arbitrary multipole structure.
Effects of ad placement and type on consumer responses to podcast ads.
Ritter, Eric A; Cho, Chang-Hoan
2009-10-01
The purpose of this study was to understand the effects of podcast ad placement and podcast ad type on consumers' perceived intrusiveness, perceived irritation, attitude toward the ad, and ad avoidance. Our 2 x 2 (traditional ad vs. sponsorship by beginning vs. middle) experimental study found that sponsorships generated better consumer responses than did traditional ads and that podcast ads placed at the beginning of audio podcasts yielded better consumer responses than those placed in the middle. Implications for marketers and advertisers are discussed.
AdS perturbations, isometries, selection rules and the Higgs oscillator
Energy Technology Data Exchange (ETDEWEB)
Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University,Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Nivesvivat, Rongvoram [Department of Physics, Faculty of Science, Chulalongkorn University,Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand)
2016-01-25
Dynamics of small-amplitude perturbations in the global anti-de Sitter (AdS) spacetime is restricted by selection rules that forbid effective energy transfer between certain sets of normal modes. The selection rules arise algebraically because some integrals of products of AdS mode functions vanish. Here, we reveal the relation of these selection rules to AdS isometries. The formulation we discover through this systematic approach is both simpler and stronger than what has been reported previously. In addition to the selection rule considerations, we develop a number of useful representations for the global AdS mode functions, with connections to algebraic structures of the Higgs oscillator, a superintegrable system describing a particle on a sphere in an inverse cosine-squared potential, where the AdS isometries play the role of a spectrum-generating algebra.
Perceived threat of Alzheimer disease (AD): the role of personal experience with AD.
Suhr, Julie A; Kinkela, Jessica H
2007-01-01
The fear of developing Alzheimer disease (AD) is highly salient, particularly for biologic family members. The current study evaluated social/cognitive explanations for perceived AD threat beyond genetic relatedness, including personal experience with AD, belief in negative aging stereotypes, and performance on delayed memory tasks. Participants were 97 healthy older adults aged 50 to 85, self-referred for a free community memory screen. Results showed that, as expected, personal AD experience was related to perceived AD threat. Furthermore, consistent with expectations, AD experience moderated the relationship between perceived AD threat and other explanatory variables, including age, belief in negative aging stereotypes, and cognitive performance. In those with AD experience, whether genetic or not, younger age was associated with more perceived AD threat, but an inverse relationship was seen in those without AD experience. Those with genetic AD experience seem particularly vulnerable to the effects of negative age stereotype beliefs on perceived AD threat, and show an inverse relationship between their actual cognitive performance and their perception of personal AD threat. Results highlight the importance of considering personal experience with AD when assessing a person's self-reported concerns about AD or his/her own memory changes.
Exploring antismoking ads: appeals, themes, and consequences.
Beaudoin, Christopher E
2002-01-01
In this study we seek a descriptive understanding of antismoking television advertising in light of the problem cigarette consumption poses for society today. We establish relationships between ad characteristics and whether ads have a youth or adult orientation, based on a content analysis of 197 antismoking television advertisements produced between 1991 and 1999. The study finds that youth-oriented ads have youth characters, sociability, and humor as common appeals, and social and short-term consequences. In contrast, adult-oriented ads relied on fear appeals and long-term, health-related consequences.
From path integrals to tensor networks for the AdS /CFT correspondence
Miyaji, Masamichi; Takayanagi, Tadashi; Watanabe, Kento
2017-03-01
In this paper, we discuss tensor network descriptions of AdS /CFT from two different viewpoints. First, we start with a Euclidean path-integral computation of ground state wave functions with a UV cutoff. We consider its efficient optimization by making its UV cutoff position dependent and define a quantum state at each length scale. We conjecture that this path integral corresponds to a time slice of anti-de Sitter (AdS) spacetime. Next, we derive a flow of quantum states by rewriting the action of Killing vectors of AdS3 in terms of the dual two-dimensional conformal field theory (CFT). Both approaches support a correspondence between the hyperbolic time slice H2 in AdS3 and a version of continuous multiscale entanglement renormalization ansatz. We also give a heuristic argument about why we can expect a sub-AdS scale bulk locality for holographic CFTs.
Value added meat marketing around the globe
DEFF Research Database (Denmark)
Grebitus, Carola; Mueller Loose, Simone
In highly competitive meat markets it is important to offer value added products to consumers. Thus, we need to understand which attributes are especially valued by consumers. This track session will contribute to a better understanding of consumer preferences for value added meats across differe...
Status Report on the Antiproton Decelerator (AD)
Erikson, T; Möhl, D
2001-01-01
CERN's new Antiproton Decelerator (AD) has been delivering a 100 MeV/c antiproton beam to three experiments (ASACUSA, AHENA and ATRAP) since July 10th, 2000. In this status report, we summarise the initial performance of the AD, draw provisional conclusions from the first month of operation and finally give some prospects for the future.
On circular strings in (AdS3 × S 3)ϰ
Banerjee, Aritra; Panigrahi, Kamal L.
2016-09-01
The so called one-parameter (often called ϰ) deformed AdS string sigma models have attracted a lot of attention lately in the study of integrability in string theory. We construct various circular string solutions in the (AdS3 × S 3) ϰ background and describe the characteristics of such solutions qualitatively. We study the Bohr-Sommerfeld like quantization for these string states to characterise the motion. Further we find a `long' string limit of such circular strings in the ϰ-deformed AdS3 and find a novel dependence of the oscillation number on the energy in the next to leading order expansion.
On circular strings in $(AdS_3 \\times S^3)_{\\varkappa}$
Banerjee, Aritra
2016-01-01
The so called one-parameter (often called $\\varkappa$) deformed $AdS$ string sigma models have attracted a lot of attention lately in the study of integrability in string theory. We construct various circular string solutions in the $(AdS_3 \\times S^3)_{\\varkappa}$ background and describe the characteristics of such solutions qualitatively. We study the Bohr-Sommerfeld like quantization for these string states to characterise the motion. Further we find a `long' string limit of such circular strings in the $\\varkappa$-deformed $AdS_3$ and find a novel dependence of the oscillation number on the energy in the next to leading order expansion.
Various types of phase transitions in the AdS soliton background
Peng, Yan; Wang, Bin
2011-01-01
We study the basic holographic insulator and superconductor phase transition in the AdS soliton background by generalizing the spontaneous breaking of a global U(1) symmetry to occur via St$\\ddot{u}$ckelberg mechanism. We construct the soliton solutions with backreaction and examine the effects of the backreaction on the condensation of the scalar hair in the generalized St$\\ddot{u}$ckelberg Lagrangian. We disclose rich physics in various phase transitions. In addition to the AdS soliton configuration, we also examine the property of the phase transition in the AdS black hole background.
Thermodynamic geometry and phase transitions of AdS braneworld black holes
Chaturvedi, Pankaj; Sengupta, Gautam
2017-02-01
The thermodynamics and phase transitions of charged RN-AdS and rotating Kerr-AdS black holes in a generalized Randall-Sundrum braneworld are investigated in the framework of thermodynamic geometry. A detailed analysis of the thermodynamics, stability and phase structures in the canonical and the grand canonical ensembles for these AdS braneworld black holes are described. The thermodynamic curvatures for both these AdS braneworld black holes are computed and studied as a function of the thermodynamic variables. Through this analysis we illustrate an interesting dependence of the phase structures on the braneworld parameter for these black holes.
Google Advertising Tools Cashing in with AdSense and AdWords
Davis, Harold
2010-01-01
With this book, you'll learn how to take full advantage of Google AdWords and AdSense, the sophisticated online advertising tools used by thousands of large and small businesses. This new edition provides a substantially updated guide to advertising on the Web, including how it works in general, and how Google's advertising programs in particular help you make money. You'll find everything you need to work with AdWords, which lets you generate text ads to accompany specific search term results, and AdSense, which automatically delivers precisely targeted text and image ads to your website.
Entropy of Warped Taub-NUT AdS Black String via the Brick Wall Method
Lee, Chong Oh
2014-01-01
When we consider five-dimensional warped Taub-NUT AdS black string with minimally coupled massive scalar field, we calculate an entropy by using the brick wall method. In extremely light effective mass, we find the entropy is proportional to an extra dimension wave number as well as quadratically divergent in a cutoff parameter. After taking zero NUT charge, we find the entropy of warped (AdS) Schwartzshield black hole string has a similar properties in as warped Taub-NUT AdS black string.
Directory of Open Access Journals (Sweden)
N.S. Mazhari
2017-03-01
Full Text Available The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.
Beyond the unitarity bound in AdS/CFT{sub (A)dS}
Energy Technology Data Exchange (ETDEWEB)
Andrade, Tomas [University of California, Santa Barbara (United States); Uhlemann, Christoph [Universitaet Wuerzburg (Germany)
2012-07-01
We study CFTs on dS and AdS spacetimes from a holographic perspective, in particular how the unitarity properties of the boundary theory are reflected in the bulk description. On geometries with an (A)dS conformal boundary we choose mass and boundary conditions for a Klein-Gordon field such that the corresponding CFT operator violates the unitarity bound. We analyze how the non-unitarity is reproduced in the bulk and discuss, for the case of an AdS boundary, prospects for multi-layered AdS/CFT-type dualities.
Phase Transition and Clapeyon Equation of Black Hole in Higher Dimensional AdS Spacetime
Zhao, Hui-Hua; Ma, Meng-Sen; Zhao, Ren
2014-01-01
By Maxwell equal area law we study the phase transition in higher dimensional Anti-de Sitter (AdS) Reissner-Nordstr\\"{o}m (RN) black hole and Kerr black hole in this paper. The coexisting region of the two phases involved in the phase transition is found and the coexisting curves are shown in $P-T$ figures. We also analytically investigate the parameters which affect the coexisting curves. To better compare with ordinary thermodynamic systems, the Clapeyon equation is derived for higher dimensional AdS black holes. This paper can help to deepen the understanding of the phase transition and phase structure of AdS black holes.
Boundary action of free AdS higher-spin gauge fields and the holographic correspondence
Joung, Euihun
2011-01-01
We determine the boundary terms of the free higher-spin action which reproduce the AdS Fronsdal equations in an AdS manifold with a finite distance boundary. The boundary terms are further constrained by the gauge invariance of the total action. We show that, for spins larger than two, no local boundary term can restore the full gauge symmetry, and the broken symmetry corresponds to higher-spin Weyl transformations on the boundary CFT. The boundary action is used for the evaluation of the on-shell higher-spin AdS action in terms of the boundary data given by a conformal higher-spin field.
Geometric Finiteness, Holography and Quasinormal Modes for the Warped AdS_3 Black Hole
Gupta, Kumar S; Sen, Siddhartha; Sivakumar, M
2009-01-01
We show that there exists a precise kinematical notion of holography for the Euclidean warped $AdS_3$ black hole. This follows from the fact that the Euclidean warped $AdS_3$ black hole spacetime is a geometrically finite hyperbolic manifold. For such manifolds a theorem of Sullivan provides a one-to-one correspondence between the hyperbolic structure in the bulk and the conformal structure of its boundary. Using this theorem we obtain the holographic quasinormal modes for the warped $AdS_3$ black hole.
An improved AFS phase for AdS3 string integrability
Abbott, Michael C
2015-01-01
We propose a number of modifications to the classical term in the dressing phase for integrable strings in AdS3 x S3 x S3 x S1, and check these against existing perturbative calculations, crossing symmetry, and the semiclassical limit of the Bethe equations. The principal change is that the phase for different masses should start with a term Q_1 Q_2, like the one-loop AdS3 dressing phase, rather than Q_2 Q_3 as for the original AdS5 AFS phase.
Mazhari, N S; Bahamonde, Sebastian; Faizal, Mir; Myrzakulov, Ratbay
2016-01-01
The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution and a solution with cylindrically symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not any such dependence.
Directory of Open Access Journals (Sweden)
Riera i Melis, Antonio
2000-12-01
Full Text Available During the 12th century, spices were known and appreciated in Catalonia and Languedoc by a great part of society. The success of spices was a result of their organoleptic qualities, their dietetic virtues and their exoticism due to their remote origin. To have pepper, ginger or cloves became a sign of distinction and good taste. In the central centuries of the Middle Ages, oriental seasonings had a social and cultural role much more important than it has been thought.[fr] Au XIIᵉ siècle, les épices furent connues et appréciées en Catalogne et en Languedoc par un grand secteur de la société. Son succès était une conséquence de ses qualités organoleptiques, de ses vertues diététiques et du caractère exotique que leur proportionnait son lointain origine. Assaisonner avec du poivre, du gingembre or du clou devint un signe de clase et de bon goût. Aux siècles centrales du Moyen Âge, les condiments provenant de l'Orient jouaient un rôle sociale et culturelle plus important qu'on n'avait pas été considéré jusqu'aujourd'hui.
[Rapid analysis of added ingredients in heroin].
Wang, Ji-fen; Yu, Jing; Guo, Xin; Sun, Xing-long; Wang, Ding-fang
2011-07-01
The method of rapid analysis of added ingredients in heroin was studied in the present paper. Adding sucrose, fructose, glucose, starch, caffeine and phenacetin to heroin with a certain percentage, the changes in the infrared spectrum with the concentration of heroin increasing and the detection limit of the additives were determined. Whether or not heroin can be detected in the sample with high concentration of added ingredients was studied using Raman spectroscopy. Similarly, in high purity of heroin, whether or not Raman spectroscopy can detect the added ingredients was tested. Through systematic experiments, the results showed that: using infrared spectroscopy and Raman spectroscopy to test the added ingredients of heroin is a rapid and effective method. Each has both advantages and disadvantages. We should select the appropriate method according to the actual cases.
The concept of added value of FM
DEFF Research Database (Denmark)
2012-01-01
Purpose: This chapter presents research perspectives and theoretical reflections on the concept of added value of FM from a variety of academic fields. Methodology: A literature review of the most influential journals within the academic fields of Facilities Management (FM), Corporate Real Estate...... conceptualization of the concept of added value of FM is of utmost importance for further research into the added value of FM and well-considered, evidence- based Value Adding Management in practice. Research limitations: Due to limited time not all FM-related journals could be included in the literature review...... Management (CREM) and Business to Business Marketing (B2B Marketing). Findings: The research shows different definitions and focus points, dependent on the academic field and the area of application. The different research perspectives explored a holistic view on the added value of FM by the integration...
Energy Technology Data Exchange (ETDEWEB)
Freivogel, Ben; /Stanford U., Phys. Dept. /LBL, Berkeley; Hubeny, Veronika E.; /LBL, Berkeley /Durham U., Dept. of Math.; Maloney, Alexander; /Stanford U., Phys. Dept.; Myers, Rob; /Perimeter Inst. Theor. Phys. /Waterloo U.; Rangamani, Mukund; /LBL, Berkeley /Durham U., Dept. of Math.; Shenker, Stephen; /Stanford U., Phys. Dept.
2005-10-07
We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.
A Grassmann Path From AdS$_3$ to Flat Space
Krishnan, Chethan; Roy, Shubho
2013-01-01
We show that interpreting the inverse AdS$_3$ radius $1/l$ as a Grassmann variable results in a formal map from gravity in AdS$_3$ to gravity in flat space. The underlying reason for this is the fact that $ISO(2,1)$ is the Inonu-Wigner contraction of $SO(2,2)$. We show how this works for the Chern-Simons actions, demonstrate how the general (Banados) solution in AdS$_3$ maps to the general flat space solution, and how the Killing vectors, charges and the Virasoro algebra in the Brown-Henneaux case map to the corresponding quantities in the BMS$_3$ case. Our results straightforwardly generalize to the higher spin case: the recently constructed flat space higher spin theories emerge automatically in this approach from their AdS counterparts. We conclude with a discussion of singularity resolution in the BMS gauge as an application.
Quantum corrections to supergravity on AdS2×S2
Larsen, Finn; Lisbão, Pedro
2015-04-01
We compute the off-shell spectrum of supergravity on AdS2×S2 by explicit diagonalization of the equations of motion for an effective AdS2 theory where all fields are dualized to scalars and spin-1/2 fermions. We classify all bulk modes as physical, gauge violating, and pure gauge then compute the physical spectrum by explicit cancellation of unphysical modes. We identify boundary modes as physical fields on S2 that are formally pure gauge but with gauge function that is non-normalizable on AdS2. As an application we compute the leading quantum correction to AdS2×S2 as a sum over physical fields including boundary states. The result agrees with a previous computation by Sen [1] where unphysical modes were canceled by ghosts.
Impaired cognition in depression and Alzheimer (AD: a gradient from depression to depression in AD
Directory of Open Access Journals (Sweden)
Narahyana Bom de Araujo
2014-09-01
Full Text Available Objective To assess cognition in major depressed (MD, Alzheimer's disease (AD, and depression in AD elderly. Method Subjects were evaluated by Mini Mental, Rey Auditory Verbal Learning Test, Rey Complex Figure, Digit Span, Similarities, Trail Making A/B, Verbal Fluency and Stroop. One-way ANOVA and multivariate models were used to compare the performance of each group on neuropsychological tests. Results We evaluated 212 subjects. Compared to MD, attention, working memory, processing speed and recall showed significantly better in controls. Controls showed significantly higher performance in all cognitive measures, except in attention compared to AD. Verbal fluency, memory, processing speed and abstract reasoning in MD was significantly higher compared to AD. AD was significantly better in general cognitive state than depression in AD. All other cognitive domains were similar. Conclusion A decreasing gradient in cognition appeared from the control to depression in AD, with MD and AD in an intermediate position.
Study of ADS-B Data Evaluation
Institute of Scientific and Technical Information of China (English)
ZHANG Jun; LIU Wei; ZHU Yanbo
2011-01-01
In western China,the terrain and meteorological conditions are so complex that it is not suitable to construct new radar stations.Automatic dependent surveillance-broadcast(ADS-B) is a totally new surveillance method,so before practically applied and operated in China,abundant tests and evaluations are necessary to validate the performance of ADS-B and guarantee the operational security.During the flight tests,we collect the data of radar,ADS-B and high accuracy position and compare the performance of ADS-B with radar based on high accuracy position.To solve the asynchronous problem among radar data,ADS-B data and real-time kinematic(RTK) data caused by different update rates,this article proposes the technique of synchronizing multi-surveil- lance data by extrapolating from the data of low update rate to high update rate according to velocity and heading.Meanwhile,because radar data,ADS-B data and RTK data are expressed in different coordinates and cannot be compared each other,this article provides a method to unifying the coordinates of multi-surveillance data.By the analysis and evaluation,we can conclude that the performance of ADS-B is better than radar.
Supergravity background of the lambda-deformed AdS_3 x S^3 supercoset
Chervonyi, Yuri
2016-01-01
We construct the solution of type IIB supergravity describing the integrable lambda-deformation of the AdS_3 x S^3 supercoset. While the geometry corresponding to the deformation of the bosonic coset has been found in the past, our background is more natural for studying superstrings, and several interesting features distinguish our solution from its bosonic counterpart. We also report progress towards constructing the lambda-deformation of the AdS_5 x S^5 supercoset.
Ad Hoc Network Securing Policy%Ad hoc网络安全策略
Institute of Scientific and Technical Information of China (English)
刘志远; 张曼曼
2006-01-01
本文首先介绍了Ad hoc网络的产生、定义、特点和应用,然后在探讨Ad hoc网络的安全需求的基础上,着重分析了移动Ad hoc网络易于遭受的攻击,最后讨论并提出了Ad Hoc网络的一些安全策略.
Yangian of AdS_3/CFT_2 and its deformation
Regelskis, Vidas
2015-01-01
We construct highest-weight modules and a Yangian extension of the centrally extended superalgebra appearing in the worldsheet scattering associated with the AdS_3 /CFT_2 duality, and show a link to the Yangian of AdS_5/CFT_4. We also consider a quantum deformation of this superalgebra, its modules and a quantum affine extension of the Drinfeld-Jimbo type which describes deformed worldsheet scattering.
Half BPS states in AdS_5 x Y^{p,q}
Gava, Edi; Milanesi, Giuseppe; O'Loughlin, Martin
2008-01-01
We study a class of solutions of IIB Supergravity which are asymptotically AdS_5 x Y^{p,q}. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS_5 x S^5 background. These geometries correspond to certain chiral primary operators of the N=1 superconformal quiver theories, dual to IIB theory on AdS_5 x Y^{p,q}. We also show how to recover the AdS_5 x Y^{p,q} backgrounds by suitably doubling the number of preserved supersymmetries. We then solve the differential equations perturbatively in a large AdS_5 radius expansion, imposing asymptotic AdS_5 x Y^{p,q} boundary conditions. We compute the global baryonic and mesonic charges, including the R-charge. As for the computation of the mass, i.e. the conformal dimension D of the dual field theory operators, which is notor...
Service placement in ad hoc networks
Wittenburg, Georg
2012-01-01
Service provisioning in ad hoc networks is challenging given the difficulties of communicating over a wireless channel and the potential heterogeneity and mobility of the devices that form the network. Service placement is the process of selecting an optimal set of nodes to host the implementation of a service in light of a given service demand and network topology. The key advantage of active service placement in ad hoc networks is that it allows for the service configuration to be adapted continuously at run time. ""Service Placement in Ad Hoc Networks"" proposes the SPi service placement fr
Value added meat marketing around the globe
DEFF Research Database (Denmark)
Grebitus, Carola; Mueller Loose, Simone
In highly competitive meat markets it is important to offer value added products to consumers. Thus, we need to understand which attributes are especially valued by consumers. This track session will contribute to a better understanding of consumer preferences for value added meats across different...... countries and simultaneously address different stages of the food chain by acknowledging factors such as breeding, forage (fat content), meat cuts as well as product labelling and packaging. Comparing consumers’ choices for value added pork and beef across different countries is the main theme and focus...
Trust Based Routing in Ad Hoc Network
Talati, Mikita V.; Valiveti, Sharada; Kotecha, K.
Ad Hoc network often termed as an infrastructure-less, self- organized or spontaneous network.The execution and survival of an ad-hoc network is solely dependent upon the cooperative and trusting nature of its nodes. However, this naive dependency on intermediate nodes makes the ad-hoc network vulnerable to passive and active attacks by malicious nodes and cause inflict severe damage. A number of protocols have been developed to secure ad-hoc networks using cryptographic schemes, but all rely on the presence of trust authority. Due to mobility of nodes and limitation of resources in wireless network one interesting research area in MANET is routing. This paper offers various trust models and trust based routing protocols to improve the trustworthiness of the neighborhood.Thus it helps in selecting the most secure and trustworthy route from the available ones for the data transfer.
Nastase, Horatiu
2007-01-01
These lectures present an introduction to AdS-CFT, and are intended both for begining and more advanced graduate students, which are familiar with quantum field theory and have a working knowledge of their basic methods. Familiarity with supersymmetry, general relativity and string theory is helpful, but not necessary, as the course intends to be as self-contained as possible. I will introduce the needed elements of field and gauge theory, general relativity, supersymmetry, supergravity, strings and conformal field theory. Then I describe the basic AdS-CFT scenario, of ${\\cal N}=4 $ Super Yang-Mills's relation to string theory in $AdS_5\\times S_5$, and applications that can be derived from it: 3-point functions, quark-antiquark potential, finite temperature and scattering processes, the pp wave correspondence and spin chains. I also describe some general properties of gravity duals of gauge theories.
Heat kernels on cone of AdS2 and k-wound circular Wilson loop in AdS5 × S5 superstring
Bergamin, R.; Tseytlin, A. A.
2016-04-01
We compute the one-loop world-sheet correction to partition function of {{AdS}}5× {{{S}}}5 superstring that should be representing k-fundamental circular Wilson loop in planar limit. The 2d metric of the minimal surface ending on k-wound circle at the boundary is that of a cone of AdS2 with deficit 2π (1-k). We compute the determinants of 2d fluctuation operators by first constructing heat kernels of scalar and spinor Laplacians on the cone using the Sommerfeld formula. The final expression for the k-dependent part of the one-loop correction has simple integral representation but is different from earlier results.
Profiling value added position in FM
DEFF Research Database (Denmark)
Katchamart, Akarapong
organizations can best add value. Based on comprehensive literature studies and 7 case studies of private and public organisations from Denmark, Holland, Hong Kong and Thailand, the dissertation analyses, how FM organizations can best create added value. From the analyses the following four value added...... - FM organizations influence the business productivities and outcome Each type of value added requires specific conditions and contingencies involved. This research thus offers a visual aid tool, “FM product-process matrix”, to assist practitioners to indicate their existing circumstances and contexts...... the unarticulated notions of added value from FM organization and activities. It will broaden the managerial perception and discussion on FM provision ´s abilities and capabilities. The results are besides the field of FM also of relevance for management of other service industries and functions....
Microbial production of value-added nutraceuticals.
Wang, Jian; Guleria, Sanjay; Koffas, Mattheos A G; Yan, Yajun
2016-02-01
Nutraceuticals are important natural bioactive compounds that confer health-promoting and medical benefits to humans. Globally growing demands for value-added nutraceuticals for prevention and treatment of human diseases have rendered nutraceuticals a multi-billion dollar market. However, supply limitations and extraction difficulties from natural sources such as plants, animals or fungi, restrict the large-scale use of nutraceuticals. Metabolic engineering via microbial production platforms has been advanced as an eco-friendly alternative approach for production of value-added nutraceuticals from simple carbon sources. Microbial platforms like the most widely used Escherichia coli and Saccharomyces cerevisiae have been engineered as versatile cell factories for production of diverse and complex value-added chemicals such as phytochemicals, prebiotics, polysaccaharides and poly amino acids. This review highlights the recent progresses in biological production of value-added nutraceuticals via metabolic engineering approaches.
Bergamin, R
2015-01-01
We compute the one-loop world-sheet correction to partition function of $AdS_5 \\times S^5$ superstring that should be representing $k$-fundamental circular Wilson loop in planar limit. The 2d metric of the minimal surface ending on $k$-wound circle at the boundary is that of a cone of $AdS_2$ with deficit $2\\pi (1-k)$. We compute determinants of 2d fluctuation operators by first constructing heat kernels of scalar and spinor Laplacians on the cone using the Sommerfeld formula. The final expression for the k-dependent part of the one-loop correction has simple integral representation but is different from earlier results.
Multilevel security model for ad hoc networks
Institute of Scientific and Technical Information of China (English)
Wang Changda; Ju Shiguang
2008-01-01
Modern battlefield doctrine is based on mobility, flexibility, and rapid response to changing situations.As is well known, mobile ad hoc network systems are among the best utilities for battlefield activity. Although much research has been done on secure routing, security issues have largely been ignored in applying mobile ad hoc network theory to computer technology. An ad hoc network is usually assumed to be homogeneous, which is an irrational assumption for armies. It is clear that soldiers, commanders, and commanders-in-chief should have different security levels and computation powers as they have access to asymmetric resources. Imitating basic military rank levels in battlefield situations, how multilevel security can be introduced into ad hoc networks is indicated, thereby controlling restricted classified information flows among nodes that have different security levels.
The Tetrahedral Zamolodchikov Algebra and the {AdS_5× S^5} S-matrix
Mitev, Vladimir; Staudacher, Matthias; Tsuboi, Zengo
2017-08-01
The S-matrix of the {AdS_5× S^5} string theory is a tensor product of two centrally extended su{(2|2)\\ltimes R^2 S-matrices, each of which is related to the R-matrix of the Hubbard model. The R-matrix of the Hubbard model was first found by Shastry, who ingeniously exploited the fact that, for zero coupling, the Hubbard model can be decomposed into two XX models. In this article, we review and clarify this construction from the AdS/CFT perspective and investigate the implications this has for the {AdS_5× S^5} S-matrix.
The Tetrahedron Zamolodchikov Algebra and the AdS5 x S5 S-matrix
Mitev, Vladimir; Tsuboi, Zengo
2012-01-01
The S-matrix of the AdS5 x S5 string theory is a tensor product of two centrally extended su(2|2) S-matrices, each of which is related to the R-matrix of the Hubbard model. The R-matrix of the Hubbard model was first found by Shastry, who ingeniously exploited the fact that, for zero coupling, the Hubbard model can be decomposed into two XX models. In this article, we review and clarify this construction from the AdS/CFT perspective and investigate the implications this has for the AdS5 x S5 S-matrix.
Adding stress plot function to NASTRAN
Katoh, S.
1978-01-01
Stress plot function was developed and added to the NASTRAN level 15.5. Computed stress distribution can be displayed by this function, with vectors showing the principal stresses of the finite elements over the specified portions of the structure. NASTRAN is reviewed in the aspect of plotting capabilities. Stress tensor field is examined in preparation of stress display. Then the stress plot function as added to the NASTRAN is described. A sample plotout by this function is shown.
Evaluation of co-added astronomical images
Nasyrova, M.; Vítek, S.
2017-07-01
The co-adding, averaging, or stacking of data are popular techniques to improve scientific outcomes in astronomy, especially in the case of extraction of very faint sources. These methods allow to increase the signal-to-noise ratio and to decrease the point spread function width, which improves the accuracy of segmentation. This paper deals with a brief review of image co-adding algorithms and their evaluation regarding improving the qualitative parameters of the image data.
AdS-Sliced Flavor Branes and Adding Flavor to the Janus Solution
Clark, Adam B; Newman, George M; Rommal, Andrea
2014-01-01
We implement D7 flavor branes in AdS-sliced coordinates on $AdS_5\\times S^5$ with the ansatz that the brane fluctuates only in the warped ($\\mu$) direction in this slicing, which is particularly appropriate for studying the Janus solution. The natural field theory dual in this slicing is $\\mathcal{N}=4$ super Yang-Mills on two copies of $AdS_4$. Branes extending from $\\mu=\\pm\\pi/2$ can end at different locations, giving rise to quarks with piecewise constant mass on each $AdS_4$ half-space, jumping discontinuously between them. A second class of flavor brane solutions exists in this coordinate system, dubbed "continuous" flavor branes, that extend across the entire range of $\\mu$. We propose that the correct dual interpretation of "disconnected" flavor brane in this ansatz is a quark hypermultiplet with constant mass on one of the AdS$_4$ half-spaces with totally reflecting boundary conditions at the boundary of AdS$_4$; whereas the dual interpretation of a continuous flavor brane has totally transparent boun...
Integrable strings for AdS/CFT
Borsato, Riccardo
2016-01-01
In this PhD thesis we review some aspects of integrable models related to string backgrounds or their deformations. In the first part we develop methods to obtain exact results in the AdS3/CFT2 correspondence. We consider the AdS_3 x S^3 x T^4 background with pure Ramond-Ramond flux and we find the all-loop worldsheet S-matrix by exploiting the symmetries of the model in light-cone gauge. As we naturally include the massless modes on the worldsheet, we derive the full set of Bethe-Yang equations. In the massive sector we give also a spin-chain description and we write down solutions compatible with crossing for the scalar factors which are not constrained by simmetries. In the second part of the thesis we consider the so-called "eta-deformation" of the superstring on AdS_5 x S^5. We first discuss the effects of the deformation at the level of the bosonic sigma-model, and we match the tree-level worldsheet scattering processes to the expansion of the q-deformed S-matrix. To identify the missing Ramond-Ramond f...
Kay, Bernard S
2011-01-01
We discuss the relationship between the bulk-boundary correspondence in Rehren's algebraic holography (and in other 'fixed-background' approaches to holography) and in mainstream 'Maldacena AdS/CFT'. Especially, we contrast the understanding of black-hole entropy from the viewpoint of QFT in curved spacetime -- in the framework of 't Hooft's 'brick wall' model -- with the understanding based on Maldacena AdS/CFT. We show that the brick-wall modification of a Klein Gordon field in the Hartle-Hawking-Israel state on 1+2-Schwarzschild AdS (BTZ) has a well-defined boundary limit with the same temperature and entropy as the brick-wall-modified bulk theory. One of our main purposes is to point out a close connection, for general AdS/CFT situations, between the puzzle raised by Arnsdorf and Smolin regarding the relationship between Rehren's algebraic holography and mainstream AdS/CFT and the puzzle embodied in the 'correspondence principle' proposed by Mukohyama and Israel in their work on the brick-wall approach to...
Gauge Symmetries and Holographic Anomalies of Chern-Simons and Transgression AdS Gravity
Mora, Pablo
2014-01-01
We review the issue of gauge and gravitational anomalies with backgrounds, maybe offering a new outlook on some aspects of these questions. We compute the holographic anomalies of hypothetical theories dual, in the sense of the AdS-CFT correspondence, to Chern-Simons AdS gravities. Those anomalies are either gauge anomalies associated to the AdS gauge group of the theory or diffeomorphism anomalies, with each kind related to the other. As a result of using suitable action principles por Chern-Simons AdS gravities, coming from Transgression forms, we obtain finite results without the need for further regularization. Our results are of potential interest for Lovelock gravity theories, as it has been shown that the boundary terms dictated by the transgressions for Chern-Simons gravities are also suitable to regularize Lovelock theories. The Wess-Zumino consistency condition ensures that anomalies of the generic form computed here should appear for these and other theories.
AdS5×S(5) mirror model as a string sigma model.
Arutyunov, Gleb; van Tongeren, Stijn J
2014-12-31
Doing a double Wick rotation in the world sheet theory of the light cone AdS5×S(5) superstring results in an inequivalent, so-called mirror theory that plays a central role in the field of integrability in the AdS-CFT correspondence. We show that this mirror theory can be interpreted as the light cone theory of a free string on a different background. This background is related to dS5×H(5) by a double T-duality, and has hidden supersymmetry. The geometry can also be extracted from an integrable deformation of the AdS5×S(5) sigma model, and we prove the observed mirror duality of these deformed models at the bosonic level as a byproduct. While we focus on AdS5×S(5), our results apply more generally.
On Thermodynamics of AdS Black Holes in M-Theory
Belhaj, A; Moumni, H EL; Masmar, K; Sedra, M B
2015-01-01
Motivated by a recent work on asymptotically AdS_4 black holes in M-theory, we investigate the thermodynamics and thermodynamical geometry of AdS black holes from M2 and M5-branes. Concretely, we consider AdS black holes in AdS_{p+2}\\times S^{11-p-2}, where p=2,5 by interpreting the number of M2 (and M5-branes) as a thermodynamical variable. We study the corresponding phase transition to examine their stabilities by calculating and discussing various thermodynamical quantities including the chemical potential. Then, we compute the thermodynamical curvatures from the Quevedo metric for M2 and M5-branes geometries to reconsider the stability of such black objects. The Quevedo metric singularities recover similar stability results provided by the phase transition program.
Higher spin contributions to holographic fluid dynamics in AdS5/CFT4
Lee, Seungjin; Polyakov, Dimitri
2014-08-01
We calculate the graviton's β function in the AdS string-theoretic sigma model, perturbed by vertex operators for Vasiliev's higher spin gauge fields in AdS5. The result is given by βmn=Rmn+4Tmn(g ,u) (with the AdS radius set to 1 and the graviton polarized along the AdS5 boundary), with the matter stress-energy tensor given by that of conformal holographic fluid in d =4, evaluated at the temperature given by T =1/π. The stress-energy tensor is given by Tmn=gmn+4umun+∑NTmn(N) where u is the vector excitation satisfying u2=-1 and N is the order of the gradient expansion in the dissipative part of the tensor. We calculate the contributions up to N =2. The higher spin excitations contribute to the β function, ensuring the overall Weyl covariance of the matter stress tensor. We conjecture that the structure of gradient expansion in d =4 conformal hydrodynamics at higher orders is controlled by the higher spin operator algebra in AdS5.
Interpolating from Bianchi Attractors to Lifshitz and AdS Spacetimes
Kachru, Shamit; Saha, Arpan; Samanta, Rickmoy; Trivedi, Sandip P
2013-01-01
We construct classes of smooth metrics which interpolate from Bianchi attractor geometries of Types II, III, VI and IX in the IR to Lifshitz or $AdS_2 \\times S^3$ geometries in the UV. While we do not obtain these metrics as solutions of Einstein gravity coupled to a simple matter field theory, we show that the matter sector stress-energy required to support these geometries (via the Einstein equations) does satisfy the weak, and therefore also the null, energy condition. Since Lifshitz or $AdS_2 \\times S^3$ geometries can in turn be connected to $AdS_5$ spacetime, our results show that there is no barrier, at least at the level of the energy conditions, for solutions to arise connecting these Bianchi attractor geometries to $AdS_5$ spacetime. The asymptotic $AdS_5$ spacetime has no non-normalizable metric deformation turned on, which suggests that furthermore, the Bianchi attractor geometries can be the IR geometries dual to field theories living in flat space, with the breaking of symmetries being either sp...
Closed string tachyons on AdS orbifolds and dual Yang-Mills instantons
Energy Technology Data Exchange (ETDEWEB)
Hikida, Y. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Iizuka, N. [California Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics
2007-06-15
We study the condensation of localized closed string tachyons on AdS orbifolds both from the bulk and boundary theory viewpoints. We first extend the known results for AdS{sub 5}/Z{sub k} to AdS{sub 3}/Z{sub k} case, and we proposed that the AdS{sub 3}/Z{sub k} decays into AdS{sub 3}/Z{sub k'} with k{sup '} < k. From the bulk viewpoint, we obtain a time-dependent gravity solution describing the decay of AdS orbifold numerically. From the dual gauge theory viewpoint, we calculated the Casimir energies of gauge theory vacua and it is found that their values are exactly the same as the masses of dual geometries, even though they are in different parameter regimes of 't Hooft coupling. We also consider AdS{sub 5} orbifold. The decay of AdS{sub 5}/Z{sub k} is dual to the transition between the vacua of dual gauge theory on R{sub t} x S{sup 3}/Z{sub k}. We constructed the instanton solutions describing the transitions by making use of instanton solutions on R{sub t} x S{sup 2}. (orig.)
Implementation of Recursion Relations in Gluon Scattering Amplitude Calculations in AdS4 /CFT3
Dokmetzoglou, Nikolaos; Kharel, Savan
2017-01-01
The Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence is a duality between a theory of gravity in curved-space (AdS) and a conformally-invariant quantum field theory in flat-space (CFT). Scattering amplitudes are observables associated with the probability of the interaction of a given assembly of particles. Gluons, being the exchange particles associated with the strong nuclear force, which holds quarks together to form protons, are abundant byproducts of fundamental particle collisions. Thus, studying gluon scattering amplitudes is an effective way of deepening our understanding of these observables in AdS/CFT. Traditionally, Feynman diagrams have been used to calculate such scattering amplitudes. In this project, we use factorization properties and recursion relations to simplify these calculations. More specifically, we calculate multiple (different helicity combinations) four-point gluon scattering amplitudes in AdS4 /CFT3 (4-D AdS and 3-D CFT) as sums of products of three-point amplitudes. And then we calculate a five-point gluon scattering amplitude in AdS4 /CFT3 by decomposing it into a sum of products of these four-point and three-point amplitudes. Finally we comment on useful identities for checking these amplitudes. This work was supported by a Weinstein Davidson College Research Initiative Summer Research grant.
Extended supersymmetric sigma models in AdS_4 from projective superspace
Butter, Daniel; Lindstrom, Ulf; Tartaglino-Mazzucchelli, Gabriele
2012-01-01
There exist two superspace approaches to describe N=2 supersymmetric nonlinear sigma models in four-dimensional anti-de Sitter (AdS_4) space: (i) in terms of N=1 AdS chiral superfields, as developed in arXiv:1105.3111 and arXiv:1108.5290; and (ii) in terms of N=2 polar supermultiplets using the AdS projective-superspace techniques developed in arXiv:0807.3368. The virtue of the approach (i) is that it makes manifest the geometric properties of the N=2 supersymmetric sigma-models in AdS_4. The target space must be a non-compact hyperkahler manifold endowed with a Killing vector field which generates an SO(2) group of rotations on the two-sphere of complex structures. The power of the approach (ii) is that it allows us, in principle, to generate hyperkahler metrics as well as to address the problem of deformations of such metrics. Here we show how to relate the formulation (ii) to (i) by integrating out an infinite number of N=1 AdS auxiliary superfields and performing a superfield duality transformation. We al...
AdS and Lifshitz scalar hairy black holes in Gauss-Bonnet gravity
Chen, Bin; Fan, Zhong-Ying; Zhu, Lu-Yao
2016-09-01
We consider Gauss-Bonnet (GB) gravity in general dimensions, which is nonminimally coupled to a scalar field. By choosing a scalar potential of the type V (ϕ )=2 Λ0+1/2 m2ϕ2+γ4ϕ4 , we first obtain large classes of scalar hairy black holes with spherical/hyperbolic/planar topologies that are asymptotic to locally anti- de Sitter (AdS) space-times. We derive the first law of black hole thermodynamics using Wald formalism. In particular, for one class of the solutions, the scalar hair forms a thermodynamic conjugate with the graviton and nontrivially contributes to the thermodynamical first law. We observe that except for one class of the planar black holes, all these solutions are constructed at the critical point of GB gravity where there exist unique AdS vacua. In fact, a Lifshitz vacuum is also allowed at the critical point. We then construct many new classes of neutral and charged Lifshitz black hole solutions for an either minimally or nonminimally coupled scalar and derive the thermodynamical first laws. We also obtain new classes of exact dynamical AdS and Lifshitz solutions which describe radiating white holes. The solutions eventually become AdS or Lifshitz vacua at late retarded times. However, for one class of the solutions, the final state is an AdS space-time with a globally naked singularity.
The Impact of Ad Characteristics on Adolescents’ Attitudes Towards Antismoking Ads
Directory of Open Access Journals (Sweden)
Domen Bajde
2008-03-01
Full Text Available Smoking exerts a considerable burden not only on those who smoke but just as well on society at large. In response, governments and institutions often resort to advertising which aims to discourage smoking. Unfortunately, our knowledge of the workings of antismoking advertising is detrimentally limited. In particular, the literature delving into the impact of antismoking ad characteristics (e. g., ad content, valence, intensity on the overall effectiveness of antismoking advertising is scarce and contradictory. This empirical study aims to enhance the knowledge of antismoking advertising by presenting results of the survey involving Slovene adolescents. The adolescents were first exposed to advertisements of different antismoking ad contents (for the purpose of this study the term ‘ad content’ refers to types of appeals used in antismoking advertising, ad valence and intensity, and later invited to respond to a number of questions measuring their attitudes toward the ads, their attitudes toward smoking, their intentions to smoke, etc. The results indicate that while the different intensity and valence of ads produce varying attitudes toward the ads, we could not confirm these differences based on ad content. Also, we found that adolescent smokers respond to antismoking ads differently than do their nonsmoking peers. Our findings offer several important implications for antismoking advertisers and the research community interested in the workings of antismoking advertising.
On the Thermodynamic Geometry and Critical Phenomena of AdS Black Holes
Sahay, Anurag; Sengupta, Gautam
2010-01-01
In this paper, we study various aspects of the equilibrium thermodynamic state space geometry of AdS black holes. We first examine the Reissner-Nordstrom-AdS (RN-AdS) and the Kerr-AdS black holes. In this context, the state space scalar curvature of these black holes are analysed in various regions of their thermodynamic parameter space. This provides important new insights into the structure and significance of the scalar curvature. We further investigate critical phenomena, and the behaviour of the scalar curvature near criticality, for KN-AdS black holes in two mixed ensembles, introduced and elucidated in our earlier work arXiv:1002.2538 [hep-th]. The critical exponents are identical to those in the RN-AdS and Kerr-AdS cases in the canonical ensemble. This suggests an universality in the scaling behaviour near critical points of AdS black holes. Our results further highlight qualitative differences in the thermodynamic state space geometry for electric charge and angular momentum fluctuations of these.
Rostworowski, Andrzej
2016-01-01
We argue that if the degeneracy of the spectrum of linear perturbations of AdS is properly taken into account, there are globally regular, time-periodic, asymptotically AdS solutions (geons) bifurcating from each linear eigenfrequency of AdS.
Kay, Bernard S.; Ortíz, L.
2014-05-01
We discuss the relationship between the bulk-boundary correspondence in Rehren's algebraic holography (and in other `fixed-background', QFT-based, approaches to holography) and in mainstream string-theoretic `Maldacena AdS/CFT'. Especially, we contrast the understanding of black-hole entropy from the point of view of QFT in curved spacetime—in the framework of 't Hooft's `brick wall' model—with the understanding based on Maldacena AdS/CFT. We show that the brick-wall modification of a Klein-Gordon field in the Hartle-Hawking-Israel state on dimensional Schwarzschild AdS has a well-defined boundary limit with the same temperature and entropy as the brick-wall-modified bulk theory. One of our main purposes is to point out a close connection, for general AdS/CFT situations, between the puzzle raised by Arnsdorf and Smolin regarding the relationship between Rehren's algebraic holography and mainstream AdS/CFT and the puzzle embodied in the `complementarity principle' proposed by Mukohyama and Israel in their work on the brick-wall approach to black hole entropy. Working on the assumption that similar results will hold for bulk QFT other than the Klein-Gordon field and for Schwarzschild AdS in other dimensions, and recalling the first author's proposed resolution to the Mukohyama-Israel puzzle based on his `matter-gravity entanglement hypothesis', we argue that, in Maldacena AdS/CFT, the algebra of the boundary CFT is isomorphic only to a proper subalgebra of the bulk algebra, albeit (at non-zero temperature) the (GNS) Hilbert spaces of bulk and boundary theories are still the `same'—the total bulk state being pure, while the boundary state is mixed (thermal). We also argue from the finiteness of its boundary (and hence, on our assumptions, also bulk) entropy at finite temperature, that the Rehren dual of the Maldacena boundary CFT cannot itself be a QFT and must, instead, presumably be something like a string theory.
Ad Hoc Access Gateway Selection Algorithm
Jie, Liu
With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. For mobile nodes in Ad Hoc network to internet, internet communications in the peer nodes must be achieved through the gateway. Therefore, the key Ad Hoc Access Networks will focus on the discovery gateway, as well as gateway selection in the case of multi-gateway and handover problems between different gateways. This paper considers the mobile node and the gateway, based on the average number of hops from an average access time and the stability of routes, improved gateway selection algorithm were proposed. An improved gateway selection algorithm, which mainly considers the algorithm can improve the access time of Ad Hoc nodes and the continuity of communication between the gateways, were proposed. This can improve the quality of communication across the network.
Higher spin holography and the AdS string sigma model
Polyakov, Dimitri
2013-05-01
We analyse the cubic spin-3 interaction in AdS space using the higher spin extension of the string-theoretic sigma-model constructed in our previous work, whose low energy limit is described by the AdS vacuum solution. We find that, in the leading order of the cosmological constant, the spin-3 correlator on the AdS4 string theory side reproduces the structure of the three-point function of composite operators, quadratic in free fields, in the dual d = 3 vector model. The cancellation of holography violating terms in d = 3 is related to the value of the Liouville background charge in d = 4. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Higher spin theories and holography’.
Vacuum type space-like string surfaces in AdS_3 x S^3
Dorn, Harald; Kalousios, Chrysostomos; Megrelidze, Luka; Wuttke, Sebastian
2010-01-01
We construct and classify all space-like minimal surfaces in AdS_3 x S^3 which globally admit coordinates with constant induced metric on both factors. Up to O(2,2) x O(4) transformations all these surfaces, except one class, are parameterized by four real parameters. The classes of surfaces correspond to different regions in this parameter space and show quite different boundary behavior. Our analysis uses a direct construction of the string coordinates via a group theoretical treatment based on the map of AdS_3 x S^3 to SL(2,R) x SU(2). This is complemented by a cross check via standard Pohlmeyer reduction. After embedding in AdS_5 x S^5 we calculate the regularized area for solutions with a boundary spanned by a four point scattering s-channel momenta configuration.
A note on vectorial AdS5/CFT4 duality for spin- j boundary theory
Bae, Jin-Beom; Joung, Euihun; Lal, Shailesh
2016-12-01
The vectorial holographic correspondences between higher-spin theories in AdS5 and free vector models on the boundary are extended to the cases where the latter is described by free massless spin- j field. The dual higher-spin theory in the bulk does not include gravity and can only be defined on rigid AdS5 background with S 4 boundary. We discuss various properties of these rather special higher-spin theories and calculate their one-loop free energies. We show that the result is proportional to the same quantity for spin- j doubleton treated as if it is a AdS5 field. Finally, we consider even more special case where the boundary theory itself is given by an infinite tower of massless higher-spin fields.
Vacuum energy in Einstein-Gauss-Bonnet AdS gravity
Kofinas, G; Kofinas, Georgios; Olea, Rodrigo
2006-01-01
A finite action principle for Einstein-Gauss-Bonnet AdS gravity is presented. The boundary term, which is different for even and odd dimensions, is a functional of the boundary metric, intrinsic curvature and extrinsic curvature. For even dimensions, the boundary term corresponds to the maximal Chern form of the spacetime, and the asymptotic AdS condition for the curvature suffices for the well-posedness of this action. For odd dimensions, the action is stationary under a boundary condition on the variation of the extrinsic curvature. The background-independent Noether charges associated to asymptotic symmetries are found and the Euclidean continuation of the action correctly describes the black hole thermodynamics in the canonical ensemble. In particular, this procedure leads to a covariant formula for the vacuum energy in odd-dimensional asymptotically AdS spacetimes.
A Stochasticity Threshold in Holography and and the Instability of AdS
Basu, Pallab; Saurabh, Ayush
2014-01-01
We give strong numerical evidence that a self-interacting probe scalar field in AdS, with only a few modes turned on initially, will undergo fast thermalization only if it is above a certain energetic threshold. Below the threshold the energy stays close to constant in a few modes for a very long time instead of cascading quickly. This indicates the existance of a Strong Stochasticity Threshold (SST) in holography. The idea of SST is familiar from certain statistical mechanical systems, and we suggest that it exists also in AdS gravity. This would naturally reconcile the generic non-linear instability of AdS observed by Bizon and Rostworowski, with the Fermi-Pasta-Ulam-Tsingou-like quasi-periodocity noticed recently for some classes of initial conditions. We show that our simple set-up captures many of the relevant features of the full gravity-scalar system.
Banados and SUSY: On Supersymmetry and Minimal Surfaces of Locally AdS3 Geometries
Colgáin, E Ó
2016-01-01
We extend the classification of supersymmetric locally AdS$_3$ geometries, beyond BTZ black holes, to the Ba\\~nados geometries, noting that supersymmetries are in one-to-one correspondence with solutions to the Hill differential condition. We show that the number of global supersymmetries is an orbit invariant quantity and identify geometries with zero, one, two, three and four global supersymmetries. As an application of our classification, we exploit supersymmetry, which is preserved locally in the bulk, to determine space-like co-dimension two surfaces in AdS$_3$. In the process, we by-pass geodesics or mappings of AdS$_3$, neither of which have an analogue in higher dimensions, to recover known Hubeny-Rangamani-Takayanagi surfaces. Our findings suggest supersymmetry can be exploited to find extremal surfaces in holographic entanglement entropy.
Quark confinement due to creation of micro AdS black holes in quarkonium model
Taki, Mehran
2016-01-01
We use the solution of the Dirac equation for quarkonium atom in the 4D Anti de sitter (AdS$_{4}$) space to investigate the effect of the large negative cosmological constant on the phenomenon of quark confinement. We do the required calculations in the AdS$_{4}$ space to indicate that large cosmological constant can describe the quark confinement. In fact using the coulomb potential in Dirac equation while we employ the AdS metric will additionally lead us to a linear potential in the quark-antiquark interaction which can be considered to explain the quark confinement. This confining term is arising essentially from the geometrical features of the space. On the other hand the origin of the large cosmological constant can be justified by assuming the appearance of micro black holes in the recent hadronic collision process which is now current, for instance, at the LHC project.
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.
Photon gas thermodynamics in dS and AdS momentum spaces
Gorji, M A; Nozari, K; Vakili, B
2016-01-01
In this paper, we study thermostatistical properties of a photon gas in the framework of two deformed special relativity models defined by the cosmological coordinatizations of the de Sitter (dS) and anti-de Sitter (AdS) momentum spaces. The dS model is a doubly special relativity theory in which an ultraviolet length scale is invariant under the deformed Lorentz transformations. For the case of AdS model, however, the Lorentz symmetry breaks at the high energy regime. We show that the existence of a maximal momentum in dS momentum space leads to maximal pressure and temperature at the thermodynamical level while maximal internal energy and entropy arise for the case of the AdS momentum space due to the existence of a maximal kinematical energy. These results show the thermodynamical duality of these models much similar to their well-known kinematical duality.
On thermodynamics of AdS black holes in M-theory
Energy Technology Data Exchange (ETDEWEB)
Belhaj, A. [Universite Sultan Moulay Slimane, Departement de Physique, LIRST, Faculte Polydisciplinaire, Beni Mellal (Morocco); Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); Chabab, M.; Masmar, K. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); El Moumni, H. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); Universite Ibn Zohr, Departement de Physique, Faculte des Sciences, Agadir (Morocco); Sedra, M.B. [Universite Ibn Tofail, Departement de Physique, LASIMO, Faculte des Sciences, Kenitra (Morocco)
2016-02-15
Motivated by recent work on asymptotically AdS{sub 4} black holes in M-theory, we investigate the thermodynamics and thermodynamical geometry of AdS black holes from M2- and M5-branes. Concretely, we consider AdS black holes in AdS{sub p+2} x S{sup 11-p-2}, where p = 2,5 by interpreting the number of M2- (and M5-branes) as a thermodynamical variable. More precisely, we study the corresponding phase transition to examine their stabilities by calculating and discussing various thermodynamical quantities including the chemical potential. Then we compute the thermodynamical curvatures from the Quevedo metric for M2- and M5-branes geometries to reconsider the stability of such black holes. The Quevedo metric singularities recover similar stability results provided by the phase-transition program. It has been shown that similar behaviors are also present in the limit of large N. (orig.)
Thermal stability analysis of nonlinearly charged asymptotic AdS black hole solutions
Dehghani, M.; Hamidi, S. F.
2017-08-01
In this paper, the four-dimensional nonlinearly charged black hole solutions have been considered in the presence of the power Maxwell invariant electrodynamics. Two new classes of anti-de Sitter (AdS) black hole solutions have been introduced according to different amounts of the parameters in the nonlinear theory of electrodynamics. The conserved and thermodynamical quantities of either of the black hole classes have been calculated from geometrical and thermodynamical approaches, separately. It has been shown that the first law of black hole thermodynamics is satisfied for either of the AdS black hole solutions we just obtained. Through the canonical and grand canonical ensemble methods, the black hole thermal stability or phase transitions have been analyzed by considering the heat capacities with the fixed black hole charge and fixed electric potential, respectively. It has been found that the new AdS black holes are stable if some simple conditions are satisfied.
QCD Condensates and Holographic Wilson Loops for Asymptotically AdS Spaces
Energy Technology Data Exchange (ETDEWEB)
Quevedo, R. Carcasses [Instituto Balseiro, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina); Goity, Jose L. [Hampton University, Hampton, VA 23668 (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Trinchero, Roberto C. [Instituto Balseiro, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina)
2014-02-01
The minimization of the Nambu-Goto (NG) 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 border is considered. This is done for asymptotically AdS spaces. The condensates of dimension n = 2, 4, 6, 8, and 10 are calculated in terms of the coefficients in the expansion in powers of the radius a of the on-shell subtracted NG action for small a->0. 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 gluon condensates is universal in the sense that it only depends on the first coefficients of the difference with the AdS case.
Wireless Ad Hoc Networks%无线特定网络--Ad Hoc网络
Institute of Scientific and Technical Information of China (English)
张筱; 张光昭
2001-01-01
Ad Hoc网络是一种没有固定结构的无线移动网络.介绍了移动Ad Hoc网络(MANETs)的主要特点和与传统有线分组交换网相比的特性,讨论了应用于Ad Hoc网络的路由机制和所需面临的问题.
Secure Clustering in Vehicular Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Zainab Nayyar
2015-09-01
Full Text Available A vehicular Ad-hoc network is composed of moving cars as nodes without any infrastructure. Nodes self-organize to form a network over radio links. Security issues are commonly observed in vehicular ad hoc networks; like authentication and authorization issues. Secure Clustering plays a significant role in VANETs. In recent years, various secure clustering techniques with distinguishing feature have been newly proposed. In order to provide a comprehensive understanding of these techniques are designed for VANETs and pave the way for the further research, a survey of the secure clustering techniques is discussed in detail in this paper. Qualitatively, as a result of highlighting various techniques of secure clustering certain conclusions are drawn which will enhance the availability and security of vehicular ad hoc networks. Nodes present in the clusters will work more efficiently and the message passing within the nodes will also get more authenticated from the cluster heads.
Introduction to AdS/CFT correspondence
Nastase, Horatiu
2015-01-01
Providing a pedagogical introduction to the rapidly developing field of AdS/CFT correspondence, this is one of the first texts to provide an accessible introduction to all the necessary concepts needed to engage with the methods, tools and applications of AdS/CFT. Without assuming anything beyond an introductory course in quantum field theory, it begins by guiding the reader through the basic concepts of field theory and gauge theory, general relativity, supersymmetry, supergravity, string theory and conformal field theory, before moving on to give a clear and rigorous account of AdS/CFT correspondence. The final section discusses the more specialised applications, including QCD, quark-gluon plasma and condensed matter. This book is self-contained and learner-focused, featuring numerous exercises and examples. It is essential reading for both students and researchers across the fields of particle, nuclear and condensed matter physics.
Online Stochastic Ad Allocation: Efficiency and Fairness
Feldman, Jon; Korula, Nitish; Mirrokni, Vahab S; Stein, Cliff
2010-01-01
We study the efficiency and fairness of online stochastic display ad allocation algorithms from a theoretical and practical standpoint. In particular, we study the problem of maximizing efficiency in the presence of stochastic information. In this setting, each advertiser has a maximum demand for impressions of display ads that will arrive online. In our model, inspired by the concept of free disposal in economics, we assume that impressions that are given to an advertiser above her demand are given to her for free. Our main theoretical result is to present a training-based algorithm that achieves a (1-\\epsilon)-approximation guarantee in the random order stochastic model. In the corresponding online matching problem, we learn a dual variable for each advertiser, based on data obtained from a sample of impressions. We also discuss different fairness measures in online ad allocation, based on comparison to an ideal offline fair solution, and develop algorithms to compute "fair" allocations. We then discuss sev...
Data Confidentiality in Mobile Ad hoc Networks
Aldabbas, Hamza; Janicke, Helge; Al-Bayatti, Ali; 10.5121/ijwmn.2012.4117
2012-01-01
Mobile ad hoc networks (MANETs) are self-configuring infrastructure-less networks comprised of mobile nodes that communicate over wireless links without any central control on a peer-to-peer basis. These individual nodes act as routers to forward both their own data and also their neighbours' data by sending and receiving packets to and from other nodes in the network. The relatively easy configuration and the quick deployment make ad hoc networks suitable the emergency situations (such as human or natural disasters) and for military units in enemy territory. Securing data dissemination between these nodes in such networks, however, is a very challenging task. Exposing such information to anyone else other than the intended nodes could cause a privacy and confidentiality breach, particularly in military scenarios. In this paper we present a novel framework to enhance the privacy and data confidentiality in mobile ad hoc networks by attaching the originator policies to the messages as they are sent between nod...
Parikh, Maulik; Samantray, Prasant; Verlinde, Erik
2012-07-01
If the Hamiltonian of a quantum field theory is taken to be a timelike isometry, the vacuum state remains empty for all time. We search for such stationary vacua in anti-de Sitter space. By considering conjugacy classes of the Lorentz group, we find interesting one-parameter families of stationary vacua in three-dimensional anti-de Sitter space. In particular, there exists a family of rotating Rindler vacua, labeled by the rotation parameter β, which are related to the usual Rindler vacuum by nontrivial Bogolubov transformations. Rotating Rindler-AdS space possesses not only an observer-dependent event horizon but even an observer-dependent ergosphere. We also find rotating vacua in global AdS provided a certain region of spacetime is excluded.
Parikh, Maulik; Verlinde, Erik
2011-01-01
If the Hamiltonian of a quantum field theory is taken to be a timelike isometry, the vacuum state remains empty for all time. We search for such stationary vacua in anti-de Sitter space. By considering conjugacy classes of the Lorentz group, we find interesting one-parameter families of stationary vacua in three-dimensional anti-de Sitter space. In particular, there exists a family of rotating Rindler vacua, labeled by the rotation parameter beta, which are related to the usual Rindler vacuum by non-trivial Bogolubov transformations. Rotating Rindler-AdS space possesses not only an observer-dependent event horizon but even an observer-dependent ergosphere. We also find rotating vacua in global AdS provided a certain region of spacetime is excluded.
AD Ejection Line Studies and Optics Improvements
Belochitskii, P
2013-01-01
This paper is a summary of the work we made to understand and improve the AD ejection line optics. In 2011 significant differences were noticed between the optical properties of the AD ejection line and the MAD model. Investigations started to find out the sources of discrepancy. Better understanding of the ejection line optics was obtained and corrections were applied to the model of ejection line. The beam delivery to the experiments is better understood now. The results obtained might be useful as well for the optics design of AD to ELENA transfer line. Potential problems with the fringing field model in MAD were pointed out, when bending magnets with large bending angles and small bending radius are involved.
New Features in the ADS Abstract Service
Eichhorn, G.; Accomazzi, A.; Grant, C. S.; Kurtz, M. J.; ReyBacaicoa, V.; Murray, S. S.
2001-11-01
The ADS Abstract Service contains over 2.3 million references in four databases: Astronomy/Astrophysics/Planetary Sciences, Instrumentation, Physics/Geophysics, and Preprints. We provide abstracts and articles free to the astronomical community for all major and many smaller astronomy journals, PhD theses, conference proceedings, and technical reports. These four databases can be queried either separately of jointly. The ADS also has scanned 1.3 million pages in 180,000 articles in the ADS Article Service. This literature archive contains all major Astronomy journals and many smaller journals, as well as conference proceedings, including the abstract books from all the LPSCs back to volume 2. A new feature gives our users the ability to see list of articles that were also read by the readers of a given article. This is a powerful tool to find out what current articles are relevant in a particular field of study. We have recently expanded the citation and reference query capabilities. It allows our users to select papers for which they want to see references or citations and then retrieve these citations/references. Another new capability is the ability to sort a list of articles by their citation count. As usual, users should be reminded that the citations in ADS are incomplete because we do not obtain reference lists from all publishers. In addition, we cannot match all references (e.g. in press, private communications, author errors, some conference papers, etc.). Anyone using the citations for analysis of publishing records should keep this in mind. More work on expanding the citation and reference features is planned over the next year. ADS Home Page http://ads.harvard.edu/
Flowing along the edge: spinning up black holes in AdS spacetimes with test particles
Rocha, Jorge V
2014-01-01
We investigate the consequences of throwing point particles into odd-dimensional Myers-Perry black holes in asymptotically anti-de Sitter (AdS) backgrounds. We restrict our attention to the case in which the angular momenta of the background geometry are all equal. This process allows us to test the generalization of the weak cosmic censorship conjecture to asymptotically AdS spacetimes in higher dimensions. We find no evidence for overspinning in D = 5, 7, 9 and 11 dimensions. Instead, test particles carrying the maximum possible angular momentum that still fall into an extremal rotating black hole generate a flow along the curve of extremal solutions.
The generalization of charged AdS black hole specific volume and number density
Wang, Zi-Liang; He, Miao; Fang, Chao; Sun, Dao-Quan; Deng, Jian-Bo
2017-04-01
In this paper, by proposing a generalized specific volume, we restudy the P- V criticality of charged AdS black holes in the extended phase space. The results show that most of the previous conclusions can be generalized without change, but the ratio {\\tilde{ρ }}_c should be 3 {\\tilde{α }}/16 in general case. Further research on the thermodynamical phase transition of black hole leads us to a natural interpretation of our assumption, and more black hole properties can be generalized. Finally, we study the number density for charged AdS black hole in higher dimensions, the results show the necessity of our assumption.
Double-trace deformations and entanglement entropy in AdS
Miyagawa, Taiki; Shiba, Noburo; Takayanagi, Tadashi
2016-01-01
We compute the bulk entanglement entropy of a massive scalar field in a Poincare AdS with the Dirichlet and Neumann boundary condition when we trace out a half space. Moreover, by taking into account the quantum back reaction to the minimal surface area, we calculate how much the entanglement entropy changes under a double-trace deformation of a holographic CFT. In the AdS3/CFT2 setup, our result agrees with the known result in 2d CFTs. In higher dimensions, our results offer holographic predictions.
Double-trace deformations and entanglement entropy in AdS
Energy Technology Data Exchange (ETDEWEB)
Miyagawa, Taiki [Department of Physics, Kyoto University (Japan); Shiba, Noburo [Yukawa Institute for Theoretical Physics (YITP), Kyoto University (Japan); Takayanagi, Tadashi [Yukawa Institute for Theoretical Physics (YITP), Kyoto University (Japan); Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), University of Tokyo, Kashiwa, Chiba (Japan)
2016-01-15
We compute the bulk entanglement entropy of a massive scalar field in a Poincare AdS with the Dirichlet and Neumann boundary condition when we trace out a half space. Moreover, by taking into account the quantum back reaction to the minimal surface area, we calculate how much the entanglement entropy changes under a double-trace deformation of a holographic CFT. In the AdS3/CFT2 setup, our result agrees with the known result in 2d CFTs. In higher dimensions, our results offer holographic predictions. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Double-Trace Deformations and Entanglement Entropy in AdS
Miyagawa, Taiki; Takayanagi, Tadashi
2016-01-01
We compute the bulk entanglement entropy of a massive scalar field in a Poincare AdS with the Dirichlet and Neumann boundary condition when we trace out a half space. Moreover, by taking into account the quantum back reaction to the minimal surface area, we calculate how much the entanglement entropy changes under a double-trace deformation of a holographic CFT. In the AdS3/CFT2 setup, our result agrees with the known result in 2d CFTs. In higher dimensions, our results offer holographic predictions.
Superradiance Instability of Small Rotating AdS Black Holes in Arbitrary Dimensions
Delice, Özgür
2015-01-01
We investigate the stability of $D$ dimensional singly rotating Myers-Perry-AdS black holes under superradiance against scalar field perturbations. It is well known that small four dimensional rotating or charged AdS black holes are unstable against superradiance instability of a scalar field. Recent works extended the existence of this instability to five dimensional rotating charged AdS black holes or static charged AdS Black holes in arbitrary dimensions. In this work we analytically prove that, rotating small AdS black holes in arbitrary dimensions also show superradiance instability irrespective of the value of the (positive) angular momentum quantum number. To do this we solve the Klein-Gordon equation in the slow rotation, low frequency limit. By using the asymptotic matching technique, we are able to calculate the real and imaginary parts of the correction terms to the frequency of the scalar field due to the presence of the black hole, confirming the presence of superradiance instability. We see that...
Horizon Conformal Field Theories from $AdS_2$ Black Holes
Halyo, Edi
2015-01-01
We show that the very near horizon region of nonextreme black holes, which can be described by horizon CFTs, are related to $AdS_2$ Rindler spaces. The latter are $AdS_2$ black holes with specific masses and can be described by states of either $D=1$ or $D=2$ CFTs. The central charges of these CFTs and the conformal weights of their states that correspond to the nonextreme black holes exactly match those predicted by the horizon CFTs, providing supporting evidence for this description.
Vehicular ad hoc network security and privacy
Lin, X
2015-01-01
Unlike any other book in this area, this book provides innovative solutions to security issues, making this book a must read for anyone working with or studying security measures. Vehicular Ad Hoc Network Security and Privacy mainly focuses on security and privacy issues related to vehicular communication systems. It begins with a comprehensive introduction to vehicular ad hoc network and its unique security threats and privacy concerns and then illustrates how to address those challenges in highly dynamic and large size wireless network environments from multiple perspectives. This book is richly illustrated with detailed designs and results for approaching security and privacy threats.
iAd Production Beginner's Guide
Collier, Ben
2012-01-01
This beginner's guide focuses on getting you through all the major learning points in a smooth, logical order. You'll also see how to avoid some common pitfalls. This book is for brands, advertisers and developers who want to create compelling, emotive, iAd advertisements that generate revenue and increase brand awareness. You don't need previous experience of creating adverts or apps for iPhone and iPad, as you'll be taken through the entire process to make motion-rich, beautiful ads.
Intermittently connected mobile ad hoc networks
Jamalipour, Abbas
2011-01-01
In the last few years, there has been extensive research activity in the emerging area of Intermittently Connected Mobile Ad Hoc Networks (ICMANs). By considering the nature of intermittent connectivity in most real word mobile environments without any restrictions placed on users' behavior, ICMANs are eventually formed without any assumption with regard to the existence of a end-to-end path between two nodes wishing to communicate. It is different from the conventional Mobile Ad Hoc Networks (MANETs), which have been implicitly viewed as a connected graph with established complete paths betwe
DEFF Research Database (Denmark)
Bechi, Jacopo
2009-01-01
This paper focuses on some issues about condensates and renormalization in AdS/QCD models. In particular we consider the consistency of the AdS/QCD approach for scale dependent quantities as the chiral condensate questioned in some recent papers and the 4D meaning of the 5D cosmological constant...... in a model in which the QCD is dual to a 5D gravity theory. We will be able to give some arguments that the cosmological constant is related to the QCD gluon condensate....
Adding value to corporate ventures through governance
DEFF Research Database (Denmark)
Skat-Rørdam, Peter
2005-01-01
than the control mechanisms widely explored in connection with the governance of large public corporations. The paper provides examples of how value can be added as well as perspectives on the challenges and effectivenes here-off as evaluated by venture CEO's and venture board members......This working paper examines the governance of corporate ventures based upon a qualitative interview based case study of a European industrial conglomerate. The purpose is to explore the value adding mechanisms of governance, that are considered more critical to the success of corporate ventures...
The Stylistic Analysis of car ads languages
Institute of Scientific and Technical Information of China (English)
张伟苹
2014-01-01
Automotive advertising language is mix of phonetics, vocabulary, rhetoric, syntax, and discourse language etc., and owning a strong promotional effect which can functioned as a bridge between language expression and promotion system for es-sential products and consumers. As a kind of the commercial advertising, car advertising with its own unique language features not only for product considerably, but also enriches the advertising language. In order to analysis the car ads, this article draws at-tention from the aspects of the phonetics, vocabulary, rhetoric and syntax features, and aims to get a further and better analysis or understanding of the car ads Languages.
Adding value to corporate ventures through governance
DEFF Research Database (Denmark)
Skat-Rørdam, Peter
2005-01-01
This working paper examines the governance of corporate ventures based upon a qualitative interview based case study of a European industrial conglomerate. The purpose is to explore the value adding mechanisms of governance, that are considered more critical to the success of corporate ventures...... than the control mechanisms widely explored in connection with the governance of large public corporations. The paper provides examples of how value can be added as well as perspectives on the challenges and effectivenes here-off as evaluated by venture CEO's and venture board members...
Ad hoc networks telecommunications and game theory
Benslama, Malek; Batatia, Hadj
2015-01-01
Random SALOHA and CSMA protocols that are used to access MAC in ad hoc networks are very small compared to the multiple and spontaneous use of the transmission channel. So they have low immunity to the problems of packet collisions. Indeed, the transmission time is the critical factor in the operation of such networks. The simulations demonstrate the positive impact of erasure codes on the throughput of the transmission in ad hoc networks. However, the network still suffers from the intermittency and volatility of its efficiency throughout its operation, and it switches quickly to the satura
Adding Users to the Website Design Process
Tomeo, Megan L.
2012-01-01
Alden Library began redesigning its website over a year ago. Throughout the redesign process the students, faculty, and staff that make up the user base were added to the conversation by utilizing several usability test methods. This article focuses on the usability testing conducted at Alden Library and delves into future usability testing, which…
Holzscheiter, M H
2014-01-01
After 7 years running the AD-4 Experiment at antiproton momentum of 502 MeV/c we have now assembled a complete data set and are preparing to combine all years into a single analysis of RBE vs. Depth for an antiproton beam stopping in water. We describe experimental challenges and computational issues which need to be resolved to achieve this final step.
Adding calcium improves lithium ferrite core
Lessoff, H.
1969-01-01
Adding calcium increases uniformity of grain growth over a wide range of sintering temperatures and reduces porosity within the grain. Ferrite cores containing calcium have square hysteresis loops and high curie temperatures, making them useful in coincident current memories of digital electronic computers.
Estimating the Value Added Product Life Cycle
Gedikoglu, Haluk; Parcell, Joseph L.; Patterson, David J.; Randle, Richard
2006-01-01
This research analyzes factors affecting product and profit life-cycles for new value added products. The methodology used shows how sales and profits evolve and how exogenous factors affecting sales and profits. Results indicate that producers can increase the level of sales and profits over time through initial marketing efforts.
Value-Added Modeling in Physical Education
Hushman, Glenn; Hushman, Carolyn
2015-01-01
The educational reform movement in the United States has resulted in a variety of states moving toward a system of value-added modeling (VAM) to measure a teacher's contribution to student achievement. Recently, many states have begun using VAM scores as part of a larger system to evaluate teacher performance. In the past decade, only "core…
Manifold invariants affect dynamics in ADS gravity
Liko, Tomas
2013-01-01
The first-order Holst action with negative cosmological constant is rendered finite by requiring functional differentiability on the configuration space of tetrads and connections. The surface terms that arise in the action for ADS gravity are equivalent to the Euler and Pontryagin densities with fixed weight factors; these terms modify the Noether charges that arise from diffeomorphism invariance of the action.
CERN Enters the Second Year AD
2001-01-01
2001 is the year that physics at CERN's new Antiproton Decelerator (AD) really gets up to speed. Changes to the AD since 2000 mean that this year the three experiments, ASACUSA, ATHENA, and ATRAP have had more intense antiproton beams to work with since physics started on 7 May. CERN's Antiproton Decelerator - major improvements for 2001. The AD is a unique machine. Its job is to decelerate not accelerate particle beams, and it has to handle beam energies that vary by an unprecedented factor of 35 from injection to ejection. Since the machine was designed to operate at fixed energy in its first incarnation as a collector of antiprotons for CERN's 1980s proton antiproton collider, this factor of 35 presented a big challenge to the AD team. The team's design goal was to hang onto a quarter of the injected antiprotons through their vertiginous fall in energy, and to repeat the deceleration cycle once per minute. Improvements to the machine over the winter shutdown and through the first four weeks of 2001 run...
Added value: The differences that count
Directory of Open Access Journals (Sweden)
Dominique Bouchet
2012-08-01
Full Text Available Clinging to a simplistic conceptualization of the concept of added value might impair our capability to develop insights to what really matters today when companies seek to make differences within the global market. Today it is more necessary than ever to take into account the importance of language and culture as competitive factors.
Test Scaling and Value-Added Measurement
Ballou, Dale
2009-01-01
Conventional value-added assessment requires that achievement be reported on an interval scale. While many metrics do not have this property, application of item response theory (IRT) is said to produce interval scales. However, it is difficult to confirm that the requisite conditions are met. Even when they are, the properties of the data that…
The Added Value of Business Models
Vliet, Harry van
2014-01-01
An overview of innovations in a particular area, for example retail developments in the fashion sector (Van Vliet, 2014), and a subsequent discussion about the probability as to whether these innovations will realise a ‘breakthrough’, has to be supplemented with the question of what the added value
de Leeuw, Marius; Moriyama, Sanefumi; Regelskis, Vidas; Torrielli, Alessandro
2012-01-01
We discuss special quantum group (secret) symmetries of the integrable system associated to the AdS/CFT correspondence. These symmetries have by now been observed in a variety of forms, including the spectral problem, the boundary scattering problem, n-point amplitudes, the pure-spinor formulation and quantum affine deformations.
Added Value of Employee Financial Participation
Poutsma, E.; Kaarsemaker, E.C.A.
2015-01-01
This chapter broadens our understanding of the added value of employee financial participation. Financial participation is a generic term for the participation of employees in profit and enterprise results including equity of their employing firm. In general, there are two forms of employee
ENEA presenta sistema ADS per trattamento scorie
2002-01-01
"Arriva il sistema Ads (Accelerator driven system) per il trattamento dei rifiuti radioattivi. Lo studio di fattibilita' per l' innovativa tecnologia, realizzato da un gruppo di lavoro congiunto Enea, Cea, Cern e Ansaldo, e' stato presentato oggi nel corso di un workshop presieduto dal premio Nobel per la fisica, Carlo Rubbia" (1/2 page).
Value Added School Review Field Guide
Alberta Education, 2009
2009-01-01
The "Value-Added School Review (VSR)" is an analytical model designed to assist schools in identifying and addressing opportunities for school improvement. The model works best when it is focused purposefully on students and the student learning outcomes as defined in the "Guide to Education". It complements the processes…
Added Value of Employee Financial Participation
Poutsma, F.; Kaarsemaker, E.C.A.
2015-01-01
This chapter broadens our understanding of the added value of employee financial participation. Financial participation is a generic term for the participation of employees in profit and enterprise results including equity of their employing firm. In general, there are two forms of employee financia
Context discovery in ad-hoc networks
Liu, Fei
2011-01-01
Mobile ad-hoc networks (MANETs) are more and more present in our daily life. Such networks are often composed of mobile and battery-supplied devices, like laptops and PDAs. With no requirement for infrastructure support, MANETs can be used as temporary networks, such as for conference and office env
Double Thermalization via AdS/CFT
Ali-Akbari, M; Kishani-Farahani, A; Shafie, N
2016-01-01
We exploit the AdS/CFT correspondence to investigate thermalization in an N=2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under variation of an external electric field leading to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS_5 X S^5 background. In the dual gravity theory, due to a time-dependent electric field an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe that two apparent horizons form on the brane. On the gauge theory side, ...
Integrable strings for AdS/CFT
Borsato, R.
2015-01-01
In this thesis we discuss certain models that arise in string theory, motivated by the AdS/CFT correspondence. For these models there exists a notion of “quantum Integrability”. Although this term is very broad, for us it will be used in the sense of factorisation of scattering for models in 1+1 dim
Correction terms to Newton law due to induced gravity in AdS background
Ito, M
2003-01-01
We calculate small correction terms to gravitational potential on Randall-Sundrum brane with an induced Einstein term. The behaviors of the correction terms depend on the magnitudes of $AdS$ radius $k^{-1}$ and a characteristic length scale $\\l$ of model. We present the gravitational potential for arbitrary $k$ and $\\l$ at all distances.
D-branes from Pure Spinor Superstring in AdS_5 x S^5 Background
Hanazawa, Sota
2016-01-01
We examine the surface term for the BRST transformation of the open pure spinor superstring in an AdS_5 x S^5 background. We find that the boundary condition to eliminate the surface term leads to a classification of possible configurations of 1/2 supersymmetric D-branes.
Geometry and supersymmetry of heterotic warped flux AdS backgrounds
Beck, S.; Gutowski, J.; Papadopoulos, G.
2015-07-01
We classify the geometries of the most general warped, flux AdS backgrounds of heterotic supergravity up to two loop order in sigma model perturbation theory. We show under some mild assumptions that there are no AdS n backgrounds with n ≠ 3. Moreover the warp factor of AdS3 backgrounds is constant, the geometry is a product AdS 3 × M 7 and such solutions preserve, 2, 4, 6 and 8 supersymmetries. The geometry of M 7 has been specified in all cases. For 2 supersymmetries, it has been found that M 7 admits a suitably restricted G 2 structure. For 4 supersymmetries, M 7 has an SU(3) structure and can be described locally as a circle fibration over a 6-dimensional KT manifold. For 6 and 8 supersymmetries, M 7 has an SU(2) structure and can be described locally as a S 3 fibration over a 4-dimensional manifold which either has an anti-self dual Weyl tensor or a hyper-Kähler structure, respectively. We also demonstrate a new Lichnerowicz type theorem in the presence of α' corrections.
Finite temperature effective action, AdS_5 black holes, and 1/N expansion
Alvarez-Gaumé, Luís; Liu, H; Wadia, S; Alvarez-Gaume, Luis; Gomez, Cesar; Liu, Hong; Wadia, Spenta
2005-01-01
We propose a phenomenological matrix model to study string theory in AdS_5 \\times S_5 in the canonical ensemble. The model reproduces all the known qualitative features of the theory. In particular, it gives a simple effective potential description of Euclidean black hole nucleation and the tunnelling between thermal AdS and the big black hole. It also has some interesting predictions. We find that there exists a critical temperature at which the Euclidean small black hole undergoes a Gross-Witten phase transition. We identify the phase transition with the Horowitz-Polchinski point where the black hole horizon size becomes comparable to the string scale. The appearance of the Hagedorn divergence of thermal AdS is due to the merger of saddle points corresponding to the Euclidean small black hole and thermal AdS. The merger can be described in terms of a cusp (A_3) catastrophe and divergences at the perturbative string level are smoothed out at finite string coupling using standard techniques of catastrophe the...
Parametrization of cosets for AdS5xS5 superstring action
Siegel, W
2015-01-01
A formulation recently proposed [arXiv:1506.07706] as an alternative to the usual coset PSU(2,2|4)/USp(2,2)USp(4) for the superspace geometry of the Type IIB superstring on an AdS5xS5 background is shown to be a particular parametrization of this coset. Standard methods can then be applied.
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
Classical strings in $AdS_4\\times\\mathbb{CP}^3$ with three angular momenta
Giardino, Sergio
2011-01-01
In this paper, rotating strings in three directions of $AdS_4 \\times \\mathbb{CP}^3$ geometry are studied; its divergent energy limit, and conserved charges are also determined. An interpretation of these configurations as either giant magnons or spiky strings are discussed.
Near horizon data and physical charges of extremal AdS black holes
Astefanesei, D.; Banerjee, N.; Dutta, S.
2011-01-01
We compute the physical charges and discuss the properties of a large class of five-dimensional extremal AdS black holes by using the near horizon data. Our examples include baryonic and electromagnetic black branes, as well as supersymmetric spinning black holes. In the presence of the gauge Chern–
S-matrix for strings on η-deformed AdS5 x S5
Arutyunov, G.E.; Borsato, R.; Frolov, S.
2013-01-01
We determine the bosonic part of the superstring sigma model Lagrangian on η-deformed AdS5 x S5, and use it to compute the perturbative world-sheet scattering matrix of bosonic particles of the model. We then compare it with the large string tension limit of the q-deformed S-matrix and find exact ag
Jordanian deformations of the AdS5×S5 superstring
Kawaguchi, I.; Matsumoto, T.; Yoshida, K
2014-01-01
We consider Jordanian deformations of the AdS_5xS^5 superstring action. The deformations correspond to non-standard q-deformation. In particular, it is possible to perform partial deformations, for example, only for the S^5 part. Then the classical action and the Lax pair are constructed with a line
S-matrix for strings on η-deformed AdS5 x S5
Arutyunov, Gleb; Borsato, Riccardo; Frolov, Sergey
2013-01-01
We determine the bosonic part of the superstring sigma model Lagrangian on η-deformed AdS5 × S5, and use it to compute the perturbative world-sheet scattering matrix of bosonic particles of the model. We then compare it with the large string tension limit of the q-deformed S-matrix and find exact ag
The spectral problem for strings on twisted AdS5 ×S5
de Leeuw, M.; van Tongeren, S.J.
2012-01-01
We discuss the spectral problem for integrable superstrings on generically twisted AdS5 × S5, meaning all its orbifolds and TsT transformed versions. We explicitly give the asymptotic description of these theories through a twisted transfer matrix, and carefully match the geometric deformations with
Simplified TBA equations of the AdS5 × S5 mirror model
Arutyunov, G.E.; Frolov, S.
2009-01-01
We use the recently found integral representation for the dressing phase in the kinematic region of the mirror theory to simplify the TBA equations for the AdS5 × S5 mirror model. The resulting set of equations provides an efficient starting point for both analytic and numerical studies.
S-matrix for strings on $\\eta$-deformed AdS5 x S5
Arutyunov, Gleb; Frolov, Sergey
2014-01-01
We determine the bosonic part of the superstring sigma model Lagrangian on $\\eta$-deformed AdS5 x S5, and use it to compute the perturbative world-sheet scattering matrix of bosonic particles of the model. We then compare it with the large string tension limit of the q-deformed S-matrix and find exact agreement.
Bound state transfer matrix for AdS5 × S5 superstring
Arutyunov, G.E.; de Leeuw, M.; Suzuki, R.; Torrielli, A.
2009-01-01
We apply the algebraic Bethe ansatz technique to compute the eigenvalues of the transfer matrix constructed from the general bound state S-matrix of the light-cone AdS5 × S5 superstring. This allows us to verify certain conjectures on the quantum characteristic function, and to extend them to the ge
The S-matrix of the AdS5xS5 superstring
de Leeuw, M.
2010-01-01
According to the gauge-string duality conjecture, the spectrum of scaling dimensions of composite gauge invariant operators of the planar maximally supersymmetric Yang-Mills theory in four dimensions should be equivalent to the energy spectrum of superstrings propagating in the AdS5 x S5 space-time,
D-branes from pure spinor superstring in AdS5 × S5 background
Hanazawa, Sota; Sakaguchi, Makoto
2017-01-01
We examine the surface term for the BRST transformation of the open pure spinor superstring in an AdS5 ×S5 background. We find that the boundary condition to eliminate the surface term leads to a classification of possible configurations of 1/2 supersymmetric D-branes.
The bound state S-matrix for AdS5×S5 superstring
Arutyunov, G.E.; de Leeuw, M.; Torrielli, A.
2009-01-01
We determine the S-matrix that describes scattering of arbitrary bound states in the light-cone string theory in AdS5×S5. The corresponding construction relies on the Yangian symmetry and the superspace formalism for the bound state representations. The basic analytic structure supporting the S-matr
Searching for AdS_3 waves and Asymptotically Lifshitz black holes in R^3-NMG
Anastasiou, Giorgos G; Vagenas, Elias C
2013-01-01
In this paper we consider the structure of the $AdS_3$ vacua in $R^3$ expansion of the New Massive Gravity ($R^3$-NMG). We obtain the degeneracies of the $AdS_3$ vacua at several points of the parametric space. Additionally, following a specific analysis we show that $AdS_3$ wave solutions are present. Using these wave solutions, we single out two special points of the parametric space for which logarithmic terms appear in the solutions. The first one is a point at which the effective mass of the wave profile which is interpreted as a scalar mode, completely saturates the Breitenlohner-Freedman bound of the $AdS_3$ space in which the wave is propagating. The second special point is a point at which the central charge of the theory vanishes. Furthermore, we investigate the possibility of asymptotically Lifshitz black solutions to be present in the three-dimensional $R^3$-NMG. We derive analytically the Lifshitz vacua considering specific relations between the mass parameters of $R^3$-NMG. A certain polynomial ...
Phase transitions of magnetic AdS4 black holes with scalar hair
Hristov, K.; Toldo, C.; Vandoren, S.
2013-01-01
We determine the thermodynamic properties of a class of spherically symmetric and static black holes in AdS4 with magnetic charges and scalar hair. These black holes are solutions in four-dimensional N=2 gauged supergravity that can arise from 11-dimensional supergravity compactified on S7. At zero
Smit, E.G.; Neijens, P.C.; Heath, R.
2013-01-01
Building on previous research on the processing of newspaper ads, this comprehensive field study, with 26,556 newspaper readers and 290 unique advertisements, investigated the combined effects of position in the newspaper, ad characteristics and reader characteristics. The results show a
EVH Black Holes, AdS3 Throats and EVH/CFT Proposal
Sheikh-Jabbaria, M M
2011-01-01
Within class of generic black holes there are extremal black holes (with vanishing Hawking temperature T) and vanishing horizon area Ah, but with finite Ah/T ratio,the Extremal Vanishing Horizon (EVH) black holes. We study the near horizon limit of a four dimensional EVH black hole solution to a generic (gauged) Einstein-Maxwell dilaton theory and show that in the near horizon limit they develop a throat which is a pinching orbifold limit of AdS3. This is an extension of the well known result for extremal black holes the near horizon limit of which contains an AdS2 throat. We show that in the near EVH near horizon limit the pinching AdS3 factor turns to a pinching BTZ black hole and that this near horizon limit is indeed a decoupling limit. We argue that the pinching AdS3 or BTZ orbifold is resolved if the near horizon limit is accompanied by taking the 4d Newton constant G4 to zero such that the Bekenstein-Hawking entropy S = Ah/(4G4) remains finite. We propose that in this limit the near horizon EVH black h...
F-string Solution in AdS4 X CP3 PP-wave Background
Banerjee, Gourav
2016-01-01
We present supergravity solution for F-string in pp wave background obtained from AdS4 X CP3 with zero flat directions.The classical solution is shown to break all space-time supersymmetries. We explicitly write down the standard as well as supernumerary Killing spinors both for the background and F-string solution.
The Complexity of Identifying Ryu-Takayanagi Surfaces in AdS3/CFT2
Bao, Ning
2016-01-01
We present a constructive algorithm for the determination of Ryu-Takayanagi surfaces in AdS3/CFT2 which exploits previously noted connections between holographic entanglement entropy and max-flow/min-cut. We then characterize its complexity as a polynomial time algorithm.
The complexity of identifying Ryu-Takayanagi surfaces in AdS3/CFT2
Bao, N.; Chatwin-Davies, A.
2016-11-01
We present a constructive algorithm for the determination of Ryu-Takayanagi surfaces in AdS3/CFT2 which exploits previously noted connections between holographic entanglement entropy and max-flow/min-cut. We then characterize its complexity as a polynomial time algorithm.
Near horizon data and physical charges of extremal AdS black holes
Astefanesei, D.; Banerjee, N.; Dutta, S.
2011-01-01
We compute the physical charges and discuss the properties of a large class of five-dimensional extremal AdS black holes by using the near horizon data. Our examples include baryonic and electromagnetic black branes, as well as supersymmetric spinning black holes. In the presence of the gauge Chern–
String hypothesis for the AdS5 × S5 mirror
Arutyunov, G.E.; Frolov, S.
2009-01-01
We discuss the states which contribute in the thermodynamic limit of the mirror theory, the latter is obtained from the light-cone gauge-fixed string theory in the AdS_5 x S^5 background by the double-Wick rotation. We analyze the Bethe-Yang equations for the mirror theory and formulate the string h
Smit, E.G.; Neijens, P.C.; Heath, R.
2013-01-01
Building on previous research on the processing of newspaper ads, this comprehensive field study, with 26,556 newspaper readers and 290 unique advertisements, investigated the combined effects of position in the newspaper, ad characteristics and reader characteristics. The results show a differentia
Entanglement Entropy and Higher Spin Holography in AdS3
de Boer, J.; Jottar, J.I.
2014-01-01
A holographic correspondence has been recently developed between higher spin theories in three-dimensional anti-de Sitter space (AdS3) and two-dimensional Conformal Field Theories (CFTs) with extended symmetries. A class of such dualities involves SL(N, R) × SL(N, R) Chern-Simons gauge theories in t
Magnetic charges in the AdS(4) superalgebra osp(4 vertical bar 2)
Dibitetto, Giuseppe; Klemm, Dietmar
2010-01-01
We discuss the issue of how to include magnetic charges in the AdS(4) superalgebra osp(4 vertical bar 2). It is shown that the usual way of introducing a pseudoscalar central charge on the right hand side of the basic anticommutator does not work, because this breaks SO(2, 3) covariance. We propose
The $AdS_{5}xS^(5)$ fermionic model
Abdalla, Elcio
2013-01-01
We consider the $AdS_{5}xS^(5)$ integrable model. As it turns out, relying on well known arguments, we claim that the conformally invariant fermionic model is solvable, the resulting solution given in terms of two current algebras realizations.
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
Ad Hoc Network Security Technology%Ad hoc网络安全技术简介
Institute of Scientific and Technical Information of China (English)
李俊; 李鑫; 黄红伟
2011-01-01
Ad hoc network is a kind of mobile network without fixed infrastructure;all nodes are composed of mobile host.As the mobility of the node leads to network topology changing quickly and node communication is based on wireless links,Ad hoc network is facing greater challenges more than cane network about security.In this paper,according to Ad hoe network security issues,we analysis common attacks in the Ad hoe network,focused on secure routing,key management and other key issues.%Ad hoc网络是一种没有有线基础设施支持的移动网络，网络中的节点均由移动主机构成。由于节点的移动性导致网络拓扑结构不断变化，节点通信完全依靠无线链路，相对于有线网络在安全性上面临更大的挑战。本文根据Ad hoc网络面临的安全问题，分析了Ad hoc网络中常见的攻击方式，并集中讨论了Ad hoc网络的安全路由、密钥管理等关键问题。
An alternative perspective to observe the critical phenomena of dilaton AdS black holes
Mo, Jie-Xiong
2016-01-01
The critical phenomena of dilaton AdS black holes are probed from a totally different perspective other than the $P-v$ criticality and the $q-U$ criticality discussed in the former literature. We investigate not only the two point correlation function but also the entanglement entropy of dilaton AdS black holes. We achieve this goal by solving the equation of motion constrained by the boundary condition numerically and we concentrate on $\\delta L$ and $\\delta S$ which have been regularized by subtracting the terms in pure AdS with the same boundary region. For both the two point correlation function and the entanglement entropy, we consider $4\\times2\\times2=16$ cases due to different choices of parameters. The van der Waals like behavior can be clearly witnessed from all the $T-\\delta L$ ($T-\\delta S$) graphs for $q
Supersymmetric $AdS_6$ vacua in six-dimensional $N=(1,1)$ gauged supergravity
Karndumri, Parinya
2016-01-01
We study fully supersymmetric $AdS_6$ vacua of half-maxi\\-mal $N=(1,1)$ gauged supergravity in six space-time dimensions coupled to $n$ vector multiplets. We show that the existence of $AdS_6$ backgrounds requires that the gauge group is of the form $G'\\times G"\\subset SO(4,n)$ where $G'\\subset SO(3,m)$ and $G"\\subset SO(1,n-m)$. In the $AdS_6$ vacua this gauge group is broken to its maximal compact subgroup $SO(3)\\times H'\\times H"$ where $H'\\subset SO(m)$ and $H"\\subset SO(n-m)$. Furthermore, the $SO(3)$ factor is the R-symmetry gauged by three of the four graviphotons. We further show that the $AdS_6$ vacua have no moduli that preserve all supercharges. This is precisely in agreement with the absence of supersymmetric marginal deformations in holographically dual five-dimensional superconformal field theories.
Unitary Supermultiplets of $OSp(8^{*}|4)$ and the $AdS_{7}/CFT_{6}$ Duality
Günaydin, M; Gunaydin, Murat; Takemae, Seiji
2000-01-01
We study the unitary supermultiplets of the N=4 d=7 anti-de Sitter (AdS_7) superalgebra OSp(8^*|4), with the even subalgebra SO(6,2) X USp(4), which is the symmetry superalgebra of M-theory on AdS_7 X S^4. We give a complete classification of the positive energy doubleton and massless supermultiplets of OSp(8^*|4) . The ultra-short doubleton supermultiplets do not have a Poincaré limit in AdS_7 and correspond to superconformal field theories on the boundary of AdS_7 which can be identified with d=6 Minkowski space. We show that the six dimensional Poincare mass operator vanishes identically for the doubleton representations. By going from the compact U(4) basis of SO^*(8)=SO(6,2) to the noncompact basis SU^*(4)XD (d=6 Lorentz group times dilatations) one can associate the positive (conformal) energy representations of SO^*(8) with conformal fields transforming covariantly under the Lorentz group in d=6. The oscillator method used for the construction of the unitary supermultiplets of OSp(8^*|4) can be given ...
Designing added functions in engineered cementitious composites
Yang, En-Hua
In this dissertation, a new and systematic material design approach is developed for ECC with added functions through material microstructures linkage to composite macroscopic behavior. The thesis research embodies theoretical development by building on previous ECC micromechanical models, and experimental investigations into three specific new versions of ECC with added functions aimed at addressing societal demands of our built infrastructure. Specifically, the theoretical study includes three important ECC modeling elements: Steady-state crack propagation analyses and simulation, predictive accuracy of the fiber bridging constitutive model, and development of the rate-dependent strain-hardening criteria. The first element establishes the steady-state cracking criterion as a fundamental requirement for multiple cracking behavior in brittle matrix composites. The second element improves the accuracy of crack-width prediction in ECC. The third element establishes the micromechanics basis for impact-resistant ECC design. Three new ECCs with added functions were developed and experimentally verified in this thesis research through the enhanced theoretical framework. A green ECC incorporating a large volume of industrial waste was demonstrated to possess reduced crack width and drying shrinkage. The self-healing ECC designed with tight crack width was demonstrated to recover transport and mechanical properties after microcrack damage when exposed to wet and dry cycles. The impact-resistant ECC was demonstrated to retain tensile ductility with increased strength under moderately high strain-rate loading. These new versions of ECC with added functions are expected to contribute greatly to enhancing the sustainability, durability, and safety of civil infrastructure built with ECC. This research establishes the effectiveness of micromechanics-based design and material ingredient tailoring for ECC with added new attributes but without losing its basic tensile ductile
Supercoset construction of Yang-Baxter deformed AdS5×S5 backgrounds
Hideki, Kyono
2017-01-01
We consider Yang-Baxter deformations of the AdS5×S5 superstring theory. In previous works, the metric and B-field of some well-known string backgrounds concerned with the AdS/CFT correspondence have been obtained as deformations of AdS5×S5 based on r-matrices satisfying the homogeneous Yang-Baxter equation. Recently, the remaining fields including the Ramond-Ramond fields and the dilaton have been derived completely by performing the supercoset construction for abelian r-matrices. We also discuss the deformation with a non-abelian r-matrix and, in this case, the resulting background is not a solution of the type IIB supergravity. This article is based on the original paper [1].
Black hole formation in AdS Einstein-Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Deppe, Nils [Cornell Center for Astrophysics and Planetary Science andDepartment of Physics, Cornell University,122 Sciences Drive, Ithaca, New York 14853 (United States); Kolly, Allison [Department of Atmospheric and Oceanic Sciences, McGill University,805 Sherbrooke Street West, Montréal, Québec H3A 0B9 (Canada); Frey, Andrew R.; Kunstatter, Gabor [Department of Physics and Winnipeg Institute for Theoretical Physics, University of Winnipeg,515 Portage Avenue, Winnipeg, Manitoba R3B 2E9 (Canada)
2016-10-17
AdS spacetime has been shown numerically to be unstable against a large class of arbitrarily small perturbations. In http://dx.doi.org/10.1103/PhysRevLett.114.071102, the authors presented a preliminary study of the effects on stability of changing the local dynamics by adding a Gauss-Bonnet term to the Einstein action. Here we provide further details as well as new results with improved numerical methods. In particular, we elucidate new structure in Choptuik scaling plots. We also provide evidence of chaotic behavior at the transition between immediate horizon formation and horizon formation after the matter pulse reflects from the AdS conformal boundary. Finally, we present data suggesting the formation of naked singularities in spacetimes with ADM mass below the algebraic bound for black hole formation.
Black Hole Formation in AdS Einstein-Gauss-Bonnet Gravity
Deppe, Nils; Frey, Andrew R; Kunstatter, Gabor
2016-01-01
AdS spacetime has been shown numerically to be unstable against a large class of arbitrarily small perturbations. In arXiv:1410.1869, the authors presented a preliminary study of the effects on stability of changing the local dynamics by adding a Gauss-Bonnet term to the Einstein action. Here we provide further details as well as new results with improved numerical methods. In particular, we elucidate new structure in Choptuik scaling plots. We also provide evidence of chaotic behavior at the transition between immediate horizon formation and horizon formation after the matter pulse reflects from the AdS conformal boundary. Finally, we present data suggesting the formation of naked singularities in spacetimes with ADM mass below the algebraic bound for black hole formation.
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 i...... 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 .......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...
Holographic Thermalization, Stability of AdS, and the FPU Paradox
Balasubramanian, Venkat; Green, Stephen R; Lehner, Luis; Liebling, Steven L
2014-01-01
For a real massless scalar field in general relativity with a negative cosmological constant, we uncover a large class of spherically symmetric initial conditions that are close to AdS, but whose numerical evolution does not result in black hole formation. According to the AdS/CFT dictionary, these bulk solutions are dual to states of a strongly interacting boundary CFT that fail to thermalize at late times. Furthermore, as these states are not stationary, they define dynamical CFT configurations that do not equilibrate. We develop a two-timescale perturbative formalism that captures both direct and inverse cascades of energy and agrees with our fully nonlinear evolutions in the appropriate regime. We also show that this formalism admits a large class of quasi-periodic solutions. Finally, we demonstrate a striking parallel between the dynamics of AdS and the classic Fermi-Pasta-Ulam-Tsingou problem.
Hairy Black Holes in AdS$_5\\times S^5$
Markeviciute, J
2016-01-01
We use numerical methods to exhaustively study a novel family of hairy black hole solutions in AdS$_5$. These solutions can be uplifted to solutions of type IIB supergravity with AdS$_5\\times S^5$ asymptotics and are thus expected to play an important role in our understanding of AdS/CFT. We find an intricate phase diagram, with the aforementioned family of hairy black hole solutions branching from the Reissner-Nordstr\\"om black hole at the onset of the superradiance instability. We analyse black holes with spherical and planar horizon topology and explain how they connect in the phase diagram. Finally, we detail their global and local thermodynamic stability across several ensembles.
The Central Charge of the Warped AdS^3 Black Hole
Gupta, Kumar S; Sen, Siddhartha; Sivakumar, M
2010-01-01
The AdS/CFT conjecture offers the possibility of a quantum description for a black hole in terms of a CFT. This has ledto the study of general AdS^3 type black holes with a view to constructing an explicit toy quantum black hole model. Such a CFT description would be characterized by its central charge and the dimensions of its primary fields. Recently the expression for the central charges (C_L, C_R) of the CFT dual to the warped AdS^3 have been determined using asymptotic symmetry arguments. The central charges depend, as expected, on the warping factor. We show that topological arguments, used by Witten to constrain central charges for the BTZ black hole, can be generalized to deal with the warped AdS^3 case. Topology constrains the warped factor to be rational numbers while quasinormal modes are conjectured to give the dimensions of primary fields. We find that in the limit when warping is large or when it takes special rational values the system tends to Witten's conjectured unique CFT's with central cha...
On 1-loop diagrams in AdS space and the random disorder problem
Hung, Ling-Yan
2010-01-01
We study the complex scalar loop corrections to the boundary-boundary gauge two point function in pure AdS space in Poincare coordinates, in the presence of a boundary quadratic perturbation to the scalar. These perturbations correspond to double trace perturbations in the dual CFT and modify the boundary conditions of the bulk scalars in AdS. We find that, in addition to the usual UV divergences, the 1-loop calculation suffers from a divergence originating in the limit as the loop vertices approach the AdS horizon. We show that this type of divergence is independent of the boundary coupling, and making use of which we extract the finite relative variation of the imaginary part of the loop via Cutkosky rules as the boundary perturbation varies. Applying our methods to compute the effects of a time-dependent impurity to the conductivities using the replica trick in AdS/CFT, we find that generally an IR-relevant disorder reduces the conductivity and that in the extreme low frequency limit the correction due to ...
Evolutionary algorithms for mobile ad hoc networks
Dorronsoro, Bernabé; Danoy, Grégoire; Pigné, Yoann; Bouvry, Pascal
2014-01-01
Describes how evolutionary algorithms (EAs) can be used to identify, model, and minimize day-to-day problems that arise for researchers in optimization and mobile networking. Mobile ad hoc networks (MANETs), vehicular networks (VANETs), sensor networks (SNs), and hybrid networks—each of these require a designer’s keen sense and knowledge of evolutionary algorithms in order to help with the common issues that plague professionals involved in optimization and mobile networking. This book introduces readers to both mobile ad hoc networks and evolutionary algorithms, presenting basic concepts as well as detailed descriptions of each. It demonstrates how metaheuristics and evolutionary algorithms (EAs) can be used to help provide low-cost operations in the optimization process—allowing designers to put some “intelligence” or sophistication into the design. It also offers efficient and accurate information on dissemination algorithms topology management, and mobility models to address challenges in the ...
Chu, Chong-Sun
2016-01-01
We propose and study a holographic dual of the type IIB superstring theory of AdS_5 x S^5 in terms of the N=4 superconformal Yang-Mills theory on dS_4. We use the bulk to boundary formalism to evaluate the boundary correlation functions and verify that it agrees with the expected result in dS conformal field theory. The gauge theory is expected to be UV finite and enjoy exact SL(2,Z) strong-weak duality. As the string theory Green-Schwarz sigma model carries an infinite number of classically conserved charges, it also suggest that the superconformal Yang-Mills theory is integrable and deserves further studies.
Noncommutative $q$-photon added coherent states
Dey, Sanjib
2016-01-01
We construct the photon added coherent states of a noncommutative harmonic oscillator associated to a $q$-deformed oscillator algebra. Various nonclassical properties of the corresponding system are explored, first, by studying two different types of higher order quadrature squeezing, namely the Hillery-type and the Hong--Mandel-type and, second, by testing the sub-Poissonian nature of photon statistics in higher order with the help of the correlation function and the Mandel parameter. By comparing our results with those of the usual harmonic oscillator, we notice that the quadratures and photon number distributions in noncommutative case are more squeezed for the same values of the parameters and, thus, the photon added coherent states of noncommutative harmonic oscillator may be more nonclassical in comparison to the ordinary harmonic oscillator.
ADS Network in Japan and in Asia
Nagai, Yasuki
2004-04-01
The management of long-lived high-level waste, such as minor actinides (MA) and long-lived fission products (LLFP), is one of the most important issues to be solved for the utilization of the nuclear fission energy. The transmutation project of the radioactive wastes based on an accelerator driven sub-critical (ADS) system is very attractive, since it could reduce the risk of long-lived radioactivity and also increase the capacity of the disposal site. In the development of the ADS project networks of researchers between different fields and between different countries are crucial, since there are many scientific and technical issues, which should be studied. The activities based on these networks are discussed.
Constrained Delaunay Triangulation for Ad Hoc Networks
Directory of Open Access Journals (Sweden)
D. Satyanarayana
2008-01-01
Full Text Available Geometric spanners can be used for efficient routing in wireless ad hoc networks. Computation of existing spanners for ad hoc networks primarily focused on geometric properties without considering network requirements. In this paper, we propose a new spanner called constrained Delaunay triangulation (CDT which considers both geometric properties and network requirements. The CDT is formed by introducing a small set of constraint edges into local Delaunay triangulation (LDel to reduce the number of hops between nodes in the network graph. We have simulated the CDT using network simulator (ns-2.28 and compared with Gabriel graph (GG, relative neighborhood graph (RNG, local Delaunay triangulation (LDel, and planarized local Delaunay triangulation (PLDel. The simulation results show that the minimum number of hops from source to destination is less than other spanners. We also observed the decrease in delay, jitter, and improvement in throughput.
Chu, Chong-Sun; Giataganas, Dimitrios
2016-11-01
We propose and study a holographic dual of the type-IIB superstring theory of AdS5×S5 in terms of the N =4 superconformal Yang-Mills theory on dS4 . We develop the bulk to boundary formalism for the computation of the correlation functions to a wide class of theories. We apply it to compute the two-point correlators in the particular duality under study and we find that they agree with the expected results in d S conformal field theory. The gauge theory is expected to be UV finite and enjoy exact S L (2 ,Z ) strong-weak duality. As the string theory Green-Schwarz sigma model carries an infinite number of classically conserved charges, it also suggests that the superconformal Yang-Mills theory is integrable and deserves further studies.
AD/HD: POSSIBLE DIAGNOSIS AND TREATMENT
Directory of Open Access Journals (Sweden)
Karl REICHELT
2008-12-01
Full Text Available The purpose of this paper is to show that a more exact diagnosis and dietary intervention in AD/HD (Attention Deficit/Hyperactivity Disorder is possible and probable. The clinical symptom based diagnosis we suggest may be supplemented with physiological tests. A genetic and environmental inter-action is clearly involved and explainable using phenylketonuria as a model.Method: Examining peer reviewed published papers on gut to blood, blood to brain interaction and effect of interventions in AD/HD and our own studies in the field. The various treatment options are discussed.Results: It can be shown that a gut to brain activity is possible and probable, and dietary intervention is useful and probably safer than drugs. Preliminary data on a small five year follow up of dietary intervention is shown.
Supporting Dynamic Ad hoc Collaboration Capabilities
Energy Technology Data Exchange (ETDEWEB)
Agarwal, Deborah A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Berket, Karlo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2003-07-14
Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.
Overlaid Cellular and Mobile Ad Hoc Networks
Huang, Kaibin; Chen, Bin; Yang, Xia; Lau, Vincent K N
2008-01-01
In cellular systems using frequency division duplex, growing Internet services cause unbalance of uplink and downlink traffic, resulting in poor uplink spectrum utilization. Addressing this issue, this paper considers overlaying an ad hoc network onto a cellular uplink network for improving spectrum utilization and spatial reuse efficiency. Transmission capacities of the overlaid networks are analyzed, which are defined as the maximum densities of the ad hoc nodes and mobile users under an outage constraint. Using tools from stochastic geometry, the capacity tradeoff curves for the overlaid networks are shown to be linear. Deploying overlaid networks based on frequency separation is proved to achieve higher network capacities than that based on spatial separation. Furthermore, spatial diversity is shown to enhance network capacities.
Hubeny, Veronika E.
2015-06-01
We give a brief review of the AdS/CFT correspondence, which posits the equivalence between a certain gravitational theory and a lower-dimensional non-gravitational one. This remarkable duality, formulated in 1997, has sparked a vigorous research program that has gained in breadth over the years, with applications to many aspects of theoretical (and even experimental) physics, not least to general relativity and quantum gravity. To put the AdS/CFT correspondence into historical context, we start by reviewing the relevant aspects of string theory (of which no prior knowledge is assumed). We then develop the statement of the correspondence, and explain how the two sides of the duality map into each other. Finally, we discuss the implications and applications of the correspondence, and indicate some of the current trends in this subject. The presentation attempts to convey the main concepts in a simple and self-contained manner, relegating supplementary remarks to footnotes.
Hubeny, Veronika E
2015-01-01
We give a brief review of the AdS/CFT correspondence, which posits the equivalence between a certain gravitational theory and a lower-dimensional non-gravitational one. This remarkable duality, formulated in 1997, has sparked a vigorous research program which has gained in breadth over the years, with applications to many aspects of theoretical (and even experimental) physics, not least to general relativity and quantum gravity. To put the AdS/CFT correspondence in historical context, we start by reviewing the relevant aspects of string theory (of which no prior knowledge is assumed). We then develop the statement of the correspondence, and explain how the two sides of the duality map into each other. Finally, we discuss the implications and applications of the correspondence, and indicate some of the current trends in this subject. The presentation attempts to convey the main concepts in a simple and self-contained manner, relegating supplementary remarks to footnotes.
Merged Sounding Value-Added Product
Energy Technology Data Exchange (ETDEWEB)
Troyan, D
2010-03-03
The Merged Sounding value-added product (VAP) uses a combination of observations from radiosonde soundings, the microwave radiometer (MWR), surface meteorological instruments, and European Centre for Medium-Range Weather Forecasts (ECMWF) model output with a sophisticated scaling/interpolation/smoothing scheme in order to define profiles of the atmospheric thermodynamic state at one-minute temporal intervals and a total of 266 altitude levels.
Hypoglycaemia when adding sulphonylurea to metformin
DEFF Research Database (Denmark)
Andersen, Stig Ejdrup; Christensen, Mikkel
2016-01-01
of hypoglycaemia was lowest with gliclazide compared to glipizide (OR 0.22, CrI: 0.05 to 0.96), glimepiride (OR 0.40, CrI: 0.13 to 1.27), and glibenclamide (OR 0.21, CrI: 0.03 to 1.48). A major limitation is varying definitions of hypoglycaemia across studies. CONCLUSIONS: When added to metformin, gliclazide...
Haas, Zygmunt; Halpern, Joseph Y.; Li, Erran L.
2002-01-01
Many ad hoc routing protocols are based on some variant of flooding. Despite various optimizations, many routing messages are propagated unnecessarily. We propose a gossiping-based approach, where each node forwards a message with some probability, to reduce the overhead of the routing protocols. Gossiping exhibits bimodal behavior in sufficiently large networks: in some executions, the gossip dies out quickly and hardly any node gets the message; in the remaining executions, a substantial fr...
DAWN: Dynamic Ad-hoc Wireless Network
2016-06-19
Wireless Networks, , ( ): . doi: Ning Li, Jennifer C. Hou. Localized Topology Control Algorithms for Heterogeneous Wireless Networks, IEEE ...Multi-User Diversity in Single-Radio OFDMA AdHoc Networks Based on Gibbs Sampling, IEEE Milcom . 03-NOV-10, . : , TOTAL: 1 Number of Peer-Reviewed...Networks, ( ) Hui Xu, , Xianren Wu, , Hamid R. Sadjadpour, , J.J. Garcia-Luna-Aceves, . A Unified Analysis of Routing Protocols inMANETs, IEEE
Geodesic Motions in AdS Soliton Background Space-time
Shi, Han-qing
2016-01-01
We study both massive and massless particle's geodesic motion in the background of general dimensional AdS-Sol space-time. We find that the massive particles oscillate along the radial direction, while massless particles experience one-time bouncing as they approach the "horizon" line of the soliton. Our results provide a direct way to understand the negative energy/masses leading to the AdS-Sol geometry. As a potential application, we extend the point particle to a 3-brane and fix the background as a 5+1 dimension AdS-Sol, thus obtain a very natural bouncing/cyclic cosmological model.
Covariant anomalies and Hawking radiation from Kaluza–Klein AdS black holes
Indian Academy of Sciences (India)
Chuan-Yi Bai
2013-02-01
In this paper, Hawking radiation is studied from four-dimensional (4D) Kaluza–Klein (KK) AdS black holes via the method of anomaly cancellation. The {|bf KK-AdS} black hole considered is a non-extremal charged rotating solution in the theory of 4D gauged supergravity. Its Hawking fluxes of electric charge, angular momentum and energy momentum tensor are derived here. Our results support the common view that Hawking radiation is the quantum effect arising at the event horizon.
Drag cancellation by added-mass pumping
Giorgio-Serchi, F
2016-01-01
A submerged body subject to a sudden shape-change experiences large forces due to the variation of added-mass energy. While this phenomenon has been studied for single actuation events, application to sustained propulsion requires studying \\textit{periodic} shape-change. We do so in this work by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. We develop an analytical model to investigate the relationship between added-mass variation and viscous damping and demonstrate its range of application with fully coupled fluid-solid Navier-Stokes simulations at large Stokes number. Our results demonstrate that the recovery of added-mass kinetic energy can be used to completely cancel the viscous damping of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius $r_0$. A quasi-linear relationship is found to link the terminal amplitude of the oscillations $X$, to the extent of size change $a$, wit...
Ad Serving Using a Compact Allocation Plan
Chen, Peiji; Mandalapu, Srinath; Nagarajan, Chandrashekhar; Shanmugasundaram, Jayavel; Vassilvitskii, Sergei; Vee, Erik; Yu, Manfai; Zien, Jason
2012-01-01
A large fraction of online display advertising is sold via guaranteed contracts: a publisher guarantees to the advertiser a certain number of user visits satisfying the targeting predicates of the contract. The publisher is then tasked with solving the ad serving problem - given a user visit, which of the thousands of matching contracts should be displayed, so that by the expiration time every contract has obtained the requisite number of user visits. The challenges of the problem come from (1) the sheer size of the problem being solved, with tens of thousands of contracts and billions of user visits, (2) the unpredictability of user behavior, since these contracts are sold months ahead of time, when only a forecast of user visits is available and (3) the minute amount of resources available online, as an ad server must respond with a matching contract in a fraction of a second. We present a solution to the guaranteed delivery ad serving problem using {\\em compact allocation plans}. These plans, computed offl...
On periodically driven AdS/CFT
Auzzi, Roberto; Gudnason, Sven Bjarke; Rabinovici, Eliezer
2013-01-01
We use the AdS/CFT correspondence to study a thermally isolated conformal field theory in four dimensions which undergoes a repeated deformation by an external periodic time-dependent source coupled to an operator of dimension Delta. The initial state of the theory is taken to be at a finite temperature. We compute the energy dissipated in the system as a function of the frequency and of the dimension Delta of the perturbing operator. This is done in the linear response regime. In order to study the details of thermalization in the dual field theory, the leading-order backreaction on the AdS black brane metric is computed. The evolution of the event and the apparent horizons is monitored; the increase of area in each cycle coincides with the increase in the equilibrium entropy corresponding to the amount of energy dissipated. The time evolution of the entanglement entropy of a spherical region and that of the two-points function of a probe operator with a large dimension are also inspected; we find a delay in...
Transmission Strategies in MIMO Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Fakih Khalil
2009-01-01
Full Text Available Abstract Precoding problem in multiple-input multiple-output (MIMO ad hoc networks is addressed in this work. Firstly, we consider the problem of maximizing the system mutual information under a power constraint. In this context, we give a brief overview of the nonlinear optimization methods, and systematically we compare their performances. Then, we propose a fast and distributed algorithm based on the quasi-Newton methods to give a lower bound of the system capacity of MIMO ad hoc networks. Our proposed algorithm solves the maximization problem while diminishing the amount of information in the feedback links needed in the cooperative optimization. Secondly, we propose a different problem formulation, which consists in minimizing the total transmit power under a quality of signal constraint. This novel problem design is motivated since the packets are captured in ad hoc networks based on their signal-to-interference-plus-noise ratio (SINR values. We convert the proposed formulation into semidefinite optimization problem, which can be solved numerically using interior point methods. Finally, an extensive set of simulations validates the proposed algorithms.
Data Confidentiality in Mobile Ad hoc Networks
Directory of Open Access Journals (Sweden)
Hamza Aldabbas
2012-03-01
Full Text Available Mobile ad hoc networks (MANETs are self-configuring infrastructure-less networks comprised of mobile nodes that communicate over wireless links without any central control on a peer-to-peer basis.These individual nodes act as routers to forward both their own data and also their neighbours’ data by sending and receiving packets to and from other nodes in the network. The relatively easy configuration and the quick deployment make ad hoc networks suitable the emergency situations (such as human or natural disasters and for military units in enemy territory. Securing data dissemination between these nodes in such networks, however, is a very challenging task. Exposing such information to anyone else other than the intended nodes could cause a privacy and confidentiality breach, particularly in military scenarios. In this paper we present a novel framework to enhance the privacy and data confidentiality in mobile ad hoc networks by attaching the originator policies to the messages as they are sent between nodes. We evaluate our framework using the Network Simulator (NS-2 to check whether the privacy and confidentiality of the originator are met. For this we implemented the Policy Enforcement Points (PEPs, as NS-2 agents that manage and enforce the policies attached to packets at every node in the MANET.
ADS: The Next Generation Search Platform
Accomazzi, Alberto; Henneken, Edwin A; Chyla, Roman; Luker, James; Grant, Carolyn S; Thompson, Donna M; Holachek, Alexandra; Dave, Rahul; Murray, Stephen S
2015-01-01
Four years after the last LISA meeting, the NASA Astrophysics Data System (ADS) finds itself in the middle of major changes to the infrastructure and contents of its database. In this paper we highlight a number of features of great importance to librarians and discuss the additional functionality that we are currently developing. Starting in 2011, the ADS started to systematically collect, parse and index full-text documents for all the major publications in Physics and Astronomy as well as many smaller Astronomy journals and arXiv e-prints, for a total of over 3.5 million papers. Our citation coverage has doubled since 2010 and now consists of over 70 million citations. We are normalizing the affiliation information in our records and, in collaboration with the CfA library and NASA, we have started collecting and linking funding sources with papers in our system. At the same time, we are undergoing major technology changes in the ADS platform which affect all aspects of the system and its operations. We hav...
A reference accelerator scheme for ADS applications
Energy Technology Data Exchange (ETDEWEB)
Biarrotte, Jean-Luc [CNRS/IN2P3, Institut de Physique Nucleaire, 91406 Orsay (France)]. E-mail: biarrott@ipno.in2p3.fr; Bousson, Sebastien [CNRS/IN2P3, Institut de Physique Nucleaire, 91406 Orsay (France); Junquera, Tomas [CNRS/IN2P3, Institut de Physique Nucleaire, 91406 Orsay (France); Mueller, Alex C. [CNRS/IN2P3, Institut de Physique Nucleaire, 91406 Orsay (France); Olivier, Aurelia [CNRS/IN2P3, Institut de Physique Nucleaire, 91406 Orsay (France)
2006-06-23
Accelerator Driven Systems (ADS) for transmutation of nuclear waste typically require 350MeV-1GeV accelerators delivering proton fluxes of 5-10mA for demonstrators, and 20-50mA for large industrial systems. Thus, such machines belong to the category of the so-called HPPA (High-Power Proton Accelerators), with multi-megawatt beam power. HPPA are presently developed and constructed at great pace for their broad utility in fundamental or applied science. Compared to other HPPA, many features and requirements are similar for the ADS driver. However, there is a need for exceptional reliability: because of the induced thermal stress to the sub-critical core, the number of unwanted 'beam-trips' should not exceed a few per year, a requirement that is several orders of magnitude above usual performance. Consecutive to the work of the European Technical Working Group (ETWG) on ADS, the Preliminary Design Study of an Experimental ADS (PDS-XADS) was launched in 2001 as a 5th Framework Program EC project. A special Working Package (WP3) was dedicated to the accelerator design, taking especially into account that the issue of 'beam-trips' could be a potential 'show-stopper' for ADS technology in general. A reference solution, based on a linear superconducting accelerator with its associated doubly achromatic beam line, has been worked out to some detail. For high reliability, the proposed design is intrinsically fault tolerant, relying on highly modular 'de-rated' components associated to a fast digital feedback system. The proposed solution also appears to be robust concerning operational aspects like maintenance and radioprotection. A roadmap for construction as well as the required consolidated budget was elaborated. A program for the remaining R and D, focused on experimental reliability demonstration of prototypical components has been elaborated. This R and D will be performed in the 6th Framework Program EC project EUROTRANS, which
G\\"odel, warped AdS$_3$ and flows from $\\mathcal{N} = (0,2)$ SCFTs
Colgáin, Eoin Ó
2015-01-01
We present all timelike supersymmetric solutions to 3D U(1)$^3$ gauged supergravity, a known consistent truncation of string theory. We uncover a rich vacuum structure, including an infinite class of new timelike (G\\"odel) and spacelike warped AdS$_3$ critical points. We outline the construction of holographic flows interpolating between AdS$_3$ and warped AdS$_3$ critical points.
Weak field collapse in AdS: introducing a charge density
Energy Technology Data Exchange (ETDEWEB)
Caceres, Elena [Facultad de Ciencias, Universidad de Colima,Bernal Diaz del Castillo 340, Colima (Mexico); Theory Group, Department of Physics and Texas Cosmology Center,The University of Texas at Austin,2515 Speedway Stop C1608, Austin, TX 78712 (United States); Kundu, Arnab [Department de Física Fondamental & Institut de Ciències del Cosmos,Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain); Saha Institute of Nuclear Physics,1/AF Bidhannagar, Kolkata 700064 (India); Pedraza, Juan F. [Theory Group, Department of Physics and Texas Cosmology Center,The University of Texas at Austin,2515 Speedway Stop C1608, Austin, TX 78712 (United States); Perimeter Institute for Theoretical Physics,31 Caroline Street North Waterloo, Ontario N2L 2Y5 (Canada); Yang, Di-Lun [Crete Center for Theoretical Physics, Department of physics, University of Crete,71003, Heraklion (Greece); Department of physics, Chung-Yuan Christian University,Chung Pei Road, Chung-Li 32023, Taiwan (China)
2015-06-17
We study the effect of a non-vanishing chemical potential on the thermalization time of a strongly coupled large N{sub c} gauge theory in (2+1)-dimensions, using a specific bottom-up gravity model in asymptotically AdS space. We first construct a perturbative solution to the gravity-equations, which dynamically interpolates between two AdS black hole backgrounds with different temperatures and chemical potentials, in a perturbative expansion of a bulk neutral scalar field. In the dual field theory, this corresponds to a quench dynamics by a marginal operator, where the corresponding coupling serves as the small parameter in which the perturbation is carried out. The evolution of non-local observables, such as the entanglement entropy, suggests that thermalization time decreases with increasing chemical potential. We also comment on the validity of our perturbative analysis.
Integrable open spin-chains in AdS3/CFT2
Prinsloo, Andrea; Torrielli, Alessandro
2015-01-01
We study integrable open boundary conditions for d(2,1;\\alpha)^2 and psu(1,1|2)^2 spin-chains. Magnon excitations of these open spin-chains are mapped to massive excitations of type IIB open superstrings ending on D-branes in the AdS_3 x S^3 x S^3 x S^1 and AdS_3 x S^3 x T^4 supergravity geometries with pure R-R flux. We derive reflection matrix solutions of the boundary Yang-Baxter equation which intertwine representations of a variety of boundary coideal subalgebras of the bulk Hopf superalgebra. Many of these integrable boundaries are matched to D1 and D5-brane maximal giant gravitons.
Radiatively induced symmetry breaking and the conformally coupled magnetic monopole in AdS space
Edery, Ariel
2013-01-01
We implement quantum corrections for a magnetic monopole in a classically conformally invariant theory containing gravity. This yields the trace (conformal) anomaly and introduces a length scale in a natural fashion via the process of renormalization. We evaluate the one-loop effective potential and extract the vacuum expectation value (VEV) from it; spontaneous symmetry breaking is radiatively induced. The VEV is set at the renormalization scale $M$ and we exchange the dimensionless scalar coupling constant for the dimensionful VEV via dimensional transmutation. The asymptotic (background) spacetime is anti-de Sitter (AdS) and its Ricci scalar is determined entirely by the VEV. We obtain analytical asymptotic solutions to the coupled set of equations governing gravitational, gauge and scalar fields that yield the magnetic monopole in an AdS spacetime.
Finite action principle for Chern-Simons AdS gravity
Mora, P; Troncoso, R; Zanelli, J
2004-01-01
A finite action action principle for Chern-Simons AdS gravity is presented. The construction is carried out in detail first in five dimensions, where the bulk action is given by a particular combination of the Einstein-Hilbert action with negative cosmological constant and a Gauss-Bonnet term; and is then generalized for arbitrary odd dimensions. The boundary term needed to render the action finite is singled out demanding the action to attain an extremum for an appropriate set of boundary conditions. The boundary term is a local function of the fields at the boundary and is sufficient to render the action finite for asymptotically AdS solutions, without requiring background fields. It is shown that the Euclidean continuation of the action correctly describes the black hole thermodynamics in the canonical ensemble. Additionally, background independent conserved charges associated with the asymptotic symmetries can be written as surface integrals by direct application of Noether's theorem.
Vector Condensate and AdS Soliton Instability Induced by a Magnetic Field
Cai, Rong-Gen; Li, Li-Fang; Wu, You
2014-01-01
We continue to study the holographic p-wave superconductor model in the Einstein-Maxwell-complex vector field theory with a non-minimal coupling between the complex vector field and the Maxwell field. In this paper we work in the AdS soliton background which describes a conformal field theory in the confined phase and focus on the probe approximation. We find that an applied magnetic field can lead to the condensate of the vector field and the AdS soliton instability. As a result, a vortex lattice structure forms in the spatial directions perpendicular to the applied magnetic field. As a comparison, we also discuss the vector condensate in the Einstein-SU(2) Yang-Mills theory and find that in the setup of the present paper, the Einstein-Maxwell-complex vector field model is a generalization of the SU(2) model in the sense that the vector field has a general mass and gyromagnetic ratio.
Stability of warped AdS3 black holes in Topologically Massive Gravity under scalar perturbations
Ferreira, Hugo R C
2013-01-01
We demonstrate that the warped AdS3 black hole solutions of Topologically Massive Gravity are classically stable against massive scalar field perturbations by analysing the quasinormal and bound state modes of the scalar field. In particular, it is found that although classical superradiance is present it does not give rise to superradiant instabilities. The stability is shown to persist even when the black hole is enclosed by a stationary mirror with Dirichlet boundary conditions. This is a surprising result in view of the similarity between the causal structure of the warped AdS3 black hole and the Kerr spacetime in 3+1 dimensions. This work provides the foundations for the study of quantum field theory in this spacetime.
Renormalization, averaging, conservation laws and AdS (in)stability
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University,Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Vanhoof, Joris [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)
2015-01-21
We continue our analytic investigations of non-linear spherically symmetric perturbations around the anti-de Sitter background in gravity-scalar field systems, and focus on conservation laws restricting the (perturbatively) slow drift of energy between the different normal modes due to non-linearities. We discover two conservation laws in addition to the energy conservation previously discussed in relation to AdS instability. A similar set of three conservation laws was previously noted for a self-interacting scalar field in a non-dynamical AdS background, and we highlight the similarities of this system to the fully dynamical case of gravitational instability. The nature of these conservation laws is best understood through an appeal to averaging methods which allow one to derive an effective Lagrangian or Hamiltonian description of the slow energy transfer between the normal modes. The conservation laws in question then follow from explicit symmetries of this averaged effective theory.
Non-Supersymmetric CS-Matter Theories with Known AdS Duals
Directory of Open Access Journals (Sweden)
Davide Forcella
2011-01-01
Full Text Available We consider three-dimensional conformal field theories living on a stack of N anti-M2 branes at the tip of eight-dimensional supersymmetric cones. The corresponding supergravity solution is obtained by changing sign to the four-form in the Freund-Rubin solution representing M2 branes (“skew-whiffing” transformation and it is known to be stable. The existence of these non-supersymmetric, stable field theories, at least in the large N limit, is a peculiarity of the AdS 4 / CFT 3 correspondence with respect to the usual AdS 5 / CFT 4 , and it is worthwhile to study it. We analyze in detail the KK spectrum of the skew-whiffed solution associated with S 7 / ℤ k and we speculate on the natural field content for a candidate non-supersymmetric dual field theory.
Weak Field Collapse in AdS: Introducing a Charge Density
Caceres, Elena; Pedraza, Juan F; Yang, Di-Lun
2014-01-01
We study the effect of a non-vanishing chemical potential on the thermalization time of a strongly coupled large Nc gauge theory in (2+1)-dimensions, using a specific bottom-up gravity model in asymptotically AdS space. We first construct a perturbative solution to the gravity-equations, which dynamically interpolates between two AdS black hole backgrounds with different temperatures and chemical potentials, in a perturbative expansion of a bulk neutral scalar field. In the dual field theory, this corresponds to a quench dynamics by a marginal operator, where the corresponding coupling serves as the small parameter in which the perturbation is carried out. The evolution of non-local observables, such as the entanglement entropy, suggests that thermalization time decreases with increasing chemical potential. We also comment on the validity of our perturbative analysis.
Gauge invariant Lagrangian formulation of higher spin massive bosonic field theory in AdS space
Buchbinder, I L; Lavrov, P M
2006-01-01
We develop the BRST approach to Lagrangian construction for the massive integer higher spin fields in an arbitrary dimensional AdS space. The theory is formulated in terms of auxiliary Fock space. Closed nonlinear symmetry algebra of higher spin bosonic theory in AdS space is found and method of deriving the BRST operator for such an algebra is proposed. General procedure of Lagrangian construction describing the dynamics of bosonic field with any spin is given on the base of the BRST operator. No off-shell constraints on the fields and the gauge parameters are used from the very beginning. As an example of general procedure, we derive the Lagrangians for massive bosonic fields with spin 0, 1 and 2 containing total set of auxiliary fields and gauge symmetries.
Gauge invariant Lagrangian formulation of higher spin massive bosonic field theory in AdS space
Energy Technology Data Exchange (ETDEWEB)
Buchbinder, I.L. [Department of Theoretical Physics, Tomsk State Pedagogical University, Tomsk 634041 (Russian Federation)]. E-mail: joseph@tspu.edu.ru; Krykhtin, V.A. [Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk 634034 (Russian Federation)]. E-mail: krykhtin@mph.phtd.tpu.edu.ru; Lavrov, P.M. [Department of Mathematical Analysis, Tomsk State Pedagogical University, Tomsk 634041 (Russian Federation)]. E-mail: lavrov@tspu.edu.ru
2007-02-05
In this work we develop the BRST approach to Lagrangian construction for the massive integer higher spin fields in an arbitrary dimensional AdS space. The theory is formulated in terms of auxiliary Fock space. Closed nonlinear symmetry algebra of higher spin bosonic theory in AdS space is found and a method of deriving the BRST operator for such an algebra is proposed. A general procedure of Lagrangian construction, describing the dynamics of a bosonic field with any spin is given on the base of the BRST operator. No off-shell constraints on the fields and the gauge parameters are used from the very beginning. As an example of general procedure, we derive the Lagrangians for massive bosonic fields with spin 0, 1 and 2, containing the total set of auxiliary fields and gauge symmetries.
Phases of planar AdS black holes with axionic charge
Caldarelli, Marco M.; Christodoulou, Ariana; Papadimitriou, Ioannis; Skenderis, Kostas
2017-04-01
Planar AdS black holes with axionic charge have finite DC conductivity due to momentum relaxation. We obtain a new family of exact asymptotically AdS4 black branes with scalar hair, carrying magnetic and axion charge, and we study the thermodynamics and dynamic stability of these, as well as of a number of previously known electric and dyonic solutions with axion charge and scalar hair. The scalar hair for all solutions satisfy mixed boundary conditions, which lead to modified holographic Ward identities, conserved charges and free energy, relative to those following from the more standard Dirichlet boundary conditions. We show that properly accounting for the scalar boundary conditions leads to well defined first law and other thermodynamic relations. Finally, we compute the holographic quantum effective potential for the dual scalar operator and show that dynamical stability of the hairy black branes is equivalent to positivity of the energy density.
Witten Diagrams Revisited: The AdS Geometry of Conformal Blocks
Hijano, Eliot; Perlmutter, Eric; Snively, River
2015-01-01
We develop a new method for decomposing Witten diagrams into conformal blocks. The steps involved are elementary, requiring no explicit integration, and operate directly in position space. Central to this construction is an appealingly simple answer to the question: what object in AdS computes a conformal block? The answer is a "geodesic Witten diagram," which is essentially an ordinary exchange Witten diagram, except that the cubic vertices are not integrated over all of AdS, but only over bulk geodesics connecting the boundary operators. In particular, we consider the case of four-point functions of scalar operators, and show how to easily reproduce existing results for the relevant conformal blocks in arbitrary dimension.
Witten diagrams revisited: the AdS geometry of conformal blocks
Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River
2016-01-01
We develop a new method for decomposing Witten diagrams into conformal blocks. The steps involved are elementary, requiring no explicit integration, and operate directly in position space. Central to this construction is an appealingly simple answer to the question: what object in AdS computes a conformal block? The answer is a "geodesic Witten diagram", which is essentially an ordinary exchange Witten diagram, except that the cubic vertices are not integrated over all of AdS, but only over bulk geodesics connecting the boundary operators. In particular, we consider the case of four-point functions of scalar operators, and show how to easily reproduce existing results for the relevant conformal blocks in arbitrary dimension.
AdS$_5$ vacua from type IIB supergravity on $T^{1,1}$
Louis, Jan
2016-01-01
We study maximally supersymmetric Anti-de Sitter backgrounds in consistent N=2 truncations of type IIB supergravity compactified on the Sasaki-Einstein manifold $T^{1,1}$. In particular, we focus on truncations that contain fields coming from the nontrivial second and third cohomology forms on $T^{1,1}$. These give rise to N=2 supergravity coupled to two vector- and two hypermultiplets (Betti-vector truncation) or one vector- and three hypermultiplets (Betti-hyper truncation), respectively. We find that both truncations admit AdS$_5$ backgrounds with the gauge group always being broken but containing at least an $U(1)_R$ factor. Moreover, in both cases we show that the moduli space of AdS vacua is nontrivial and of maximal dimension. Finally, we explicitly compute the metrics on these moduli spaces.
Non-supersymmetric CS-matter theories with known AdS duals
Forcella, Davide
2011-01-01
We consider three dimensional conformal field theories living on a stack of N anti-M2 branes at the tip of eight-dimensional supersymmetric cones. The corresponding supergravity solution is obtained by changing sign to the four-form in the Freund-Rubin solution representing M2 branes ("skew-whiffing" transformation) and it is known to be stable. The existence of these non supersymmetric, stable field theories, at least in the large N limit, is a peculiarity of the AdS4/CFT3 correspondence with respect to the usual AdS5/CFT4, and it is worthwhile to study it. We analyze in detail the KK spectrum of the skew-whiffed solution associated with S^7/Z_k and we speculate on the natural field content for a candidate non-supersymmetric dual field theory.
Tachyon inflation in an AdS braneworld with back-reaction
Bilic, Neven; Djordjevic, Goran; Milosevic, Milan
2016-01-01
We analyze the inflationary scenario based on the tachyon field coupled with the radion of the second Randall-Sundrum model (RSII). The tachyon Lagrangian is derived from the dynamics of a 3-brane moving in the five dimensional bulk. The AdS$_5$ geometry of the bulk is extended to include the radion. Using the Hamiltonian formalism we find four nonlinear field equations supplemented by the modified Friedmann equations of the RSII braneworld cosmology. After a suitable rescaling we reduce the parameters of our model to only one free parameter related to the brane tension and the AdS$_5$ curvature. We solve the equations numerically assuming a reasonably wide range of initial conditions determined by physical considerations. Varying the free parameter and initial conditions we confront our results with the Planck 2015 data.
P-V criticality of AdS black holes in a general framework
Majhi, Bibhas Ranjan
2016-01-01
Interpreting the cosmological constant as pressure, it has been observed that AdS black holes behave as van der Waals system. The critical exponents for the phase transition for all AdS black holes are exactly same as those for the van der Waals system. Till now this has been observed case by case. Here, without using any specific form of the black hole metric, we present a general framework based on just two universal inputs. These are the general forms of the Smarr formula and the first law of thermodynamics. We find that the same values of the critical exponents can be obtained by this general analysis. Therefore there is no need to investigate for a particular metric. The importance of our analysis is that it highlights the observed universality, as well as revels the reason for such universality.
Extremal Static AdS Black Hole/CFT Correspondence in Gauged Supergravities
Lü, H; Pope, C N; Vazquez-Poritz, J
2009-01-01
A recently proposed holographic duality allows the Bekenstein-Hawking entropy of extremal rotating black holes to be calculated microscopically, by applying the Cardy formula to the two-dimensional chiral CFTs associated with certain reparameterisations of azimuthal angular coordinates in the solutions. The central charges are proportional to the angular momenta of the black hole, and so the method degenerates in the case of static (non-rotating) black holes. We show that the method can be extended to encompass such charged static extremal AdS black holes by using consistent Kaluza-Klein sphere reduction ansatze to lift them to exact solutions in the low-energy limits of string theory or M-theory, where the electric charges become reinterpreted as angular momenta associated with internal rotations in the reduction sphere. We illustrate the procedure for the examples of extremal charged static AdS black holes in four, five, six and seven dimensions.
Pre-potential in the $AdS_{5}\\,\\times\\,S^{5}$ Type IIB superspace
Poláček, Martin
2016-01-01
We found the pre-potential in the superspace with $AdS_{5}\\,\\times\\,S^{5}$ background. The pre-potential appears as part of the vielbeins, without derivatives. The space-cone gauge destroys the bulk Lorentz covariance, but still preserves boundary Lorentz covariance (projective superspace) $SO\\,(\\,3,\\,1\\,)\\,\\otimes\\,SO\\,(\\,4\\,)$, i.e. symmetries of boundary CFT are manifest.
Finite-size corrections for quantum strings on AdS4 x CP3
DEFF Research Database (Denmark)
Astolfi, D.; Puletti, V.G.M.; Grignani, G.;
2011-01-01
We revisit the calculation of curvature corrections to the pp-wave energy of type IIA string states on AdS4×CP3 initiated in arXiv:0807.1527. Using the near pp-wave Hamiltonian found in arXiv:0912.2257, we compute the first non-vanishing correction to the energy of a set of bosonic string states ...
A comparative note on tunneling in AdS and in its boundary matrix dual
Chandrasekhar, B.; Mukherji, Sudipta; Sahay, Anurag; Sarkar, Swarnendu
2012-05-01
For charged black hole, within the grand canonical ensemble, the decay rate from thermal AdS to the black hole at a fixed high temperature increases with the chemical potential. We check that this feature is well captured by a phenomenological matrix model expected to describe its strongly coupled dual. This comparison is made by explicitly constructing the kink and bounce solutions around the de-confinement transition and evaluating the matrix model effective potential on the solutions.
A Comparative Note on Tunneling in AdS and in its Boundary Matrix Dual
Chandrasekhar, B; Sahay, Anurag; Sarkar, Swarnendu
2012-01-01
For charged black hole, within the grand canonical ensemble, the decay rate from thermal AdS to the black hole at a fixed high temperature increases with the chemical potential. We check that this feature is well captured by a phenomenological matrix model expected to describe its strongly coupled dual. This comparison is made by explicitly constructing the kink and bounce solutions around the de-confinement transition and evaluating the matrix model effective potential on the solutions.
$\\mathcal{N}=1$ AdS$_4$ sourceless vacua in type IIB
Solard, Gautier
2016-01-01
In this paper, we are looking for $\\mathcal{N}=1$, AdS$_4$ sourceless vacua in type IIB. While several examples exist in type IIA , there exists only one example of such vacua in type IIB . Thanks to the framework of generalized geometry we were able to devise a semi-algorithmical method to look for sourceless vacua. We present this method, which can easily be generalized to more complex cases, and give two new sourceless vacua in type IIB.
Quantum Consistency of the Superstring in AdS_5 x S^5 Background
Berkovits, N
2005-01-01
Using arguments based on BRST cohomology, the pure spinor formalism for the superstring in an AdS_5 x S^5 background is proven to be BRST invariant and conformally invariant at the quantum level to all orders in perturbation theory. Cohomology arguments are also used to prove the existence of an infinite set of non-local BRST-invariant charges at the quantum level.
Exact microstate counting for dyonic black holes in AdS4
Benini, Francesco; Hristov, Kiril; Zaffaroni, Alberto
2017-08-01
We present a counting of microstates of a class of dyonic BPS black holes in AdS4 which precisely reproduces their Bekenstein-Hawking entropy. The counting is performed in the dual boundary description, that provides a non-perturbative definition of quantum gravity, in terms of a twisted and mass-deformed ABJM theory. We evaluate its twisted index and propose an extremization principle to extract the entropy, which reproduces the attractor mechanism in gauged supergravity.
Exact microstate counting for dyonic black holes in AdS4
Benini, Francesco; Zaffaroni, Alberto
2016-01-01
We present a counting of microstates of a class of dyonic BPS black holes in AdS$_4$ which precisely reproduces their Bekenstein-Hawking entropy. The counting is performed in the dual boundary description, that provides a non-perturbative definition of quantum gravity, in terms of a twisted and mass-deformed ABJM theory. We evaluate its twisted index and propose an extremization principle to extract the entropy, which reproduces the attractor mechanism in gauged supergravity.
Full Poncelet Theorem in Minkowski dS and AdS Spaces
Institute of Scientific and Technical Information of China (English)
WANG Yao-Xiong; FAN Heng; SHI Kang-Jie; WANG Chun; ZHANG Kai; ZENG Yu
2009-01-01
We study the reflection of a straight line or a billiard on a plane in an n-dimensional Minkowski space. It is found that the reflection law coincides with that defined with respect to confocal quadratic surfaces in projective geometry. We then establish the full Poncelet theorem which holds in projective geometry in n-dimensional Minkowski space and in their quadratic surfaces including de Sitter and AdS spaces.
Generalized thermodynamic identity and new Maxwell's law for charged AdS black hole
Zhao, Zixu
2016-01-01
We study the thermodynamic properties of the RN-AdS black hole in full phase space and propose a generalized thermodynamic identity. As an example, we use it to find relations of thermodynamical coefficients between the grand canonical and canonical ensembles. We also show, for the first order phase transition, that the usual Maxwell's equal area law should be extended to a new form for the RN-AdS black hole.
Quarter-BPS Black Holes in AdS$_4$-NUT from $N=2$ Gauged Supergravity
Erbin, Harold
2015-01-01
We study $N=2$ gauged supergravity with $U(1)$ gauge group coupled to $n_v$ vector multiplets and find quite general analytic solutions for quarter-BPS black holes with mass, NUT and dyonic Maxwell charges. The solutions we find have running scalar fields and flow in the IR region to a horizon geometry of the form AdS$_2\\times \\Sigma_g$.
Free boundary conditions and the AdS$_3$/CFT$_2$ correspondence
Apolo, Luis
2014-01-01
We show that the recently proposed free boundary conditions for AdS$_3$ are dual to two-dimensional quantum gravity in certain fixed gauges. In particular, we note that an appropriate identification of the generator of Virasoro transformations leads to a vanishing total central charge in agreement with the theory at the boundary. We argue that this identification is necessary to match the bulk and boundary generators of Virasoro transformations and for consistency with the constraint equations.
One loop partition function of six dimensional conformal gravity using heat kernel on AdS
Energy Technology Data Exchange (ETDEWEB)
Lovreković, Iva [Institute for Theoretical Physics, Technische Universität Wien,Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria)
2016-10-13
We compute the heat kernel for the Laplacians of symmetric transverse traceless fields of arbitrary spin on the AdS background in even number of dimensions using the group theoretic approach introduced in http://dx.doi.org/10.1007/JHEP11(2011)010 and apply it on the partition function of six dimensional conformal gravity. The obtained partition function consists of the Einstein gravity, conformal ghost and two modes that contain mass.
Time-Dependent AdS Backgrounds from S-Branes
Deger, Nihat Sadik
2016-01-01
We construct time and radial dependent solutions that describe p-branes in chargeless S-brane backgrounds. In particular, there are some new M5- and D3-branes among our solutions which have AdS limits and contain a cosmological singularity as well. We also find a time-dependent version of the dyonic membrane configuration in 11-dimensions by applying a Lunin-Maldacena deformation to our new M5-brane solution.
Time-dependent AdS backgrounds from S-branes
Deger, Nihat Sadik
2016-11-01
We construct time and radial dependent solutions that describe p-branes in chargeless S-brane backgrounds. In particular, there are some new M5- and D3-branes among our solutions which have AdS limits and contain a cosmological singularity as well. We also find a time-dependent version of the dyonic membrane configuration in 11-dimensions by applying a Lunin-Maldacena deformation to our new M5-brane solution.
STATISTICAL ENTROPIES OF THE TAUB-NUT/BOLT AdS SPACES FROM THE HORIZON CONFORMAL FIELD THEORY
Institute of Scientific and Technical Information of China (English)
JING JI-LIANG; ZHOU SAN-QING; HUANG YI-BIN
2001-01-01
The covariant phase technique is used to compute the constraint algebra of the four-dimensional space-times which are asymptotic to anti-de Sitter (AdS), such as the planar Taub-NUT AdS and Taub-bolt AdS spaces, and the hyperbolic Taub-bolt AdS space. The standard Virasoro subalgebrae with corresponding central charges for these objects are constructed and the resulting densities of states yield the expected Bekenstein-Hawking entropies.
Supersymmetry of IIA warped flux AdS and flat backgrounds
Beck, S.; Gutowski, J.; Papadopoulos, G.
2015-09-01
We identify the fractions of supersymmetry preserved by the most general warped flux AdS and flat backgrounds in both massive and standard IIA supergravities. We find that AdS n × w M 10 - n preserve {2}^{[n/2]}k for n ≤ 4 and {2}^{[n/2]+1}k for 4 0. In addition we show that, for suitably restricted fields and M 10 - n , the killing spinors of AdS backgrounds are given in terms of the zero modes of Dirac like operators on M 10 - n . This generalizes the Lichnerowicz theorem for connections whose holonomy is included in a general linear group. We also adapt our results to ℝ 1, n - 1 × w M 10 - n backgrounds which underpin flux compactifications to ℝ 1, n - 1 and show that these preserve {2}^{[n/2]}k for 2
Stringy correlations on deformed AdS3 × S 3
Roychowdhury, Dibakar
2017-03-01
In this paper, following the basic prescriptions of Gauge/String duality, we perform a strong coupling computation on classical two point correlation between local (single trace) operators in a gauge theory dual to κ-deformed AdS3 × S 3 background. Our construction is based on the prescription that relates every local operator in a gauge theory to that with the (semi)classical string states propagating within the physical region surrounded by the holographic screen in deformed AdS3. In our analysis, we treat strings as being that of a point like object located near the physical boundary of the κ-deformed Euclidean Poincare AdS3 and as an extended object with non trivial dynamics associated to S 3. It turns out that in the presence of small background deformations, the usual power law behavior associated with two point functions is suppressed exponentially by a non trivial factor which indicates a faster decay of two point correlations with larger separations. On the other hand, in the limit of large background deformations ( κ ≫ 1), the corresponding two point function reaches a point of saturation. In our analysis, we also compute finite size corrections associated with these two point functions at strong coupling. As a consistency check of our analysis, we find perfect agreement between our results to that with the earlier observations made in the context of vanishing deformation.
Superradiance and instability of small rotating charged AdS black holes in all dimensions
Energy Technology Data Exchange (ETDEWEB)
Aliev, Alikram N. [Yeni Yuezyil University, Faculty of Engineering and Architecture, Istanbul (Turkey)
2016-02-15
Rotating small AdS black holes exhibit the superradiant instability to low-frequency scalar perturbations, which is amenable to a complete analytic description in four dimensions. In this paper, we extend this description to all higher dimensions, focusing on slowly rotating charged AdS black holes with a single angular momentum. We divide the spacetime of these black holes into the near-horizon and far regions and find solutions to the scalar wave equation in each of these regions. Next, we perform the matching of these solutions in the overlap between the regions, by employing the idea that the orbital quantum number l can be thought of as an approximate integer. Thus, we obtain the complete low-frequency solution that allows us to calculate the complex frequency spectrum of quasinormal modes, whose imaginary part is determined by a small damping parameter. Finally, we find a remarkably instructive expression for the damping parameter, which appears to be a complex quantity in general. We show that the real part of the damping parameter can be used to give a universal analytic description of the superradiant instability for slowly rotating charged AdS black holes in all spacetime dimensions. (orig.)
State Operator Correspondence and Entanglement in AdS2/CFT1
Directory of Open Access Journals (Sweden)
Ashoke Sen
2011-07-01
Full Text Available Since Euclidean global AdS2 space represented as a strip has two boundaries, the state-operator correspondence in the dual CFT1 reduces to the standard map from the operators acting on a single copy of the Hilbert space to states in the tensor product of two copies of the Hilbert space. Using this picture we argue that the corresponding states in the dual string theory living on AdS2 × K are described by the twisted version of the Hartle–Hawking states, the twists being generated by a large unitary group of symmetries that this string theory must possess. This formalism makes natural the dual interpretation of the black hole entropy—as the logarithm of the degeneracy of ground states of the quantum mechanics describing the low energy dynamics of the black hole, and also as an entanglement entropy between the two copies of the same quantum theory living on the two boundaries of global AdS2 separated by the event horizon.
Planar AdS black holes in Lovelock gravity with a nonminimal scalar field
Gaete, Moises Bravo
2013-01-01
In arbitrary dimension D, we consider a self-interacting scalar field nonminimally coupled with a gravity theory given by a particular Lovelock action indexed by an integer k. To be more precise, the coefficients appearing in the Lovelock expansion are fixed by requiring the theory to have a unique AdS vacuum with a fixed value of the cosmological constant. This yields to k=1,2,...,[(D-1)/2] inequivalent possible gravity theories; here the case k=1 corresponds to the standard Einstein-Hilbert Lagrangian. For each par (D,k), we derive two classes of AdS black hole solutions with planar even horizon topology for particular values of the nonminimal coupling parameter. The first family of solutions depends on a unique constant and is valid only for k>1. In fact, its GR counterpart k=1 reduces to the pure AdS metric with a vanishing scalar field. The second family of solutions involves two independent constants and corresponds to a stealth black hole configuration; that is a nontrivial scalar field together with a...
$AdS_3$ vacua and RG flows in three dimensional gauged supergravities
Gava, Edi; Parinya, K
2010-01-01
We study $AdS_3$ supersymmetric vacua in N=4 and N=8, three dimensional gauged supergravities, with scalar manifolds $(\\frac{SO(4,4)}{SO(4)\\times SO(4)})^2$ and $\\frac{SO(8,8)}{SO(8)\\times SO(8)}$, non-semisimple Chern-Simons gaugings $SO(4)\\ltimes {\\bf R}^6$ and $(SO(4)\\ltimes {\\bf R}^6)^2$, respectively. These are in turn equivalent to SO(4) and $SO(4)\\times SO(4)$ Yang-Mills theories coupled to supergravity. For the N=4 case, we study renormalization group flows between UV and IR $AdS_3$ vacua with the same amount of supersymmetry: in one case, with (3,1) supersymmetry, we can find an analytic solution whereas in another, with (2,0) supersymmetry, we give a numerical solution. In both cases, the flows turn out to be v.e.v. flows, i.e. they are driven by the expectation value of a relevant operator in the dual $SCFT_2$. These provide examples of v.e.v. flows between two $AdS_3$ vacua within a gauged supergravity framework.
On Elliptic String Solutions in AdS$_3$ and dS$_3$
Bakas, Ioannis
2016-01-01
Classical String actions in AdS$_3$ and dS$_3$ can be connected to the sinh-Gordon and cosh-Gordon equations through Pohlmeyer reduction. We show that the problem of constructing a classical string solution with a given static or translationally invariant Pohlmeyer counterpart is equivalent to solving four pairs of effective Schr\\"{o}dinger problems. Each pair consists of a flat potential and an $n = 1$ Lam\\'e potential whose eigenvalues are connected, and, additionally, the four solutions satisfy a set of constraints. An approach for solving this system is developed by employing an interesting connection between the specific class of classical string solutions and the band structure of the Lam\\'e potential. This method is used for the construction of several families of classical string solutions, one of which turns out to be the spiky strings in AdS$_3$. New solutions include circular rotating strings in AdS$_3$ with singular time evolution of their radius and angular velocity as well as classical string so...
Hairy black holes and the endpoint of AdS$_4$ charged superradiance
Dias, Oscar J C
2016-01-01
We construct hairy black hole solutions that merge with the anti-de Sitter (AdS$_4$) Reissner-Nordstr\\"om black hole at the onset of superradiance. These hairy black holes have, for a given mass and charge, higher entropy than the corresponding AdS$_4$-Reissner-Nordstr\\"om black hole. Therefore, they are natural candidates for the endpoint of the charged superradiant instability. On the other hand, hairy black holes never dominate the canonical and grand-canonical ensembles. The zero-horizon radius of the hairy black holes is a soliton (i.e. a boson star under a gauge transformation). We construct our solutions perturbatively, for small mass and charge, so that the properties of hairy black holes can be used to testify and compare with the endpoint of initial value simulations. We further discuss the near-horizon scalar condensation instability which is also present in global AdS$_4$-Reissner-Nordstr\\"om black holes. We highlight the different nature of the near-horizon and superradiant instabilities and that...
Korean Nova Records in A.D. 1073 and A.D. 1074: R Aquarii
Yang, H J; Cho, S H; Park, C; Yang, Hong-Jin; Park, Myeong-Gu; Cho, Se-Hyung; Park, Changbom
2005-01-01
R Aqr is known to be a symbiotic binary system with an associated extended emission nebula, possibly produced by a historic outburst. To find the associated historic records, we searched for and compiled all 'Guest Star' and 'Peculiar Star' records in three Korean 'official' history books that cover almost two thousand years, Samguksagi, Goryeosa, Joseonwangjosillok. In addition to the record of A.D. 1073, previously noted by Li (1985), we have found in Goryeosa another candidate record of A.D. 1074, which has the same positional description as that of A.D. 1073 with an additional brightness description. We examined various aspects of the two records and conclude that they both are likely to be the records of outburst of R Aqr. This means that there were two successive outbursts in A.D. 1073 and in A.D. 1074, separated by approximately one year. Based on these records, we estimate the distance to R Aqr to be 273 pc if the expansion of the nebula has been at a constant rate. The brightness record of A.D. 1074 ...
Moduli Space of IIB Superstring and SUYM in AdS5 × S5
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
This paper consists of two parts. In part Ⅰ, we interpret the hidden symmetry of the moduli space of IIB superstring on AdS5 × S5 in terms of the chiral embedding in AdS5, which turns out to be the CP3 conformal affine Toda model. We review how the position μ of poles in the Riemann-Hilbert formulation of dressing transformation and the value of loop parameter μ in the vertex operator of affine algebra determine the moduli space of the soliton solutions, which describes the moduli space of the Green-Schwarz superstring. We show also how this affine SU(4) symmetry affinizes the con formal symmetry in the twistor space, and how a soliton string corresponds to a Robinson congruence with twist and dilation spin coefficients μ of twistor. In part H, by extending the dressing symmetric action of IIB string in AdS5 × S5 to the Da brane, we find a gauged WZW action of Higgs Yang-Mills field including the 2-cocycle of axially anomaly. The left and right twistor structures of left and right α-planes glue into an ambitwistor. The symmetry group of Nahm equations is centrally extended to an affine group, thus we explain why the spectral curve is given by affine Toda.
Nonlinear sigma models with AdS supersymmetry in three dimensions
Butter, Daniel; Tartaglino-Mazzucchelli, Gabriele
2012-01-01
In three-dimensional anti-de Sitter (AdS) space, there exist several realizations of N-extended supersymmetry, which are traditionally labelled by two non-negative integers p>=q such that p+q=N. Different choices of p and q, with N fixed, prove to lead to different restrictions on the target space geometry of supersymmetric nonlinear sigma-models. We classify all possible types of hyperkahler target spaces for the cases N=3 and N=4 by making use of two different realizations for the most general (p,q) supersymmetric sigma-models: (i) off-shell formulations in terms of N=3 and N=4 projective supermultiplets; and (ii) on-shell formulations in terms of covariantly chiral scalar superfields in (2,0) AdS superspace. Depending on the type of N=3,4 AdS supersymmetry, nonlinear sigma-models can support one of the following target space geometries: (i) hyperkahler cones; (ii) non-compact hyperkahler manifolds with a U(1) isometry group which acts non-trivially on the two-sphere of complex structures; (iii) arbitrary h...
Variations of 14-C around AD 775 and AD 1795 - due to solar activity
Neuhaeuser, Ralph
2015-01-01
The motivation for our study is the disputed cause for the strong variation of 14-C around AD 775. Our method is to compare the 14-C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14-C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14-C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14-C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects...
Non-split and split deformations of AdS_5
Hoare, Ben
2016-01-01
The eta-deformation of the AdS_5 x S^5 superstring depends on a non-split r matrix for the superalgebra psu(2,2|4). Much of the investigation into this model has considered one particular choice, however there are a number of inequivalent alternatives. This is also true for the bosonic sector of the theory with su(2,2), the isometry algebra of AdS_5, admitting one split and three non-split r matrices. In this article we explore these r matrices and the corresponding geometries. We investigate their contraction limits, comment on supergravity backgrounds and demonstrate their relation to gauged-WZW deformations. We then extend the three non-split cases to AdS_5 x S^5 and compute four separate bosonic two-particle tree-level S-matrices based on inequivalent BMN-type light-cone gauges. The resulting S-matrices, while different, are related by momentum-dependent one-particle changes of basis.
Exact black hole formation in asymptotically (AdS and flat spacetimes
Directory of Open Access Journals (Sweden)
Xuefeng Zhang
2014-09-01
Full Text Available We consider four-dimensional Einstein gravity minimally coupled to a dilaton scalar field with a supergravity-inspired scalar potential. We obtain an exact time-dependent spherically symmetric solution describing gravitational collapse to a static scalar-hairy black hole. The solution can be asymptotically AdS, flat or dS depending on the value of the cosmological constant parameter Λ in the potential. As the advanced time u increases, the metric approaches the static limit in an exponential fashion, i.e., e−u/u0 with u0∼1/(α4M01/3, where M0 is the mass of the final black hole and α is the second parameter in the potential. Similarly to the Vaidya solution, at u=0, the spacetime can be matched to an (AdS or flat vacuum except that at the origin a naked singularity may occur. Moreover, a limiting case of our solution with α=0 gives rise to an (AdS generalization of the Roberts solution. Our results provide a new model for investigating formation of real life black holes with Λ≥0. For Λ<0, it can be instead used to study non-equilibrium thermalization of certain strongly-coupled field theory.
On elliptic string solutions in AdS3 and dS3
Bakas, Ioannis; Pastras, Georgios
2016-07-01
Classical string actions in AdS3 and dS3 can be connected to the sinh-Gordon and cosh-Gordon equations through Pohlmeyer reduction. We show that the problem of constructing a classical string solution with a given static or translationally invariant Pohlmeyer counterpart is equivalent to solving four pairs of effective Schrödinger problems. Each pair consists of a flat potential and an n = 1 Lamé potential whose eigenvalues are connected, and, additionally, the four solutions satisfy a set of constraints. An approach for solving this system is developed by employing an interesting connection between the specific class of classical string solutions and the band structure of the Lamé potential. This method is used for the construction of several families of classical string solutions, one of which turns out to be the spiky strings in AdS3. New solutions include circular rotating strings in AdS3 with singular time evolution of their radius and angular velocity as well as classical string solutions in dS3.
ADS-B- Automatic Dependent Surveillance- Broadcast
Directory of Open Access Journals (Sweden)
Borivoj Galović
2002-01-01
Full Text Available The CU/Tent system of air traffic is facing many drawbacksand problems that restrict its further development and makes itdifficult to follow the trends of increase in the traffic volume.By means of their technology, the systems such as ADS-8create rhe basis for further building, upgrading, improving anddeveloping of a completely new concept of the air traffic system.Through their functions they fully fit into and support the basicfunctions of communication, navigation and swveillancewhich form the basis of the new concept that needs to be implementedas soon as possible.
Interpolated Sounding Value-Added Product
Energy Technology Data Exchange (ETDEWEB)
Troyan, D [Brookhaven National Laboratory
2013-04-01
The Interpolated Sounding (INTERPSONDE) value-added product (VAP) uses a combination of observations from radiosonde soundings, the microwave radiometer (MWR), and surface meteorological instruments in order to define profiles of the atmospheric thermodynamic state at one-minute temporal intervals and a total of at least 266 altitude levels. This VAP is part of the Merged Sounding (MERGESONDE) suite of VAPs. INTERPSONDE is the profile of the atmospheric thermodynamic state created using the algorithms of MERGESONDE without including the model data from the European Centre for Medium-range Weather Forecasting (ECMWF). More specifically, INTERPSONDE VAP represents an intermediate step within the larger MERGESONDE process.
Noncommutative q -photon-added coherent states
Dey, Sanjib; Hussin, Véronique
2016-05-01
We construct the photon-added coherent states of a noncommutative harmonic oscillator associated to a q -deformed oscillator algebra. Various nonclassical properties of the corresponding system are explored, first, by studying two different types of higher-order quadrature squeezing, namely, the Hillery type and the Hong-Mandel type, and second, by testing the sub-Poissonian nature of photon statistics in higher order with the help of the correlation function and the Mandel parameter. Also, we compare the behavior of different types of quadrature and photon number squeezing of our system with those of the ordinary harmonic oscillator by considering the same set of parameters.
AORTA: Adding Organizational Reasoning to Agents
DEFF Research Database (Denmark)
Jensen, Andreas Schmidt; Dignum, Virginia
2014-01-01
the expected behavior of the agents. Agents need to be able to reason about the regulations, so that they can act within the expected boundaries and work towards the objectives of the organization. This extended abstract introduces AORTA, a component that can be integrated into agents’ reasoning mechanism......, allowing them to reason about (and act upon) regulations specified by an organizational model using simple reasoning rules. The added value is that the organizational model is independent of that of the agents, and that the approach is not tied to a specific organizational model....
Gubser, Steven S.; Knaute, Johannes; Parikh, Sarthak; Samberg, Andreas; Witaszczyk, Przemek
2017-01-01
We construct a p-adic analog to AdS/CFT, where an unramified extension of the p-adic numbers replaces Euclidean space as the boundary and a version of the Bruhat-Tits tree replaces the bulk. Correlation functions are computed in the simple case of a single massive scalar in the bulk, with results that are strikingly similar to ordinary holographic correlation functions when expressed in terms of local zeta functions. We give some brief discussion of the geometry of p-adic chordal distance and of Wilson loops. Our presentation includes an introduction to p-adic numbers.
Gubser, Steven S; Parikh, Sarthak; Samberg, Andreas; Witaszczyk, Przemek
2016-01-01
We construct a $p$-adic analog to AdS/CFT, where an unramified extension of the $p$-adic numbers replaces Euclidean space as the boundary and a version of the Bruhat-Tits tree replaces the bulk. Correlation functions are computed in the simple case of a single massive scalar in the bulk, with results that are strikingly similar to ordinary holographic correlation functions when expressed in terms of local zeta functions. We give some brief discussion of the geometry of $p$-adic chordal distance and of Wilson loops. Our presentation includes an introduction to $p$-adic numbers.
Adding Recursive Constructs to Bialgebraic Semantics
DEFF Research Database (Denmark)
Klin, Bartek
2004-01-01
This paper aims at fitting a general class of recursive equations into the framework of ‘well-behaved' structural operational semantics, formalized as bialgebraic semantics by Turi and Plotkin. Rather than interpreting recursive constructs by means of operational rules, separate recursive equations...... are added to semantic descriptions of languages. The equations, together with the remaining rules, are then interpreted in a suitable category and merged by means of certain fixpoint constructions. For a class of recursive equations called regular unfolding rules, this construction yields distributive laws...
Forkel, Hilmar
2012-01-01
Multiquark correlations inside hadrons can have a significant and in some cases even striking impact on the hadron spectrum. We show how such correlations in general, and mesons with a dominant tetraquark content in particular, emerge holographically in the AdS/QCD framework. On this basis, we arrive at a holographic realization of an exceptionally strong four-quark binding and a correspondingly large tetraquark component in the lightest scalar mesons. Higher-lying tetraquark excitations, on the other hand, become too broad to form supernumeral scalar states.
Interpolating from Bianchi attractors to Lifshitz and AdS spacetimes
Energy Technology Data Exchange (ETDEWEB)
Kachru, Shamit [SITP, Department of Physics and Theory Group, SLAC, Stanford University,Stanford, CA 94305 (United States); Kundu, Nilay [Tata Institute for Fundamental Research, Mumbai 400005 (India); Saha, Arpan [Indian Institute of Technology - Bombay,Powai, Mumbai (India); Samanta, Rickmoy; Trivedi, Sandip P. [Tata Institute for Fundamental Research, Mumbai 400005 (India)
2014-03-17
We construct classes of smooth metrics which interpolate from Bianchi attractor geometries of Types II, III, VI and IX in the IR to Lifshitz or AdS{sub 2}×S{sup 3} geometries in the UV. While we do not obtain these metrics as solutions of Einstein gravity coupled to a simple matter field theory, we show that the matter sector stress-energy required to support these geometries (via the Einstein equations) does satisfy the weak, and therefore also the null, energy condition. Since Lifshitz or AdS{sub 2}×S{sup 3} geometries can in turn be connected to AdS{sub 5} spacetime, our results show that there is no barrier, at least at the level of the energy conditions, for solutions to arise connecting these Bianchi attractor geometries to AdS{sub 5} spacetime. The asymptotic AdS{sub 5} spacetime has no non-normalizable metric deformation turned on, which suggests that furthermore, the Bianchi attractor geometries can be the IR geometries dual to field theories living in flat space, with the breaking of symmetries being either spontaneous or due to sources for other fields. Finally, we show that for a large class of flows which connect two Bianchi attractors, a C-function can be defined which is monotonically decreasing from the UV to the IR as long as the null energy condition is satisfied. However, except for special examples of Bianchi attractors (including AdS space), this function does not attain a finite and non-vanishing constant value at the end points.
The AD: The unique anti-accelerator
Slide show by Maximilien Brice. Voice (French only): Jacques Fichet. Content: Paola Catapano, Django Manglunki, CERN Bulletin
2011-01-01
Unlike other machines whose performance is measured in terms of energy records, AD's uniqueness resides in the fact that it can very effectively decelerate beams. At the hearth of antimatter production at CERN, the AD is making headlines in the world's press. This provides an excellent opportunity for us to retrace its history in images. var flash_video_player=get_video_player_path(); insert_player_for_external('Video/Public/Movies/2011/CERN-MOVIE-2011-083/CERN-MOVIE-2011-083-0753-kbps-480x360-25-fps-audio-64-kbps-44-kHz-stereo', 'mms://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2011/CERN-MOVIE-2011-083/CERN-MOVIE-2011-083-0480-kbps-384x288-25-fps-audio-128-kbps-48-kHz-stereo.wmv', 'false', 480, 360, 'http://mediaarchive.cern.ch/MediaArchive/Video/Public/Movies/2011/CERN-MOVIE-2011-083/CERN-MOVIE-2011-083-posterframe-480x360-at-5-percent.jpg', '1357551', true, '');
AD Consolidation for operation beyond 2010
Eriksson, T
2008-01-01
The Antiproton Decelerator (AD), which started up for physics in 2000 and today supplies low-energy antiprotons to the ATRAP, ALPHA, ASACUSA and ACE experiments is based on the ACOL machine from which it still retains most of the components. ACOL construction was completed in 1986 at a total cost of approximately 80 MCHF (excluding infrastructure) which today would correspond to a value of around 160 MCHF. During recent years, a reduction of maintenance and modernisation has been unavoidable due to budgetary restraints. In order to identify the resources needed for continued AD operation beyond 2010 with a reasonably low risk of failures and to avoid increasing maintenance and repair costs, a study has been conducted involving groups from the AB, AT and TS departments. Analysis of breakdown risks, identification of items and costs for consolidation has been done as well as a risk score classification. To be noted is the relatively modest cost of the proposed items in view of the value of the facility and in c...
Frozen yogurt with added inulin and isomalt.
Isik, U; Boyacioglu, D; Capanoglu, E; Erdil, D Nilufer
2011-04-01
The objective of this study was to produce a frozen yogurt containing low fat and no added sugar. Samples containing 5% polydextrose, 0.065% aspartame and acesulfame-K mixture, and different levels of inulin and isomalt (5.0, 6.5, and 8.0%) were produced at pilot scale and analyzed for their physical and chemical properties including proximate composition, viscosity, acidity, overrun, melting rate, heat shock stability, as well as sensory characteristics, and viability of lactic acid bacteria. With the addition of inulin and isomalt, viscosity increased by 19 to 52% compared with that of sample B (reduced-fat control). The average calorie values of samples substituted with sweeteners were about 43% lower than that of original sample. Low-calorie frozen yogurt samples melted about 33 to 48% slower than the reduced-fat control sample at 45 min. Based on quantitative descriptive profile test results, statistically significant differences among products were observed for hardness, iciness, foamy melting, whey separation, and sweetness characteristics. The results of principal component analysis showed that the sensory properties of the sample containing 6.5% inulin and 6.5% isomalt were similar to those of control. Lactic acid bacteria counts of frozen yogurt were found to be between 8.12 and 8.49 log values, 3 mo after the production. The overall results showed that it is possible to produce an attractive frozen yogurt product with the incorporation of inulin and isomalt with no added sugar and reduced fat.
Kajantie, Keijo; Yee, J T; Yee, Jung-Tay
2007-01-01
We study finite temperature properties of four dimensional QCD-like gauge theories in the gauge theory/gravity duality picture. The gravity dual contains two deformed 5d AdS metrics, with and without a black hole, and a dilaton. We study the thermodynamics of the 4d boundary theory and constrain the two metrics so that they correspond to a high and a low temperature phase separated by a first order phase transition. The equation of state has the standard form for the pressure of a strongly coupled fluid modified by a vacuum energy, a bag constant. We determine the parameters of the deformation by using QCD results for $T_c$ and the hadron spectrum. With these parameters, we show that the phase transition in the 4d boundary theory and the 5d bulk Hawking-Page transition agree. We probe the dynamics of the two phases by computing the quark-antiquark free energy in them and confirm that the transition corresponds to confinement-deconfinement transition.
POSSIBLE CHROMOSPHERIC ACTIVITY CYCLES IN AD LEO
Energy Technology Data Exchange (ETDEWEB)
Buccino, Andrea P.; Petrucci, Romina; Mauas, Pablo J. D. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), C.C. 67 Sucursal 28, C1428EHA-Buenos Aires (Argentina); Jofré, Emiliano [Observatorio Astronómico de Córdoba, Córdoba (Argentina)
2014-01-20
AD Leo (GJ 388) is an active dM3 flare star that has been extensively observed both in the quiescent and flaring states. Since this active star is near the fully convective boundary, studying its long-term chromospheric activity in detail could be an appreciable contribution to dynamo theory. Here, using the Lomb-Scargle periodogram, we analyze the Ca II K line-core fluxes derived from CASLEO spectra obtained between 2001 and 2013 and the V magnitude from the ASAS database between 2004 and 2010. From both of these totally independent time series, we obtain a possible activity cycle with a period of approximately seven years and a less significant shorter cycle of approximately two years. A tentative interpretation is that a dynamo operating near the surface could be generating the longer cycle, while a second dynamo operating in the deep convection zone could be responsible for the shorter one. Based on the long duration of our observing program at CASLEO and the fact that we observe different spectral features simultaneously, we also analyze the relation between simultaneous measurements of the Na I index (R{sub D}{sup ′}), Hα, and Ca II K fluxes at different activity levels of AD Leo, including flares.
Added values of photovoltaic power systems
Energy Technology Data Exchange (ETDEWEB)
NONE
2001-03-15
The structure, ownership and operation of electricity systems around the world are changing in response to industry restructuring, the availability of new technologies and increasing environmental awareness. At the same time, many countries have yet to provide basic energy services for their populations, particularly in areas not served by the electricity grid. Large-scale, central power generation and distribution which characterized the electricity industry for much of the 20{sup th} century is being challenged by new technologies, which are cleaner, faster to deploy and better matched to local requirements. Higher values are being placed on ancillary services, such as power system reliability and voltage stability, so that a simple comparison of energy cost is no longer appropriate as a measure of competitiveness. Solar photovoltaic electricity is unique amongst the new energy sources for the wide range of energy and non-energy benefits which can be provided, while the use of photovoltaic power systems as an integral part of a building provides the greatest opportunity for exploiting non-energy benefits and for adding value to the photovoltaic power system. This report documents the potential added values or non-energy benefits photovoltaic power systems can provide, the current state of market development and the key barriers faced by renewable energy technologies generally and photovoltaic power systems in particular. Means by which non-energy benefits may be used to overcome barriers to the use of photovoltaic power systems are then discussed, with specific attention to the use of building integrated photovoltaics. (author)
Recent highlights from the CERN-AD
Tranquille, Gerard
2004-01-01
The Antiproton Decelerator and cooling ring (AD) provides dense and cold beams of antiprotons to low energy experiments for the study of basic properties of antiprotons and antihydrogen. It combines stochastic cooling (at 3.5 and 2GeV/c) with electron cooling at 0.3 and 0.1GeV/c. In 2002 the AD gave beam during more than 1900h to its three experiments (ASACUSA, ATHENA and ATRAP) with beam properties meeting, and often exceeding design specification. Stochastic cooling with cool-down times of 18s works as aimed for in the design. Electron cooling using the "old LEAR cooler" reaches the very small equilibrium emittances required but still takes more time (12s instead of 6s anticipated in the 1996 design). However the increase in cycle length is made up for by the higher deceleration efficiency. ASACUSA has very successfully continued the program of antiprotonic helium 3 spectroscopy and ATHENA and ATRAP have reported last autumn the synthesis of copious numbers of cold antihydrogen atoms.
Adding Asymmetrically Dominated Alternatives: Violations of Regularity & the Similarity Hypothesis.
1981-07-01
target but not by the competitor. ADDING ASYMMET-.ICALLY DOMINATED ALTERNATIVES EXHIBIT 1 PLACEMIENT OF ASYMETRICALLY DOMINATED DECOY (P re i. C t2r cc...adding the decoy. Thus, .... " ADDING ASYMETRICALLY DOMINATED ALTERNATIVES 16 EXHIBIT 3 VIOLATIONS OF REGULARITY DUE TO ADDING DECOY Probability of...expanding A.DDING ASYMETRICALLY DOMINATED ALTERNATIVES 22 the degree of the range extention, suggests that a simple range extention ex- planation is not
RG flow and thermodynamics of causal horizons in higher-derivative AdS gravity
Banerjee, Shamik; Bhattacharyya, Arpan
2016-05-01
In arXiv:1508.01343 URL"/> [hep-th], one of the authors proposed that in AdS/CFT the gravity dual of the boundary c-theorem is the second law of thermodynamics satisfied by causal horizons in AdS and this was verified for Einstein gravity in the bulk. In this paper we verify this for higher derivative theories. We pick up theories for which an entropy expression satisfying the second law exists and show that the entropy density evaluated on the causal horizon in a RG flow geometry is a holographic c-function. We also prove that given a theory of gravity described by a local covariant action in the bulk a sufficient condition to ensure holographic c-theorem is that the second law of causal horizon thermodynamics be satisfied by the theory. This allows us to explicitly construct holographic c-function in a theory where there is curvature coupling between gravity and matter and standard null energy condition cannot be defined although second law is known to hold. Based on the duality between c-theorem and the second law of causal horizon thermodynamics proposed in arXiv:1508.01343 URL"/> [hep-th] and the supporting calculations of this paper we conjecture that every Unitary higher derivative theory of gravity in AdS satisfies the second law of causal horizon thermodynamics. If this is not true then c-theorem will be violated in a unitary Lorentz invariant field theory.
Euclidean Wilson loops and Minimal Area Surfaces in Minkowski AdS3
Irrgang, Andrew
2015-01-01
The AdS/CFT correspondence relates Wilson loops in N=4 SYM theory to minimal area surfaces in AdS5xS5 space. If the Wilson loop is Euclidean and confined to a plane (t,x) then the dual surface is Euclidean and lives in Minkowski AdS3. In this paper we study such minimal area surfaces generalizing previous results obtained in the Euclidean case. Since the surfaces we consider have the topology of a disk, the holonomy of the flat current vanishes which is equivalent to the condition that a certain boundary Schroedinger equation has all its solutions anti-periodic. If the potential for that Schroedinger equation is found then reconstructing the surface and finding the area become simpler. In particular we write a formula for the Area in terms of the Schwarzian derivative of the contour. Finally an infinite parameter family of analytical solutions using Riemann Theta functions is described. In this case, both the area and the shape of the surface are given analytically and used to check the previous results.
Black hole bound states in AdS_3 x S^2
de Boer, Jan; El-Showk, Sheer; Messamah, Ilies; Bleeken, Dieter Van den
2008-01-01
We systematically construct the geometries dual to the 1+1 dimensional (0,4) conformal field theories that arise in the low-energy description of wrapped M5-branes in S^1 x CY_3 compactifications of M-theory. This includes a large number of multicentered black hole bound states asymptotic to AdS_3 x S^2. In addition, we find many geometries that develop multiple, mutually decoupled AdS_3 x S^2 throats. We argue there is a useful one to one correspondence between the connected components of the space of solutions and particular limits of type IIA attractor flow trees. We point out that there is a thermodynamic instability of small supersymmetric BTZ black holes to localization on the S^2, a supersymmetric and exactly solvable analog of the well known AdS-Schwarzschild localization instability, and identify this with the ``Entropy Enigma'' in four dimensions. We discuss the phase transition this suggests, and initiate the CFT interpretation of these results.
Alternative approach to the regularization of odd-dimensional AdS gravity
Energy Technology Data Exchange (ETDEWEB)
Mora, Pablo [Instituto de Fisica, Facultad de Ciencias, Igua 4225, Montevideo (Uruguay)]. E-mail: pablmora@gmail.com
2007-07-16
In this paper I present an action principle for odd-dimensional AdS gravity which consists of introducing another manifold with the same boundary and a very specific boundary term. This new action allows and alternative approach to the regularization of the theory, yielding a finite Euclidean action and finite conserved charges. The choice of the boundary term is justified on the grounds that an enhanced 'almost off-shell' local AdS/Conformal symmetry arises for that very special choice. One may say that the boundary term is dictated by a guiding symmetry principle. Two sets of boundary conditions are considered, which yield regularization procedures analogous to (but different from) the standard 'background subtraction' and 'counterterms' regularization methods. The Noether charges are constructed in general. As an application it is shown that for Schwarzschild-AdS black holes the charge associated to the time-like Killing vector is finite and is indeed the mass. The Euclidean action for Schwarzschild-AdS black holes is computed, and it turns out to be finite, and to yield the right thermodynamics. The previous sentence may be interpreted in the sense that the boundary term dictated by the symmetry principle is the one that correctly regularizes the action.
Orbits of the visual binaries ADS 8814 and ADS 8065 from observations along a short arc
Kiselev, A. A.; Kiyaeva, O. V.; Romanenko, L. G.; Gorynya, N. A.
2012-07-01
The orbits of the visual binaries ADS 8814 and ADS 8065 are determined for the first time. The orbits were calculated using the parameters of the apparent motion, based on position observations along short arcs obtained on the 26-inch refrector of the Pulkovo Observatory, supplemented with radial-velocity observations for the stellar components in both pairs obtained on the 1-m telescope of the Simeiz Section of the Crimean Astrophysical Observatory. All previous visual and photographic observations of these stars after 1832 were also taken into account. The orbit of ADS 8814 was refined using the differential-correction method. The orbital periods of these two stars are about 800 and 6000 years, respectively. The mass estimates derived for the known parallaxes from the Hipparcos catalog correspond to the spectral types of these stars. The polar vectors of the obtained orbits in Galactic coordinates are also given.
Unfolding Mixed-Symmetry Fields in AdS and the BMV Conjecture II. Oscillator Realization
Boulanger, Nicolas; Sundell, Per
2009-01-01
The unfolded equations of motion for general tensor fields in AdS_D are derived by radial reduction of Skvortsov's equations in one higher dimension. The constraints on the radial derivatives introduce the AdS mass. At critical masses the Weyl zero-form module carries Metsaev's massless representations plus additional lower-spin modules that we project out. The complement of the Weyl zero-form module contains Stueckelberg fields for a cosmological constant $\\Lambda$ < 0 except in the unitary massless case where it contains the Alkalaev--Shaynkman--Vasiliev frame-like potential. The Stueckelberg fields yield a smooth flat limit in the spirit of the Brink--Metsaev--Vasiliev (BMV) conjecture. The present analysis -- based on a formalism presented in a companion paper referred to as Paper I -- is facilitated by the use of bosonic (symmetric basis) and fermionic (anti-symmetric basis) oscillator realizations of Schur modules.
On Thermodynamical Behaviors of Kerr-Newman AdS Black Holes
Belhaj, A; Moumni, H El; Medari, L; Sedra, M B
2013-01-01
We reconsider the study of critical behaviors of Kerr-Newman AdS black holes in four dimensions. The study is made in terms of the moduli space parameterized by the charge Q and the rotation parameter a, relating the mass M of the black hole and its angular momentum J via the relation a=J/M. Specifically, we discuss such thermodynamical behaviors in the presence of a positive cosmological constant considered as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume. The equation of state for a charged RN-AdS black hole predicts a critical universal number depending on the (Q,a) moduli space. In the vanishing limit of the a parameter, this prediction recovers the usual universal number in four dimensions. Then, we find the bounded regions of the moduli space allowing the consistency of the model with real thermodynamical variables.
On Thermodynamics of AdS Black Holes in Arbitrary Dimensions
Belhaj, A; Moumni, H El; Sedra, M B
2012-01-01
Considering the cosmological constant $\\Lambda$ as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume as proposed in Kubiznak and Mann (2012), we discuss the critical behavior of charged AdS black hole in arbitrary dimensions $d$. In particular, we present a comparative study in terms of the spacetime dimension $d$ and the displacement of critical points controlling the transition between the small and the large black holes. Such behaviors vary nicely in terms of $d$. Among our result in this context consists in showing that the equation of state for a charged RN-AdS black hole predicts an universal number given by $\\frac{2d-5}{4d-8}$. The three dimensional solution is also discussed.
Varying Overhead Ad Hoc on Demand Vector Routing in Highly Mobile Ad Hoc Network
Directory of Open Access Journals (Sweden)
V. Balaji
2011-01-01
Full Text Available Problem statement: An inherent feature of mobile ad hoc networks is the frequent change of network topology leading to stability and reliability problems of the network. Highly dynamic and dense network have to maintain acceptable level of service to data packets and limit the network control overheads. This capability is closely related as how quickly the network protocol control overhead is managed as a function of increased link changes. Dynamically limiting the routing control overheads based on the network topology improves the throughput of the network. Approach: In this study we propose Varying Overhead - Ad hoc on Demand Vector routing protocol (VO-AODV for highly dynamic mobile Ad hoc network. The VO-AODV routing protocol proposed dynamically modifies the active route time based on the network topology. Results and Conclusion: Simulation results prove that the proposed model decreases the control overheads without decreasing the QOS of the network.
Wess-Zumino term for the AdS superstring and generalized Inoenue-Wigner contraction
Hatsuda, M
2003-01-01
We examine a Wess-Zumino term, written in a form of bilinear in superinvariant currents, for a superstring in anti-de Sitter (AdS) space, and derive a procedure for obtaining the correct flat limit. The standard Inoenue-Wigner contraction does not give the correct flat limit but, rather, gives zero. This erroneous result originates from the fact that the fermionic metric of the super-Poincare group is degenerate. We propose a generalization of the Inoenue-Wigner contraction from which a 'nondegenerate' super-Poincare group is derived from the super-AdS group. For this reason, this contraction gives the correct flat limit of this Wess-Zumino term. We also discuss the M-algebra obtained using this generalized Inoenue-Wigner contraction from osp(1|32). (author)
Critical Phenomena in Higher Curvature Charged AdS Black Holes
Directory of Open Access Journals (Sweden)
Arindam Lala
2013-01-01
Full Text Available In this paper, we have studied the critical phenomena in higher curvature charged AdS black holes. We have considered Lovelock-Born-Infeld-AdS black hole as an example. The thermodynamics of the black hole have been studied which reveals the onset of a higher-order phase transition in the black hole in the canonical ensemble (fixed charge ensemble framework. We have analytically derived the critical exponents associated with these thermodynamic quantities. We find that our results fit well with the thermodynamic scaling laws and consistent with the mean field theory approximation. The suggestive values of the other two critical exponents associated with the correlation function and correlation length on the critical surface have been derived.
One-loop tests of the supersymmetric higher spin AdS4/CFT3 correspondence
Pang, Yi; Sezgin, Ergin; Zhu, Yaodong
2017-01-01
We compute one-loop free energy for D =4 Vasiliev higher spin gravities based on Konstein-Vasiliev algebras h u (m ;n |4 ) , h o (m ;n |4 ) , or h u s p (m ;n |4 ) and subject to higher spin-preserving boundary conditions, which are conjectured to be dual to the U (N ) , O (N ) or U S p (N ) singlet sectors, respectively, of free conformal field theories (CFTs) on the boundary of AdS4 . Ordinary supersymmetric higher spin theories appear as special cases of Konstein-Vasiliev theories, when the corresponding higher spin algebra contains O S p (N |4 ) as a subalgebra. In AdS4 with an S3 boundary, we use a regularization scheme for individual spins that employs their character such that the subsequent sum over all spins is finite, thereby avoiding the need for additional regularization. We find that the contribution of the infinite tower of bulk fermions vanishes. As a result, the free energy is the sum of those which arise in type A and type B models with internal symmetries, the known mismatch between the bulk and boundary free energies for type B model persists, and ordinary supersymmetric higher spin theories exhibit the mismatch as well. The only models that have a match are type A models with internal symmetries, corresponding to n =0 . The matching requires identification of the inverse Newton constant GN-1 with N plus a proper integer as was found previously for special cases. In AdS4 with an S1×S2 boundary, the bulk one-loop free energies match those of the dual free CFTs for arbitrary m and n . We also show that a supersymmetric double-trace deformation of free CFT based on O S p (1 |4 ) does not contribute to the O (N0) free energy, as expected from the bulk.
Non-minimally coupled pseudoscalars in AdS4 for instantons in CFT3
Naghdi, M.
2016-06-01
For the 11-dimensional supergravity over {{{AdS}}}4× {{{S}}}7/{Z}k, beginning with a general four-form ansatz and the main geometry unchanged, we get a tower of massive and tachyonic pseudoscalars. Indeed, the resultant equations can be assigned to the so-called {φ }4 actions of the non-minimally coupled scalar-tensor theories with a cosmological constant. We focus on a well-known tachyonic and a new massive bulk mode, which are singlet under the internal group and break all supersymmetries, associated with skew-whiffing and Wick-rotating of the background four-form flux, respectively. The first one is the conformally coupled {m}2=-2 pseudoscalar in the bulk of Euclidean AdS4, where an exact instanton solution is found and a marginally triple-trace deformation with a proper dimension-1 operator produces an agreeing boundary solution with finite action. From the action evaluated on the solution, we estimate the decay rate of the vacuum tunneling mediated by the instanton. Another massive {m}2=+4 mode, with the so-called non-minimal coupling parameter ξ =-1/3, also breaks the conformal invariance and so there is no exact solution. Then, based on the AdS4/CFT3 correspondence rules, we propose the dimension-4 ({{{Δ }}}+=+4) boundary operator in the skew-whiffed (anti-M2-branes) theory with which to deform the boundary action—consisting of a singlet fermion, an original scalar and U(1) gauges fields—and find some solutions to be matched with the bulk solutions.
Ts...sT transformation on $AdS_{5}\\times S^{5}$ background
Rashkov, R C; Yang, Y; Yang, Yi
2005-01-01
In this paper we consider a simple generalization of Lunin and Maldacena procedure of generating new string backgrounds based on TsT-transformations. We study multi-shift $Ts... sT$ transformations applied to backgrounds with at least two U(1) isometries. We prove that the string currents in any two backgrounds related by Ts...sT-transformations are equal. Performing this procedure to the $AdS_{5}\\times S^{5}$ we find a new background and study some properties of the semiclassical strings.
The Worldvolume Action of Kink Solitons in AdS Spacetime
Khoury, Justin; Stokes, James
2012-01-01
A formalism is presented for computing the higher-order corrections to the worldvolume action of co-dimension one solitons. By modifying its potential, an explicit "kink" solution of a real scalar field in AdS space-time is found. The formalism is then applied to explicitly compute the kink worldvolume action to quadratic order in its extrinsic and intrinsic curvatures. Two alternative methods are given for doing this. In addition to conformal Galileon interactions, we find a non-Galileon term which is never sub-dominant. This method can be extended to any conformally flat bulk space-time.
Quantum fluctuations of rotating strings in AdS_5 \\times S^5
Fuji, H; Fuji, Hiroyuki; Satoh, Yuji
2005-01-01
We discuss quantum fluctuations of a class of rotating strings in AdS_5 \\times S^5. In particular, we develop a systematic method to compute the one-loop sigma-model effective actions in closed forms as expansions for large spins. As examples, we explicitly evaluate the leading terms for the constant radii strings in the SO(6) sector with two equal spins, the SU(2) sector, and the SL(2) sector. We also obtain the leading quantum corrections to the space-time energy for these sectors.
Geons and Spin-2 Condensates in the AdS Soliton
Hartnett, Gavin S
2012-01-01
We construct geons starting with gravitational perturbations of the AdS soliton. Previous studies of a charged scalar field in the soliton background showed a holographic insulator/superconductor transition at a critical chemical potential. We explore the possibility that dimensional reduction of the geon could model a transition to a d-wave superconductor. We find that although one does get a charged spin-2 condensate, it has higher free energy than the state without the condensate, so there is no phase transition.
Magnetic Field Effect on the Phase Transition in AdS Soliton Spacetime
Cai, Rong-Gen; Zhang, Hai-Qing; Zhang, Yun-Long
2011-01-01
We investigate the scalar perturbations in an AdS soliton background coupled to a Maxwell field via marginally stable modes. In the probe limit, we study the magnetic field effect on the holographic insulator/superconductor phase transition numerically and analytically. The condensate will be localized in a finite circular region for any finite constant magnetic field. Near the critical point, we find that there exists a simple relation among the critical chemical potential, magnetic field, the charge and mass of the scalar field. This relation indicates that the presence of the magnetic field causes the phase transition hard.
Art as an Evolutionary Adaptation: Inspiration from the Visible Supernovae of AD 1054 and AD 3054
Corbally, C. J.; Rappaport, M. B.
2016-01-01
The authors, an astronomer/priest and an anthropologist/biologist, describe their use of the dramatic arts at the INSAP VIII meeting in their performance of two short skits on the sighting of a supernova in AD 1054 (creating the beautiful Crab Nebula) and a future “Rho Cas” stellar explosion in the constellation Cassiopeia, in AD 3054. They speculate on the emergence of science, religion, and art as bona fide adaptations, responding to natural selection, which served early hominins well in their struggle for existence. They draw parallels to the continued functions of science, religion, and art in modern society.
The kinematical AdS5 × S5 Neumann coefficient
Bajnok, Zoltan; Janik, Romuald A.
2016-02-01
For the case of two particles a solution of the string field theory vertex axioms can be factorized into a standard form factor and a kinematical piece which includes the dependence on the size of the third string. In this paper we construct an exact solution of the kinematical axioms for AdS 5 × S 5 which includes all order wrapping corrections w.r.t. the size of the third string. This solution is expressed in terms of elliptic Gamma functions and ordinary elliptic functions. The solution is valid at any coupling and we analyze its weak coupling, pp-wave and large L limit.
A $\\mathcal{N}=2$ Supersymmetric $AdS_4$ Solution in M-theory
Lozano, Yolanda; Montero, Jesús
2015-01-01
We find a new $\\mathcal{N}=2$ $AdS_4$ solution in M-theory supported by purely magnetic flux via a sequence of abelian and non-abelian T-dualities. This provides the second known example in this class besides the uplift of the Pernici and Sezgin solution to 7d gauged supergravity constructed in the eighties. We compute the free energy of the solution, and show that it scales as $N^{3/2}$. It is intriguing that even though the natural holographic interpretation is in terms of M5-branes wrapped on a special Lagrangian 3-cycle, this solution does not exhibit the expected $N^3$ behavior.
The fate of stringy AdS vacua and the WGC
Danielsson, Ulf
2016-01-01
The authors of arXiv:1610.01533 have recently proposed a stronger version of the weak gravity conjecture (WGC), based on which they concluded that all those non-supersymmetric AdS vacua that can be embedded within a constistent theory of quantum gravity necessarily develop instabilities. In this paper we further elaborate on this proposal by arguing that the aforementioned instabilities have a perturbative nature and arise from the crucial interplay between the closed and the open string sectors of the theory.
Phase Transition of AdS Black Holes with Non Linear Source in the Holographic Framework
Moumni, H. El
2017-02-01
In this work we investigate the phase transition of AdS black hole solution in the presence of a generalized Maxwell theory, namely power Maxwell invariant (PMI). This phase structure is probed by the nonlocal observables such as holographic entanglement entropy and two point correlation function. We show that the both observables exhibit a Van der Waals-like phase transition as the case of the thermal entropy. By checking the Maxwell's equal area law for different space dimension n and nonlinearity parameter s we confirm this result.
Charged Rotating AdS Black Hole and Its Thermodynamics in Conformal Gravity
Liu, Hai-Shan
2013-01-01
We obtain the charged rotating black hole in conformal gravity. The metric is asymptotic to the (anti-)de Sitter spacetime. The contribution to the metric from the charges has a slower falloff than that in the Kerr-Newman AdS black hole. We analyse the global structure and obtain all the thermodynamical quantities including the mass, angular momentum, electric/magnetic charges and their thermodynamical conjugates. We verify that the first law of thermodynamics holds. We also obtain the new neutral rotating black holes that are beyond Einstein metrics. In contrast to the static ones, these rotating black holes have no parameters associated with the massive spin-2 hair.
Causality and the conformal boundary of AdS in real-time holography
Enciso, Alberto
2012-01-01
We consider the holographic prescription problem in a (Lorentzian) AdS background, deriving from first principles the explicit formulas that relate the field at infinity with the field in the bulk. In contrast with the previous studies of the "real-time" holography problem, our derivation uses purely classical arguments that involve causality, as in the usual treatment of the holographic prescription problem in Wick-rotated spaces of Euclidean signature. We show that there is a unique propagator that preserves causality and see that this provides a simple picture of the relationship between the bulk manifold and its conformal boundary.
Fate of stringy AdS vacua and the weak gravity conjecture
Danielsson, Ulf; Dibitetto, Giuseppe
2017-07-01
Ooguri and Vafa [arXiv:1610.01533] have recently proposed a stronger version of the weak gravity conjecture (WGC), based on which they concluded that all those nonsupersymmetric AdS vacua that can be embedded within a consistent theory of quantum gravity necessarily develop instabilities. In this paper we further elaborate on this proposal by arguing that the aforementioned instabilities have a perturbative nature and arise from the crucial interplay between the closed and the open string sectors of the theory.
Chern-Simons interactions in AdS$_3$ and the current conformal block
Keranen, Ville
2014-01-01
We compute the four point function of scalar fields in AdS$_3$ charged under $U(1)$ Chern-Simons fields using the bulk version of the operator state mapping. Then we show how this four point function is reproduced from a CFT$_2$ with a global $U(1)$ symmetry, through the contribution of the corresponding current operator in the operator product expansion, i.e. through the conformal block of the current operator. We work in a "probe approximation" where the gravitational interactions are ignored, which corresponds to leaving out the energy momentum tensor from the operator product expansion.
Symmetry operators of Killing spinors and superalgebras in AdS_5
Ertem, Ümit
2016-01-01
We construct the first-order symmetry operators of Killing spinor equation in terms of odd Killing-Yano forms. By modifying the Schouten-Nijenhuis bracket of Killing-Yano forms, we show that the symmetry operators of Killing spinors close into an algebra in AdS_5 spacetime. Since the symmetry operator algebra of Killing spinors corresponds to a Jacobi identity in extended Killing superalgebras, we investigate the possible extensions of Killing superalgebras to include higher-degree Killing-Ya...
On Heat Properties of AdS Black Holes in Higher Dimensions
Belhaj, A; Moumni, H EL; Masmar, K; Sedra, B; Segui, A
2015-01-01
We investigate the heat properties of AdS Black Holes in higher dimensions. We consider the study of the corresponding thermodynamical properties including the heat capacity explored in the determination of the black hole stability. In particular, we compute the heat latent. To overcome the instability problem, the Maxwell construction, in the (T,S)-plane, is elaborated. This method is used to modify the the Hawking-Page phase structure by removing the negative heat capacity regions. Then, we discuss the thermodynamic cycle and the heat engines using the way based on the extraction of the work from a black hole solution.
AdS2/CFT1, Whittaker vector and Wheeler-De Witt equation
Okazaki, Tadashi
2015-01-01
We study the energy representation of conformal quantum mechanics as the Whittaker vector without specifying classical Lagrangian. We show that a generating function of expectation values among two excited states of the dilatation operator in conformal quantum mechanics is a solution to the Wheeler-DeWitt equation and it corresponds to the AdS2 partition function evaluated as the minisuperspace wave function in Liouville field theory. We also show that the dilatation expectation values in conformal quantum mechanics lead to the asymptotic smoothed counting function of the Riemann zeros.
Ehrenfest's scheme and thermodynamic geometry in Born-Infeld AdS black holes
Lala, Arindam
2011-01-01
In this paper we analyze the phase transition phenomena in Born-Infeld AdS black holes using Ehrenfest's scheme of standard thermodynamics. The critical points are marked by the divergences in the heat capacity. In order to investigate the nature of the phase transition, we analytically check both the Ehrenfest's equations near the critical points. Our analysis reveals that this is indeed a second order phase transition. Finally, we analyze the nature of the phase transition using state space geometry approach. This is found to be compatible with the Ehrenfest's scheme.
Giant magnon on deformed AdS3×S3
Khouchen, Malak; KlusoÅ, Josef
2014-09-01
We study giant magnon solutions for strings moving on a deformed AdS3×S3 background. We impose a conformal gauge on the Polyakov action and proceed with solving the Virasoro constraints. The expressions of the conserved charge J and the energy of a single magnon excitation are then computed. Then we determine the dispersion relation of a giant magnon in the infinite J limit configuration and we find that for κ =0 it reduces to the celebrated Hofman-Maldacena dispersion relation.
Giant Magnon on Deformed AdS(3)xS(3)
Khouchen, Malak
2014-01-01
We study giant magnon solutions for strings moving on a deformed AdS(3)xS(3) background. We impose a conformal gauge on the Polyakov action and proceed with solving the Virasoro constraints. The expressions of the conserved charge J and the energy of a single magnon excitation are then computed. Then we determine the dispersion relation in the infinite J limit configuration and we find that it reduces to celebrated Hofman-Maldacena dispersion relation when the deformation parameter goes to zero.
Energy Technology Data Exchange (ETDEWEB)
Chhabildas, L.C.; Furnish, M.D.; Reinhart, W.D. [Sandia National Labs., Albuquerque, NM (United States); Grady, D.E. [Applied Research Associates, Inc., Albuquerque, NM (United States)
1997-10-01
Gas guns and velocity interferometric techniques have been used to determine the loading behavior of an AD995 alumina rod 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.
Droplet Number Concentration Value-Added Product
Energy Technology Data Exchange (ETDEWEB)
Riihimaki, L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McFarlane, S. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2014-06-01
The ndrop_mfrsr value-added product (VAP) provides an estimate of the cloud droplet number concentration of overcast water clouds retrieved from cloud optical depth from the multi-filter rotating shadowband radiometer (MFRSR) instrument and liquid water path (LWP) retrieved from the microwave radiometer (MWR). When cloud layer information is available from vertically pointing lidar and radars in the Active Remote Sensing of Clouds (ARSCL) product, the VAP also provides estimates of the adiabatic LWP and an adiabatic parameter (beta) that indicates how divergent the LWP is from the adiabatic case. quality control (QC) flags (qc_drop_number_conc), an uncertainty estimate (drop_number_conc_toterr), and a cloud layer type flag (cloud_base_type) are useful indicators of the quality and accuracy of any given value of the retrieval. Examples of these major input and output variables are given in sample plots in section 6.0.
de Paula, W; 10.1007/s00601-011-0267-0
2012-01-01
We discuss applications of gauge/gravity duality to describe the spectrum of light hadrons. We compare two particular 5-dimensional approaches: a model with an infrared deformed Anti-de Sitter metric and another one based on a dynamical AdS/QCD framework with back-reacted geometry in a dilaton/gravity background. The models break softly the scale invariance in the infrared region and allow mass gap for the field excitations in the gravity description, while keeping the conformal property of the metric close to the four-dimensional boundary. The models provide linear Regge trajectories for light mesons, associated with specially designed infrared gravity properties. We also review the results for the decay widths of the f0's into two pions, as overlap integrals between mesonic string amplitudes, which are in qualitative agreement with data.
Accelerator development in India for ADS programme
Singh, P.; Rao, S. V. L. S.; Pande, Rajni; Basak, T.; Roy, Shweta; Aslam, M.; Jain, P.; Srivastava, S. C. L.; Kumar, Rajesh; Nema, P. K.; Kailas, S.; Sahni, V. C.
2007-02-01
At BARC, development of a Low Energy High Intensity Proton Accelerator (LEHIPA), as front-end injector of the 1 GeV accelerator for the ADS programme, has been initiated. The major components of LEHIPA (20 MeV, 30 mA) are a 50 keV ECR ion source, a 3 MeV Radio Frequency Quadrupole (RFQ) and a 20 MeV drift tube linac (DTL). The Low Energy Beam Transport (LEBT) and Medium Energy Beam Transport (MEBT) lines match the beam from the ion source to RFQ and from RFQ to DTL respectively. Design of these systems has been completed and fabrication of their prototypes has started. Physics studies of the 20-1000 MeV part of the Linac are also in progress. In this paper, the present status of this project is presented.
Adding a lens Improves spinning speed characterization.
Mihaliuk, Eugene; Gullion, Terry
2015-11-01
Highly stable sample rotation is important in many solid-state NMR experiments. Whether the necessary stability is achieved is not always clear. Typically only an average frequency over some time interval (often relatively long and unknown) is available from the spinning speed controller readout, which is not representative of the short-term variations of instantaneous rotation frequency. The necessity of the relatively slow measurement of spinning speed is a consequence of phase noise in the tachometer, which prevents speed measurement to be both rapid and precise at the same time. We show that adding a lens to the tachometer, without any other changes in the probe, reduces phase noise by nearly an order of magnitude and allows improved measurement of the spinning speed.
MR enterography: how to deliver added value.
Dillman, Jonathan R; Trout, Andrew T; Smith, Ethan A
2016-05-01
MR enterography (MRE) is increasingly vital to the diagnosis and follow-up of children with Crohn disease. This diagnostic test, which can provide valuable information regarding the presence of intestinal inflammation, intestinal and intra-abdominal complications, and extra-intestinal disease-related manifestations, has the potential to directly impact both medical and surgical decision-making. Consequently, it is imperative that the interpretation and reporting of these examinations provide as much clinical information as possible. This article reviews specific ways radiologists can provide added value when interpreting MRE examinations in the setting of pediatric Crohn disease by (1) establishing the true extent of disease involvement, (2) subjectively and objectively assessing response to medical treatment and (3) accurately characterizing disease-related complications.
An Approach to Ad hoc Cloud Computing
Kirby, Graham; Macdonald, Angus; Fernandes, Alvaro
2010-01-01
We consider how underused computing resources within an enterprise may be harnessed to improve utilization and create an elastic computing infrastructure. Most current cloud provision involves a data center model, in which clusters of machines are dedicated to running cloud infrastructure software. We propose an additional model, the ad hoc cloud, in which infrastructure software is distributed over resources harvested from machines already in existence within an enterprise. In contrast to the data center cloud model, resource levels are not established a priori, nor are resources dedicated exclusively to the cloud while in use. A participating machine is not dedicated to the cloud, but has some other primary purpose such as running interactive processes for a particular user. We outline the major implementation challenges and one approach to tackling them.
Accelerator development in India for ADS programme
Indian Academy of Sciences (India)
P Singh; S V L S Rao; Rajni Pande; T Basak; Shwetha Roy; M Aslam; P Jain; S C L Srivastava; Rajesh Kumar; P K Nema; S Kailas; V C Sahni
2007-02-01
At BARC, development of a Low Energy High Intensity Proton Accelerator (LEHIPA), as front-end injector of the 1 GeV accelerator for the ADS programme, has been initiated. The major components of LEHIPA (20 MeV, 30 mA) are a 50 keV ECR ion source, a 3 MeV Radio Frequency Quadrupole (RFQ) and a 20 MeV drift tube linac (DTL). The Low Energy Beam Transport (LEBT) and Medium Energy Beam Transport (MEBT) lines match the beam from the ion source to RFQ and from RFQ to DTL respectively. Design of these systems has been completed and fabrication of their prototypes has started. Physics studies of the 20{1000 MeV part of the Linac are also in progress. In this paper, the present status of this project is presented.
Janik, R A
2002-01-01
Using the AdS/CFT correspondence in a confining backgroundand the worldline formalism of gauge field theories,we compute scattering amplitudes with an exchange of quark andantiquark in the $t$-channel corresponding to Reggeon exchange. Itrequires going beyond the eikonal approximation, which was used when studying Pomeron exchange. The wordline path integral is evaluated through the determination of minimal surfaces and their boundaries by the saddle-point method at large gauge coupling g^2N_c. We find a Regge behaviour with linear Regge trajectories. The slope is related to the $q\\bar q$ static potential and is four times the Pomeronslope obtained in the same framework. A contribution to the intercept, related to the L\\"uscher term, comes from the fluctuations around the minimal surface.
Aerosol Best Estimate Value-Added Product
Energy Technology Data Exchange (ETDEWEB)
Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C
2012-07-19
The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.
Optimizing number of online ad impressions per user
Strehar, Davorin
2014-01-01
This thesis deals with the optimization of displaying online ads (frequency capping), where ad serving represents a cost, and clicks on the ads represent advertising revenue. In this case we would like to display the ad to the user so many times to have the biggest probability of the ad click. For this purpose, we converted the ad serving data to the appropriate format, analyzed it and used machine learning methods to make predictive models with the aim of predicting the optimal number of vie...
Geometric free energy of toric AdS4/CFT3 models
Lee, Sangmin
2014-01-01
We study the supersymmetric free energy of three dimensional Chern-Simons-matter theories holographically dual to AdS$_4$ times toric Sasaki-Einstein seven-manifolds. In the large $N$ limit, we argue that the square of the free energy can be written as a quartic polynomial of trial R-charges. The coefficients of the polynomial are determined geometrically from the toric diagrams. We present the coefficients of the quartic polynomial explicitly for generic toric diagrams with up to 6 vertices, and some particular diagrams with 8 vertices. Decomposing the trial R-charges into mesonic and baryonic variables, and eliminating the baryonic ones, we show that the quartic polynomial reproduces the inverse of the Martelli-Sparks-Yau volume function. On the gravity side, we explore the possibility of using the same quartic polynomial as the prepotential in the AdS gauged supergravity. Comparing Kaluza-Klein gravity and gauged supergravity descriptions, we find perfect agreement in the mesonic sector but some discrepanc...
P-V criticality of AdS black holes in a general framework
Majhi, Bibhas Ranjan; Samanta, Saurav
2017-10-01
In black hole thermodynamics, it has been observed that AdS black holes behave as van der Waals system if one interprets the cosmological constant as a pressure term. Also the critical exponents for the phase transition of AdS black holes and the van der Waals systems are same. Till now this type of analysis is done by two steps. In the first step one shows that a particular metric allows phase transition and in the second step, using this information, one calculates the exponents. Here, we present a different approach based on two universal inputs (the general forms of the Smarr formula and the first law of thermodynamics) and one assumption regarding the existence of van der Waals like critical point for a metric. We find that the same values of the critical exponents can be obtained by this approach. Thus we demonstrate that, though the existence of van der Waals like phase transition depends on specific metrics, the values of critical exponents are then fixed for that set of metrics.
Holographic Dual of de Sitter Universe with AdS Bubbles
Kanno, Sugumi; Soda, Jiro
2011-01-01
We study the proposal that a de Sitter (dS) universe with an Anti-de Sitter (AdS) bubble can be replaced by a dS universe with a boundary CFT. To explore this duality, we consider incident gravitons coming from the dS universe through the bubble wall into the AdS bubble in the original picture. In the dual picture, this process has to be identified with the absorption of gravitons by CFT matter. We have obtained a general formula for the absorption probability in general $d+1$ spacetime dimensions. The result shows the different behavior depending on whether spacetime dimensions are even or odd. We find that the absorption process of gravitons from the dS universe by CFT matter is controlled by localized gravitons (massive bound state modes in the Kaluza-Klein decomposition) in the dS universe. The absorption probability is determined by the effective degrees of freedom of the CFT matter and the effective gravitational coupling constant which encodes information of localized gravitons. We speculate that the d...
On gravitational interactions for massive higher spins in AdS3
Buchbinder, I. L.; Snegirev, T. V.; Zinoviev, Yu M.
2013-05-01
In this paper we investigate gravitational interactions of massive higher spin fields in three dimensional AdS space with arbitrary value of cosmological constant including flat Minkowski space. We use the frame-like gauge description for such massive fields adapted to the three-dimensional case. First, we carefully analyze the procedure of switching on gravitational interactions in the linear approximation in the example of a massive spin-3 field and then proceed with the generalization to the case of an arbitrary integer spin field. As a result we construct a cubic interaction vertex linear in a spin-2 field and quadratic in a higher spin field on the AdS3 background. As in the massless case the vertex does not contain any higher derivative corrections to the Lagrangian and/or gauge transformations. Thus, even after switching on gravitational interactions, one can freely consider any massless or partially massless limits as well as the flat one. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Higher spin theories and holography’.
On the Pulsating Strings in AdS4×ℂℙ3
Directory of Open Access Journals (Sweden)
H. Dimov
2009-01-01
we quasiclassically quantize the theory and obtain the first corrections to the energy. The latter, due to AdS/CFT correspondence, is supposed to give the anomalous dimensions of operators of the gauge theory dual 𝒩=6 Chern-Simons theory.
Exploring the bulk in AdS /CFT : A covariant approach
Engelhardt, Netta
2017-03-01
I propose a general, covariant way of defining when one region is "deeper in the bulk" than another. This definition is formulated outside of an event horizon (or in the absence thereof) in generic geometries; it may be applied to both points and surfaces, and it may be used to compare the depth of bulk points or surfaces relative to a particular boundary subregion or relative to the entire boundary. Using the recently proposed "light-cone cut" formalism, the comparative depth between two bulk points can be determined from the singularity structure of Lorentzian correlators in the dual field theory. I prove that, by this definition, causal wedges of progressively larger regions probe monotonically deeper in the bulk. The definition furthermore matches expectations in pure AdS and in static AdS black holes with isotropic spatial slices, where a well-defined holographic coordinate exists. In terms of holographic renormalization group flow, this new definition of bulk depth makes contact with coarse graining over both large distances and long time scales.
Action Principles for Transgression and Chern-Simons AdS Gravities
Mora, Pablo
2014-01-01
Chern-Simons gravities are theories with a lagrangian given by a Chern-Simons form constructed from a space-time gauge group. In previous investigations we showed that, for some special field configurations that are solutions of the field equations, the extension from Chern-Simons to Transgression forms as lagrangians, motivated by gauge invariance, automatically yields the boundary terms required to regularize the theory, giving finite conserved charges and black hole thermodynamics. Further work by other researchers showed that one of the action functionals considered in the above mentioned work yields a well defined action principle in the metric (zero torsion) case and for asymptotically Anti de Sitter (AdS) space-times. In the present work we consider several action functionals for Chern-Simons AdS gravity constructed from Transgression forms, and show the action principles to be well defined and the Noether charges and Euclidean action to be finite for field configurations satisfying only that the gauge...
Thermodynamics of AdS Black Holes in Einstein-Scalar Gravity
Lu, H; Wen, Qiang
2014-01-01
We study the thermodynamics of $n$-dimensional static asymptotically AdS black holes in Einstein gravity coupled to a scalar field with a potential admitting a stationary point with an AdS vacuum. Such black holes with non-trivial scalar hair can exist provided that the mass-squared of the scalar field is negative, and above the Breitenlohner-Freedman bound. We use the Wald procedure to derive the first law of thermodynamics for these black holes, showing how the scalar hair (or charge) contributes non-trivially in the expression. We show in general that the black hole mass can be deduced by isolating an integrable contribution to the (non-integrable) variation of the Hamiltonian arising in the Wald construction, and that this is consistent with the mass calculated using the renormalised holographic stress tensor and also, in those cases where it is defined, with the mass calculated using the conformal method of Ashtekar, Magnon and Das. Similar arguments can also be given for the smooth solitonic solutions i...
A new AdS_4/CFT_3 Dual with Extended SUSY and a Spectral Flow
Lozano, Yolanda
2014-01-01
We construct a new AdS_4 background in Type IIB supergravity by means of a non-Abelian T-duality transformation on the Type IIA dual of ABJM. The analysis of probe and particle-like branes suggests a dual CFT in which each of the gauge groups is doubled. A common feature of non-Abelian T-duality is that in the absence of any global information coming from String Theory it gives rise to non-compact dual backgrounds, with coordinates living in the Lie algebra of the Lie group involved in the dualization. In backgrounds with CFT duals this poses obvious problems to the CFTs. In this paper we show that for the new AdS_4 background the gauge groups of the associated dual CFT undergo a spectral flow as the non-compact internal direction runs from 0 to infinity, which resembles Seiberg duality in N=1. This phenomenon, very reminiscent of the cascade, provides an interpretation in the CFT for the running of the non-compact coordinate, and suggests that at the end of the flow the extra charges disappear and the dual C...
Conformal flow on S$^3$ and weak field integrability in AdS$_4$
Bizoń, Piotr; Evnin, Oleg; Hunik, Dominika; Luyten, Vincent; Maliborski, Maciej
2016-01-01
We consider the conformally invariant cubic wave equation on the Einstein cylinder $\\mathbb{R} \\times \\mathbb{S}^3$ for small rotationally symmetric initial data. This simple equation captures many key challenges of nonlinear wave dynamics in confining geometries, while a conformal transformation relates it to a self-interacting conformally coupled scalar in four-dimensional anti-de Sitter spacetime (AdS$_4$) and connects it to various questions of AdS stability. We construct an effective infinite-dimensional time-averaged dynamical system accurately approximating the original equation in the weak field regime. It turns out that this effective system, which we call the \\emph{conformal flow}, exhibits some remarkable features, such as low-dimensional invariant subspaces, a wealth of stationary states (for which energy does not flow between the modes), as well as solutions with nontrivial exactly periodic energy flows. Based on these observations and close parallels to the cubic Szeg\\H{o} equation, which was sh...
Quantum compositeness of gravity: black holes, AdS and inflation
Energy Technology Data Exchange (ETDEWEB)
Dvali, Gia [Arnold Sommerfeld Center for Theoretical Physics, Department für Physik, Ludwig-Maximilians-Universität München, Theresienstr. 37, 80333 München (Germany); Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany); Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Gomez, Cesar [Arnold Sommerfeld Center for Theoretical Physics, Department für Physik, Ludwig-Maximilians-Universität München, Theresienstr. 37, 80333 München (Germany); Instituto de Física Teórica UAM-CSIC, C-XVI, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain)
2014-01-14
Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.
Quantum compositeness of gravity: black holes, AdS and inflation
Energy Technology Data Exchange (ETDEWEB)
Dvali, Gia; Gomez, Cesar, E-mail: Georgi.Dvali@cern.ch, E-mail: cesar.gomez@uam.es [Arnold Sommerfeld Center for Theoretical Physics, Department für Physik, Ludwig-Maximilians-Universität München, Theresienstr. 37, 80333 München (Germany)
2014-01-01
Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.
Horizon Fluffs: Near Horizon Soft Hairs as Microstates of Generic AdS_3 Black Holes
Sheikh-Jabbari, M M
2016-01-01
In \\cite{Afshar:2016uax} the \\emph{horizon fluffs} proposal is put forward to identify the microstates of three-dimensional Ba\\~nados--Teitelboim--Zanelli (BTZ) black holes. The proposal is that black hole microstates, the horizon fluffs, are states labelled by the conserved charges associated with non-trivial diffeomorphisms on the near horizon geometry which are not distinguishable by the (Brown-Henneaux) conserved charges associated with the asymptotic symmetry algebra. It is also known that AdS_3 Einstein gravity has more general black hole solutions than the BTZ family. These black holes are generically described by two periodic, but otherwise arbitrary, holomorphic and anti-holomorphic functions. We show that these general AdS_3 black holes appear as coherent states in the enhanced asymptotic symmetry algebra, which is the Brown-Henneaux Virasoro algebra plus a u(1) current. These black holes are typically conformal descendants of the BTZ black holes, characterised by specific Virasoro coadjoint orbits....
Null-polygonal minimal surfaces in AdS_4 from perturbed W minimal models
Hatsuda, Yasuyuki; Satoh, Yuji
2012-01-01
We study the null-polygonal minimal surfaces in AdS_4, which correspond to the gluon scattering amplitudes/Wilson loops in N=4 super Yang-Mills theory at strong coupling. The area of the minimal surfaces with n cusps is characterized by the thermodynamic Bethe ansatz (TBA) integral equations or the Y-system of the homogeneous sine-Gordon model, which is regarded as the SU(n-4)_4/U(1)^{n-5} generalized parafermion theory perturbed by the weight-zero adjoint operators. Based on the relation to the TBA systems of the perturbed W minimal models, we solve the TBA equations by using the conformal perturbation theory, and obtain the analytic expansion of the remainder function around the UV/regular-polygonal limit for n=6 and 7. We compare the rescaled remainder function for n=6 with the two-loop one, to observe that they are close to each other similarly to the AdS_3 case.
One Loop Tests of Supersymmetric Higher Spin $AdS_4/CFT_3$
Pang, Yi; Zhu, Yaodong
2016-01-01
We compute one loop free energy for D=4 Vasiliev higher spin gravities based on Konstein-Vasiliev algebras hu(m;n|4), ho(m;n|4) or husp(m;n|4) and subject to higher spin preserving boundary conditions, which are conjectured to be dual to the U(N), O(N) or USp(N) singlet sectors, respectively, of free CFTs on the boundary of $AdS_4$. Ordinary supersymmetric higher spin theories appear as special cases of Konstein-Vasiliev theories, when the corresponding higher spin algebra contains $OSp({\\cal N}|4)$ as subalgebra. In $AdS_4$ with $S^3$ boundary, we use a modified spectral zeta function method, which avoids the ambiguity arising from summing over infinite number of spins. We find that the contribution of the infinite tower of bulk fermions vanishes. As a result, the free energy is the sum of those which arise in type A and type B models with internal symmetries, the known mismatch between the bulk and boundary free energies for type B model persists, and ordinary supersymmetric higher spin theories exhibit the...
Quartic AdS Interactions in Higher-Spin Gravity from Conformal Field Theory
Bekaert, Xavier; Ponomarev, Dmitry; Sleight, Charlotte
2015-01-01
Clarifying the locality properties of higher-spin gravity is a pressing task, but notoriously difficult due to the absence of a weakly-coupled flat regime. The simplest non-trivial case where this question can be addressed is the quartic self-interaction of the AdS scalar field present in the higher-spin multiplet. We investigate this issue in the context of the holographic duality between the minimal bosonic higher-spin theory on AdS$_4$ and the free $O\\left(N\\right)$ vector model in three dimensions. In particular, we determine the exact explicit form of the derivative expansion of the bulk scalar quartic vertex. The quartic vertex is obtained from the field theory four-point function of the operator dual to the bulk scalar, by making use of our previous results for the Witten diagrams of higher-spin exchanges. This is facilitated by establishing the conformal block expansions of both the boundary four-point function and the dual bulk Witten diagram amplitudes. We show that the vertex we find satisfies a ge...
AdS and Lifshitz Scalar Hairy Black Holes in Gauss-Bonnet Gravity
Chen, Bin; Zhu, Lu-Yao
2016-01-01
We consider Gauss-Bonnet (GB) gravity in general dimensions, which is non-minimally coupled to a scalar field, together with a generic scalar potential. By choosing the scalar potential of the type $V(\\phi)=2\\Lambda_0+\\frac{1}{2}m^2\\phi^2+\\gamma_4\\phi^4$, we first obtain large classes of scalar hairy black holes with spherical/hyperbolic/planar topologies that are asymptotic to locally anti-de Sitter (AdS) space-times. We derive the first law of black hole thermodynamics using Wald formalism. In particular, for one class of the solutions, the scalar hair forms a thermodynamic conjugate with the graviton and nontrivially contributes to the thermodynamical first law. We observe that except for one class of planar black holes, all these solutions are constructed at the critical point of GB gravity where there exists an unique AdS vacua. Actually Lifshitz vacuum is also allowed at the critical point. We then construct many new classes of neutral and charged Lifshitz black hole solutions for a either minimally or ...
ECONOMIC VALUE ADDED DAN MARKET VALUE ADDED DAMPAKNYA TERHADAP NILAI PERUSAHAAN
Directory of Open Access Journals (Sweden)
Mursalim Mursalim
2017-03-01
Full Text Available The aim of research was to fi nd out an infl uence of Economic Value Added (EVA andMarket Value Added (MVA towards share price of PT. International Nickel Indonesia, tbk (PT.INCO.The secondary data was gathered by capital market information centre (PIPM Makasar. The data wascultivated by using multiple regression analyze using software SPSS 15.0 for windows. The analysisresult showed that variable independent that consisted of economic value added (EVA and marketvalue added (MVA had a simultaneously positive infl uence and signifi cant impact towards sharemarket price of PT. INCO Tbk as variable dependent. Partially, variable EVA (X1 had weak positiveand signifi cant infl uence meanwhile MVA (X2 had strong positive and signifi cant towards share pricePT. INCO, tbk infl uence. Both of variable independent (EVA and MVA would be able to explain shareprice result (dependent variable at that time as big as 85%. The other factor which was not studiedin this study that infl uenced social condition was for example share price, policies, economy unstablewith corporate action like stock split, bonus stock distribution, and right issue.
Cosmological Solutions on Compactified AdS_5 with a Thermal Bulk
Rothstein, I Z
2001-01-01
This paper is an investigation of the effects of a thermal bulk fluid in brane world models compactified on AdS_5. Our primary purpose is to study how such a fluid changes the bulk dynamics and to compare these effects with those generated by matter localized to the branes. We find an exact cosmological solution for a thermally excited massless bulk field, as well as perturbative solutions with matter on the brane and in the bulk. We then perturb around these solutions to find solutions for a massive bulk mode in the limit where the bulk mass (m_B) is small compared to the AdS curvature scale and T< m_B. We find that without a stabilizing potential there are no physical solutions for a thermal bulk fluid. We then include a stabilizing potential and calculate the shift in the radion as well as the time dependence of the weak scale as a function of the bulk mass. It is shown that, as opposed to a brane fluid, the bulk fluid contribution to the bulk dynamics is controlled by the bulk mass.
Critical phenomena in higher curvature charged AdS black holes
Lala, Arindam
2012-01-01
In this paper we have studied the critical phenomena in higher curvature charged black holes in the anti-de Sitter (AdS) space-time. As an example we have considered the third order Lovelock-Born-Infeld black holes in AdS space-time. We have analytically derived the thermodynamic quantities of the system. Our analysis revealed the onset of a higher order phase transition in the black hole leading to an infinite discontinuity in the specific heat at constant charge at the critical points. Our entire analysis is based on the canonical framework where we have fixed the charge of the black hole. In an attempt to study the behavior of the thermodynamic quantities near the critical points we have derived the critical exponents of the system explicitly. Although the values of the critical points have been determined numerically, the critical exponents are calculated analytically. Our results fit well with the thermodynamic scaling laws. The scaling hypothesis is also seen to be consistent with these scaling laws. We...
AdS Description of Induced Higher-Spin Gauge Theory
Giombi, Simone; Pufu, Silviu S; Safdi, Benjamin R; Tarnopolsky, Grigory
2013-01-01
We study deformations of three-dimensional large N CFTs by double-trace operators constructed from spin s single-trace operators of dimension \\Delta. These theories possess UV fixed points, and we calculate the change of the 3-sphere free energy \\delta F= F_{UV}- F_{IR}. To describe the UV fixed point using the dual AdS_4 space we modify the boundary conditions on the spin s field in the bulk; this approach produces \\delta F in agreement with the field theory calculations. If the spin s operator is a conserved current, then the fixed point is described by an induced parity invariant conformal spin s gauge theory. The low spin examples are QED_3 (s=1) and the 3-d induced conformal gravity (s=2). When the original CFT is that of N conformal complex scalar or fermion fields, the U(N) singlet sector of the induced 3-d gauge theory is dual to Vasiliev's theory in AdS_4 with alternate boundary conditions on the spin s massless gauge field. We test this correspondence by calculating the leading term in \\delta F for ...
Aspects of AdS$_2$ holography with non-constant dilaton
Grumiller, Daniel; Vassilevich, Dmitri
2016-01-01
In this proceedings contribution we summarize and discuss results of Refs. \\cite{Grumiller:2013swa, Grumiller:2015vaa} in the light of recent developments in $\\textrm{AdS}_2$ holography \\cite{Maldacena:2016upp, Jensen:2016pah, Engelsoy:2016xyb}.
Expression profiles for macrophage alternative activation genes in AD and in mouse models of AD
Directory of Open Access Journals (Sweden)
Van Nostrand William E
2006-09-01
Full Text Available Abstract Background Microglia are associated with neuritic plaques in Alzheimer disease (AD and serve as a primary component of the innate immune response in the brain. Neuritic plaques are fibrous deposits composed of the amyloid beta-peptide fragments (Abeta of the amyloid precursor protein (APP. Numerous studies have shown that the immune cells in the vicinity of amyloid deposits in AD express mRNA and proteins for pro-inflammatory cytokines, leading to the hypothesis that microglia demonstrate classical (Th-1 immune activation in AD. Nonetheless, the complex role of microglial activation has yet to be fully explored since recent studies show that peripheral macrophages enter an "alternative" activation state. Methods To study alternative activation of microglia, we used quantitative RT-PCR to identify genes associated with alternative activation in microglia, including arginase I (AGI, mannose receptor (MRC1, found in inflammatory zone 1 (FIZZ1, and chitinase 3-like 3 (YM1. Results Our findings confirmed that treatment of microglia with anti-inflammatory cytokines such as IL-4 and IL-13 induces a gene profile typical of alternative activation similar to that previously observed in peripheral macrophages. We then used this gene expression profile to examine two mouse models of AD, the APPsw (Tg-2576 and Tg-SwDI, models for amyloid deposition and for cerebral amyloid angiopathy (CAA respectively. AGI, MRC1 and YM1 mRNA levels were significantly increased in the Tg-2576 mouse brains compared to age-matched controls while TNFα and NOS2 mRNA levels, genes commonly associated with classical activation, increased or did not change, respectively. Only TNFα mRNA increased in the Tg-SwDI mouse brain. Alternative activation genes were also identified in brain samples from individuals with AD and were compared to age-matched control individuals. In AD brain, mRNAs for TNFα, AGI, MRC1 and the chitinase-3 like 1 and 2 genes (CHI3L1; CHI3L2 were
Rigid Holography and Six-Dimensional N=(2,0) Theories on AdS_5 times S^1
Aharony, Ofer; Rey, Soo-Jong
2015-01-01
Field theories on anti-de Sitter (AdS) space can be studied by realizing them as low-energy limits of AdS vacua of string/M theory. In an appropriate limit, the field theories decouple from the rest of string/M theory. Since these vacua are dual to conformal field theories (CFTs), this relates some of the observables of these field theories on AdS to a subsector of the dual CFTs. We exemplify this `rigid holography' by studying in detail the 6d N=(2,0) A_{K-1} superconformal field theory (SCFT) on AdS_5xS^1, with equal radii for AdS_5 and for S^1. We choose specific boundary conditions preserving sixteen supercharges that arise when this theory is embedded into Type IIB string theory on AdS_5xS^5/Z_K. On R^{4,1}xS^1, this 6d theory has a 5(K-1)-dimensional moduli space, with unbroken 5d SU(K) gauge symmetry at (and only at) the origin. On AdS_5xS^1, the theory has a 2(K-1)-dimensional `moduli space' of supersymmetric configurations. We argue that in this case the SU(K) gauge symmetry is unbroken everywhere in...
The effect of viscosity on ad libitum food intake
National Research Council Canada - National Science Library
Zijlstra, N; Mars, M; Wijk, de, R.A; Westerterp-Plantenga, M; Graaf, de, C
2008-01-01
.... Objective: To investigate the effect of viscosity on ad libitum food intake in real-life setting and to investigate whether a difference in ad libitum intake is related to eating rate and/or eating effort. Design...
SILAGE CANE SUGAR ADDED WITH DRIED BREWER
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W. J. R. Castro
2015-02-01
Full Text Available The objective of this experiment was to evaluate the fermentative parameters and chemical composition of silage cane sugar added with residue dried brewery. The experimental design was completely randomized with four treatments and four replications: 100% cane sugar; 90% of cane sugar + 10% residue dried brewer; 80% of cane sugar + 20% residue dried brewer and 70% cane sugar + 30% dried brewer based on natural matter, composed silages. The sugar cane was chopped in a stationary machine with forage particle size of approximately 2 cm, and homogenized manually with the additives. For storage chopped fresh weight were used in experimental silos capacity of about 4 liters. The results showed that the contents of dry matter and crude protein showed positive linear (P0.05 with mean value of 3.81, while for ether extract and ash results were positive linear (P0.05 for N ammonia presented average value of 4.18. It is concluded that the addition of brewer dehydrated improves the fermentation process of silage cane sugar, in addition to improving their nutritional characteristics.
Vehicular Ad Hoc Network Mobility Model
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Budi Rahmadya
2014-01-01
Full Text Available Indonesia is one of developing countries with high land traffic density. This traffic density could cause traffic jam, traffic accidents and other disturbances. This research had developed a simulator that could calculate the traffic density of roads in urban areas. With the use of this simulator, the researcher could calculate the time needed if the source node transports the message to the destination node by using the ad hoc network communication facility. In this research, every vehicle utilizes multi-hop communication in a communication network. The vehicle sends the message through flooding message and passes on the received message to other vehicles. Based on the simulation done on map size 10 km x 10 km with a total of 20 vehicles on the road, it was calculated that the simulator could transmit the message to its destination on the 106th second from node 3 and with the total of 200 vehicles on the road, the simulator could transmit the message to its destination on the 22nd second from node 5.