Quasilinear theory and simulation of Buneman instability
International Nuclear Information System (INIS)
Pavan, J.; Yoon, P. H.; Umeda, T.
2011-01-01
In a recently developed nonlinear theory of Buneman instability, a simplifying assumption of self-similarity was imposed for the electron distribution function, based upon which, a set of moment kinetic equations was derived and solved together with nonlinear wave kinetic equation [P. H. Yoon and T. Umeda, Phys. Plasmas 17, 112317 (2010)]. It was found that the theoretical result compared reasonably against one-dimensional electrostatic Vlasov simulation. In spite of this success, however, the simulated distribution deviated appreciably from the assumed self-similar form during the late stages of nonlinear evolution. In order to rectify this shortcoming, in this paper, the distribution function is computed on the basis of rigorous velocity space diffusion equation. A novel theoretical scheme is developed so that both the quasilinear particle diffusion equation and the adiabatic dispersion relation can be solved for an arbitrary particle distribution function. Comparison with Vlasov simulation over relatively early quasilinear phase of the instability shows a reasonable agreement, despite the fact that quasilinear theory lacks coherent nonlinear effects as well as mode-mode coupling effects.
Quasilinear theory of laser-plasma interactions
International Nuclear Information System (INIS)
Neil, A.J.
1992-01-01
The interaction of a high intensity laser beam with a plasma is generally susceptible to the filamentation instability due to nonuniformities in the laser profile. In ponderomotive filamentation high intensity spots in the beam expell plasma by pondermotive force, lowering the local density, causing even more light to be focused into the already high intensity region. The result-the beam is broken up into a filamentary structure. Several optical smoothing techniques have been proposed to eliminate this problem. In the Random Phase Plates (RPS) approach, the beam is split into a very fine scale, time-stationary interference pattern. The irregularities in this pattern are small enough that thermal diffusion is then responsible for smoothing the illumination. In the Induced Spatial Incoherence (ISI) approach the beam is broken up into a larger scale but non-time-stationary interference pattern. In this dissertation the author proposes that the photons in an ISI beam resonantly interact with the sound waves in the wake of the beam. Such a resonant interaction induces diffusion in the velocity space of the photons. The diffusion will tend to spread the distribution of photons, thus if the diffusion time is much shorter than the e-folding time of the filamentation instability, the instability will be suppressed. Using a wave-kinetic description of laser-plasma interactions the author has applied quasilinear theory to model the resonant interactions of the photons in an ISI beam with the beam's wake field. An analytic expression is derived for the transverse diffusion coefficient. The quasilinear hypothesis was tested numerically and shown to yield an underestimate of the diffusion rate. By comparing the quasilinear diffusion rate with the maximum growth rate for the ponderomotive filamentation of a uniform beam, the author derived a worst case criterion for stability against ponderomotive filamentation
Quasilinear theory without the random phase approximation
International Nuclear Information System (INIS)
Weibel, E.S.; Vaclavik, J.
1980-08-01
The system of quasilinear equations is derived without making use of the random phase approximation. The fluctuating quantities are described by the autocorrelation function of the electric field using the techniques of Fourier analysis. The resulting equations posses the necessary conservation properties, but comprise new terms which hitherto have been lost in the conventional derivations
Simulation and quasilinear theory of proton firehose instability
Energy Technology Data Exchange (ETDEWEB)
Seough, Jungjoon [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Faculty of Human Development, University of Toyama, 3190, Gofuku, Toyama City, Toyama, 930-8555 (Japan); Yoon, Peter H. [University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Hwang, Junga [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Korea, University of Science and Technology, Daejeon (Korea, Republic of)
2015-01-15
The electromagnetic proton firehose instability is driven by excessive parallel temperature anisotropy, T{sub ∥} > T{sub ⊥} (or more precisely, parallel pressure anisotropy, P{sub ∥} > P{sub ⊥}) in high-beta plasmas. Together with kinetic instabilities driven by excessive perpendicular temperature anisotropy, namely, electromagnetic proton cyclotron and mirror instabilities, its role in providing the upper limit for the temperature anisotropy in the solar wind is well-known. A recent Letter [Seough et al., Phys. Rev. Lett. 110, 071103 (2013)] employed quasilinear kinetic theory for these instabilities to explain the observed temperature anisotropy upper bound in the solar wind. However, the validity of quasilinear approach has not been rigorously tested until recently. In a recent paper [Seough et al., Phys. Plasmas 21, 062118 (2014)], a comparative study is carried out for the first time in which quasilinear theory of proton cyclotron instability is tested against results obtained from the particle-in-cell simulation method, and it was demonstrated that the agreement was rather excellent. The present paper addresses the same issue involving the proton firehose instability. Unlike the proton cyclotron instability, however, it is found that the quasilinear approximation enjoys only a limited range of validity, especially for the wave dynamics and for the relatively high-beta regime. Possible causes and mechanisms responsible for the discrepancies are speculated and discussed.
When is quasi-linear theory exact. [particle acceleration
Jones, F. C.; Birmingham, T. J.
1975-01-01
We use the cumulant expansion technique of Kubo (1962, 1963) to derive an integrodifferential equation for the average one-particle distribution function for particles being accelerated by electric and magnetic fluctuations of a general nature. For a very restricted class of fluctuations, the equation for this function degenerates exactly to a differential equation of Fokker-Planck type. Quasi-linear theory, including the adiabatic assumption, is an exact theory only for this limited class of fluctuations.
Quasilinear theory of a spin-flip laser
International Nuclear Information System (INIS)
Arunasalam, V.
1973-09-01
A discussion of the nonlinear electrodynamic behavior of a gas of spin 1/2 particles in a uniform external magnetic field is presented. In particular, the quasilinear time evolution of a spin-flip laser system is examined in detail both from the point of view of the thermodynamics of negative temperature systems and the quantum kinetic methods of nonequilibrium statistical mechanics. It is shown that the quasilinear steady state of a spin-flip laser system is that state at which the populations of the spin-up and the spin-down states are equal to each other, and this quasilinear steady state is the state of minimum entropy production. The maximum output power of the spin-flip laser predicted by the theory presented in this paper is shown to be in reasonably good agreement with experimental results. The method used here is based on the general principles of nonrelativistic quantum theory and takes account of the Doppler broadening, collisional broadening, and Compton recoil effects. 30 refs., 1 fig
Is renormalization in the quasilinear theory of Langmuir oscillations necessary
International Nuclear Information System (INIS)
Galeev, A.A.; Sagdeev, R.Z.; Shapiro, V.D.; Shevchenko, V.I.
1980-01-01
The conditions of applicability of the quasilinear approximation to describe resonant interaction between waves and particles are elucidated. It is shown that if the conditions of rapid phase mixing and collectivization of the resonance particles (overlapping of neighboring resonances) are satisfied, the nonlinear corrections to the increment and to the diffusion coefficient are negligible
Weak turbulence theory of Langmuir waves: A reconsideration of validity of quasilinear theory
International Nuclear Information System (INIS)
Liang, Y.M.; Diamond, P.H.
1991-01-01
The weak turbulence theory of Langmuir waves in a one-dimensional, one-species plasma is discussed. Analytical calculations using the theory of two-point correlation functions show that in the weak turbulence regime τ ac much-lt min[τ tr , γ k -1 ], the nonlinear enhancement of the mode growth rate relative to the linear Landau mode growth rate γ k L is rather weak, and quasilinear theory is reproduced at the lowest order. Hence this work also proves the validity of the quasilinear theory. Here τ ac ∼ (kΔv ph ) -1 is the phase-mixing time or the auto-correlation time, and τ tr ∼ (k 2 D ql ) -1/3 is the particle decorrelation time or the turbulence trapping time. In particular, the lowest order nonlinear correction to γ k L in the regime τ ac much-lt τ tr much-lt γ k -1 is proportional to (1/ω k τ tr )γ k L . Both corrections are additive, not multiplicative, and are of higher order in the weak turbulence expansion. The smallness of the corrections is due to the fact that the only mechanism for the relaxation of the plasma distribution function in a one-dimensional, one-species plasma is momentum exchange between waves and particles, which is exactly the interaction considered in the quasilinear theory. No like-like particle momentum exchange is allowed due to momentum conservation constraints. Similar calculations are also done for the traveling wave tube, which can be used to test this theory experimentally, especially for the case of bump-on-tail instability. A comparison of theoretical predictions with experimental results is presented. 3 refs
Anomalous energy exchange in the gBL and quasilinear theories
International Nuclear Information System (INIS)
Mynick, H.E.
1992-02-01
The rate of turbulence-induced energy exchange W o between species is computed in the framework of the quasilinear and gBL transport theories, and the relationship between these two theories, and the relationship between these two similar theories is thereby elucidated. For both theories, general formal expressions for W o are developed, and then applied to the trapped electron mode for illustration. The general expressions for W o in the two theories are formally closely related, but can yield predictions of very different magnitude in concrete applications. The fact that quasilinear theory is not valid for saturated steady-state turbulence gives rise to certain peculiarities in its predictions for this normal experimental situation, such as permitting energy to flow from the cooler to the hotter species, even in the limit of thermal equilibrium, where real-space gradients vanish. The gBL theory may be viewed as a modification of quasilinear theory to be valid for steady-state turbulence, keeping extra terms due to the self-consistent back reaction of particles on the fluctuations, which are just such as to eliminate these peculiarities
Stochastic field-line wandering in magnetic turbulence with shear. I. Quasi-linear theory
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Shalchi, A. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Negrea, M.; Petrisor, I. [Department of Physics, University of Craiova, Association Euratom-MEdC, 13A.I.Cuza Str, 200585 Craiova (Romania)
2016-07-15
We investigate the random walk of magnetic field lines in magnetic turbulence with shear. In the first part of the series, we develop a quasi-linear theory in order to compute the diffusion coefficient of magnetic field lines. We derive general formulas for the diffusion coefficients in the different directions of space. We like to emphasize that we expect that quasi-linear theory is only valid if the so-called Kubo number is small. We consider two turbulence models as examples, namely, a noisy slab model as well as a Gaussian decorrelation model. For both models we compute the field line diffusion coefficients and we show how they depend on the aforementioned Kubo number as well as a shear parameter. It is demonstrated that the shear effect reduces all field line diffusion coefficients.
Stochastic field-line wandering in magnetic turbulence with shear. I. Quasi-linear theory
International Nuclear Information System (INIS)
Shalchi, A.; Negrea, M.; Petrisor, I.
2016-01-01
We investigate the random walk of magnetic field lines in magnetic turbulence with shear. In the first part of the series, we develop a quasi-linear theory in order to compute the diffusion coefficient of magnetic field lines. We derive general formulas for the diffusion coefficients in the different directions of space. We like to emphasize that we expect that quasi-linear theory is only valid if the so-called Kubo number is small. We consider two turbulence models as examples, namely, a noisy slab model as well as a Gaussian decorrelation model. For both models we compute the field line diffusion coefficients and we show how they depend on the aforementioned Kubo number as well as a shear parameter. It is demonstrated that the shear effect reduces all field line diffusion coefficients.
Quasilinear theory of plasma turbulence. Origins, ideas, and evolution of the method
Bakunin, O. G.
2018-01-01
The quasilinear method of describing weak plasma turbulence is one of the most important elements of current plasma physics research. Today, this method is not only a tool for solving individual problems but a full-fledged theory of general physical interest. The author's objective is to show how the early ideas of describing the wave-particle interactions in a plasma have evolved as a result of the rapid expansion of the research interests of turbulence and turbulent transport theorists.
International Nuclear Information System (INIS)
Lemons, Don S.
2012-01-01
We develop a Markov process theory of charged particle scattering from stationary, transverse, magnetic waves. We examine approximations that lead to quasilinear theory, in particular the resonant diffusion approximation. We find that, when appropriate, the resonant diffusion approximation simplifies the result of the weak turbulence approximation without significant further restricting the regime of applicability. We also explore a theory generated by expanding drift and diffusion rates in terms of a presumed small correlation time. This small correlation time expansion leads to results valid for relatively small pitch angle and large wave energy density - a regime that may govern pitch angle scattering of high-energy electrons into the geomagnetic loss cone.
Real-space quasilinear theory of drift waves in a sheared magnetic field
International Nuclear Information System (INIS)
1977-02-01
A real-space quasilinear theory is developed for the collisional and the collisionless drift waves in a plasma with a sheared magnetic field of slab geometry. The equation obtained describes the interaction between many localized modes around different rational surfaces through the density modulation of the energy source region of each mode. The wave amplitudes approach to the stationary values through a relaxation oscillation process. When the width x sub(s) of the energy source region becomes comparable to the spacing Δx of the two adjacent rational surfaces, diffusion coefficient due to the wave is enhanced over the classical value, while the nonlocal heat transport due to the wave propagation is shown to be negligible compared to that associated with the diffusion process. (auth.)
Quasi-linear theory for a tokamak plasma in the presence of cyclotron resonance
International Nuclear Information System (INIS)
Belikov, V.S.; Kolesnichenko, Ya.I.
1993-01-01
Quasi-linear diffusion equations for the distribution function of trapped and circulating particles interacting with waves in a tokamak by means of cyclotron resonance are derived. The resulting equations reveal new features of quasi-linear diffusion and are of two kinds, one which involves bounce resonances overlapping in velocity space and one with well separated bounce resonances. These two cases correspond to situations where the phase of the wave-particle interaction between successive resonances can be considered as random or deterministic, respectively. An analysis of the conditions of applicability of the new equations is carried out and previous well-known forms of the quasi-linear diffusion equations are shown to be recovered in the proper limits. (10 refs., 3 figs.)
Quasi-linear theory and transport theory. [particle acceleration in interplanetary medium
Smith, Charles W.
1992-01-01
The theory of energetic particle scattering by magnetostatic fluctuations is reviewed in so far as it fails to produce the rigidity-independent mean-free-paths observed. Basic aspects of interplanetary magnetic field fluctuations are reviewed with emphasis placed on the existence of dissipation range spectra at high wavenumbers. These spectra are then incorporated into existing theories for resonant magnetostatic scattering and are shown to yield infinite mean-free-paths. Nonresonant scattering in the form of magnetic mirroring is examined and offered as a partial solution to the magnetostatic problem. In the process, mean-free-paths are obtained in good agreement with observations in the interplanetary medium at 1 AU and upstream of planetary bow shocks.
Regularity theory for quasilinear elliptic systems and Monge—Ampère equations in two dimensions
Schulz, Friedmar
1990-01-01
These lecture notes have been written as an introduction to the characteristic theory for two-dimensional Monge-Ampère equations, a theory largely developed by H. Lewy and E. Heinz which has never been presented in book form. An exposition of the Heinz-Lewy theory requires auxiliary material which can be found in various monographs, but which is presented here, in part because the focus is different, and also because these notes have an introductory character. Self-contained introductions to the regularity theory of elliptic systems, the theory of pseudoanalytic functions and the theory of conformal mappings are included. These notes grew out of a seminar given at the University of Kentucky in the fall of 1988 and are intended for graduate students and researchers interested in this area.
Lafleur, T.; Martorelli, R.; Chabert, P.; Bourdon, A.
2018-06-01
Kinetic drift instabilities have been implicated as a possible mechanism leading to anomalous electron cross-field transport in E × B discharges, such as Hall-effect thrusters. Such instabilities, which are driven by the large disparity in electron and ion drift velocities, present a significant challenge to modelling efforts without resorting to time-consuming particle-in-cell (PIC) simulations. Here, we test aspects of quasi-linear kinetic theory with 2D PIC simulations with the aim of developing a self-consistent treatment of these instabilities. The specific quantities of interest are the instability growth rate (which determines the spatial and temporal evolution of the instability amplitude), and the instability-enhanced electron-ion friction force (which leads to "anomalous" electron transport). By using the self-consistently obtained electron distribution functions from the PIC simulations (which are in general non-Maxwellian), we find that the predictions of the quasi-linear kinetic theory are in good agreement with the simulation results. By contrast, the use of Maxwellian distributions leads to a growth rate and electron-ion friction force that is around 2-4 times higher, and consequently significantly overestimates the electron transport. A possible method for self-consistently modelling the distribution functions without requiring PIC simulations is discussed.
Soliton solutions for a quasilinear Schrodinger equation
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Duchao Liu
2013-12-01
Full Text Available In this article, critical point theory is used to show the existence of nontrivial weak solutions to the quasilinear Schrodinger equation $$ -\\Delta_p u-\\frac{p}{2^{p-1}}u\\Delta_p(u^2=f(x,u $$ in a bounded smooth domain $\\Omega\\subset\\mathbb{R}^{N}$ with Dirichlet boundary conditions.
Quasilinear Hyperbolic Systems, Compressible Flows, and Waves
Sharma, Vishnu D
2010-01-01
Filled with practical examples, this book presents a self-contained discussion of quasilinear hyperbolic equations and systems with applications. It emphasizes nonlinear theory and introduces some of the most active research in the field. The author elucidates all necessary mathematical concepts in the first three chapters, including an introduction to general wave propagation problems. He highlights the application of various approaches, such as singular surface theory, asymptotic methods, and self-similarity, to solve practical physical problems from areas, including gasdynamics, radiation g
Systems of quasilinear equations and their applications to gas dynamics
Roždestvenskiĭ, B L; Schulenberger, J R
1983-01-01
This book is essentially a new edition, revised and augmented by results of the last decade, of the work of the same title published in 1968 by "Nauka." It is devoted to mathematical questions of gas dynamics. Topics covered include Foundations of the Theory of Systems of Quasilinear Equations of Hyperbolic Type in Two Independent Variables; Classical and Generalized Solutions of One-Dimensional Gas Dynamics; Difference Methods for Solving the Equations of Gas Dynamics; and Generalized Solutions of Systems of Quasilinear Equations of Hyperbolic Type.
Moving interfaces and quasilinear parabolic evolution equations
Prüss, Jan
2016-01-01
In this monograph, the authors develop a comprehensive approach for the mathematical analysis of a wide array of problems involving moving interfaces. It includes an in-depth study of abstract quasilinear parabolic evolution equations, elliptic and parabolic boundary value problems, transmission problems, one- and two-phase Stokes problems, and the equations of incompressible viscous one- and two-phase fluid flows. The theory of maximal regularity, an essential element, is also fully developed. The authors present a modern approach based on powerful tools in classical analysis, functional analysis, and vector-valued harmonic analysis. The theory is applied to problems in two-phase fluid dynamics and phase transitions, one-phase generalized Newtonian fluids, nematic liquid crystal flows, Maxwell-Stefan diffusion, and a variety of geometric evolution equations. The book also includes a discussion of the underlying physical and thermodynamic principles governing the equations of fluid flows and phase transitions...
Exact boundary controllability of nodal profile for quasilinear hyperbolic systems
Li, Tatsien; Gu, Qilong
2016-01-01
This book provides a comprehensive overview of the exact boundary controllability of nodal profile, a new kind of exact boundary controllability stimulated by some practical applications. This kind of controllability is useful in practice as it does not require any precisely given final state to be attained at a suitable time t=T by means of boundary controls, instead it requires the state to exactly fit any given demand (profile) on one or more nodes after a suitable time t=T by means of boundary controls. In this book we present a general discussion of this kind of controllability for general 1-D first order quasilinear hyperbolic systems and for general 1-D quasilinear wave equations on an interval as well as on a tree-like network using a modular-structure construtive method, suggested in LI Tatsien's monograph "Controllability and Observability for Quasilinear Hyperbolic Systems"(2010), and we establish a complete theory on the local exact boundary controllability of nodal profile for 1-D quasilinear hyp...
Existence of multiple solutions for quasilinear diagonal elliptic systems
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Marco Squassina
1999-05-01
Full Text Available Nonsmooth-critical-point theory is applied in proving multiplicity results for the quasilinear symmetric elliptic system $$ -sum_{i,j=1}^{n}D_j(a^{k}_{ij}(x,uD_iu_k+ {1over 2}sum_{i,j=1}^{n}sum_{h=1}^N D_{s_k}a^{h}_{ij}(x,uD_iu_hD_ju_h=g_k(x,u,, $$ for $k=1,..,N$.
Dirichlet problem for quasi-linear elliptic equations
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Azeddine Baalal
2002-10-01
Full Text Available We study the Dirichlet Problem associated to the quasilinear elliptic problem $$ -sum_{i=1}^{n}frac{partial }{partial x_i}mathcal{A}_i(x,u(x, abla u(x+mathcal{B}(x,u(x,abla u(x=0. $$ Then we define a potential theory related to this problem and we show that the sheaf of continuous solutions satisfies the Bauer axiomatic theory. Submitted April 9, 2002. Published October 2, 2002. Math Subject Classifications: 31C15, 35B65, 35J60. Key Words: Supersolution; Dirichlet problem; obstacle problem; nonlinear potential theory.
Fokker-Planck and quasilinear codes
International Nuclear Information System (INIS)
Karney, C.F.F.
1985-11-01
The interaction of radio-frequency waves with a plasma is described by a Fokker-Planck equation with an added quasilinear term. Methods for solving this equation on a computer are discussed. 40 refs., 12 figs., 3 tabs
Existence of solutions for quasilinear random impulsive neutral differential evolution equation
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B. Radhakrishnan
2018-07-01
Full Text Available This paper deals with the existence of solutions for quasilinear random impulsive neutral functional differential evolution equation in Banach spaces and the results are derived by using the analytic semigroup theory, fractional powers of operators and the Schauder fixed point approach. An application is provided to illustrate the theory. Keywords: Quasilinear differential equation, Analytic semigroup, Random impulsive neutral differential equation, Fixed point theorem, 2010 Mathematics Subject Classification: 34A37, 47H10, 47H20, 34K40, 34K45, 35R12
New Inner Product Quasilinear Spaces on Interval Numbers
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Hacer Bozkurt
2016-01-01
Full Text Available Primarily we examine the new example of quasilinear spaces, namely, “IRn interval space.” We obtain some new theorems and results related to this new quasilinear space. After giving some new notions of quasilinear dependence-independence and basis on quasilinear functional analysis, we obtain some results on IRn interval space related to these concepts. Secondly, we present Is,Ic0,Il∞, and Il2 quasilinear spaces and we research some algebraic properties of these spaces. We obtain some new results and provide an important contribution to the improvement of quasilinear functional analysis.
Critical spaces for quasilinear parabolic evolution equations and applications
Prüss, Jan; Simonett, Gieri; Wilke, Mathias
2018-02-01
We present a comprehensive theory of critical spaces for the broad class of quasilinear parabolic evolution equations. The approach is based on maximal Lp-regularity in time-weighted function spaces. It is shown that our notion of critical spaces coincides with the concept of scaling invariant spaces in case that the underlying partial differential equation enjoys a scaling invariance. Applications to the vorticity equations for the Navier-Stokes problem, convection-diffusion equations, the Nernst-Planck-Poisson equations in electro-chemistry, chemotaxis equations, the MHD equations, and some other well-known parabolic equations are given.
Quasi-linear evolution of tearing modes
International Nuclear Information System (INIS)
Pellat, R.; Frey, M.; Tagger, M.
1983-07-01
The growth of a Tearing instability in Rutherford's nonlinear regime is investigated. Using a singular perturbation technique, lowest order Rutherford's result is recovered. To the following order it is shown that the mode generates a quasi-linear deformation of the equilibrium flux profile, whose resistive diffusion slows down the growth and shows the possibility of a saturation of the instability
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Tengfei Shen
2015-12-01
Full Text Available This paper deals with the multiplicity of solutions for Dirichlet boundary conditions of second-order quasilinear equations with impulsive effects. By using critical point theory, a new result is obtained. An example is given to illustrate the main result.
LBQ2D, Extending the Line Broadened Quasilinear Model to TAE-EP Interaction
Ghantous, Katy; Gorelenkov, Nikolai; Berk, Herbert
2012-10-01
The line broadened quasilinear model was proposed and tested on the one dimensional electrostatic case of the bump on tailfootnotetextH.L Berk, B. Breizman and J. Fitzpatrick, Nucl. Fusion, 35:1661, 1995 to study the wave particle interaction. In conventional quasilinear theory, the sea of overlapping modes evolve with time as the particle distribution function self consistently undergo diffusion in phase space. The line broadened quasilinear model is an extension to the conventional theory in a way that allows treatment of isolated modes as well as overlapping modes by broadening the resonant line in phase space. This makes it possible to treat the evolution of modes self consistently from onset to saturation in either case. We describe here the model denoted by LBQ2D which is an extension of the proposed one dimensional line broadened quasilinear model to the case of TAEs interacting with energetic particles in two dimensional phase space, energy as well as canonical angular momentum. We study the saturation of isolated modes in various regimes and present the analytical derivation and numerical results. Finally, we present, using ITER parameters, the case where multiple modes overlap and describe the techniques used for the numerical treatment.
Quasi-linear equation for magnetoplasma oscillations in the weakly relativistic approximation
International Nuclear Information System (INIS)
Rizzato, F.B.
1985-01-01
Some limitations which are present in the dynamical equations for collisionless plasmas are discussed. Some elementary corrections to the linear theories are obtained in a heuristic form, which directly lead to the so-called quasi-linear theories in its non-relativistic and relativistic forms. The effect of the relativistic variation of the gyrofrequency on the diffusion coefficient is examined in a typically perturbative approximation. (author)
Quasilinear kinetic modeling of RMP penetration into a tokamak plasma
International Nuclear Information System (INIS)
Heyn, M.F.; Kernbichler, W.; Leitner, P.; Ivanov, I.B.; Kasilov, S.V.
2013-01-01
The linear as well as the quasilinear problem of RMP penetration in tokamaks is solved consistently with a particle and energy conserving collision operator. The new collision operator ensures the Onsager symmetry of the quasilinear transport coefficient matrix and avoids artifacts such as fake heat convection connected with simplified collision models.
Line-broadened quasilinear burst model
International Nuclear Information System (INIS)
Berk, H.L.; Breizman, B.N.; Wong, H.V.; Fitzpatrick, J.
1995-07-01
A quasilinear model is developed to produce realistic self-consistent saturation levels when modes do not overlap, and give self-consistent diffusion and wave evolution when modes do overlap. Both regimes give steady or pulsating behavior in weakly driven systems with classical relaxation and background dissipation present. An avalanche response is demonstrated: wave momentum release caused by the overlap of closely spaced modes can produce mode overlap of more widely spaced modes (a domino effect) or the growth of modes which would be stable in systems unaffected by the closely-spaced modes' diffusion. Detailed analysis and calculations are performed for the bump-on-tail instability, and extension of the method to more general problems is briefly discussed
Is the time-dependent behaviour of the aortic valve intrinsically quasi-linear?
Anssari-Benam, Afshin
2014-05-01
The widely popular quasi-linear viscoelasticity (QLV) theory has been employed extensively in the literature for characterising the time-dependent behaviour of many biological tissues, including the aortic valve (AV). However, in contrast to other tissues, application of QLV to AV data has been met with varying success, with studies reporting discrepancies in the values of the associated quantified parameters for data collected from different timescales in experiments. Furthermore, some studies investigating the stress-relaxation phenomenon in valvular tissues have suggested discrete relaxation spectra, as an alternative to the continuous spectrum proposed by the QLV. These indications put forward a more fundamental question: Is the time-dependent behaviour of the aortic valve intrinsically quasi-linear? In other words, can the inherent characteristics of the tissue that govern its biomechanical behaviour facilitate a quasi-linear time-dependent behaviour? This paper attempts to address these questions by presenting a mathematical analysis to derive the expressions for the stress-relaxation G( t) and creep J( t) functions for the AV tissue within the QLV theory. The principal inherent characteristic of the tissue is incorporated into the QLV formulation in the form of the well-established gradual fibre recruitment model, and the corresponding expressions for G( t) and J( t) are derived. The outcomes indicate that the resulting stress-relaxation and creep functions do not appear to voluntarily follow the observed experimental trends reported in previous studies. These results highlight that the time-dependent behaviour of the AV may not be quasi-linear, and more suitable theoretical criteria and models may be required to explain the phenomenon based on tissue's microstructure, and for more accurate estimation of the associated material parameters. In general, these results may further be applicable to other planar soft tissues of the same class, i.e. with the same
Qualitative behavior of global solutions to inhomogeneous quasilinear hyperbolic systems
International Nuclear Information System (INIS)
Hsiao, L.
1994-01-01
The emphasis is the influence to the qualitative behavior of solutions caused by the lower order term, which is certain dissipation, in quasilinear hyperbolic systems. Both classical solutions and discontinuous weak solutions are discussed. (author). 12 refs
Local full-wave energy and quasilinear analysis in nonuniform plasmas
International Nuclear Information System (INIS)
Smithe, D.N.
1989-01-01
The subject of local wave energy in plasmas is treated via quasilinear theory from the dual perspectives of the action-angle formalism and gyrokinetic analysis. An extension is presented to all orders in the gyroradius of the self-consistent wave-propagation/quasilinear-absorption problem using gyrokinetics. Questions of when and under what conditions local energy should be of definite sign are answered using the action-angle formalism. An important result is that the ''dielectric operators'' of the linearized wave equation and of the local energy are not the same, a fact which is obscured when the eikonal or WKB assumption is invoked. Even though the two dielectrics are very different in character, it is demonstrated that they are nevertheless related by a simple mathematical statement. This study was originally motivated by concern over the question of local energy for r.f.-heating of plasmas, where in certain instances, full-wave effects such as refraction, strong absorption, and mode conversion are of primary importance. Fundamentally, the r.f.-absorption must equate with the energy moment of the quasilinear term to achieve a correct energy balance. This fact governs the derivation (as opposed to postulation) of the local absorption. The troublesome ''kinetic flux'' may then be chosen (it is not unique) to satisfy a wave-energy balance relation with the Poynting flux and local absorption. It is shown that at least one such choice reduces asymptotically to the Stix form away from nonuniformities. (author)
Zacharegkas, Georgios; Isliker, Heinz; Vlahos, Loukas
2016-11-01
The limitation of the Quasilinear Theory (QLT) to describe the diffusion of electrons and ions in velocity space when interacting with a spectrum of large amplitude electrostatic Langmuir, Upper and Lower hybrid waves, is analyzed. We analytically and numerically estimate the threshold for the amplitude of the waves above which the QLT breaks down, using a test particle code. The evolution of the velocity distribution, the velocity-space diffusion coefficients, the driven current, and the heating of the particles are investigated, for the interaction with small and large amplitude electrostatic waves, that is, in both regimes, where QLT is valid and where it clearly breaks down.
Non-local quasi-linear parabolic equations
International Nuclear Information System (INIS)
Amann, H
2005-01-01
This is a survey of the most common approaches to quasi-linear parabolic evolution equations, a discussion of their advantages and drawbacks, and a presentation of an entirely new approach based on maximal L p regularity. The general results here apply, above all, to parabolic initial-boundary value problems that are non-local in time. This is illustrated by indicating their relevance for quasi-linear parabolic equations with memory and, in particular, for time-regularized versions of the Perona-Malik equation of image processing
On some perturbation techniques for quasi-linear parabolic equations
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Igor Malyshev
1990-01-01
Full Text Available We study a nonhomogeneous quasi-linear parabolic equation and introduce a method that allows us to find the solution of a nonlinear boundary value problem in explicit form. This task is accomplished by perturbing the original equation with a source function, which is then found as a solution of some nonlinear operator equation.
Multiple solutions for a quasilinear (p,q-elliptic system
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Seyyed Mohsen Khalkhali
2013-06-01
Full Text Available In this article we show the existence of three weak solutions of a Dirichlet quasilinear elliptic system of differential equations which involves a general (p,q-elliptic operator in divergence, with $1
Quasi-linear score for capturing heterogeneous structure in biomarkers.
Omae, Katsuhiro; Komori, Osamu; Eguchi, Shinto
2017-06-19
Linear scores are widely used to predict dichotomous outcomes in biomedical studies because of their learnability and understandability. Such approaches, however, cannot be used to elucidate biodiversity when there is heterogeneous structure in target population. Our study was focused on describing intrinsic heterogeneity in predictions. Because heterogeneity can be captured by a clustering method, integrating different information from different clusters should yield better predictions. Accordingly, we developed a quasi-linear score, which effectively combines the linear scores of clustered markers. We extended the linear score to the quasi-linear score by a generalized average form, the Kolmogorov-Nagumo average. We observed that two shrinkage methods worked well: ridge shrinkage for estimating the quasi-linear score, and lasso shrinkage for selecting markers within each cluster. Simulation studies and applications to real data show that the proposed method has good predictive performance compared with existing methods. Heterogeneous structure is captured by a clustering method. Quasi-linear scores combine such heterogeneity and have a better predictive ability compared with linear scores.
Parker, Jeffrey B.
2018-05-01
Zonal flows have been observed to appear spontaneously from turbulence in a number of physical settings. A complete theory for their behavior is still lacking. Recently, a number of studies have investigated the dynamics of zonal flows using quasilinear (QL) theories and the statistical framework of a second-order cumulant expansion (CE2). A geometrical-optics (GO) reduction of CE2, derived under an assumption of separation of scales between the fluctuations and the zonal flow, is studied here numerically. The reduced model, CE2-GO, has a similar phase-space mathematical structure to the traditional wave-kinetic equation, but that wave-kinetic equation has been shown to fail to preserve enstrophy conservation and to exhibit an ultraviolet catastrophe. CE2-GO, in contrast, preserves nonlinear conservation of both energy and enstrophy. We show here how to retain these conservation properties in a pseudospectral simulation of CE2-GO. We then present nonlinear simulations of CE2-GO and compare with direct simulations of quasilinear (QL) dynamics. We find that CE2-GO retains some similarities to QL. The partitioning of energy that resides in the zonal flow is in good quantitative agreement between CE2-GO and QL. On the other hand, the length scale of the zonal flow does not follow the same qualitative trend in the two models. Overall, these simulations indicate that CE2-GO provides a simpler and more tractable statistical paradigm than CE2, but CE2-GO is missing important physics.
A note on quasilinear elliptic eigenvalue problems
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Gianni Arioli
1999-11-01
Full Text Available We study an eigenvalue problem by a non-smooth critical point theory. Under general assumptions, we prove the existence of at least one solution as a minimum of a constrained energy functional. We apply some results on critical point theory with symmetry to provide a multiplicity result.
A quasi-linear control theory analysis of timesharing skills
Agarwal, G. C.; Gottlieb, G. L.
1977-01-01
The compliance of the human ankle joint is measured by applying 0 to 50 Hz band-limited gaussian random torques to the foot of a seated human subject. These torques rotate the foot in a plantar-dorsal direction about a horizontal axis at a medial moleolus of the ankle. The applied torques and the resulting angular rotation of the foot are measured, digitized and recorded for off-line processing. Using such a best-fit, second-order model, the effective moment of inertia of the ankle joint, the angular viscosity and the stiffness are calculated. The ankle joint stiffness is shown to be a linear function of the level of tonic muscle contraction, increasing at a rate of 20 to 40 Nm/rad/Kg.m. of active torque. In terms of the muscle physiology, the more muscle fibers that are active, the greater the muscle stiffness. Joint viscosity also increases with activation. Joint stiffness is also a linear function of the joint angle, increasing at a rate of about 0.7 to 1.1 Nm/rad/deg from plantar flexion to dorsiflexion rotation.
Existence of solutions to quasilinear Schrodinger equations with indefinite potential
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Zupei Shen
2015-04-01
Full Text Available In this article, we study the existence and multiplicity of solutions of the quasilinear Schrodinger equation $$ -u''+V(xu-(|u| ^2''u=f(u $$ on $\\mathbb{R}$, where the potential $V$ allows sign changing and the nonlinearity satisfies conditions weaker than the classical Ambrosetti-Rabinowitz condition. By a local linking theorem and the fountain theorem, we obtain the existence and multiplicity of solutions for the equation.
Linear and quasi-linear equations of parabolic type
Ladyženskaja, O A; Ural′ceva, N N; Uralceva, N N
1968-01-01
Equations of parabolic type are encountered in many areas of mathematics and mathematical physics, and those encountered most frequently are linear and quasi-linear parabolic equations of the second order. In this volume, boundary value problems for such equations are studied from two points of view: solvability, unique or otherwise, and the effect of smoothness properties of the functions entering the initial and boundary conditions on the smoothness of the solutions.
A quasilinear model for solute transport under unsaturated flow
International Nuclear Information System (INIS)
Houseworth, J.E.; Leem, J.
2009-01-01
We developed an analytical solution for solute transport under steady-state, two-dimensional, unsaturated flow and transport conditions for the investigation of high-level radioactive waste disposal. The two-dimensional, unsaturated flow problem is treated using the quasilinear flow method for a system with homogeneous material properties. Dispersion is modeled as isotropic and is proportional to the effective hydraulic conductivity. This leads to a quasilinear form for the transport problem in terms of a scalar potential that is analogous to the Kirchhoff potential for quasilinear flow. The solutions for both flow and transport scalar potentials take the form of Fourier series. The particular solution given here is for two sources of flow, with one source containing a dissolved solute. The solution method may easily be extended, however, for any combination of flow and solute sources under steady-state conditions. The analytical results for multidimensional solute transport problems, which previously could only be solved numerically, also offer an additional way to benchmark numerical solutions. An analytical solution for two-dimensional, steady-state solute transport under unsaturated flow conditions is presented. A specific case with two sources is solved but may be generalized to any combination of sources. The analytical results complement numerical solutions, which were previously required to solve this class of problems.
A quasi-linear gyrokinetic transport model for tokamak plasmas
International Nuclear Information System (INIS)
Casati, A.
2009-10-01
After a presentation of some basics around nuclear fusion, this research thesis introduces the framework of the tokamak strategy to deal with confinement, hence the main plasma instabilities which are responsible for turbulent transport of energy and matter in such a system. The author also briefly introduces the two principal plasma representations, the fluid and the kinetic ones. He explains why the gyro-kinetic approach has been preferred. A tokamak relevant case is presented in order to highlight the relevance of a correct accounting of the kinetic wave-particle resonance. He discusses the issue of the quasi-linear response. Firstly, the derivation of the model, called QuaLiKiz, and its underlying hypotheses to get the energy and the particle turbulent flux are presented. Secondly, the validity of the quasi-linear response is verified against the nonlinear gyro-kinetic simulations. The saturation model that is assumed in QuaLiKiz, is presented and discussed. Then, the author qualifies the global outcomes of QuaLiKiz. Both the quasi-linear energy and the particle flux are compared to the expectations from the nonlinear simulations, across a wide scan of tokamak relevant parameters. Therefore, the coupling of QuaLiKiz within the integrated transport solver CRONOS is presented: this procedure allows the time-dependent transport problem to be solved, hence the direct application of the model to the experiment. The first preliminary results regarding the experimental analysis are finally discussed
Quasilinear Carbon Transport In An Impurity Hole Plasma In LHD
Energy Technology Data Exchange (ETDEWEB)
Mikkelsen, David R. [PPPL; Tanaka, K. [NIFS; Nunami, M. [NIFS; Watanabe, T-H. [Nagoya University; Sugama, H. [NIFS; Yoshinuma, M. [NIFS; Suzuki, Y. [NIFS; Goto, M. [NIFS; Morita, S. [NIFS; Wieland, B. [NIFS; Yamada, I. [NIFS; Yashura, R. [NIFS; Akiyama, T. [NIFS; Pablant, Novimir A. [PPPL
2014-04-01
Comprehensive electrostatic gyrokinetic linear stability calculations for ion-scale microinstabilities in an LHD plasma with an ion-ITB and carbon "impurity hole" are used to make quasilinear estimates of particle flux to explore whether microturbulence can explain the observed outward carbon fluxes that flow "up" the impurity density gradient. The ion temperature is not stationary in the ion-ITB phase of the simulated discharge, during which the core carbon density decreases continuously. To fully sample these varying conditions the calculations are carried out at three radial locations and four times. The plasma parameter inputs are based on experimentally measured profiles of electron and ion temperature, as well as electron and carbon density. The spectroscopic line-average ratio of hydrogen and helium densities is used to set the density of these species. Three ion species (H,He,C) and the electrons are treated kinetically, including collisions. Electron instability drive does enhance the growth rate significantly, but the most unstable modes have characteristics of ion temperature gradient (ITG) modes in all cases. As the carbon density gradient is scanned between the measured value and zero, the quasilinear carbon flux is invariably inward when the carbon density profile is hollow, so turbulent transport due to the instabilities considered here does not explain the observed outward flux of impurities in impurity hole plasmas. The stiffness of the quasilinear ion heat flux is found to be 1.7-2.3, which is lower than several estimates in tokamaks.
Nonlinear Mirror and Weibel modes: peculiarities of quasi-linear dynamics
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O. A. Pokhotelov
2010-12-01
Full Text Available A theory for nonlinear evolution of the mirror modes near the instability threshold is developed. It is shown that during initial stage the major instability saturation is provided by the flattening of the velocity distribution function in the vicinity of small parallel ion velocities. The relaxation scenario in this case is accompanied by rapid attenuation of resonant particle interaction which is replaced by a weaker adiabatic interaction with mirror modes. The saturated plasma state can be considered as a magnetic counterpart to electrostatic BGK modes. After quasi-linear saturation a further nonlinear scenario is controlled by the mode coupling effects and nonlinear variation of the ion Larmor radius. Our analytical model is verified by relevant numerical simulations. Test particle and PIC simulations indeed show that it is a modification of distribution function at small parallel velocities that results in fading away of free energy driving the mirror mode. The similarity with resonant Weibel instability is discussed.
Quasilinear Line Broadened Model for Energetic Particle Transport
Ghantous, Katy; Gorelenkov, Nikolai; Berk, Herbert
2011-10-01
We present a self-consistent quasi-linear model that describes wave-particle interaction in toroidal geometry and computes fast ion transport during TAE mode evolution. The model bridges the gap between single mode resonances, where it predicts the analytically expected saturation levels, and the case of multiple modes overlapping, where particles diffuse across phase space. Results are presented in the large aspect ratio limit where analytic expressions are used for Fourier harmonics of the power exchange between waves and particles, . Implemention of a more realistic mode structure calculated by NOVAK code are also presented. This work is funded by DOE contract DE-AC02-09CH11466.
Existence of infinitely many radial solutions for quasilinear Schrodinger equations
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Gui Bao
2014-10-01
Full Text Available In this article we prove the existence of radial solutions with arbitrarily many sign changes for quasilinear Schrodinger equation $$ -\\sum_{i,j=1}^{N}\\partial_j(a_{ij}(u\\partial_iu +\\frac{1}{2}\\sum_{i,j=1}^{N}a'_{ij}(u\\partial_iu\\partial_ju+V(xu =|u|^{p-1}u,~x\\in\\mathbb{R}^N, $$ where $N\\geq3$, $p\\in(1,\\frac{3N+2}{N-2}$. The proof is accomplished by using minimization under a constraint.
Quasi-Linear Algebras and Integrability (the Heisenberg Picture
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Alexei Zhedanov
2008-02-01
Full Text Available We study Poisson and operator algebras with the ''quasi-linear property'' from the Heisenberg picture point of view. This means that there exists a set of one-parameter groups yielding an explicit expression of dynamical variables (operators as functions of ''time'' t. We show that many algebras with nonlinear commutation relations such as the Askey-Wilson, q-Dolan-Grady and others satisfy this property. This provides one more (explicit Heisenberg evolution interpretation of the corresponding integrable systems.
The eigenvalue problem for a singular quasilinear elliptic equation
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Benjin Xuan
2004-02-01
Full Text Available We show that many results about the eigenvalues and eigenfunctions of a quasilinear elliptic equation in the non-singular case can be extended to the singular case. Among these results, we have the first eigenvalue is associated to a $C^{1,alpha}(Omega$ eigenfunction which is positive and unique (up to a multiplicative constant, that is, the first eigenvalue is simple. Moreover the first eigenvalue is isolated and is the unique positive eigenvalue associated to a non-negative eigenfunction. We also prove some variational properties of the second eigenvalue.
Particle Dynamics under Quasi-linear Interaction with Electromagnetic Waves
Energy Technology Data Exchange (ETDEWEB)
Castejon, F.; Eguilior, S.
2003-07-01
Langevin equations for quasi-linear wave particle interaction are obtained taking advantage of the unique vocal equivalence between Fokker-Plank equation and the former ones. Langevin equations are solved numerically and, hence, the evolution of a single particle embedded in an electromagnetic field in momentum space is obtained. The equations are relativistic and valid for any wave. It is also shown that the stochastic part of the equations is negligible in comparison with the deterministic term, except for the momentum to the resonance condition for the main parallel refractive index. (Author) 24 refs.
Particle Dynamics under Quasi-linear Interaction with Electromagnetic Waves
International Nuclear Information System (INIS)
Castejon, F.; Eguilior, S.
2003-01-01
Langevin equations for quasi-linear wave particle interaction are obtained taking advantage of the unique vocal equivalence between Fokker-Plank equation and the former ones. Langevin equations are solved numerically and, hence, the evolution of a single particle embedded in an electromagnetic field in momentum space is obtained. The equations are relativistic and valid for any wave. It is also shown that the stochastic part of the equations is negligible in comparison with the deterministic term, except for the momentum to the resonance condition for the main parallel refractive index. (Author) 24 refs
Quasivariational Solutions for First Order Quasilinear Equations with Gradient Constraint
Rodrigues, José Francisco; Santos, Lisa
2012-08-01
We prove the existence of solutions for a quasi-variational inequality of evolution with a first order quasilinear operator and a variable convex set which is characterized by a constraint on the absolute value of the gradient that depends on the solution itself. The only required assumption on the nonlinearity of this constraint is its continuity and positivity. The method relies on an appropriate parabolic regularization and suitable a priori estimates. We also obtain the existence of stationary solutions by studying the asymptotic behaviour in time. In the variational case, corresponding to a constraint independent of the solution, we also give uniqueness results.
Quasilinear simulations of interplanetary shocks and Earth's bow shock
Afanasiev, Alexandr; Battarbee, Markus; Ganse, Urs; Vainio, Rami; Palmroth, Minna; Pfau-Kempf, Yann; Hoilijoki, Sanni; von Alfthan, Sebastian
2016-04-01
We have developed a new self-consistent Monte Carlo simulation model for particle acceleration in shocks. The model includes a prescribed large-scale magnetic field and plasma density, temperature and velocity profiles and a self-consistently computed incompressible ULF foreshock under the quasilinear approximation. Unlike previous analytical treatments, our model is time dependent and takes full account of the anisotropic particle distributions and scattering in the wave-particle interaction process. We apply the model to the problem of particle acceleration at traveling interplanetary (IP) shocks and Earth's bow shock and compare the results with hybrid-Vlasov simulations and spacecraft observations. A qualitative agreement in terms of spectral shape of the magnetic fluctuations and the polarization of the unstable mode is found between the models and the observations. We will quantify the differences of the models and explore the region of validity of the quasilinear approach in terms of shock parameters. We will also compare the modeled IP shocks and the bow shock, identifying the similarities and differences in the spectrum of accelerated particles and waves in these scenarios. The work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA). The Academy of Finland is thanked for financial support. We acknowledge the computational resources provided by CSC - IT Centre for Science Ltd., Espoo.
Quasilinear ion distribution function during first harmonic ion cyclotron heating
International Nuclear Information System (INIS)
Brambilla, M.
1993-12-01
The quasilinear modification of the ion distribution function during first harmonic ion cyclotron (FHIC) heating is investigated both with a simple already well established analytic one-dimensional approach, and with a new two dimensional steady state solver of the quasilinear kinetic equation, SSFPQL. By accepting to disregard the effects of ion trapping in banana orbits, but including finite Larmor radius effects, the latter code has been made much faster than full surface-averaged codes; yet it can provide most of the relevant information on the suprathermal ion tail produced by this heating method. With SSFPQL we confirm that the one-dimensional model gives fair approximations for global properties of the distribution function, such as the average energy content of the tail and the fusion reactivity. On the other hand the tail is found to be very anisotropic, the increase of the parallel effective temperature being a small fraction of the total energy increase. Information on the anisotropy is essential to study the feedback of the fast ion tail on wave propagation and absorption, which is quite sensitive to the distribution of parallel velocities. The insight gained in the derivation and discussion of this model can be used to build a selfconsistent description of this heating scenario, whose implementation requires only a reasonable numerical effort. (orig.)
Assessment of Haar Wavelet-Quasilinearization Technique in Heat Convection-Radiation Equations
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Umer Saeed
2014-01-01
Full Text Available We showed that solutions by the Haar wavelet-quasilinearization technique for the two problems, namely, (i temperature distribution equation in lumped system of combined convection-radiation in a slab made of materials with variable thermal conductivity and (ii cooling of a lumped system by combined convection and radiation are strongly reliable and also more accurate than the other numerical methods and are in good agreement with exact solution. According to the Haar wavelet-quasilinearization technique, we convert the nonlinear heat transfer equation to linear discretized equation with the help of quasilinearization technique and apply the Haar wavelet method at each iteration of quasilinearization technique to get the solution. The main aim of present work is to show the reliability of the Haar wavelet-quasilinearization technique for heat transfer equations.
Parameter identification in a nonlinear nuclear reactor model using quasilinearization
International Nuclear Information System (INIS)
Barreto, J.M.; Martins Neto, A.F.; Tanomaru, N.
1980-09-01
Parameter identification in a nonlinear, lumped parameter, nuclear reactor model is carried out using discrete output power measurements during the transient caused by an external reactivity change. In order to minimize the difference between the model and the reactor power responses, the parameter promt neutron generation time and a parameter in fuel temperature reactivity coefficient equation are adjusted using quasilinearization. The influences of the external reactivity disturbance, the number and frequency of measurements and the measurement noise level on the method accuracy and rate of convergence are analysed through simulation. Procedures for the design of the identification experiments are suggested. The method proved to be very effective for low level noise measurements. (Author) [pt
Comparing the line broadened quasilinear model to Vlasov code
International Nuclear Information System (INIS)
Ghantous, K.; Berk, H. L.; Gorelenkov, N. N.
2014-01-01
The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations
Comparing the line broadened quasilinear model to Vlasov code
Energy Technology Data Exchange (ETDEWEB)
Ghantous, K. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Berk, H. L. [Institute for Fusion Studies, University of Texas, 2100 San Jacinto Blvd, Austin, Texas 78712-1047 (United States); Gorelenkov, N. N. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)
2014-03-15
The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations.
Comparing the line broadened quasilinear model to Vlasov code
Ghantous, K.; Berk, H. L.; Gorelenkov, N. N.
2014-03-01
The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations.
Quasilinear analysis of absorption of ion Bernstein waves by electrons
International Nuclear Information System (INIS)
Cardinali, A.; Paoletti, F.; Bernabei, S.; Ono, M.
1995-01-01
The effects induced on plasma electrons by an externally launched ion Bernstein wave (IBW), in the presence of a lower hybrid wave (LHW) in the current drive regime, are studied by analytical integration of the IBW ray-tracing equations along with the amplitude transport equation (Poynting theorem). The electric field amplitude parallel and perpendicular to the external magnetic field, the quasilinear diffusion coefficient, and the modified electron distribution function are analytically calculated in the case of IBW. The analytical calculation is compared to the numerical solution obtained by using a 2-D Fokker-Planck code for the distribution function, without any approximation for the collision operator. The synergy between the IBW and LHW can be accounted for, and the absorption of the IBW power when the electron distribution function presents a tail generated by the LHW in the current drive regime can be calculated
Directory of Open Access Journals (Sweden)
Guanwei Chen
2014-01-01
Full Text Available We study the existence of positive solutions and multiplicity of nontrivial solutions for a class of quasilinear elliptic equations by using variational methods. Our obtained results extend some existing ones.
Solutions to quasilinear equations of $N$-biharmonic type with degenerate coercivity
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Sami Aouaoui
2014-10-01
Full Text Available In this article we show the existence of multiple solutions for quasilinear equations in divergence form with degenerate coercivity. Our strategy is to combine a variational method and an iterative technique to obtain the solutions.
Instantaneous Switching Processes in Quasi-Linear Circuits
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Rositsa Angelova
2004-01-01
Full Text Available The paper considers instantaneous processes in electrical circuits produced by the stepwise change of the capacitance of the capacitor and the inductance of the inductor and by the switching on and switching off of the circuit. In order to determine the set of electrical circuits, for which it is possible to explicitly obtain the values of the currents and the voltages at the end of the instantaneous process, a classification of the networks with nonlinear elements is introduced in the paper. The instantaneous switching process in the moment t0 is approximated when T->t0 with a sequence of processes in the interval [t0, T]. For quasi-linear inductive and capacitive circuits; we present the type of the system satisfied by the currents and the voltages, the charges, as well as the fluxes in the interval [t0, T]. From this system, after passage to the limit T->t0, we obtain the formulas for the values of the circuits at the end of the instantaneous process. The obtained results are applied for the analysis of particular processes.
Quasilinear parabolic variational inequalities with multi-valued lower-order terms
Carl, Siegfried; Le, Vy K.
2014-10-01
In this paper, we provide an analytical frame work for the following multi-valued parabolic variational inequality in a cylindrical domain : Find and an such that where is some closed and convex subset, A is a time-dependent quasilinear elliptic operator, and the multi-valued function is assumed to be upper semicontinuous only, so that Clarke's generalized gradient is included as a special case. Thus, parabolic variational-hemivariational inequalities are special cases of the problem considered here. The extension of parabolic variational-hemivariational inequalities to the general class of multi-valued problems considered in this paper is not only of disciplinary interest, but is motivated by the need in applications. The main goals are as follows. First, we provide an existence theory for the above-stated problem under coercivity assumptions. Second, in the noncoercive case, we establish an appropriate sub-supersolution method that allows us to get existence, comparison, and enclosure results. Third, the order structure of the solution set enclosed by sub-supersolutions is revealed. In particular, it is shown that the solution set within the sector of sub-supersolutions is a directed set. As an application, a multi-valued parabolic obstacle problem is treated.
Quasi-linear viscoelastic properties of the human medial patello-femoral ligament.
Criscenti, G; De Maria, C; Sebastiani, E; Tei, M; Placella, G; Speziali, A; Vozzi, G; Cerulli, G
2015-12-16
The evaluation of viscoelastic properties of human medial patello-femoral ligament is fundamental to understand its physiological function and contribution as stabilizer for the selection of the methods of repair and reconstruction and for the development of scaffolds with adequate mechanical properties. In this work, 12 human specimens were tested to evaluate the time- and history-dependent non linear viscoelastic properties of human medial patello-femoral ligament using the quasi-linear viscoelastic (QLV) theory formulated by Fung et al. (1972) and modified by Abramowitch and Woo (2004). The five constant of the QLV theory, used to describe the instantaneous elastic response and the reduced relaxation function on stress relaxation experiments, were successfully evaluated. It was found that the constant A was 1.21±0.96MPa and the dimensionless constant B was 26.03±4.16. The magnitude of viscous response, the constant C, was 0.11±0.02 and the initial and late relaxation time constants τ1 and τ2 were 6.32±1.76s and 903.47±504.73s respectively. The total stress relaxation was 32.7±4.7%. To validate our results, the obtained constants were used to evaluate peak stresses from a cyclic stress relaxation test on three different specimens. The theoretically predicted values fit the experimental ones demonstrating that the QLV theory could be used to evaluate the viscoelastic properties of the human medial patello-femoral ligament. Copyright © 2015 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Hizanidis, K.
1984-04-01
The relativistic collisional Fokker-Planck equation combined with an externally imposed unidirectional quasilinear (rf) diffusion is solved for arbitrary values of rf diffusion coefficient under conditions of detailed balance of the staionary joint distribution involved. The detailed balance condition imposes a restriction on the functional form of the quasilinear diffusion coefficient which might be associated with the existence of a saturated spectrum of fluctuation in a quasilinearly rf-driven plasma
International Nuclear Information System (INIS)
Misguich, J.H.
2004-04-01
As a first step toward a nonlinear renormalized description of turbulence phenomena in magnetized plasmas, the lowest order quasi-linear description is presented here from a unified point of view for collisionless as well as for collisional plasmas in a constant magnetic field. The quasi-linear approximation is applied to a general kinetic equation obtained previously from the Klimontovich exact equation, by means of a generalised Dupree-Weinstock method. The so-obtained quasi-linear description of electromagnetic turbulence in a magnetoplasma is applied to three separate physical cases: -) weak electrostatic turbulence, -) purely magnetic field fluctuations (the classical quasi-linear results are obtained for cosmic ray diffusion in the 'slab model' of magnetostatic turbulence in the solar wind), and -) collisional kinetic equations of magnetized plasmas. This mathematical technique has allowed us to derive basic kinetic equations for turbulent plasmas and collisional plasmas, respectively in the quasi-linear and Landau approximation. In presence of a magnetic field we have shown that the systematic use of rotation matrices describing the helical particle motion allows for a much more compact derivation than usually performed. Moreover, from the formal analogy between turbulent and collisional plasmas, the results derived here in detail for the turbulent plasmas, can be immediately translated to obtain explicit results for the Landau kinetic equation
Energy Technology Data Exchange (ETDEWEB)
Misguich, J.H
2004-04-01
As a first step toward a nonlinear renormalized description of turbulence phenomena in magnetized plasmas, the lowest order quasi-linear description is presented here from a unified point of view for collisionless as well as for collisional plasmas in a constant magnetic field. The quasi-linear approximation is applied to a general kinetic equation obtained previously from the Klimontovich exact equation, by means of a generalised Dupree-Weinstock method. The so-obtained quasi-linear description of electromagnetic turbulence in a magnetoplasma is applied to three separate physical cases: -) weak electrostatic turbulence, -) purely magnetic field fluctuations (the classical quasi-linear results are obtained for cosmic ray diffusion in the 'slab model' of magnetostatic turbulence in the solar wind), and -) collisional kinetic equations of magnetized plasmas. This mathematical technique has allowed us to derive basic kinetic equations for turbulent plasmas and collisional plasmas, respectively in the quasi-linear and Landau approximation. In presence of a magnetic field we have shown that the systematic use of rotation matrices describing the helical particle motion allows for a much more compact derivation than usually performed. Moreover, from the formal analogy between turbulent and collisional plasmas, the results derived here in detail for the turbulent plasmas, can be immediately translated to obtain explicit results for the Landau kinetic equation.
Quasi-linear analysis of water flow in the unsaturated zone at Yucca Mountain, Nevada, USA
International Nuclear Information System (INIS)
Ross, B.
1990-01-01
Philip's method of quasi-linear approximation, applied to the fractured welded tuffs at Yucca Mountain, Nevada, USA, yields simple relations describing groundwater movement in the unsaturated zone. These relations suggest that water flux through the Topopah Spring welded tuff unit, in which a proposed high-level radioactive waste repository would be built, may be fixed at a value close to the saturated hydraulic conductivity of the unit's porous matrix by a capillary barrier at the unit's upper contact. Quasi-linear methods may also be useful for predicting whether free water will enter tunnels excavated in the tuff
Quasi-linear absorption of lower hybrid waves by fusion generated alpha particles
International Nuclear Information System (INIS)
Barbato, E.; Santini, F.
1991-01-01
Lower hybrid waves are expected to be used in a steady state reactor to produce current and to control the current profile and the stability of internal modes. In the ignition phase, however, the presence of energetic alpha particles may prevent wave-electron interaction, thus reducing the current drive efficiency. This is due to the very high birth energy of the alpha particles that may absorb much of the lower hybrid wave power. This unfavourable effect is absent at high frequencies (∼ 8 GHz for typical reactor parameters). Nevertheless, because of the technical difficulties involved in using such high frequencies, it is very important to investigate whether power absorption by alpha particles would be negligible also at relatively low frequencies. Such a study has been carried out on the basis of the quasi-linear theory of wave-alpha particle interaction, since the distortion of the alpha distribution function may enhance the radiofrequency absorption above the linear level. New effects have been found, such as local alpha concentration and acceleration. The model for alpha particles is coupled with a 1-D deposition code for lower hybrid waves to calculate the competition in the power absorption between alphas and electrons as the waves propagate into the plasma core for typical reactor (ITER) parameters. It is shown that at a frequency as low as 5 GHz, power absorption by alpha particles is negligible for conventional plasma conditions and realistic alpha particle concentrations. In more ''pessimistic'' and severe conditions, negligible absorption occurs at 6 GHz. (author). 19 refs, 11 figs, 2 tabs
International Nuclear Information System (INIS)
Li Tatsien
1994-01-01
By means of the concept of the weak linear degeneracy, one gets the global existence and the sharp estimate of the lifespan of C 1 solutions to the Cauchy problem for general first order quasilinear hyperbolic systems with small initial data with compact support. (author). 23 refs, 1 fig
Blow-up Mechanism of Classical Solutions to Quasilinear Hyperbolic Systems in the Critical Case
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
This paper deals with the blow-up phenomenon, particularly, the geometric blow-up mechanism, of classical solutions to the Cauchy problem for quasilinear hyperbolic systems in the critical case. We prove that it is still the envelope of the same family of characteristics which yields the blowup of classical solutions to the Cauchy problem in the critical case.
Khazanov, George V.; Sibeck, David G.
2013-01-01
The interaction of electrons with coherent chorus waves in the random phase approximation can be described as quasi-linear diffusion for waves with amplitudes below some limit. The limit is calculated for relativistic and non-relativistic electrons. For stronger waves, the friction force should be taken into account.
Peeters, A.G.; Westerhof, E.
1996-01-01
Numerical simulations using a three-dimensional Fokker-Planck code show that for small tokamaks the transport of electrons across the magnetic surfaces at a level consistent with anomalous transport has a large influence on the formation of the quasilinear plateau during electron cyclotron resonant
1.5D quasilinear model and its application on beams interacting with Alfven eigenmodes in DIII-D
Energy Technology Data Exchange (ETDEWEB)
Ghantous, K.; Gorelenkov, N. N. [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, New Jersey 08543-0451 (United States); Berk, H. L. [Institute for Fusion Studies, University of Texas, 2100 San Jacinto Blvd., Austin, Texas 78712-1047 (United States); Heidbrink, W. W. [Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697 (United States); Van Zeeland, M. A. [General Atomics, PO Box 85608, San Diego, California 92186-560 (United States)
2012-09-15
We propose a model, denoted here by 1.5D, to study energetic particle (EP) interaction with toroidal Alfvenic eigenmodes (TAE) in the case where the local EP drive for TAE exceeds the stability limit. Based on quasilinear theory, the proposed 1.5D model assumes that the particles diffuse in phase space, flattening the pressure profile until its gradient reaches a critical value where the modes stabilize. Using local theories and NOVA-K simulations of TAE damping and growth rates, the 1.5D model calculates the critical gradient and reconstructs the relaxed EP pressure profile. Local theory is improved from previous study by including more sophisticated damping and drive mechanisms such as the numerical computation of the effect of the EP finite orbit width on the growth rate. The 1.5D model is applied on the well-diagnosed DIII-D discharges no. 142111 [M. A. Van Zeeland et al., Phys. Plasmas 18, 135001 (2011)] and no. 127112 [W. W. Heidbrink et al., Nucl. Fusion. 48, 084001 (2008)]. We achieved a very satisfactory agreement with the experimental results on the EP pressure profiles redistribution and measured losses. This agreement of the 1.5D model with experimental results allows the use of this code as a guide for ITER plasma operation where it is desired to have no more than 5% loss of fusion alpha particles as limited by the design.
Cesario, Roberto; Cardinali, Alessandro; Castaldo, Carmine; Amicucci, Luca; Ceccuzzi, Silvio; Galli, Alessandro; Napoli, Francesco; Panaccione, Luigi; Santini, Franco; Schettini, Giuseppe; Tuccillo, Angelo Antonio
2017-10-01
The main research on the energy from thermonuclear fusion uses deuterium plasmas magnetically trapped in toroidal devices. To suppress the turbulent eddies that impair thermal insulation and pressure tight of the plasma, current drive (CD) is necessary, but tools envisaged so far are unable accomplishing this task while efficiently and flexibly matching the natural current profiles self-generated at large radii of the plasma column [1-5]. The lower hybrid current drive (LHCD) [6] can satisfy this important need of a reactor [1], but the LHCD system has been unexpectedly mothballed on JET. The problematic extrapolation of the LHCD tool at reactor graded high values of, respectively, density and temperatures of plasma has been now solved. The high density problem is solved by the FTU (Frascati Tokamak Upgrade) method [7], and solution of the high temperature one is presented here. Model results based on quasi-linear (QL) theory evidence the capability, w.r.t linear theory, of suitable operating parameters of reducing the wave damping in hot reactor plasmas. Namely, using higher RF power densities [8], or a narrower antenna power spectrum in refractive index [9,10], the obstacle for LHCD represented by too high temperature of reactor plasmas should be overcome. The former method cannot be used for routinely, safe antenna operations, Thus, only the latter key is really exploitable in a reactor. The proposed solutions are ultimately necessary for viability of an economic reactor.
Zilletti, Michele; Marker, Arthur; Elliott, Stephen John; Holland, Keith
2017-05-01
In this study model identification of the nonlinear dynamics of a micro-speaker is carried out by purely electrical measurements, avoiding any explicit vibration measurements. It is shown that a dynamic model of the micro-speaker, which takes into account the nonlinear damping characteristic of the device, can be identified by measuring the response between the voltage input and the current flowing into the coil. An analytical formulation of the quasi-linear model of the micro-speaker is first derived and an optimisation method is then used to identify a polynomial function which describes the mechanical damping behaviour of the micro-speaker. The analytical results of the quasi-linear model are compared with numerical results. This study potentially opens up the possibility of efficiently implementing nonlinear echo cancellers.
Quasilinear analysis of loss-cone driven weakly relativistic electron cyclotron maser instability
International Nuclear Information System (INIS)
Ziebell, L.F.; Yoon, P.H.
1995-01-01
This paper presents a quasilinear analysis of the relativistic electron cyclotron maser instability. Two electron populations are assumed: a low-temperature background component and a more energetic loss-cone population. The dispersion relation is valid for any ratio of the energetic to cold populations, and includes thermal and relativistic effects. The quasilinear analysis is based upon an efficient kinetic moment method, in which various moment equations are derived from the particle kinetic equation. A model time-dependent loss-cone electron distribution function is assumed, which allows one to evaluate the instantaneous linear growth rate as well as the moment kinetic equations. These moment equations along with the wave kinetic equation form a fully self-consistent set of equations which governs the evolution of the particles as well as unstable waves. This set of equations is solved with physical parameters typical of the earth's auroral zone plasma. copyright 1995 American Institute of Physics
Niu, Q; Yu, W C; Yip, K Y; Lim, Z L; Kotegawa, H; Matsuoka, E; Sugawara, H; Tou, H; Yanase, Y; Goh, Swee K
2017-06-05
In conventional metals, modification of electron trajectories under magnetic field gives rise to a magnetoresistance that varies quadratically at low field, followed by a saturation at high field for closed orbits on the Fermi surface. Deviations from the conventional behaviour, for example, the observation of a linear magnetoresistance, or a non-saturating magnetoresistance, have been attributed to exotic electron scattering mechanisms. Recently, linear magnetoresistance has been observed in many Dirac materials, in which the electron-electron correlation is relatively weak. The strongly correlated helimagnet CrAs undergoes a quantum phase transition to a nonmagnetic superconductor under pressure. Here we observe, near the magnetic instability, a large and non-saturating quasilinear magnetoresistance from the upper critical field to 14 T at low temperatures. We show that the quasilinear magnetoresistance may arise from an intricate interplay between a nontrivial band crossing protected by nonsymmorphic crystal symmetry and strong magnetic fluctuations.
International Nuclear Information System (INIS)
Karimov, Ruslan Kh; Kozhevnikova, Larisa M
2010-01-01
The first mixed problem with homogeneous Dirichlet boundary condition and initial function with compact support is considered for quasilinear second order parabolic equations in a cylindrical domain D=(0,∞)xΩ. Upper bounds are obtained, which give the rate of decay of the solutions as t→∞ as a function of the geometry of the unbounded domain Ω subset of R n , n≥2. Bibliography: 18 titles.
Parameter Identification for Salinity in a Quasilinear Thermodynamic System of Sea Ice
Wei Lv; Xiaojiao Li; Enmin Feng
2014-01-01
This study is intended to provide a parameter identification method to determine salinity of sea ice by temperature and salinity observations. A quasilinear thermodynamic system of sea ice with unknown salinity is described and its property is proved. Then, a parameter identification model is established and the existence of its optimal solution is discussed. The salinity profile is calculated by the temperature and salinity data, which were measured at Nella Fjord around Zhongshan Station, A...
Quasilinear simulation of auroral kilometric radiation by a relativistic Fokker-Planck code
International Nuclear Information System (INIS)
Matsuda, Y.
1991-01-01
An intense terrestrial radiation called the auroral kilometric radiation (AKR) is believed to be generated by cyclotron maser instability. We study a quasilinear evolution of this instability by means of a two-dimensional relativistic Fokker-Planck code which treats waves and distributions self-consistently, including radiation loss and electron source and sink. We compare the distributions and wave amplitude with spacecraft observations to elucidate physical processes involved. 3 refs., 1 fig
A quasilinear kinetic model for solar wind electrons and protons instabilities
Sarfraz, M.; Yoon, P. H.
2017-12-01
In situ measurements confirm the anisotropic behavior in temperatures of solar wind species. These anisotropies associated with charge particles are observed to be relaxed. In collionless limit, kinetic instabilities play a significant role to reshape particles distribution. The linear analysis results are encapsulated in inverse relationship between anisotropy and plasma beta based observations fittings techniques, simulations methods, or solution of linearized Vlasov equation. Here amacroscopic quasilinear technique is adopted to confirm inverse relationship through solutions of set of self-consistent kinetic equations. Firstly, for a homogeneous and non-collisional medium, quasilinear kinetic model is employed to display asymptotic variations of core and halo electrons temperatures and saturations of wave energy densities for electromagnetic electron cyclotron (EMEC) instability sourced by, T⊥}>T{∥ . It is shown that, in (β ∥ , T⊥}/T{∥ ) phase space, the saturations stages of anisotropies associated with core and halo electrons lined up on their respective marginal stability curves. Secondly, for case of electrons firehose instability ignited by excessive parallel temperature i.e T⊥}>T{∥ , both electrons and protons are allowed to dynamically evolve in time. It is also observed that, the trajectories of protons and electrons at saturation stages in phase space of anisotropy and plasma beta correspond to proton cyclotron and firehose marginal stability curves, respectively. Next, the outstanding issue that most of observed proton data resides in nearly isotropic state in phase space is interpreted. Here, in quasilinear frame-work of inhomogeneous solar wind system, a set of self-consistent quasilinear equations is formulated to show a dynamical variations of temperatures with spatial distributions. On choice of different initial parameters, it is shown that, interplay of electron and proton instabilities provides an counter-balancing force to slow
Linear and Nonlinear Theories of Cosmic Ray Transport
International Nuclear Information System (INIS)
Shalchi, A.
2005-01-01
The transport of charged cosmic rays in plasmawave turbulence is a modern and interesting field of research. We are mainly interested in spatial diffusion parallel and perpendicular to a large scale magnetic field. During the last decades quasilinear theory was the standard tool for the calculation of diffusion coefficients. Through comparison with numerical simulations we found several cases where quasilinear theory is invalid. On could define three major problems of transport theory. I will demonstrate that new nonlinear theories which were proposed recently can solve at least some to these problems
International Nuclear Information System (INIS)
Cottier, Pierre
2013-01-01
The magnetic confinement in tokamaks is for now the most advanced way towards energy production by nuclear fusion. Both theoretical and experimental studies showed that rotation generation can increase its performance by reducing the turbulent transport in tokamak plasmas. The rotation influence on the heat and particle fluxes is studied along with the angular momentum transport with the quasi-linear gyro-kinetic eigenvalue code QuaLiKiz. For this purpose, the QuaLiKiz code is modified in order to take the plasma rotation into account and compute the angular momentum flux. It is shown that QuaLiKiz framework is able to correctly predict the angular momentum flux including the E*B shear induced residual stress as well as the influence of rotation on the heat and particle fluxes. The major approximations of QuaLiKiz formalisms are reviewed, in particular the ballooning representation at its lowest order and the eigenfunctions calculated in the hydrodynamic limit. The construction of the quasi-linear fluxes is also reviewed in details and the quasi-linear angular momentum flux is derived. The different contributions to the turbulent momentum flux are studied and successfully compared both against non-linear gyro-kinetic simulations and experimental data. (author) [fr
Cosmic ray diffusion: report of the workshop in cosmic ray diffusion theory
International Nuclear Information System (INIS)
Birmingham, T.J.; Jones, F.C.
1975-02-01
A workshop in cosmic ray diffusion theory was held at Goddard Space Flight Center on May 16-17, 1974. Topics discussed and summarized are: (1) cosmic ray measurements as related to diffusion theory; (2) quasi-linear theory, nonlinear theory, and computer simulation of cosmic ray pitch-angle diffusion; and (3) magnetic field fluctuation measurements as related to diffusion theory. (auth)
Quasilinear theory of the ordinary-mode electron-cyclotron resonance in plasmas
International Nuclear Information System (INIS)
Arunasalam, V.; Efthimion, P.C.; Hosea, J.C.; Hsuan, H.; Taylor, G.
1983-11-01
A coupled set of equations, one describing the time evolution of the ordinary-mode wave energy and the other describing the time evolution of the electron distribution function is presented. The wave damping is mainly determined by T/sub parallel/ while the radiative equilibrium is mainly an equipartition with T/sub perpendicular/. The time rate of change of T/sub perpendicular/, T/sub parallel/, particle (N 0 ), and current (J/sub parellel/) densities are examined for finite k/sub parallel/ electron-cyclotron-resonance heating of plasmas
Reactor Network Synthesis Using Coupled Genetic Algorithm with the Quasi-linear Programming Method
Soltani, H.; Shafiei, S.; Edraki, J.
2016-01-01
This research is an attempt to develop a new procedure for the synthesis of reactor networks (RNs) using a genetic algorithm (GA) coupled with the quasi-linear programming (LP) method. The GA is used to produce structural configuration, whereas continuous variables are handled using a quasi-LP formulation for finding the best objective function. Quasi-LP consists of LP together with a search loop to find the best reactor conversions (xi), as well as split and recycle ratios (yi). Quasi-LP rep...
H-convergence for quasi-linear elliptic equations under natural hypotheses on the correctors
International Nuclear Information System (INIS)
Bensoussan, A.; Boccardo, L.; Dall'Aglio, A.; Murat, F.
1995-01-01
In this paper we study the behavior of the solutions of quasi-linear Dirichlet problems when the principal parts H-converge and when the lower order terms have quadratic growth with respect to the gradient. We show that the limit problem consists of a principal part which is the H-limit of the principal parts and of the lower order term which is constructed from the corresponding terms by using a linear corrector result. We assume only natural hypotheses on the correctors (i.e. L 2 equi-integrability and not L ∞ boundedness). (author)
Existence and concentration of positive solutions for a quasilinear elliptic equation in R
Directory of Open Access Journals (Sweden)
Elisandra Gloss
2010-05-01
Full Text Available We study the existence and concentration of positive solutions for the quasilinear elliptic equation $$ -varepsilon^2u'' -varepsilon^2(u^2''u+V(x u = h(u $$ in $mathbb{R}$ as $varepsilono 0$, where the potential $V:mathbb{R}o mathbb{R}$ has a positive infimum and $inf_{partial Omega}V>inf_{ Omega}V$ for some bounded domain $Omega$ in $mathbb{R}$, and $h$ is a nonlinearity without having growth conditions such as Ambrosetti-Rabinowitz.
Blow-Up Analysis for a Quasilinear Degenerate Parabolic Equation with Strongly Nonlinear Source
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Pan Zheng
2012-01-01
Full Text Available We investigate the blow-up properties of the positive solution of the Cauchy problem for a quasilinear degenerate parabolic equation with strongly nonlinear source ut=div(|∇um|p−2∇ul+uq, (x,t∈RN×(0,T, where N≥1, p>2 , and m, l, q>1, and give a secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and nonexistence of global solutions of the Cauchy problem. Moreover, under some suitable conditions we prove single-point blow-up for a large class of radial decreasing solutions.
Directory of Open Access Journals (Sweden)
Rica Gonen
2013-11-01
Full Text Available We analyze the space of deterministic, dominant-strategy incentive compatible, individually rational and Pareto optimal combinatorial auctions. We examine a model with multidimensional types, nonidentical items, private values and quasilinear preferences for the players with one relaxation; the players are subject to publicly-known budget constraints. We show that the space includes dictatorial mechanisms and that if dictatorial mechanisms are ruled out by a natural anonymity property, then an impossibility of design is revealed. The same impossibility naturally extends to other abstract mechanisms with an arbitrary outcome set if one maintains the original assumptions of players with quasilinear utilities, public budgets and nonnegative prices.
One-dimensional energetic particle quasilinear diffusion for realistic TAE instabilities
Duarte, Vinicius; Ghantous, Katy; Berk, Herbert; Gorelenkov, Nikolai
2014-10-01
Owing to the proximity of the characteristic phase (Alfvén) velocity and typical energetic particle (EP) superthermal velocities, toroidicity-induced Alfvén eigenmodes (TAEs) can be resonantly destabilized endangering the plasma performance. Thus, it is of ultimate importance to understand the deleterious effects on the confinement resulting from fast ion driven instabilities expected in fusion-grade plasmas. We propose to study the interaction of EPs and TAEs using a line broadened quasilinear model, which captures the interaction in both regimes of isolated and overlapping modes. The resonance particles diffuse in the phase space where the problem essentially reduces to one dimension with constant kinetic energy and the diffusion mainly along the canonical toroidal angular momentum. Mode structure and wave particle resonances are computed by the NOVA code and are used in a quasilinear diffusion code that is being written to study the evolution of the distribution function, under the assumption that they can be considered virtually unalterable during the diffusion. A new scheme for the resonant particle diffusion is being proposed that builds on the 1-D nature of the diffusion from a single mode, which leads to a momentum conserving difference scheme even when there is mode overlap.
Sparse signals recovered by non-convex penalty in quasi-linear systems.
Cui, Angang; Li, Haiyang; Wen, Meng; Peng, Jigen
2018-01-01
The goal of compressed sensing is to reconstruct a sparse signal under a few linear measurements far less than the dimension of the ambient space of the signal. However, many real-life applications in physics and biomedical sciences carry some strongly nonlinear structures, and the linear model is no longer suitable. Compared with the compressed sensing under the linear circumstance, this nonlinear compressed sensing is much more difficult, in fact also NP-hard, combinatorial problem, because of the discrete and discontinuous nature of the [Formula: see text]-norm and the nonlinearity. In order to get a convenience for sparse signal recovery, we set the nonlinear models have a smooth quasi-linear nature in this paper, and study a non-convex fraction function [Formula: see text] in this quasi-linear compressed sensing. We propose an iterative fraction thresholding algorithm to solve the regularization problem [Formula: see text] for all [Formula: see text]. With the change of parameter [Formula: see text], our algorithm could get a promising result, which is one of the advantages for our algorithm compared with some state-of-art algorithms. Numerical experiments show that our method performs much better than some state-of-the-art methods.
Directory of Open Access Journals (Sweden)
Mitsuhiro Nakao
2014-01-01
Full Text Available We prove the existence and uniqueness of a global decaying solution to the initial boundary value problem for the quasilinear wave equation with Kelvin-Voigt dissipation and a derivative nonlinearity. To derive the required estimates of the solutions we employ a 'loan' method and use a difference inequality on the energy.
1.5D quasilinear model and its application on beams interacting with Alfvén eigenmodes in DIII-D
Ghantous, K.; Gorelenkov, N. N.; Berk, H. L.; Heidbrink, W. W.; Van Zeeland, M. A.
2012-09-01
We propose a model, denoted here by 1.5D, to study energetic particle (EP) interaction with toroidal Alfvenic eigenmodes (TAE) in the case where the local EP drive for TAE exceeds the stability limit. Based on quasilinear theory, the proposed 1.5D model assumes that the particles diffuse in phase space, flattening the pressure profile until its gradient reaches a critical value where the modes stabilize. Using local theories and NOVA-K simulations of TAE damping and growth rates, the 1.5D model calculates the critical gradient and reconstructs the relaxed EP pressure profile. Local theory is improved from previous study by including more sophisticated damping and drive mechanisms such as the numerical computation of the effect of the EP finite orbit width on the growth rate. The 1.5D model is applied on the well-diagnosed DIII-D discharges #142111 [M. A. Van Zeeland et al., Phys. Plasmas 18, 135001 (2011)] and #127112 [W. W. Heidbrink et al., Nucl. Fusion. 48, 084001 (2008)]. We achieved a very satisfactory agreement with the experimental results on the EP pressure profiles redistribution and measured losses. This agreement of the 1.5D model with experimental results allows the use of this code as a guide for ITER plasma operation where it is desired to have no more than 5% loss of fusion alpha particles as limited by the design.
An Efficient Higher-Order Quasilinearization Method for Solving Nonlinear BVPs
Directory of Open Access Journals (Sweden)
Eman S. Alaidarous
2013-01-01
Full Text Available In this research paper, we present higher-order quasilinearization methods for the boundary value problems as well as coupled boundary value problems. The construction of higher-order convergent methods depends on a decomposition method which is different from Adomain decomposition method (Motsa and Sibanda, 2013. The reported method is very general and can be extended to desired order of convergence for highly nonlinear differential equations and also computationally superior to proposed iterative method based on Adomain decomposition because our proposed iterative scheme avoids the calculations of Adomain polynomials and achieves the same computational order of convergence as authors have claimed in Motsa and Sibanda, 2013. In order to check the validity and computational performance, the constructed iterative schemes are also successfully applied to bifurcation problems to calculate the values of critical parameters. The numerical performance is also tested for one-dimension Bratu and Frank-Kamenetzkii equations.
Quasilinear Extreme Learning Machine Model Based Internal Model Control for Nonlinear Process
Directory of Open Access Journals (Sweden)
Dazi Li
2015-01-01
Full Text Available A new strategy for internal model control (IMC is proposed using a regression algorithm of quasilinear model with extreme learning machine (QL-ELM. Aimed at the chemical process with nonlinearity, the learning process of the internal model and inverse model is derived. The proposed QL-ELM is constructed as a linear ARX model with a complicated nonlinear coefficient. It shows some good approximation ability and fast convergence. The complicated coefficients are separated into two parts. The linear part is determined by recursive least square (RLS, while the nonlinear part is identified through extreme learning machine. The parameters of linear part and the output weights of ELM are estimated iteratively. The proposed internal model control is applied to CSTR process. The effectiveness and accuracy of the proposed method are extensively verified through numerical results.
Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons
Energy Technology Data Exchange (ETDEWEB)
Pokol, G. I.; Kómár, A.; Budai, A. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Budapest (Hungary); Stahl, A.; Fülöp, T. [Department of Applied Physics, Chalmers University of Technology, Göteborg (Sweden)
2014-10-15
Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the 100–1000 μs time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.
Gyrokinetic modelling of the quasilinear particle flux for plasmas with neutral-beam fuelling
Narita, E.; Honda, M.; Nakata, M.; Yoshida, M.; Takenaga, H.; Hayashi, N.
2018-02-01
A quasilinear particle flux is modelled based on gyrokinetic calculations. The particle flux is estimated by determining factors, namely, coefficients of off-diagonal terms and a particle diffusivity. In this paper, the methodology to estimate the factors is presented using a subset of JT-60U plasmas. First, the coefficients of off-diagonal terms are estimated by linear gyrokinetic calculations. Next, to obtain the particle diffusivity, a semi-empirical approach is taken. Most experimental analyses for particle transport have assumed that turbulent particle fluxes are zero in the core region. On the other hand, even in the stationary state, the plasmas in question have a finite turbulent particle flux due to neutral-beam fuelling. By combining estimates of the experimental turbulent particle flux and the coefficients of off-diagonal terms calculated earlier, the particle diffusivity is obtained. The particle diffusivity should reflect a saturation amplitude of instabilities. The particle diffusivity is investigated in terms of the effects of the linear instability and linear zonal flow response, and it is found that a formula including these effects roughly reproduces the particle diffusivity. The developed framework for prediction of the particle flux is flexible to add terms neglected in the current model. The methodology to estimate the quasilinear particle flux requires so low computational cost that a database consisting of the resultant coefficients of off-diagonal terms and particle diffusivity can be constructed to train a neural network. The development of the methodology is the first step towards a neural-network-based particle transport model for fast prediction of the particle flux.
Fokker-Planck code for the quasi-linear absorption of electron cyclotron waves in a tokamak plasma
International Nuclear Information System (INIS)
Meyer, R.L.; Giruzzi, G.; Krivenski, V.
1986-01-01
We present the solution of the kinetic equation describing the quasi-linear evolution of the electron momentum distribution function under the influence of the electron cyclotron wave absorption. Coulomb collisions and the dc electric field in a tokamak plasma. The solution of the quasi-linear equation is obtained numerically using a two-dimensional initial value code following an ADI scheme. Most emphasis is given to the full non-linear and self-consistent problem, namely, the wave amplitude is evaluated at any instant and any point in space according to the actual damping. This is necessary since wave damping is a very sensitive function of the slope of the local momentum distribution function because the resonance condition relates the electron momentum to the location of wave energy deposition. (orig.)
International Nuclear Information System (INIS)
Rax, J.M.
1992-04-01
The dynamics of electrons in two-dimensional, linearly or circularly polarized, ultra-high intensity (above 10 18 W/cm 2 ) laser waves, is investigated. The Compton harmonic resonances are identified as the source of various stochastic instabilities. Both Arnold diffusion and resonance overlap are considered. The quasilinear kinetic equation, describing the evolution of the electron distribution function, is derived, and the associated collisionless damping coefficient is calculated. The implications of these new processes are considered and discussed
International Nuclear Information System (INIS)
Li, Xiaoyu; Fan, Guodong; Rizzoni, Giorgio; Canova, Marcello; Zhu, Chunbo; Wei, Guo
2016-01-01
The design of a simplified yet accurate physics-based battery model enables researchers to accelerate the processes of the battery design, aging analysis and remaining useful life prediction. In order to reduce the computational complexity of the Pseudo Two-Dimensional mathematical model without sacrificing the accuracy, this paper proposes a simplified multi-particle model via a predictor-corrector strategy and quasi-linearization. In this model, a predictor-corrector strategy is used for updating two internal states, especially used for solving the electrolyte concentration approximation to reduce the computational complexity and reserve a high accuracy of the approximation. Quasi-linearization is applied to the approximations of the Butler-Volmer kinetics equation and the pore wall flux distribution to predict the non-uniform electrochemical reaction effects without using any nonlinear iterative solver. Simulation and experimental results show that the isothermal model and the model coupled with thermal behavior are greatly improve the computational efficiency with almost no loss of accuracy. - Highlights: • A simplified multi-particle model with high accuracy and computation efficiency is proposed. • The electrolyte concentration is solved based on a predictor-corrector strategy. • The non-uniform electrochemical reaction is solved based on quasi-linearization. • The model is verified by simulations and experiments at various operating conditions.
Unified kinetic theory in toroidal systems
International Nuclear Information System (INIS)
Hitchcock, D.A.; Hazeltine, R.D.
1980-12-01
The kinetic theory of toroidal systems has been characterized by two approaches: neoclassical theory which ignores instabilities and quasilinear theory which ignores collisions. In this paper we construct a kinetic theory for toroidal systems which includes both effects. This yields a pair of evolution equations; one for the spectrum and one for the distribution function. In addition, this theory yields a toroidal generalization of the usual collision operator which is shown to have many similar properties - conservation laws, H theorem - to the usual collision operator
Building 1D resonance broadened quasilinear (RBQ) code for fast ions Alfvénic relaxations
Gorelenkov, Nikolai; Duarte, Vinicius; Berk, Herbert
2016-10-01
The performance of the burning plasma is limited by the confinement of superalfvenic fusion products, e.g. alpha particles, which are capable of resonating with the Alfvénic eigenmodes (AEs). The effect of AEs on fast ions is evaluated using a resonance line broadened diffusion coefficient. The interaction of fast ions and AEs is captured for cases where there are either isolated or overlapping modes. A new code RBQ1D is being built which constructs diffusion coefficients based on realistic eigenfunctions that are determined by the ideal MHD code NOVA. The wave particle interaction can be reduced to one-dimensional dynamics where for the Alfvénic modes typically the particle kinetic energy is nearly constant. Hence to a good approximation the Quasi-Linear (QL) diffusion equation only contains derivatives in the angular momentum. The diffusion equation is then one dimensional that is efficiently solved simultaneously for all particles with the equation for the evolution of the wave angular momentum. The evolution of fast ion constants of motion is governed by the QL diffusion equations which are adapted to find the ion distribution function.
A quasi-linear formulation for chemically reacting compressible mixtures of imperfect gases
Lentini, D.
2008-01-01
A quasi-linear formulation is proposed for high-speed finite-rate chemically reacting mixtures of imperfect gases, i.e., thermally perfect gases with specific heat varying with temperature. It retains the same formalism of a well-tried counterpart formulation for perfect gases, which has been proven to be suited for application of accurate and fast algorithms. Equations for both quasi-monodimensional flows, and for axisymmetric viscous flows are presented. The approach is based on the definition of an appropriate function F of temperature and concentration, which allows to identify Riemann variables for the flow under consideration; the formulation also includes equations for the entropy and the mass fractions of the N chemical species present in the reacting mixture. The key function F must be computed by numerical quadrature, together with its derivatives with respect to the individual species mass fractions. An example of computation of these quantities is reported, with reference to conditions in the combustion chamber of the Vulcain engine powering the first stage of the Ariane 5 launcher. Such a computation is demonstrated to be both economic and accurate, thus proving the workability of the proposed approach. Further, an estimate of the variation of the mixture specific heat ratio with temperature is given, in order to underline the importance of the effect under consideration.
Global existence and blow-up analysis for some degenerate and quasilinear parabolic systems
Directory of Open Access Journals (Sweden)
Haihua Lu
2009-08-01
Full Text Available This paper deals with positive solutions of some degenerate and quasilinear parabolic systems not in divergence form: $u_{1t}=f_1(u_2(\\Delta u_1+a_1u_1,\\cdots, u_{(n-1t}=f_{n-1}(u_n(\\Delta u_{n-1}+a_{n-1} u_{n-1},\\ u_{nt}=f_n(u_1(\\Delta u_n+a_nu_n$ with homogeneous Dirichlet boundary condition and positive initial condition, where $a_i\\ (i=1,2,\\cdots,n$ are positive constants and $f_i\\ (i=1,2,\\cdots,n$ satisfy some conditions. The local existence and uniqueness of classical solution are proved. Moreover, it will be proved that: (i when $\\min\\{a_1,\\cdots,\\ a_n\\}\\leq\\lambda_1$ then there exists global positive classical solution, and all positive classical solutions can not blow up in finite time in the meaning of maximum norm; (ii when $\\min\\{a_1,\\cdots,\\ a_n\\}>\\lambda_1$, and the initial datum $(u_{10},\\cdots,\\ u_{n0}$ satisfies some assumptions, then the positive classical solution is unique and blows up in finite time, where $\\lambda_1$ is the first eigenvalue of $-\\Delta$ in $\\Omega$ with homogeneous Dirichlet boundary condition.
Nonlinear turbulence theory and simulation of Buneman instability
International Nuclear Information System (INIS)
Yoon, P. H.; Umeda, T.
2010-01-01
In the present paper, the weak turbulence theory for reactive instabilities, formulated in a companion paper [P. H. Yoon, Phys. Plasmas 17, 112316 (2010)], is applied to the strong electron-ion two-stream (or Buneman) instability. The self-consistent theory involves quasilinear velocity space diffusion equation for the particles and nonlinear wave kinetic equation that includes quasilinear (or induced emission) term as well as nonlinear wave-particle interaction term (or a term that represents an induced scattering off ions). We have also performed one-dimensional electrostatic Vlasov simulation in order to benchmark the theoretical analysis. Under the assumption of self-similar drifting Gaussian distribution function for the electrons it is shown that the current reduction and the accompanying electron heating as well as electric field turbulence generation can be discussed in a self-consistent manner. Upon comparison with the Vlasov simulation result it is found that quasilinear wave kinetic equation alone is insufficient to account for the final saturation amplitude. Upon including the nonlinear scattering term in the wave kinetic equation, however, we find that a qualitative agreement with the simulation is recovered. From this, we conclude that the combined quasilinear particle diffusion plus induced emission and scattering (off ions) processes adequately account for the nonlinear development of the Buneman instability.
Weak turbulence theory for beam-plasma interaction
Yoon, Peter H.
2018-01-01
The kinetic theory of weak plasma turbulence, of which Ronald C. Davidson was an important early pioneer [R. C. Davidson, Methods in Nonlinear Plasma Theory, (Academic Press, New York, 1972)], is a venerable and valid theory that may be applicable to a large number of problems in both laboratory and space plasmas. This paper applies the weak turbulence theory to the problem of gentle beam-plasma interaction and Langmuir turbulence. It is shown that the beam-plasma interaction undergoes various stages of physical processes starting from linear instability, to quasilinear saturation, to mode coupling that takes place after the quasilinear stage, followed by a state of quasi-static "turbulent equilibrium." The long term quasi-equilibrium stage is eventually perturbed by binary collisional effects in order to bring the plasma to a thermodynamic equilibrium with increased entropy.
Energy Technology Data Exchange (ETDEWEB)
Fuentes, Carlos [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Parlangue, Jean-Yves [Departamento de Agricultura e Ingenieria Biologica (United States); Haverkamp, Randel; Vauclin, Michael [Laboratorio de Estudio de las Transferencias en Hidrologia y Medio ambiente (France)
2001-12-01
The exact solution of the one-dimensional vertical infiltration equation is deducted, when the hydraulic diffusivity is considered constant and the hydraulic conductivity is a combination of both a linear and quadratic functions of the soil water content. This quasi-linear solution includes as particular cases, both the classical solution known as linear soil and the Knight solution. The cumulative infiltrated water as a function of time provided by the quasi-linear solution has been compared with the cumulative infiltrated water obtained from the numerical solution of the Richards equation on three different soils of contrasting hydrodynamic properties. The good agreement between the two solutions has shown that the quasi-linear solution can be used on soils where the accepted hypothesis, on hydraulic diffusivity and hydraulic conductivity, for its deduction is not satisfied. [Spanish] Se deduce la solucion exacta de la ecuacion de la infiltracion unidimensional vertical cuando la difusividad hidraulica es considerada constante y la conductividad hidraulica es una combinacion de una funcion lineal y una cuadratica del contenido volumetrico de agua. Esta solucion cuasi-lineal de la infiltracion contiene, como casos particulares, la solucion clasica conocida como suelo lineal y la solucion de Knight. La lamina infiltrada acumulada en funcion del tiempo proporcionada por la solucion cuasi-lineal se ha comparado con la lamina infiltrada proporcionada por la solucion numerica de la ecuacion de Richards en tres suelos de propiedades hidrodinamicas contrastantes. El buen acuerdo entre las laminas infiltradas ha mostrado que la solucion cuasi-lineal puede utilizarse en suelos donde la difusividad y la conductividad hidraulicas no satisfacen los supuestos de la deduccion.
On the theory of the type III burst exciter
Smith, R. A.; Goldstein, M. L.; Papadopoulos, K.
1976-01-01
In situ satellite observations of type III burst exciters at 1 AU show that the beam does not evolve into a plateau in velocity space, contrary to the prediction of quasilinear theory. The observations can be explained by a theory that includes mode coupling effects due to excitation of the parametric oscillating two-stream instability and its saturation by anomalous resistivity. The time evolution of the beam velocity distribution is included in the analysis.
International Nuclear Information System (INIS)
Kozhevnikova, L M; Mukminov, F Kh
2000-01-01
A quasilinear system of parabolic equations with energy inequality is considered in a cylindrical domain {t>0}xΩ. In a broad class of unbounded domains Ω two geometric characteristics of a domain are identified which determine the rate of convergence to zero as t→∞ of the L 2 -norm of a solution. Under additional assumptions on the coefficients of the quasilinear system estimates of the derivatives and uniform estimates of the solution are obtained; they are proved to be best possible in the order of convergence to zero in the case of one semilinear equation
International Nuclear Information System (INIS)
Catto, P.J.; Myra, J.R.; Russell, D.A.
1994-01-01
The off-axis quasilinear fast wave minority heating description of Catto and Myra [Phys. Fluids B 4, 187 (1992)] has been improved and implemented in a code which solves the combined quasilinear and collision operator equation for the minority distribution function. Geometrical complications of a minority resonance nearly tangent to a flux surface in the presence of trapped as well as passing particles are retained. The tangency interactions alter the moments and the fusion reaction rate parameter in a model which explores heating on a single flux surface. The strong tangency interactions enhance the more familiar interactions due to trapped particles turning in the vicinity of the minority resonance. An asymmetry in off-axis heating effects occurs because heating on the low field side of the magnetic axis heats more trapped particles than high field side heating. This asymmetry is responsible for the better performance of the low field side case relative to the high and on-axis cases and provides some control over the power absorbed by and the energy stored in the trapped particles
Citrin, J.; Bourdelle, C.; Casson, F. J.; Angioni, C.; Bonanomi, N.; Camenen, Y.; Garbet, X.; Garzotti, L.; Görler, T.; Gürcan, O.; Koechl, F.; Imbeaux, F.; Linder, O.; van de Plassche, K.; Strand, P.; Szepesi, G.; Contributors, JET
2017-12-01
Quasilinear turbulent transport models are a successful tool for prediction of core tokamak plasma profiles in many regimes. Their success hinges on the reproduction of local nonlinear gyrokinetic fluxes. We focus on significant progress in the quasilinear gyrokinetic transport model QuaLiKiz (Bourdelle et al 2016 Plasma Phys. Control. Fusion 58 014036), which employs an approximated solution of the mode structures to significantly speed up computation time compared to full linear gyrokinetic solvers. Optimisation of the dispersion relation solution algorithm within integrated modelling applications leads to flux calculations × {10}6-7 faster than local nonlinear simulations. This allows tractable simulation of flux-driven dynamic profile evolution including all transport channels: ion and electron heat, main particles, impurities, and momentum. Furthermore, QuaLiKiz now includes the impact of rotation and temperature anisotropy induced poloidal asymmetry on heavy impurity transport, important for W-transport applications. Application within the JETTO integrated modelling code results in 1 s of JET plasma simulation within 10 h using 10 CPUs. Simultaneous predictions of core density, temperature, and toroidal rotation profiles for both JET hybrid and baseline experiments are presented, covering both ion and electron turbulence scales. The simulations are successfully compared to measured profiles, with agreement mostly in the 5%-25% range according to standard figures of merit. QuaLiKiz is now open source and available at www.qualikiz.com.
Dynamical theory of anomalous particle transport
International Nuclear Information System (INIS)
Meiss, J.D.; Cary, J.R.; Escande, D.F.; MacKay, R.S.; Percival, I.C.; Tennyson, J.L.
1985-01-01
The quasi-linear theory of transport applies only in a restricted parameter range, which does not necessarily correspond to experimental conditions. Theories are developed which extend transport calculations to the regimes of marginal stochasticity and strong turbulence. Near the stochastic threshold the description of transport involves the leakage through destroyed invariant surfaces, and the dynamical scaling theory is used to obtain a universal form for transport coefficients. In the strong-turbulence regime, there is an adiabatic invariant which is preserved except near separatrices. Breakdown of this invariant leads to a new form for the diffusion coefficient. (author)
A synthesis theory for self-oscillating adaptive systems /SOAS/
Horowitz, I.; Smay, J.; Shapiro, A.
1974-01-01
A quantitative synthesis theory is presented for the Self-Oscillating Adaptive System (SOAS), whose nonlinear element has a static, odd character with hard saturation. The synthesis theory is based upon the quasilinear properties of the SOAS to forced inputs, which permits the extension of quantitative linear feedback theory to the SOAS. A reasonable definition of optimum design is shown to be the minimization of the limit cycle frequency. The great advantages of the SOAS is its zero sensitivity to pure gain changes. However, quasilinearity and control of the limit cycle amplitude at the system output, impose additional constraints which partially or completely cancel this advantage, depending on the numerical values of the design parameters. By means of narrow-band filtering, an additional factor is introduced which permits trade-off between filter complexity and limit cycle frequency minimization.
The theory of singular perturbations
De Jager, E M
1996-01-01
The subject of this textbook is the mathematical theory of singular perturbations, which despite its respectable history is still in a state of vigorous development. Singular perturbations of cumulative and of boundary layer type are presented. Attention has been given to composite expansions of solutions of initial and boundary value problems for ordinary and partial differential equations, linear as well as quasilinear; also turning points are discussed. The main emphasis lies on several methods of approximation for solutions of singularly perturbed differential equations and on the mathemat
International Nuclear Information System (INIS)
Teh, R.
1993-06-01
We pointed out that there exists a critical frequency of oscillation for the vortex-like solution above which the system switches to the fields of an alternating current inside a solenoid. We also show the existence a non-abelian gauge for which the fields can alternate periodically in space between the abelian fields and another abelian (or non-abelian) field pointing in a different isospin space direction. The solution discussed here are real, zero-action Minkowski space configurations. (author). 18 refs
A theory for the Langmuir waves in the electron foreshock
International Nuclear Information System (INIS)
Cairns, I.H.
1987-01-01
A theory for the Langmuir (L) waves observed in the electron foreshock is suggested. Free energy for the Langmuir wave growth is contained in cutoff distributions of energetic electrons streaming from the bow shock. These cutoff distributions drive Langmuir wave growth primarily by the kinetic version of the beam instability, and wave growth is limited by quasi-linear relaxation. The observed bump-on-tail electron distributions are interpreted as the remnants of cutoff distributions after quasi-linear relaxation has limited the wave growth. Only plausibility arguments for this theory are given since suitable treatments of quasi-linear relaxation are not presently available. However, it is shown that the wave processes L ± S → L' and L ± S → T (where S and T denote ion sound and transverse waves, respectively), refraction in steady-state density structures, diffusion due to interactions with ion sound turbulence, and effects due to wave convection and spatial gradients in the beam velocity, are unable to suppress the beam instability. The theory leads to natural interpretations of the Langmuir electric field waveforms observed and of the decrease in the Langmuir wave electric fields with increasing distance from the foreshock boundary. The theory for the beam instability is reviewed, and previous analytic and numerical treatments of the beam instability are related
International Nuclear Information System (INIS)
Tanomaru, N.
1979-12-01
The problem of parameter identification in a pontual model for a thermal reactor is dealt with using the quasilinearization technique. The model considers one group of delayed neutrons and a heavily non-linear temperature feedback in the reactivity. The parameter prompt neutron generation time and a parameter of the fuel temperatura reactivity coefficient equation are identified simultaneously, considering discrete measurements of the reactor power, during the transient produced by a change in the external reactivity. The influences of the choice of the external reactivity disturbance, of the two parameters values initial guesses, of the interval between measurements and the measurement noise level in the method accuracy and rate of convergence are analysed. For noiseless or low level noise measurements, the method proved to be very effective. (Author) [pt
Finite-time blow-up for quasilinear degenerate Keller-Segel systems of parabolic-parabolic type
Hashira, Takahiro; Ishida, Sachiko; Yokota, Tomomi
2018-05-01
This paper deals with the quasilinear degenerate Keller-Segel systems of parabolic-parabolic type in a ball of RN (N ≥ 2). In the case of non-degenerate diffusion, Cieślak-Stinner [3,4] proved that if q > m + 2/N, where m denotes the intensity of diffusion and q denotes the nonlinearity, then there exist initial data such that the corresponding solution blows up in finite time. As to the case of degenerate diffusion, it is known that a solution blows up if q > m + 2/N (see Ishida-Yokota [13]); however, whether the blow-up time is finite or infinite has been unknown. This paper gives an answer to the unsolved problem. Indeed, the finite-time blow-up of energy solutions is established when q > m + 2/N.
Yang, Yongge; Xu, Wei; Yang, Guidong; Jia, Wantao
2016-08-01
The Poisson white noise, as a typical non-Gaussian excitation, has attracted much attention recently. However, little work was referred to the study of stochastic systems with fractional derivative under Poisson white noise excitation. This paper investigates the stationary response of a class of quasi-linear systems with fractional derivative excited by Poisson white noise. The equivalent stochastic system of the original stochastic system is obtained. Then, approximate stationary solutions are obtained with the help of the perturbation method. Finally, two typical examples are discussed in detail to demonstrate the effectiveness of the proposed method. The analysis also shows that the fractional order and the fractional coefficient significantly affect the responses of the stochastic systems with fractional derivative.
International Nuclear Information System (INIS)
Yang, Yongge; Xu, Wei; Yang, Guidong; Jia, Wantao
2016-01-01
The Poisson white noise, as a typical non-Gaussian excitation, has attracted much attention recently. However, little work was referred to the study of stochastic systems with fractional derivative under Poisson white noise excitation. This paper investigates the stationary response of a class of quasi-linear systems with fractional derivative excited by Poisson white noise. The equivalent stochastic system of the original stochastic system is obtained. Then, approximate stationary solutions are obtained with the help of the perturbation method. Finally, two typical examples are discussed in detail to demonstrate the effectiveness of the proposed method. The analysis also shows that the fractional order and the fractional coefficient significantly affect the responses of the stochastic systems with fractional derivative.
Energy Technology Data Exchange (ETDEWEB)
Yang, Yongge; Xu, Wei, E-mail: weixu@nwpu.edu.cn; Yang, Guidong; Jia, Wantao [Department of Applied Mathematics, Northwestern Polytechnical University, Xi' an 710072 (China)
2016-08-15
The Poisson white noise, as a typical non-Gaussian excitation, has attracted much attention recently. However, little work was referred to the study of stochastic systems with fractional derivative under Poisson white noise excitation. This paper investigates the stationary response of a class of quasi-linear systems with fractional derivative excited by Poisson white noise. The equivalent stochastic system of the original stochastic system is obtained. Then, approximate stationary solutions are obtained with the help of the perturbation method. Finally, two typical examples are discussed in detail to demonstrate the effectiveness of the proposed method. The analysis also shows that the fractional order and the fractional coefficient significantly affect the responses of the stochastic systems with fractional derivative.
Directory of Open Access Journals (Sweden)
Anat Lerner
2014-04-01
Full Text Available We characterize the efficiency space of deterministic, dominant-strategy incentive compatible, individually rational and Pareto-optimal combinatorial auctions in a model with two players and k nonidentical items. We examine a model with multidimensional types, private values and quasilinear preferences for the players with one relaxation: one of the players is subject to a publicly known budget constraint. We show that if it is publicly known that the valuation for the largest bundle is less than the budget for at least one of the players, then Vickrey-Clarke-Groves (VCG uniquely fulfills the basic properties of being deterministic, dominant-strategy incentive compatible, individually rational and Pareto optimal. Our characterization of the efficient space for deterministic budget constrained combinatorial auctions is similar in spirit to that of Maskin 2000 for Bayesian single-item constrained efficiency auctions and comparable with Ausubel and Milgrom 2002 for non-constrained combinatorial auctions.
International Nuclear Information System (INIS)
Foroutan, G.; Khalilpour, H.; Moslehi-Fard, M.; Li, B.; Robinson, P. A.
2008-01-01
The effects of plasma inhomogeneities on the propagation of a cloud of hot electrons through a cold background plasma and generation of Langmuir waves are investigated using numerical simulations of the quasilinear equations. It is found that in a plasma with decreasing density the quasilinear relaxation of the electron distribution in velocity space is accelerated and the levels of the generated Langmuir waves are enhanced. The magnitude of the induced emission rate is increased and its maximum value moves to lower velocities. Due to density gradient the height of plateau shows an increase at small distances and a corresponding decrease at large distances. It is also found that in a plasma with decreasing temperature, the relaxation of the beam is retarded, the spectral density of Langmuir waves is broadened, and the height of the plateau decreases below its value in a uniform plasma. In the presence of both density and temperature gradients, at given position, the height and upper boundary of the plateau and the level of Langmuir waves are all increased at small velocities. The spatial expansion of the beam is increased by the plasma inhomogeneities, but its average velocity of propagation decreases. Initially, at a given position, the velocity at the upper boundary of the plateau is smaller in the presence of the density gradient than in the uniform plasma but the reverse is true at longer times. Due to temperature gradient, at large times and small distances, the upper boundary of the plateau is increased above its value in the uniform plasma. Because of fast relaxation, the value of the lower boundary of the plateau in the plasma with decreasing density is always less than its value in the uniform plasma. It is found that the local velocity of the beam decreases when the density gradient is present. The local velocity spread of the beam remains unchanged during the propagation of the beam in the uniform plasma, but increases in the presence of inhomogeneities.
Present status of mirror stability theory
International Nuclear Information System (INIS)
Baldwin, D.E.; Berk, H.L.; Byers, J.A.
1976-01-01
A status report of microinstability as it applies to 2XIIB and MX theory for mirror machines is presented. It is shown that quasilinear computations reproduce many of the parameters observed in the 2XIIB experiment. In regard to large mirror machines, there are presented detailed calculations of the linear theory of the drift cyclotron loss-cone mode, with inhomogeneous geometry and nonlinear diffusive effects. Further, the stability of a mirror machine to the Alfven ion-cyclotron instability is assessed, and the Baldwin-Callen diffusion is estimated for a spatially varying plasma
On geometrized gravitation theories
International Nuclear Information System (INIS)
Logunov, A.A.; Folomeshkin, V.N.
1977-01-01
General properties of the geometrized gravitation theories have been considered. Geometrization of the theory is realized only to the extent that by necessity follows from an experiment (geometrization of the density of the matter Lagrangian only). Aor a general case the gravitation field equations and the equations of motion for matter are formulated in the different Riemann spaces. A covariant formulation of the energy-momentum conservation laws is given in an arbitrary geometrized theory. The noncovariant notion of ''pseudotensor'' is not required in formulating the conservation laws. It is shown that in the general case (i.e., when there is an explicit dependence of the matter Lagrangian density on the covariant derivatives) a symmetric energy-momentum tensor of the matter is explicitly dependent on the curvature tensor. There are enlisted different geometrized theories that describe a known set of the experimental facts. The properties of one of the versions of the quasilinear geometrized theory that describes the experimental facts are considered. In such a theory the fundamental static spherically symmetrical solution has a singularity only in the coordinate origin. The theory permits to create a satisfactory model of the homogeneous nonstationary Universe
Soliton solutions for a quasilinear Schrödinger equation via Morse ...
Indian Academy of Sciences (India)
In this paper, Morse theory is used to show the existence of nontrivial ... equation defined in the domain RN (for example, see [4, 5, 7, 17, 26, 29]). .... for X; Lp( ) denotes Lebesgue space with the norm |·|p; 〈·, ·〉 is the dual pairing on the.
Renardy, M.
A semigroup approach to differential-delay equations is developed which reduces such equations to ordinary differential equations on a Banach space of histories and seems more suitable for certain partial integro-differential equations than the standard theory. The method is applied to prove a local-time existence theorem for equations of the form utt = g( uxt, uxt) x, where {∂g}/{∂u xt} > 0 . On a formal level, it is demonstrated that the stretching of filaments of viscoelastic liquids can be described by an equation of this form.
Cai, Yunpeng; Sun, Yijun
2011-08-01
Taxonomy-independent analysis plays an essential role in microbial community analysis. Hierarchical clustering is one of the most widely employed approaches to finding operational taxonomic units, the basis for many downstream analyses. Most existing algorithms have quadratic space and computational complexities, and thus can be used only for small or medium-scale problems. We propose a new online learning-based algorithm that simultaneously addresses the space and computational issues of prior work. The basic idea is to partition a sequence space into a set of subspaces using a partition tree constructed using a pseudometric, then recursively refine a clustering structure in these subspaces. The technique relies on new methods for fast closest-pair searching and efficient dynamic insertion and deletion of tree nodes. To avoid exhaustive computation of pairwise distances between clusters, we represent each cluster of sequences as a probabilistic sequence, and define a set of operations to align these probabilistic sequences and compute genetic distances between them. We present analyses of space and computational complexity, and demonstrate the effectiveness of our new algorithm using a human gut microbiota data set with over one million sequences. The new algorithm exhibits a quasilinear time and space complexity comparable to greedy heuristic clustering algorithms, while achieving a similar accuracy to the standard hierarchical clustering algorithm.
Galaktionov, Victor A.
2009-02-01
As a basic higher-order model, the fourth-order Boussinesq-type quasilinear wave equation (the QWE-4) \\[ \\begin{equation*}\\fl u_{tt} = -(|u|^n u)_{xxxx} \\tqs in\\ \\mathbb{R} \\times \\mathbb{R}_+, \\quad with\\ exponent\\ n > 0,\\end{equation*} \\] is considered. Self-similar blow-up solutions \\[ \\begin{eqnarray*}\\tqs\\tqs u_-(x,t)=g(z), \\quad\\, z=\\frac x{\\sqrt{T-t}},\\\\ where\\ g\\ solved\\ the\\ ODE\\ \\frac 14 g'' z^2 + \\frac 34 g'z = -(|g|^n g)^{(4)},\\end{eqnarray*} \\] are shown to exist that generate as t → T- discontinuous shock waves. The QWE-4 is also shown to admit a smooth (for t > 0) global 'fundamental solution' \\[ \\begin{eqnarray*}\\fl b_n(x,t)= t^{\\frac{2}{n+4}} F_n(y),\\ y = x/t^{\\frac{n+2}{n+4}},\\ such\\ that\\ b_{n}(x,0)= 0,\\ b_{nt}(x,0)= {\\delta}(x),\\end{eqnarray*} \\] i.e. having a measure as initial data. A 'homotopic' limit n → 0 is used to get b_0(x,t)= \\sqrt t \\, F_0(x/\\sqrt t) being the classic fundamental solution of the 1D linear beam equation \\[ \\begin{equation*}u_{tt} = -u_{xxxx} \\tqs in\\ \\mathbb{R} \\times \\mathbb{R}_+.\\end{equation*} \\
A kinetic approach to some quasi-linear laws of macroeconomics
Gligor, M.; Ignat, M.
2002-11-01
Some previous works have presented the data on wealth and income distributions in developed countries and have found that the great majority of population is described by an exponential distribution, which results in idea that the kinetic approach could be adequate to describe this empirical evidence. The aim of our paper is to extend this framework by developing a systematic kinetic approach of the socio-economic systems and to explain how linear laws, modelling correlations between macroeconomic variables, may arise in this context. Firstly we construct the Boltzmann kinetic equation for an idealised system composed by many individuals (workers, officers, business men, etc.), each of them getting a certain income and spending money for their needs. To each individual a certain time variable amount of money is associated this meaning him/her phase space coordinate. In this way the exponential distribution of money in a closed economy is explicitly found. The extension of this result, including states near the equilibrium, give us the possibility to take into account the regular increase of the total amount of money, according to the modern economic theories. The Kubo-Green-Onsager linear response theory leads us to a set of linear equations between some macroeconomic variables. Finally, the validity of such laws is discussed in relation with the time reversal symmetry and is tested empirically using some macroeconomic time series.
A Quasi-Linear Behavioral Model and an Application to Self-Directed Learning
Ponton, Michael K.; Carr, Paul B.
1999-01-01
A model is presented that describes the relationship between one's knowledge of the world and the concomitant personal behaviors that serve as a mechanism to obtain desired outcomes. Integrated within this model are the differing roles that outcomes serve as motivators and as modifiers to one's worldview. The model is dichotomized between general and contextual applications. Because learner self-directedness (a personal characteristic) involves cognition and affection while self-directed learning (a pedagogic process) encompasses conation, behavior and introspection, the model can be dichotomized again in another direction. Presented also are the roles that cognitive motivation theories play in moving an individual through this behavioral model and the roles of wishes, self-efficacy, opportunity and self-influence.
The large-scale gravitational bias from the quasi-linear regime.
Bernardeau, F.
1996-08-01
It is known that in gravitational instability scenarios the nonlinear dynamics induces non-Gaussian features in cosmological density fields that can be investigated with perturbation theory. Here, I derive the expression of the joint moments of cosmological density fields taken at two different locations. The results are valid when the density fields are filtered with a top-hat filter window function, and when the distance between the two cells is large compared to the smoothing length. In particular I show that it is possible to get the generating function of the coefficients C_p,q_ defined by _c_=C_p,q_ ^p+q-2^ where δ({vec}(x)) is the local smoothed density field. It is then possible to reconstruct the joint density probability distribution function (PDF), generalizing for two points what has been obtained previously for the one-point density PDF. I discuss the validity of the large separation approximation in an explicit numerical Monte Carlo integration of the C_2,1_ parameter as a function of |{vec}(x)_1_-{vec}(x)_2_|. A straightforward application is the calculation of the large-scale ``bias'' properties of the over-dense (or under-dense) regions. The properties and the shape of the bias function are presented in details and successfully compared with numerical results obtained in an N-body simulation with CDM initial conditions.
Numerical Test of Analytical Theories for Perpendicular Diffusion in Small Kubo Number Turbulence
Energy Technology Data Exchange (ETDEWEB)
Heusen, M.; Shalchi, A., E-mail: husseinm@myumanitoba.ca, E-mail: andreasm4@yahoo.com [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada)
2017-04-20
In the literature, one can find various analytical theories for perpendicular diffusion of energetic particles interacting with magnetic turbulence. Besides quasi-linear theory, there are different versions of the nonlinear guiding center (NLGC) theory and the unified nonlinear transport (UNLT) theory. For turbulence with high Kubo numbers, such as two-dimensional turbulence or noisy reduced magnetohydrodynamic turbulence, the aforementioned nonlinear theories provide similar results. For slab and small Kubo number turbulence, however, this is not the case. In the current paper, we compare different linear and nonlinear theories with each other and test-particle simulations for a noisy slab model corresponding to small Kubo number turbulence. We show that UNLT theory agrees very well with all performed test-particle simulations. In the limit of long parallel mean free paths, the perpendicular mean free path approaches asymptotically the quasi-linear limit as predicted by the UNLT theory. For short parallel mean free paths we find a Rechester and Rosenbluth type of scaling as predicted by UNLT theory as well. The original NLGC theory disagrees with all performed simulations regardless what the parallel mean free path is. The random ballistic interpretation of the NLGC theory agrees much better with the simulations, but compared to UNLT theory the agreement is inferior. We conclude that for this type of small Kubo number turbulence, only the latter theory allows for an accurate description of perpendicular diffusion.
Numerical Test of Analytical Theories for Perpendicular Diffusion in Small Kubo Number Turbulence
International Nuclear Information System (INIS)
Heusen, M.; Shalchi, A.
2017-01-01
In the literature, one can find various analytical theories for perpendicular diffusion of energetic particles interacting with magnetic turbulence. Besides quasi-linear theory, there are different versions of the nonlinear guiding center (NLGC) theory and the unified nonlinear transport (UNLT) theory. For turbulence with high Kubo numbers, such as two-dimensional turbulence or noisy reduced magnetohydrodynamic turbulence, the aforementioned nonlinear theories provide similar results. For slab and small Kubo number turbulence, however, this is not the case. In the current paper, we compare different linear and nonlinear theories with each other and test-particle simulations for a noisy slab model corresponding to small Kubo number turbulence. We show that UNLT theory agrees very well with all performed test-particle simulations. In the limit of long parallel mean free paths, the perpendicular mean free path approaches asymptotically the quasi-linear limit as predicted by the UNLT theory. For short parallel mean free paths we find a Rechester and Rosenbluth type of scaling as predicted by UNLT theory as well. The original NLGC theory disagrees with all performed simulations regardless what the parallel mean free path is. The random ballistic interpretation of the NLGC theory agrees much better with the simulations, but compared to UNLT theory the agreement is inferior. We conclude that for this type of small Kubo number turbulence, only the latter theory allows for an accurate description of perpendicular diffusion.
Nowotarski, C. J.
2017-12-01
Though most strong to violent tornadoes are associated with supercell thunderstorms, quasi-linear convective systems (QLCSs) pose a risk of tornadoes, often at times and locations where supercell tornadoes are less common. Because QLCS low-level mesocyclones and tornado signatures tend to be less coherent, forecasting such tornadoes remains particularly difficult. The majority of simulations of such storms rely on horizontally homogeneous base states lacking resolved boundary layer turbulence and surface fluxes. Previous work has suggested that heterogeneities associated with boundary layer turbulence in the form of horizontal convective rolls can influence the evolution and characteristics of low-level mesocyclones in supercell thunderstorms. This study extends methods for generating boundary layer convection to idealized simulations of QLCSs. QLCS simulations with resolved boundary layer turbulence will be compared against a control simulation with a laminar boundary layer. Effects of turbulence, the resultant heterogeneity in the near-storm environment, and surface friction on bulk storm characteristics and the intensity, morphology, and evolution of low-level rotation will be presented. Although maximum surface vertical vorticity values are similar, when boundary layer turbulence is included, a greater number of miso- and meso-scale vortices develop along the QLCS gust front. The source of this vorticity is analyzed using Eulerian decomposition of vorticity tendency terms and trajectory analysis to delineate the relative importance of surface friction and baroclinicity in generating QLCS vortices. The role of anvil shading in suppressing boundary layer turbulence in the near-storm environment and subsequent effects on QLCS vortices will also be presented. Finally, implications of the results regarding inclusion of more realistic boundary layers in future idealized simulations of deep convection will be discussed.
Fokker-Planck theory of electron cyclotron assisted startup and breakdown in Tokamaks
International Nuclear Information System (INIS)
Fidone, I.; Granata, G.
1993-04-01
The kinetic theory of plasma startup in a tokamak in the presence of electron cyclotron resonance heating is discussed. The linear theory of the X-mode and the upper-hybrid converted mode damping in low density and temperature plasmas are first reviewed. Then, the kinetic equation for the electron velocity distribution is considered, which is determined by the perpendicular electron cyclotron quasilinear diffusion operator, the parallel electric field, elastic and inelastic electron-neutral collisions and various losses. Two different time scales, namely the elastic electron-neutral collision time and the much longer ionization time, are identified. Thus a two time scale ordering procedure is legitimated for which the velocity distribution is determined by the quasilinear diffusion and the electron-neutral collision frequency; the ionization rate is computed using the Fokker-Planck solution for the electron velocity distribution
Kinetic theory of rf current drive and helicity injection
International Nuclear Information System (INIS)
Mett, R.R.
1992-01-01
Current drive and helicity injection by plasma waves are examined with the use of kinetic theory. The Vlasov equation yields a general current drive formula that contains resonant and nonresonant (ponderomotivelike) contributions. Standard quasilinear current drive is described by the former, while helicity current drive may be contained in the latter. Since direct analytical comparison of the sizes of the two terms is, in general, difficult, a new approach is taken. Solution of the drift-kinetic equation shows that the standard Landau damping/transit time magnetic pumping quasilinear diffusion coefficient is the only contribution to steady-state current drive to leading order in ε=ρ L /l, where ρ L is the Larmor radius and l is the inhomogeneity scale length. All nonresonant contributions, including the helicity, appear at higher order, after averages are taken over a flux surface, over azimuth, and over time. Consequently, at wave frequencies well below the electron cyclotron frequency, a wave helicity flux perpendicular to the magnetic field does not influence the parallel motion of electrons to leading order and therefore will not drive a significant current. Any current associated with a wave helicity flux is then either ion current (and thus inefficient) or electron current stemming from effects not included in the drift-kinetic treatment, such as cyclotron, collisional, or nonlinear (i.e., not quasilinear)
Theory of electron cyclotron heating in the Constance II experiment
International Nuclear Information System (INIS)
Mauel, M.E.
1981-03-01
The bounce-averaged quasi-linear equation for a non-relativistic mirror-confined plasma interacting with electromagnetic waves is derived for use in the study of ECRH of the Constance II mirror experiment. The derivations follows the more formal examples given by Berk for electrostatic waves and Bernstein and Baxter for relativistic plasmas. The validity of the theory is discussed by examining individual particle orbits in an EM field. The local dispersion relation is found while deriving a self-consistent WKB theory which can be used to estimate the power transferred from the launching horn to the plasma
Physics of pitch angle scattering and velocity diffusion. I - Theory
Karimabadi, H.; Krauss-Varban, D.; Terasawa, T.
1992-01-01
A general theory for the pitch angle scattering and velocity diffusion of particles in the field of a spectrum of waves in a magnetized plasma is presented. The test particle theory is used to analyze the particle motion. The form of diffusion surfaces is examined, and analytical expressions are given for the resonance width and bounce frequency. The resonance widths are found to vary strongly as a function of harmonic number. The resulting diffusion can be quite asymmetric with respect to pitch angle of 90 deg. The conditions for the onset of pitch angle scattering and energy diffusion are explained in detail. Some of the known shortcomings of the standard quasi-linear theory are also addressed, and ways to overcome them are shown. In particular, the often stated quasi-linear gap at 90 deg is found to exist only under very special cases. For instance, oblique wave propagation can easily remove the gap. The conditions for the existence of the gap are described in great detail. A new diffusion equation which takes into account the finite resonance widths is also discussed. The differences between this new theory and the standard resonance broadening theory is explained.
Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth
2013-01-01
This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output
Energy Technology Data Exchange (ETDEWEB)
Buerger, R.; Frid, H.; Karlsen, K.H.
2002-07-01
We consider a free boundary problem of a quasilinear strongly degenerate parabolic equation arising from a model of pressure filtration of flocculated suspensions. We provide definitions of generalized solutions of the free boundary problem in the framework of L2 divergence-measure fields. The formulation of boundary conditions is based on a Gauss-Green theorem for divergence-measure fields on bounded domains with Lipschitz deformable boundaries and avoids referring to traces of the solution. This allows to consider generalized solutions from a larger class than BV. Thus it is not necessary to derive the usual uniform estimates on spatial and time derivatives of the solutions of the corresponding regularized problem requires in the BV approach. We first prove existence and uniqueness of the solution of the regularized parabolic free boundary problem and then apply the vanishing viscosity method to prove existence of a generalized solution to the degenerate free boundary problem. (author)
Xu, Xiaofeng; Jiao, W H; Zhou, N; Guo, Y; Li, Y K; Dai, Jianhui; Lin, Z Q; Liu, Y J; Zhu, Zengwei; Lu, Xin; Yuan, H Q; Cao, Guanghan
2015-08-26
We report on the quasi-linear in field intrachain magnetoresistance in the normal state of a quasi-one-dimensional superconductor Ta4Pd3Te16 (Tc ~ 4.6 K). Both the longitudinal and transverse in-chain magnetoresistance shows a power-law dependence, Δρ∝B(α) with the exponent α close to 1 over a wide temperature and field range. The magnetoresistance shows no sign of saturation up to 50 T studied. The linear magnetoresistance observed in Ta4Pd3Te16 is found to be overall inconsistent with the interpretations based on the Dirac fermions in the quantum limit, charge conductivity fluctuations as well as quantum electron-electron interference. Moreover, it is observed that the Kohler's rule, regardless of the field orientations, is violated in its normal state. This result suggests the loss of charge carriers in the normal state of this chain-containing compound, due presumably to the charge-density-wave fluctuations.
International Nuclear Information System (INIS)
Gormezano, C.; Hess, W.; Ichtchenko, G.
1980-07-01
The already obtained data on the Wega Tokamak by lower hybrid heating (f=500 MHz - Psub(HF)=130 KW) are revisited in the light of recent theories on ion stochastic heating and quasi-linear electron Landau damping. It is possible to correctly estimate with these theories the fast ion mean energy, the H.F. power density coupled to the ions and that coupled to the electrons. The values of the parallel index of refraction, Nsub(//), which are necessary to obtain a good quantitative agreement between experiment and theoretical estimates, are the same for the ions and for the electrons, even though at higher values than expected
The basic equations for a four-component theory of turbulent magneto-plasmadynamics
International Nuclear Information System (INIS)
Kaeppeler, H.J.
1983-04-01
In the case of strong electric fields and high currents in magneto-plasmas, it is necessary to use four components in order to consider the acceleration of ions and electrons and the consecutive effects in detail. As the time scales for the microscopic and macroscopic phenomena differ by several orders of magnitude, micro-effects were treated analytically, while macroscopic flows are solved by Reduce/Fortran hybrid code. Microturbulence is considered in a quasi-linear approximation, while the hybrid code permits complete non-linear approach via a macroscopic dispersion relation. The basic equations necessary for this four-component theory are compiled in this report. (orig.)
Whitham modulation theory for the two-dimensional Benjamin-Ono equation.
Ablowitz, Mark; Biondini, Gino; Wang, Qiao
2017-09-01
Whitham modulation theory for the two-dimensional Benjamin-Ono (2DBO) equation is presented. A system of five quasilinear first-order partial differential equations is derived. The system describes modulations of the traveling wave solutions of the 2DBO equation. These equations are transformed to a singularity-free hydrodynamic-like system referred to here as the 2DBO-Whitham system. Exact reductions of this system are discussed, the formulation of initial value problems is considered, and the system is used to study the transverse stability of traveling wave solutions of the 2DBO equation.
Problem of energy-momentum and theory of gravitation
International Nuclear Information System (INIS)
Logunov, A.A.; Folomeshkin, V.N.
1977-01-01
General properties of geometrised theories of gravitation are considered. Covariant formulation of conservation laws in arbitrary riemannian space-time is given. In the Einstein theory the symmetric as well as canonical energy-momentum tensor of the system ''matter plus gravitational field'' and in particular, the energy-momentum of free gravitational waves, turns out to be equal to zero. To understand the origin of the problems and difficulties concerning the energy-momentum in the Einstein theory, the gravitational filed is considered in the usual framework of the Lorentz invariant field theory, just like any other physical field. Combination of the approach proposed with the Einstein's idea of geometrization makes it possible to formulate the geometrised gravitation theory, in which there are no inner contradictions, the energy-momentum of gravitational field is defined precisely and all the known experimental facts are described successfully. For strong gravitational fields the predictions of the quasilinear geometrised theory under consideration are different from those of the gravitational theory in the Einstein formulation. Black holes are absent in the theory. Evaluation of the energy-flux of gravitational waves leads to unambiguous results and shows that the gravitational waves transfer the positive-definite energy
International Nuclear Information System (INIS)
Shi Run; Ni, Binbin; Gu Xudong; Zhao Zhengyu; Zhou Chen
2012-01-01
The resonance regions for resonant interactions of radiation belt electrons with obliquely propagating whistler-mode chorus waves are investigated in detail in the Dungey magnetic fields that are parameterized by the intensity of uniform southward interplanetary magnetic field (IMF) Bz or, equivalently, by the values of D=(M/B z,0 ) 1/3 (where M is the magnetic moment of the dipole and B z,0 is the uniform southward IMF normal to the dipole’s equatorial plane). Adoption of background magnetic field model can considerably modify the determination of resonance regions. Compared to the results for the case of D = 50 (very close to the dipole field), the latitudinal coverage of resonance regions for 200 keV electrons interacting with chorus waves tends to become narrower for smaller D-values, regardless of equatorial pitch angle, resonance harmonics, and wave normal angle. In contrast, resonance regions for 1 MeV electrons tend to have very similar spatial lengths along the field line for various Dungey magnetic field models but cover different magnetic field intervals, indicative of a strong dependence on electron energy. For any given magnetic field line, the resonance regions where chorus-electron resonant interactions can take place rely closely on equatorial pitch angle, resonance harmonics, and kinetic energy. The resonance regions tend to cover broader latitudinal ranges for smaller equatorial pitch angles, higher resonance harmonics, and lower electron energies, consistent with the results in Ni and Summers [Phys. Plasmas 17, 042902, 042903 (2010)]. Calculations of quasi-linear bounce-averaged diffusion coefficients for radiation belt electrons due to nightside chorus waves indicate that the resultant scattering rates differ from using different Dungey magnetic field models, demonstrating a strong dependence of wave-induced electron scattering effect on the adoption of magnetic field model. Our results suggest that resonant wave-particle interaction processes
Nonlocal quasilinear damped differential inclusions
Directory of Open Access Journals (Sweden)
Mouffak Benchohra
2002-01-01
Full Text Available In this paper we investigate the existence of mild solutions to second order initial value problems for a class of damped differential inclusions with nonlocal conditions. By using suitable fixed point theorems, we study the case when the multivalued map has convex and nonconvex values.
Quasilinear diffusion in inhomogeneous plasmas
International Nuclear Information System (INIS)
Hooley, D.L.
1975-05-01
The problem of inhomogeneous diffusion in a plasma is considered with emphasis on its possible application to relativistic electron beams. A one-dimensional model with a background electrostatic field is used to illustrate the basic approach, which is then extended to a two-dimensional plasma with a background magnetic field. Only preliminary results are available. (U.S.)
Mathematical Theory of Dispersion-Managed Optical Solitons
Biswas, Anjan; Edwards, Matthew
2010-01-01
"Mathematical Theory of Dispersion-Managed Optical Solitons" discusses recent advances covering optical solitons, soliton perturbation, optical cross-talk, Gabitov-Turitsyn Equations, quasi-linear pulses, and higher order Gabitov-Turitsyn Equations. Focusing on a mathematical perspective, the book bridges the gap between concepts in engineering and mathematics, and gives an outlook to many new topics for further research. The book is intended for researchers and graduate students in applied mathematics, physics and engineering and also it will be of interest to those who are conducting research in nonlinear fiber optics. Dr. Anjan Biswas is an Associate Professor at the Department of Applied Mathematics & Theoretical Physics, Delaware State University, Dover, DE, USA; Dr. Daniela Milovic is an Associate Professor at the Department of Telecommunications, Faculty of Electronic Engineering, University of Nis, Serbia; Dr. Matthew Edwards is the Dean of the School of Arts and Sciences at Alabama A & M Univ...
The energy-momentum problem and gravitation theory
International Nuclear Information System (INIS)
Logunov, A.A.; Folomeshkin, V.N.
1977-01-01
General properties of geometrized gravitation theories are considered. A covariant formulation of conservation laws in an arbitrary Riemann space-time is presented. In the Einstein theory both symmetric and canonical energy-momentum tensors of the matter and gravitational field system and, in particular, energy-momentum of free gravitational waves prove to be equal to zero. Since gravitational waves carry the curvature and, consequently, affect the detector, this bears witness to an intrinsic contradiction of the Einstein theory. To realize the sources of difficulties concerning energy-momentum in the Einstein theory the gravitational field is treated in the same way as all the other physical fields, i.e. in terms of usual Lorentz-invariant field theory. Unification of this approach with the Einstein idea of geometrization enables to construct the geometrized theory, which is free from contradictions, has clearly defined the notions of gravitation field energy-momentum and satisfactorily describes all known experimental facts. To construct a logically consistent theory one should geometrize only the density of the matter Lagrangian. The gravitation field equations are formulated in terms of the Euclidean space-time with a metric tensor γsub(ik), while the matter motion may be completely described in terms of the non-Euclidean space-time with a metric tensor gsub(ik). For strong gravitational fields the predictions of the quasi-linear theory under consideration appriciably differ from those of the Einstein formulation of the gravitation theory. No black holes are present in the theory. The results of the calculation for the energy flow of gravitational waves are rigorously unambiguous and show that gravitational waves carry positively definite energy
DEFF Research Database (Denmark)
Wæver, Ole
2009-01-01
-empiricism and anti-positivism of his position. Followers and critics alike have treated Waltzian neorealism as if it was at bottom a formal proposition about cause-effect relations. The extreme case of Waltz being so victorious in the discipline, and yet being consistently mis-interpreted on the question of theory......, shows the power of a dominant philosophy of science in US IR, and thus the challenge facing any ambitious theorising. The article suggests a possible movement of fronts away from the ‘fourth debate' between rationalism and reflectivism towards one of theory against empiricism. To help this new agenda...
Extended Thermodynamics: a Theory of Symmetric Hyperbolic Field Equations
Müller, Ingo
2008-12-01
Extended thermodynamics is based on a set of equations of balance which are supplemented by local and instantaneous constitutive equations so that the field equations are quasi-linear first order differential equations. If the constitutive functions are subject to the requirements of the entropy principle, one may write them in symmetric hyperbolic form by a suitable choice of fields. The kinetic theory of gases, or the moment theories based on the Boltzmann equation provide an explicit example for extended thermodynamics. The theory proves its usefulness and practicality in the successful treatment of light scattering in rarefied gases. This presentation is based upon the book [1] of which the author of this paper is a co-author. For more details about the motivation and exploitation of the basic principles the interested reader is referred to that reference. It would seem that extended thermodynamics is worthy of the attention of mathematicians. It may offer them a non-trivial field of study concerning hyperbolic equations, if ever they get tired of the Burgers equation. Physicists may prefer to appreciate the success of extended thermodynamics in light scattering and to work on the open problems concerning the modification of the Navier-Stokes-Fourier theory in rarefied gases as predicted by extended thermodynamics of 13, 14, and more moments.
Restricted Interval Guelph permeameter: Theory and application
International Nuclear Information System (INIS)
Freifeld, Barry M.; Oldenburg, Curtis M.
2003-01-01
A constant head permeameter system has been developed for use in small diameter boreholes with any orientation. It is based upon the original Guelph permeameter concept of using a Mariotte siphon reservoir to control the applied head. The new tool, called a Restricted Interval Guelph (RIG) permeameter uses either a single pneumatic packer or straddle packer to restrict the area through which water is allowed to flow so that the borehole wetted area is independent of the applied head. The RIG permeameter has been used at Yucca Mountain, Nevada, in the nonwelded rhyolitic Paintbrush Tuff. Analysis of the acquired data is based upon saturated-unsaturated flow theory that relies upon the quasi-linear approximation to estimate field-saturated hydraulic conductivity (Kfs) and the a parameter (sorptive number) of the exponential relative hydraulic conductivity pressure head relationship. These results are compared with a numerical model based upon the solution of the Richards equation using a van Genuchten capillary pressure-saturation formulation. The numerical model incorporates laboratory capillary pressure versus saturation functions measured from cores taken from nearby boreholes. Comparison between the analytical and numerical approaches shows that the simple analytic model is valid for analyzing the data collected. Sensitivity analysis performed with the numerical model shows that the RIG permeameter is an effective tool for estimating permeability and sorptive number for the nonwelded Paintbrush Tuff
Jara, Pascual; Torrecillas, Blas
1988-01-01
The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.
DEFF Research Database (Denmark)
Hendricks, Vincent F.
Game Theory is a collection of short interviews based on 5 questions presented to some of the most influential and prominent scholars in game theory. We hear their views on game theory, its aim, scope, use, the future direction of game theory and how their work fits in these respects....
International Nuclear Information System (INIS)
Chan Hongmo.
1987-10-01
The paper traces the development of the String Theory, and was presented at Professor Sir Rudolf Peierls' 80sup(th) Birthday Symposium. The String theory is discussed with respect to the interaction of strings, the inclusion of both gauge theory and gravitation, inconsistencies in the theory, and the role of space-time. The physical principles underlying string theory are also outlined. (U.K.)
String theory or field theory?
International Nuclear Information System (INIS)
Marshakov, A.V.
2002-01-01
The status of string theory is reviewed, and major recent developments - especially those in going beyond perturbation theory in the string theory and quantum field theory frameworks - are analyzed. This analysis helps better understand the role and place of experimental phenomena, it is emphasized that there are some insurmountable problems inherent in it - notably the impossibility to formulate the quantum theory of gravity on its basis - which prevent it from being a fundamental physical theory of the world of microscopic distances. It is this task, the creation of such a theory, which string theory, currently far from completion, is expected to solve. In spite of its somewhat vague current form, string theory has already led to a number of serious results and greatly contributed to progress in the understanding of quantum field theory. It is these developments, which are our concern in this review [ru
International Nuclear Information System (INIS)
Uehara, S.
1985-01-01
Of all supergravity theories, the maximal, i.e., N = 8 in 4-dimension or N = 1 in 11-dimension, theory should perform the unification since it owns the highest degree of symmetry. As to the N = 1 in d = 11 theory, it has been investigated how to compactify to the d = 4 theories. From the phenomenological point of view, local SUSY GUTs, i.e., N = 1 SUSY GUTs with soft breaking terms, have been studied from various angles. The structures of extended supergravity theories are less understood than those of N = 1 supergravity theories, and matter couplings in N = 2 extended supergravity theories are under investigation. The harmonic superspace was recently proposed which may be useful to investigate the quantum effects of extended supersymmetry and supergravity theories. As to the so-called Kaluza-Klein supergravity, there is another possibility. (Mori, K.)
Johnstone, PT
2014-01-01
Focusing on topos theory's integration of geometric and logical ideas into the foundations of mathematics and theoretical computer science, this volume explores internal category theory, topologies and sheaves, geometric morphisms, other subjects. 1977 edition.
Kinetic theory of interaction of high frequency waves with a rotating plasma
International Nuclear Information System (INIS)
Chiu, S. C.; Chan, V. S.; Chu, M. S.; Lin-Liu, Y. R.
2000-01-01
The equations of motion of charged particles of a strongly magnetized flowing plasma under the influence of high frequency waves are derived in the guiding center approximation. A quasilinear theory of the interactions of waves with rotating plasmas is formulated. This is applied to investigate the effect of radio frequency waves on a rotating tokamak plasma with a heated minority species. The angular momentum drive is mainly due to the rf-induced radial minority current. The return current by the bulk plasma gives an equal and opposite rotation drive on the bulk. Using moment equations and a small banana width approximation, the JxB drive was evaluated for the bulk plasma. Quite remarkably, although collisions are included, the net rotation drive is due to a term which can be obtained by neglecting collisions. (c) 2000 American Institute of Physics
Dorogovtsev, A Ya; Skorokhod, A V; Silvestrov, D S; Skorokhod, A V
1997-01-01
This book of problems is intended for students in pure and applied mathematics. There are problems in traditional areas of probability theory and problems in the theory of stochastic processes, which has wide applications in the theory of automatic control, queuing and reliability theories, and in many other modern science and engineering fields. Answers to most of the problems are given, and the book provides hints and solutions for more complicated problems.
International Nuclear Information System (INIS)
Lee, B.W.
1976-01-01
Some introductory remarks to Yang-Mills fields are given and the problem of the Coulomb gauge is considered. The perturbation expansion for quantized gauge theories is discussed and a survey of renormalization schemes is made. The role of Ward-Takahashi identities in gauge theories is discussed. The author then discusses the renormalization of pure gauge theories and theories with spontaneously broken symmetry. (B.R.H.)
Loring, FH
2014-01-01
Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec
Harris, Tina
2015-04-29
Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.
Number theory via Representation theory
Indian Academy of Sciences (India)
2014-11-09
Number theory via Representation theory. Eknath Ghate. November 9, 2014. Eightieth Annual Meeting, Chennai. Indian Academy of Sciences1. 1. This is a non-technical 20 minute talk intended for a general Academy audience.
International Nuclear Information System (INIS)
Schwarz, J.H.
1985-01-01
Dual string theories, initially developed as phenomenological models of hadrons, now appear more promising as candidates for a unified theory of fundamental interactions. Type I superstring theory (SST I), is a ten-dimensional theory of interacting open and closed strings, with one supersymmetry, that is free from ghosts and tachyons. It requires that an SO(eta) or Sp(2eta) gauge group be used. A light-cone-gauge string action with space-time supersymmetry automatically incorporates the superstring restrictions and leads to the discovery of type II superstring theory (SST II). SST II is an interacting theory of closed strings only, with two D=10 supersymmetries, that is also free from ghosts and tachyons. By taking six of the spatial dimensions to form a compact space, it becomes possible to reconcile the models with our four-dimensional perception of spacetime and to define low-energy limits in which SST I reduces to N=4, D=4 super Yang-Mills theory and SST II reduces to N=8, D=4 supergravity theory. The superstring theories can be described by a light-cone-gauge action principle based on fields that are functionals of string coordinates. With this formalism any physical quantity should be calculable. There is some evidence that, unlike any conventional field theory, the superstring theories provide perturbatively renormalizable (SST I) or finite (SST II) unifications of gravity with other interactions
String theory or field theory?
International Nuclear Information System (INIS)
Marshakov, Andrei V
2002-01-01
The status of string theory is reviewed, and major recent developments - especially those in going beyond perturbation theory in the string theory and quantum field theory frameworks - are analyzed. This analysis helps better understand the role and place of string theory in the modern picture of the physical world. Even though quantum field theory describes a wide range of experimental phenomena, it is emphasized that there are some insurmountable problems inherent in it - notably the impossibility to formulate the quantum theory of gravity on its basis - which prevent it from being a fundamental physical theory of the world of microscopic distances. It is this task, the creation of such a theory, which string theory, currently far from completion, is expected to solve. In spite of its somewhat vague current form, string theory has already led to a number of serious results and greatly contributed to progress in the understanding of quantum field theory. It is these developments which are our concern in this review. (reviews of topical problems)
Dependence theory via game theory
Grossi, D.; Turrini, P.
2011-01-01
In the multi-agent systems community, dependence theory and game theory are often presented as two alternative perspectives on the analysis of social interaction. Up till now no research has been done relating these two approaches. The unification presented provides dependence theory with the sort
Beyond WKB quantum corrections to Hamilton-Jacobi theory
International Nuclear Information System (INIS)
Jurisch, Alexander
2007-01-01
In this paper, we develop quantum mechanics of quasi-one-dimensional systems upon the framework of the quantum-mechanical Hamilton-Jacobi theory. We will show that the Schroedinger point of view and the Hamilton-Jacobi point of view are fully equivalent in their description of physical systems, but differ in their descriptive manner. As a main result of this, a wavefunction in Hamilton-Jacobi theory can be decomposed into travelling waves in any point in space, not only asymptotically. Using the quasi-linearization technique, we derive quantum correction functions in every order of h-bar. The quantum correction functions will remove the turning-point singularity that plagues the WKB-series expansion already in zeroth order and thus provide an extremely good approximation to the full solution of the Schroedinger equation. In the language of quantum action it is also possible to elegantly solve the connection problem without asymptotic approximations. The use of quantum action further allows us to derive an equation by which the Maslov index is directly calculable without any approximations. Stationary quantum trajectories will also be considered and thoroughly discussed
Chang, CC
2012-01-01
Model theory deals with a branch of mathematical logic showing connections between a formal language and its interpretations or models. This is the first and most successful textbook in logical model theory. Extensively updated and corrected in 1990 to accommodate developments in model theoretic methods - including classification theory and nonstandard analysis - the third edition added entirely new sections, exercises, and references. Each chapter introduces an individual method and discusses specific applications. Basic methods of constructing models include constants, elementary chains, Sko
Aubin, Jean-Pierre; Saint-Pierre, Patrick
2011-01-01
Viability theory designs and develops mathematical and algorithmic methods for investigating the adaptation to viability constraints of evolutions governed by complex systems under uncertainty that are found in many domains involving living beings, from biological evolution to economics, from environmental sciences to financial markets, from control theory and robotics to cognitive sciences. It involves interdisciplinary investigations spanning fields that have traditionally developed in isolation. The purpose of this book is to present an initiation to applications of viability theory, explai
Cox, David A
2012-01-01
Praise for the First Edition ". . .will certainly fascinate anyone interested in abstract algebra: a remarkable book!"—Monatshefte fur Mathematik Galois theory is one of the most established topics in mathematics, with historical roots that led to the development of many central concepts in modern algebra, including groups and fields. Covering classic applications of the theory, such as solvability by radicals, geometric constructions, and finite fields, Galois Theory, Second Edition delves into novel topics like Abel’s theory of Abelian equations, casus irreducibili, and the Galo
Dufwenberg, Martin
2011-03-01
Game theory is a toolkit for examining situations where decision makers influence each other. I discuss the nature of game-theoretic analysis, the history of game theory, why game theory is useful for understanding human psychology, and why game theory has played a key role in the recent explosion of interest in the field of behavioral economics. WIREs Cogni Sci 2011 2 167-173 DOI: 10.1002/wcs.119 For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.
Hashiguchi, Koichi
2009-01-01
This book details the mathematics and continuum mechanics necessary as a foundation of elastoplasticity theory. It explains physical backgrounds with illustrations and provides descriptions of detailed derivation processes..
Otsuka, F.; Matsukiyo, S.; Kis, A.; Hada, T.
2017-12-01
Spatial diffusion of energetic particles is an important problem not only from a fundamental physics point of view but also for its application to particle acceleration processes at astrophysical shocks. Quasi-linear theory can provide the spatial diffusion coefficient as a function of the wave turbulence spectrum. By assuming a simple power-law spectrum for the turbulence, the theory has been successfully applied to diffusion and acceleration of cosmic rays in the interplanetary and interstellar medium. Near the earth's foreshock, however, the wave spectrum often has an intense peak, presumably corresponding to the upstream ULF waves generated by the field-aligned beam (FAB). In this presentation, we numerically and theoretically discuss how the intense ULF peak in the wave spectrum modifies the spatial parallel diffusion of energetic ions. The turbulence is given as a superposition of non-propagating transverse MHD waves in the solar wind rest frame, and its spectrum is composed of a piecewise power-law spectrum with different power-law indices. The diffusion coefficients are then estimated by using the quasi-linear theory and test particle simulations. We find that the presence of the ULF peak produces a concave shape of the diffusion coefficient when it is plotted versus the ion energy. The results above are used to discuss the Cluster observations of the diffuse ions at the Earth's foreshock. Using the density gradients of the energetic ions detected by the Cluster spacecraft, we determine the e-folding distances, equivalently, the spatial diffusion coefficients, of ions with their energies from 10 to 32 keV. The observed e-folding distances are significantly smaller than those estimated in the past statistical studies. This suggests that the particle acceleration at the foreshock can be more efficient than considered before. Our test particle simulation explains well the small estimate of the e-folding distances, by using the observed wave turbulence spectrum
International Nuclear Information System (INIS)
Bartlett, R.; Kirtman, B.; Davidson, E.R.
1978-01-01
After noting some advantages of using perturbation theory some of the various types are related on a chart and described, including many-body nonlinear summations, quartic force-field fit for geometry, fourth-order correlation approximations, and a survey of some recent work. Alternative initial approximations in perturbation theory are also discussed. 25 references
R. Veenhoven (Ruut)
2014-01-01
markdownabstract__Abstract__ Need theory of happiness is linked to affect theory, which holds that happiness is a reflection of how well we feel generally. In this view, we do not "calculate" happiness but rather "infer" it, the typical heuristic being "I feel good most of the time, hence
Bouwkamp, C.J.
1954-01-01
A critical review is presented of recent progress in classical diffraction theory. Both scalar and electromagnetic problems are discussed. The report may serve as an introduction to general diffraction theory although the main emphasis is on diffraction by plane obstacles. Various modifications of
Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří
1988-01-01
Within the tradition of meetings devoted to potential theory, a conference on potential theory took place in Prague on 19-24, July 1987. The Conference was organized by the Faculty of Mathematics and Physics, Charles University, with the collaboration of the Institute of Mathematics, Czechoslovak Academy of Sciences, the Department of Mathematics, Czech University of Technology, the Union of Czechoslovak Mathematicians and Physicists, the Czechoslovak Scientific and Technical Society, and supported by IMU. During the Conference, 69 scientific communications from different branches of potential theory were presented; the majority of them are in cluded in the present volume. (Papers based on survey lectures delivered at the Conference, its program as well as a collection of problems from potential theory will appear in a special volume of the Lecture Notes Series published by Springer-Verlag). Topics of these communications truly reflect the vast scope of contemporary potential theory. Some contributions deal...
DEFF Research Database (Denmark)
Bjerg, Ole; Presskorn-Thygesen, Thomas
2017-01-01
The paper is a contribution to current debates about conspiracy theories within philosophy and cultural studies. Wittgenstein’s understanding of language is invoked to analyse the epistemological effects of designating particular questions and explanations as a ‘conspiracy theory......’. It is demonstrated how such a designation relegates these questions and explanations beyond the realm of meaningful discourse. In addition, Agamben’s concept of sovereignty is applied to explore the political effects of using the concept of conspiracy theory. The exceptional epistemological status assigned...... to alleged conspiracy theories within our prevalent paradigms of knowledge and truth is compared to the exceptional legal status assigned to individuals accused of terrorism under the War on Terror. The paper concludes by discussing the relation between conspiracy theory and ‘the paranoid style...
1999-11-08
In these lectures I will build up the concept of field theory using the language of Feynman diagrams. As a starting point, field theory in zero spacetime dimensions is used as a vehicle to develop all the necessary techniques: path integral, Feynman diagrams, Schwinger-Dyson equations, asymptotic series, effective action, renormalization etc. The theory is then extended to more dimensions, with emphasis on the combinatorial aspects of the diagrams rather than their particular mathematical structure. The concept of unitarity is used to, finally, arrive at the various Feynman rules in an actual, four-dimensional theory. The concept of gauge-invariance is developed, and the structure of a non-abelian gauge theory is discussed, again on the level of Feynman diagrams and Feynman rules.
Liu, Baoding
2015-01-01
When no samples are available to estimate a probability distribution, we have to invite some domain experts to evaluate the belief degree that each event will happen. Perhaps some people think that the belief degree should be modeled by subjective probability or fuzzy set theory. However, it is usually inappropriate because both of them may lead to counterintuitive results in this case. In order to rationally deal with belief degrees, uncertainty theory was founded in 2007 and subsequently studied by many researchers. Nowadays, uncertainty theory has become a branch of axiomatic mathematics for modeling belief degrees. This is an introductory textbook on uncertainty theory, uncertain programming, uncertain statistics, uncertain risk analysis, uncertain reliability analysis, uncertain set, uncertain logic, uncertain inference, uncertain process, uncertain calculus, and uncertain differential equation. This textbook also shows applications of uncertainty theory to scheduling, logistics, networks, data mining, c...
DEFF Research Database (Denmark)
Hjørland, Birger
2009-01-01
Concept theory is an extremely broad, interdisciplinary and complex field of research related to many deep fields with very long historical traditions without much consensus. However, information science and knowledge organization cannot avoid relating to theories of concepts. Knowledge...... organizing systems (e.g. classification systems, thesauri and ontologies) should be understood as systems basically organizing concepts and their semantic relations. The same is the case with information retrieval systems. Different theories of concepts have different implications for how to construe......, evaluate and use such systems. Based on "a post-Kuhnian view" of paradigms this paper put forward arguments that the best understanding and classification of theories of concepts is to view and classify them in accordance with epistemological theories (empiricism, rationalism, historicism and pragmatism...
Andrews, George E
1994-01-01
Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic.In this book the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. In studying number theory from such a perspective, mathematics majors are spared repetition and provided with new insights, while other students benefit from the consequent simpl
Schmidli, Hanspeter
2017-01-01
This book provides an overview of classical actuarial techniques, including material that is not readily accessible elsewhere such as the Ammeter risk model and the Markov-modulated risk model. Other topics covered include utility theory, credibility theory, claims reserving and ruin theory. The author treats both theoretical and practical aspects and also discusses links to Solvency II. Written by one of the leading experts in the field, these lecture notes serve as a valuable introduction to some of the most frequently used methods in non-life insurance. They will be of particular interest to graduate students, researchers and practitioners in insurance, finance and risk management.
DEFF Research Database (Denmark)
Smith, Shelley
This paper came about within the context of a 13-month research project, Focus Area 1 - Method and Theory, at the Center for Public Space Research at the Royal Academy of the Arts School of Architecture in Copenhagen, Denmark. This project has been funded by RealDania. The goals of the research...... project, Focus Area 1 - Method and Theory, which forms the framework for this working paper, are: * To provide a basis from which to discuss the concept of public space in a contemporary architectural and urban context - specifically relating to theory and method * To broaden the discussion of the concept...
Lubliner, Jacob
2008-01-01
The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and
DEFF Research Database (Denmark)
Linder, Stefan; Foss, Nicolai Juul
Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting and informational conditions, the theory addresses problems of ex...... ante (“hidden characteristics”) as well as ex post information asymmetry (“hidden action”), and examines conditions under which various kinds of incentive instruments and monitoring arrangements can be deployed to minimize the welfare loss. Its clear predictions and broad applicability have allowed...... agency theory to enjoy considerable scientific impact on social science; however, it has also attracted considerable criticism....
DEFF Research Database (Denmark)
Linder, Stefan; Foss, Nicolai Juul
2015-01-01
Agency theory studies the problems and solutions linked to delegation of tasks from principals to agents in the context of conflicting interests between the parties. Beginning from clear assumptions about rationality, contracting, and informational conditions, the theory addresses problems of ex...... ante (‘hidden characteristics’) as well as ex post information asymmetry (‘hidden action’), and examines conditions under which various kinds of incentive instruments and monitoring arrangements can be deployed to minimize the welfare loss. Its clear predictions and broad applicability have allowed...... agency theory to enjoy considerable scientific impact on social science; however, it has also attracted considerable criticism....
Nel, Louis
2016-01-01
This book presents a detailed, self-contained theory of continuous mappings. It is mainly addressed to students who have already studied these mappings in the setting of metric spaces, as well as multidimensional differential calculus. The needed background facts about sets, metric spaces and linear algebra are developed in detail, so as to provide a seamless transition between students' previous studies and new material. In view of its many novel features, this book will be of interest also to mature readers who have studied continuous mappings from the subject's classical texts and wish to become acquainted with a new approach. The theory of continuous mappings serves as infrastructure for more specialized mathematical theories like differential equations, integral equations, operator theory, dynamical systems, global analysis, topological groups, topological rings and many more. In light of the centrality of the topic, a book of this kind fits a variety of applications, especially those that contribute to ...
Hodges, Wilfrid
1993-01-01
An up-to-date and integrated introduction to model theory, designed to be used for graduate courses (for students who are familiar with first-order logic), and as a reference for more experienced logicians and mathematicians.
Lunardi, Alessandra
2018-01-01
This book is the third edition of the 1999 lecture notes of the courses on interpolation theory that the author delivered at the Scuola Normale in 1998 and 1999. In the mathematical literature there are many good books on the subject, but none of them is very elementary, and in many cases the basic principles are hidden below great generality. In this book the principles of interpolation theory are illustrated aiming at simplification rather than at generality. The abstract theory is reduced as far as possible, and many examples and applications are given, especially to operator theory and to regularity in partial differential equations. Moreover the treatment is self-contained, the only prerequisite being the knowledge of basic functional analysis.
International Nuclear Information System (INIS)
1989-06-01
This report discusses concepts in nuclear theory such as: neutrino nucleosynthesis; double beta decay; neutrino oscillations; chiral symmetry breaking; T invariance; quark propagator; cold fusion; and other related topics
R. Veenhoven (Ruut)
2014-01-01
markdownabstract__Abstract__ Assumptions Livability theory involves the following six key assumptions: 1. Like all animals, humans have innate needs, such as for food, safety, and companionship. 2. Gratification of needs manifests in hedonic experience. 3. Hedonic experience determines how
SAIDANI Lassaad
2015-01-01
The nokton theory is an attempt to construct a theory adapted to every physical phenomenon. Space and time have been discretized. Its laws are iterative and precise. Probability plays an important role here. At first I defined the notion of image function and its mathematical framework. The notion of nokton and its state are the basis of several definitions. I later defined the canonical image function and the canonical contribution. Two constants have been necessary to define the dynam...
SAIDANI Lassaad
2017-01-01
The nokton theory is an attempt to construct a theory adapted to every physical phenomenon. Space and time have been discretized. Its laws are iterative and precise. Probability plays an important role here. At first I defined the notion of image function and its mathematical framework. The notion of nokton and its state are the basis of several definitions. I later defined the canonical image function and the canonical contribution. Two constants have been necessary to define the dynam...
Gould, Ronald
2012-01-01
This introduction to graph theory focuses on well-established topics, covering primary techniques and including both algorithmic and theoretical problems. The algorithms are presented with a minimum of advanced data structures and programming details. This thoroughly corrected 1988 edition provides insights to computer scientists as well as advanced undergraduates and graduate students of topology, algebra, and matrix theory. Fundamental concepts and notation and elementary properties and operations are the first subjects, followed by examinations of paths and searching, trees, and networks. S
A Thermodynamic Theory Of Solid Viscoelasticity. Part 1: Linear Viscoelasticity.
Freed, Alan D.; Leonov, Arkady I.
2002-01-01
The present series of three consecutive papers develops a general theory for linear and finite solid viscoelasticity. Because the most important object for nonlinear studies are rubber-like materials, the general approach is specified in a form convenient for solving problems important for many industries that involve rubber-like materials. General linear and nonlinear theories for non-isothermal deformations of viscoelastic solids are developed based on the quasi-linear approach of non-equilibrium thermodynamics. In this, the first paper of the series, we analyze non-isothermal linear viscoelasticity, which is applicable in a range of small strains not only to all synthetic polymers and bio-polymers but also to some non-polymeric materials. Although the linear case seems to be well developed, there still are some reasons to implement a thermodynamic derivation of constitutive equations for solid-like, non-isothermal, linear viscoelasticity. The most important is the thermodynamic modeling of thermo-rheological complexity , i.e. different temperature dependences of relaxation parameters in various parts of relaxation spectrum. A special structure of interaction matrices is established for different physical mechanisms contributed to the normal relaxation modes. This structure seems to be in accord with observations, and creates a simple mathematical framework for both continuum and molecular theories of the thermo-rheological complex relaxation phenomena. Finally, a unified approach is briefly discussed that, in principle, allows combining both the long time (discrete) and short time (continuous) descriptions of relaxation behaviors for polymers in the rubbery and glassy regions.
Das, Animesh; Gieb, Klaus; Krupskaya, Yulia; Demeshko, Serhiy; Dechert, Sebastian; Klingeler, Rüdiger; Kataev, Vladislav; Büchner, Bernd; Müller, Paul; Meyer, Franc
2011-03-16
First members of a new family of heterometallic Mn/Ni complexes [Mn(2)Ni(3)X(2)L(4)(LH)(2)(H(2)O)(2)] (X = Cl: 1; X = Br: 2) with the new ligand 2-{3-(2-hydroxyphenyl)-1H-pyrazol-1-yl}ethanol (H(2)L) have been synthesized, and single crystals obtained from CH(2)Cl(2) solutions have been characterized crystallographically. The molecular structures feature a quasi-linear Mn(III)-Ni(II)-Ni(II)-Ni(II)-Mn(III) core with six-coordinate metal ions, where elongated axes of all the distorted octahedral coordination polyhedra are aligned parallel and are fixed with respect to each other by intramolecular hydrogen bonds. 1 and 2 exhibit quite strong ferromagnetic exchange interactions throughout (J(Mn-Ni) ≈ 40 K (1) or 42 K (2); J(Ni-Ni) ≈ 22 K (1) or 18 K (2)) that lead to an S(tot) = 7 ground state, and a sizable uniaxial magnetoanisotropy with D(mol) values -0.55 K (1) and -0.45 K (2). These values are directly derived also from frequency- and temperature-dependent high-field EPR spectra. Slow relaxation of the magnetization at low temperatures and single-molecule magnet (SMM) behavior are evident from frequency-dependent peaks in the out-of-phase ac susceptibilities and magnetization versus dc field measurements, with significant energy barriers to spin reversal U(eff) = 27 K (1) and 22 K (2). Pronounced quantum tunnelling steps are observed in the hysteresis loops of the temperature- and scan rate-dependent magnetization data, but with the first relaxation step shifted above (1) or below (2) the zero crossing of the magnetic field, despite the very similar molecular structures. The different behavior of 1 and 2 is interpreted in terms of antiferromagnetic (1) or ferromagnetic (2) intermolecular interactions, which are discussed in view of the subtle differences of intermolecular contacts within the crystal lattice.
Kodaira, Kunihiko
2017-01-01
This book deals with the classical theory of Nevanlinna on the value distribution of meromorphic functions of one complex variable, based on minimum prerequisites for complex manifolds. The theory was extended to several variables by S. Kobayashi, T. Ochiai, J. Carleson, and P. Griffiths in the early 1970s. K. Kodaira took up this subject in his course at The University of Tokyo in 1973 and gave an introductory account of this development in the context of his final paper, contained in this book. The first three chapters are devoted to holomorphic mappings from C to complex manifolds. In the fourth chapter, holomorphic mappings between higher dimensional manifolds are covered. The book is a valuable treatise on the Nevanlinna theory, of special interests to those who want to understand Kodaira's unique approach to basic questions on complex manifolds.
International Nuclear Information System (INIS)
Kenyon, I.R.
1986-01-01
Modern theories of the interactions between fundamental particles are all gauge theories. In the case of gravitation, application of this principle to space-time leads to Einstein's theory of general relativity. All the other interactions involve the application of the gauge principle to internal spaces. Electromagnetism serves to introduce the idea of a gauge field, in this case the electromagnetic field. The next example, the strong force, shows unique features at long and short range which have their origin in the self-coupling of the gauge fields. Finally the unification of the description of the superficially dissimilar electromagnetic and weak nuclear forces completes the picture of successes of the gauge principle. (author)
Stewart, Ian
2003-01-01
Ian Stewart's Galois Theory has been in print for 30 years. Resoundingly popular, it still serves its purpose exceedingly well. Yet mathematics education has changed considerably since 1973, when theory took precedence over examples, and the time has come to bring this presentation in line with more modern approaches.To this end, the story now begins with polynomials over the complex numbers, and the central quest is to understand when such polynomials have solutions that can be expressed by radicals. Reorganization of the material places the concrete before the abstract, thus motivating the g
International Nuclear Information System (INIS)
Sitenko, A.
1991-01-01
This book emerged out of graduate lectures given by the author at the University of Kiev and is intended as a graduate text. The fundamentals of non-relativistic quantum scattering theory are covered, including some topics, such as the phase-function formalism, separable potentials, and inverse scattering, which are not always coverded in textbooks on scattering theory. Criticisms of the text are minor, but the reviewer feels an inadequate index is provided and the citing of references in the Russian language is a hindrance in a graduate text
Constant-roll (quasi-)linear inflation
Karam, A.; Marzola, L.; Pappas, T.; Racioppi, A.; Tamvakis, K.
2018-05-01
In constant-roll inflation, the scalar field that drives the accelerated expansion of the Universe is rolling down its potential at a constant rate. Within this framework, we highlight the relations between the Hubble slow-roll parameters and the potential ones, studying in detail the case of a single-field Coleman-Weinberg model characterised by a non-minimal coupling of the inflaton to gravity. With respect to the exact constant-roll predictions, we find that assuming an approximate slow-roll behaviour yields a difference of Δ r = 0.001 in the tensor-to-scalar ratio prediction. Such a discrepancy is in principle testable by future satellite missions. As for the scalar spectral index ns, we find that the existing 2-σ bound constrains the value of the non-minimal coupling to ξphi ~ 0.29–0.31 in the model under consideration.
Quasilinear infiltration from an elliptical cavity
Kuhlman, Kristopher L.; Warrick, Arthur W.
2008-08-01
We develop analytic solutions to the linearized steady-state Richards equation for head and total flowrate due to an elliptic cylinder cavity with a specified pressure head boundary condition. They are generalizations of the circular cylinder cavity solutions of Philip [Philip JR. Steady infiltration from circular cylindrical cavities. Soil Sci Soc Am J 1984;48:270-8]. The circular and strip sources are limiting cases of the elliptical cylinder solution, derived for both horizontally- and vertically-aligned ellipses. We give approximate rational polynomial expressions for total flowrate from an elliptical cylinder over a range of sizes and shapes. The exact elliptical solution is in terms of Mathieu functions, which themselves are generalizations of and computed from trigonometric and Bessel functions. The required Mathieu functions are computed from a matrix eigenvector problem, a modern approach that is straightforward to implement using available linear algebra libraries. Although less efficient and potentially less accurate than the iterative continued fraction approach, the matrix approach is simpler to understand and implement and is valid over a wider parameter range.
A quasilinear formulation of turbulence driven current
Energy Technology Data Exchange (ETDEWEB)
McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2014-02-15
Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude.
A quasilinear formulation of turbulence driven current
International Nuclear Information System (INIS)
McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua
2014-01-01
Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude
Sferra, Bobbie A.; Paddock, Susan C.
This booklet describes various theoretical aspects of leadership, including the proper exercise of authority, effective delegation, goal setting, exercise of control, assignment of responsibility, performance evaluation, and group process facilitation. It begins by describing the evolution of general theories of leadership from historic concepts…
Hall, Marshall
2011-01-01
Includes proof of van der Waerden's 1926 conjecture on permanents, Wilson's theorem on asymptotic existence, and other developments in combinatorics since 1967. Also covers coding theory and its important connection with designs, problems of enumeration, and partition. Presents fundamentals in addition to latest advances, with illustrative problems at the end of each chapter. Enlarged appendixes include a longer list of block designs.
Toso, Robert B.
2000-01-01
Inspired by William Glasser's Reality Therapy ideas, Control Theory (CT) is a disciplinary approach that stresses people's ability to control only their own behavior, based on internal motivations to satisfy five basic needs. At one North Dakota high school, CT-trained teachers are the program's best recruiters. (MLH)
de Vreese, C.H.; Lecheler, S.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.
2016-01-01
Political issues can be viewed from different perspectives and they can be defined differently in the news media by emphasizing some aspects and leaving others aside. This is at the core of news framing theory. Framing originates within sociology and psychology and has become one of the most used
International Nuclear Information System (INIS)
Gong, Ha Soung
2006-12-01
The text book composed of five parts, which are summary of this book, arrangement of electricity theory including electricity nad magnetism, a direct current, and alternating current. It has two dictionary electricity terms for a synonym. The last is an appendix. It is for preparing for test of officer, electricity engineer and fire fighting engineer.
DEFF Research Database (Denmark)
Monthoux, Pierre Guillet de; Statler, Matt
2014-01-01
The recent Carnegie report (Colby, et al., 2011) characterizes the goal of business education as the development of practical wisdom. In this chapter, the authors reframe Scharmer’s Theory U as an attempt to develop practical wisdom by applying certain European philosophical concepts. Specifically...
DEFF Research Database (Denmark)
Guillet de Monthoux, Pierre; Statler, Matt
2017-01-01
The recent Carnegie report (Colby, et al., 2011) characterizes the goal of business education as the development of practical wisdom. In this chapter, the authors reframe Scharmer's Theory U as an attempt to develop practical wisdom by applying certain European philosophical concepts. Specifically...
International Nuclear Information System (INIS)
Tang, W.M.
2001-01-01
This is a summary of the advances in magnetic fusion energy theory research presented at the 17th International Atomic Energy Agency Fusion Energy Conference from 19 24 October, 1998 in Yokohama, Japan. Theory and simulation results from this conference provided encouraging evidence of significant progress in understanding the physics of thermonuclear plasmas. Indeed, the grand challenge for this field is to acquire the basic understanding that can readily enable the innovations which would make fusion energy practical. In this sense, research in fusion energy is increasingly able to be categorized as fitting well the 'Pasteur's Quadrant' paradigm, where the research strongly couples basic science ('Bohr's Quadrant') to technological impact ('Edison's Quadrant'). As supported by some of the work presented at this conference, this trend will be further enhanced by advanced simulations. Eventually, realistic three-dimensional modeling capabilities, when properly combined with rapid and complete data interpretation of results from both experiments and simulations, can contribute to a greatly enhanced cycle of understanding and innovation. Plasma science theory and simulation have provided reliable foundations for this improved modeling capability, and the exciting advances in high-performance computational resources have further accelerated progress. There were 68 papers presented at this conference in the area of magnetic fusion energy theory
Penland, Patrick R.
Three papers are presented which delineate the foundation of theory and principles which underlie the research and instructional approach to communications at the Graduate School of Library and Information Science, University of Pittsburgh. Cybernetic principles provide the integration, and validation is based in part on a situation-producing…
Lee, William H K.
2016-01-01
A complex system consists of many interacting parts, generates new collective behavior through self organization, and adaptively evolves through time. Many theories have been developed to study complex systems, including chaos, fractals, cellular automata, self organization, stochastic processes, turbulence, and genetic algorithms.
Plummer, MD
1986-01-01
This study of matching theory deals with bipartite matching, network flows, and presents fundamental results for the non-bipartite case. It goes on to study elementary bipartite graphs and elementary graphs in general. Further discussed are 2-matchings, general matching problems as linear programs, the Edmonds Matching Algorithm (and other algorithmic approaches), f-factors and vertex packing.
DEFF Research Database (Denmark)
Bertelsen, Olav Wedege; Bødker, Susanne
2003-01-01
the young HCI research tradition. But HCI was already facing problems: lack of consideration for other aspects of human behavior, for interaction with other people, for culture. Cognitive science-based theories lacked means to address several issues that came out of the empirical projects....
DEFF Research Database (Denmark)
Stein, Irene F.; Stelter, Reinhard
2011-01-01
Communication theory covers a wide variety of theories related to the communication process (Littlejohn, 1999). Communication is not simply an exchange of information, in which we have a sender and a receiver. This very technical concept of communication is clearly outdated; a human being...... is not a data processing device. In this chapter, communication is understood as a process of shared meaning-making (Bruner, 1990). Human beings interpret their environment, other people, and themselves on the basis of their dynamic interaction with the surrounding world. Meaning is essential because people...... ascribe specific meanings to their experiences, their actions in life or work, and their interactions. Meaning is reshaped, adapted, and transformed in every communication encounter. Furthermore, meaning is cocreated in dialogues or in communities of practice, such as in teams at a workplace or in school...
2015-01-01
A one-sentence definition of operator theory could be: The study of (linear) continuous operations between topological vector spaces, these being in general (but not exclusively) Fréchet, Banach, or Hilbert spaces (or their duals). Operator theory is thus a very wide field, with numerous facets, both applied and theoretical. There are deep connections with complex analysis, functional analysis, mathematical physics, and electrical engineering, to name a few. Fascinating new applications and directions regularly appear, such as operator spaces, free probability, and applications to Clifford analysis. In our choice of the sections, we tried to reflect this diversity. This is a dynamic ongoing project, and more sections are planned, to complete the picture. We hope you enjoy the reading, and profit from this endeavor.
Helms, Lester L
2014-01-01
Potential Theory presents a clear path from calculus to classical potential theory and beyond, with the aim of moving the reader into the area of mathematical research as quickly as possible. The subject matter is developed from first principles using only calculus. Commencing with the inverse square law for gravitational and electromagnetic forces and the divergence theorem, the author develops methods for constructing solutions of Laplace's equation on a region with prescribed values on the boundary of the region. The latter half of the book addresses more advanced material aimed at those with the background of a senior undergraduate or beginning graduate course in real analysis. Starting with solutions of the Dirichlet problem subject to mixed boundary conditions on the simplest of regions, methods of morphing such solutions onto solutions of Poisson's equation on more general regions are developed using diffeomorphisms and the Perron-Wiener-Brelot method, culminating in application to Brownian motion. In ...
DEFF Research Database (Denmark)
Jensen, Klaus Bruhn
2016-01-01
This article revisits the place of normative and other practical issues in the wider conceptual architecture of communication theory, building on the tradition of philosophical pragmatism. The article first characterizes everyday concepts of communication as the accumulated outcome of natural...... evolution and history: practical resources for human existence and social coexistence. Such practical concepts have served as the point of departure for diverse theoretical conceptions of what communication is. The second part of the article highlights the past neglect and current potential of normative...... communication theories that ask, in addition, what communication ought to be, and what it could be, taking the relationship between communication and justice as a case in point. The final section returns to empirical conceptualizations of different institutions, practices and discourses of communication...
International Nuclear Information System (INIS)
Jarlskog, C.
An introduction to the unified gauge theories of weak and electromagnetic interactions is given. The ingredients of gauge theories and symmetries and conservation laws lead to discussion of local gauge invariance and QED, followed by weak interactions and quantum flavor dynamics. The construction of the standard SU(2)xU(1) model precedes discussion of the unification of weak and electromagnetic interactions and weak neutral current couplings in this model. Presentation of spontaneous symmetry breaking and spontaneous breaking of a local symmetry leads to a spontaneous breaking scheme for the standard SU(2)xU(1) model. Consideration of quarks, leptons, masses and the Cabibbo angles, of the four quark and six quark models and CP violation lead finally to grand unification, followed by discussion of mixing angles in the Georgi-Glashow model, the Higgses of the SU(5) model and proton/ neutron decay in SU(5). (JIW)
International Nuclear Information System (INIS)
Perjes, Z.
1982-01-01
Particle models in twistor theory are reviewed, starting with an introduction into the kinematical-twistor formalism which describes massive particles in Minkowski space-time. The internal transformations of constituent twistors are then discussed. The quantization rules available from a study of twistor scattering situations are used to construct quantum models of fundamental particles. The theory allows the introduction of an internal space with a Kaehlerian metric where hadron structure is described by spherical states of bound constituents. It is conjectured that the spectrum of successive families of hadrons might approach an accumulation point in energy. Above this threshold energy, the Kaehlerian analog of ionization could occur wherein the zero-mass constituents (twistors) of the particle break free. (Auth.)
DEFF Research Database (Denmark)
Carroll, Joseph; Clasen, Mathias; Jonsson, Emelie
2017-01-01
Biocultural theory is an integrative research program designed to investigate the causal interactions between biological adaptations and cultural constructions. From the biocultural perspective, cultural processes are rooted in the biological necessities of the human life cycle: specifically human...... of research as contributions to a coherent, collective research program. This article argues that a mature biocultural paradigm needs to be informed by at least 7 major research clusters: (a) gene-culture coevolution; (b) human life history theory; (c) evolutionary social psychology; (d) anthropological...... forms of birth, growth, survival, mating, parenting, and sociality. Conversely, from the biocultural perspective, human biological processes are constrained, organized, and developed by culture, which includes technology, culturally specific socioeconomic and political structures, religious...
Weber, Rebecca
2012-01-01
What can we compute--even with unlimited resources? Is everything within reach? Or are computations necessarily drastically limited, not just in practice, but theoretically? These questions are at the heart of computability theory. The goal of this book is to give the reader a firm grounding in the fundamentals of computability theory and an overview of currently active areas of research, such as reverse mathematics and algorithmic randomness. Turing machines and partial recursive functions are explored in detail, and vital tools and concepts including coding, uniformity, and diagonalization are described explicitly. From there the material continues with universal machines, the halting problem, parametrization and the recursion theorem, and thence to computability for sets, enumerability, and Turing reduction and degrees. A few more advanced topics round out the book before the chapter on areas of research. The text is designed to be self-contained, with an entire chapter of preliminary material including re...
Hashiguchi, Koichi
2014-01-01
This book was written to serve as the standard textbook of elastoplasticity for students, engineers and researchers in the field of applied mechanics. The present second edition is improved thoroughly from the first edition by selecting the standard theories from various formulations and models, which are required to study the essentials of elastoplasticity steadily and effectively and will remain universally in the history of elastoplasticity. It opens with an explanation of vector-tensor analysis and continuum mechanics as a foundation to study elastoplasticity theory, extending over various strain and stress tensors and their rates. Subsequently, constitutive equations of elastoplastic and viscoplastic deformations for monotonic, cyclic and non-proportional loading behavior in a general rate and their applications to metals and soils are described in detail, and constitutive equations of friction behavior between solids and its application to the prediction of stick-slip phenomena are delineated. In additi...
Veenhoven, Ruut
2014-01-01
markdownabstract__Abstract__ Assumptions Livability theory involves the following six key assumptions: 1. Like all animals, humans have innate needs, such as for food, safety, and companionship. 2. Gratification of needs manifests in hedonic experience. 3. Hedonic experience determines how much we like the life we live (happiness). Hence, happiness depends on need gratification. 4.Need gratification depends on both external living conditions and inner abilities to use these. Hence, bad living...
International Nuclear Information System (INIS)
Casten, R F
2015-01-01
This paper discusses some simple issues that arise in testing models, with a focus on models for low energy nuclear structure. By way of simplified examples, we illustrate some dangers in blind statistical assessments, pointing out especially the need to include theoretical uncertainties, the danger of over-weighting precise or physically redundant experimental results, the need to assess competing theories with independent and physically sensitive observables, and the value of statistical tests properly evaluated. (paper)
Diestel, Reinhard
2017-01-01
This standard textbook of modern graph theory, now in its fifth edition, combines the authority of a classic with the engaging freshness of style that is the hallmark of active mathematics. It covers the core material of the subject with concise yet reliably complete proofs, while offering glimpses of more advanced methods in each field by one or two deeper results, again with proofs given in full detail. The book can be used as a reliable text for an introductory course, as a graduate text, and for self-study. From the reviews: “This outstanding book cannot be substituted with any other book on the present textbook market. It has every chance of becoming the standard textbook for graph theory.”Acta Scientiarum Mathematiciarum “Deep, clear, wonderful. This is a serious book about the heart of graph theory. It has depth and integrity. ”Persi Diaconis & Ron Graham, SIAM Review “The book has received a very enthusiastic reception, which it amply deserves. A masterly elucidation of modern graph theo...
Friedrich, Harald
2016-01-01
This corrected and updated second edition of "Scattering Theory" presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is k...
Goldie, Charles M
1991-01-01
This book is an introduction, for mathematics students, to the theories of information and codes. They are usually treated separately but, as both address the problem of communication through noisy channels (albeit from different directions), the authors have been able to exploit the connection to give a reasonably self-contained treatment, relating the probabilistic and algebraic viewpoints. The style is discursive and, as befits the subject, plenty of examples and exercises are provided. Some examples and exercises are provided. Some examples of computer codes are given to provide concrete illustrations of abstract ideas.
2009-01-01
This book deals with the basic subjects of design theory. It begins with balanced incomplete block designs, various constructions of which are described in ample detail. In particular, finite projective and affine planes, difference sets and Hadamard matrices, as tools to construct balanced incomplete block designs, are included. Orthogonal latin squares are also treated in detail. Zhu's simpler proof of the falsity of Euler's conjecture is included. The construction of some classes of balanced incomplete block designs, such as Steiner triple systems and Kirkman triple systems, are also given.
International business theory and marketing theory
Soldner, Helmut
1984-01-01
International business theory and marketing theory : elements for internat. marketing theory building. - In: Marketing aspects of international business / Gerald M. Hampton ... (eds.). - Boston u.a. : Kluwer, 1984. - S. 25-57
International Nuclear Information System (INIS)
Markland, J.T.
1992-01-01
Techniques used in conventional project appraisal are mathematically very simple in comparison to those used in reservoir modelling, and in the geosciences. Clearly it would be possible to value assets in mathematically more sophisticated ways if it were meaningful and worthwhile so to do. The DCf approach in common use has recognized limitations; the inability to select a meaningful discount rate being particularly significant. Financial Theory has advanced enormously over the last few years, along with computational techniques, and methods are beginning to appear which may change the way we do project evaluations in practice. The starting point for all of this was a paper by Black and Scholes, which asserts that almost all corporate liabilities can be viewed as options of varying degrees of complexity. Although the financial presentation may be unfamiliar to engineers and geoscientists, some of the concepts used will not be. This paper outlines, in plain English, the basis of option pricing theory for assessing the market value of a project. it also attempts to assess the future role of this type of approach in practical Petroleum Exploration and Engineering economics. Reference is made to relevant published Natural Resource literature
Two-point theory of current-driven ion-cyclotron turbulence
International Nuclear Information System (INIS)
Chiueh, T.; Diamond, P.H.
1985-02-01
An analytical theory of current-driven ion-cyclotron turbulenc which treats incoherent phase space density granulations (clumps) is presented. In contrast to previous investigations, attention is focused on the physically relevant regime of weak collective dissipation, where waves and clumps coexist. The threshold current for nonlinear instability is calculated, and is found to deviate from the linear threshold. A necessary condition for the existence of stationary wave-clump turbulence is derived, and shown to be analogous to the test particle model fluctuation-dissipation theorem result. The structure of three dimensional magnetized clumps is characterized. It is proposed that instability is saturated by collective dissipation due to ion-wave scattering. For this wave-clump turbulence regime, it is found that the fluctuation level (e psi/T/sub e/)/sub rms/ less than or equal to 0.1, and that the modification of anomalous resistivity to levels predicted by conventional nonlinear wave theories is moderate. It is also shown that, in marked contrast to the quasilinear prediction, ion heating significantly exceeds electron heating
International Nuclear Information System (INIS)
Gong, Ha Seong
2006-02-01
This book explains electric theory which is divided into four chapters. The first chapter includes electricity and material, electric field, capacitance, magnetic field and electromagnetic force, inductance. The second chapter mentions electronic circuit analysis, electric resistance,heating and power, chemical activity on current and battery with electrolysis. The third chapter deals with an alternating current circuit about the basics of an AC circuit, operating of resistance, inductance and capacitance, series circuit and parallel circuit of PLC, an alternating current circuit, Three-phase Alternating current, two terminal pair network and voltage and current of non-linearity circuit. The last explains transient phenomena of RC series circuit, RL series circuit, transient phenomena of an alternating current circuit and transient phenomena of RLC series circuit.
International Nuclear Information System (INIS)
Nobile, G.
1993-07-01
With reference to highly debated sustainable growth strategies to counter pressing interrelated global environmental and socio-economic problems, this paper reviews economic and resource development theories proposed by classical and neoclassical economists. The review evidences the growing debate among public administration decision makers regarding appropriate methods to assess the worth of natural resources and ecosystems. Proposed methods tend to be biased either towards environmental protection or economic development. Two major difficulties in the effective implementation of sustainable growth strategies are also evidenced - the management of such strategies would require appropriate revisions to national accounting systems, and the dynamic flow of energy and materials between an economic system and the environment would generate a sequence of unstable structures evolving in a chaotic and unpredictable way
A Future of Communication Theory: Systems Theory.
Lindsey, Georg N.
Concepts of general systems theory, cybernetics and the like may provide the methodology for communication theory to move from a level of technology to a level of pure science. It was the purpose of this paper to (1) demonstrate the necessity of applying systems theory to the construction of communication theory, (2) review relevant systems…
International Nuclear Information System (INIS)
Maillard, S.; Skorek, R.; Maugis, P.; Dumont, M.
2015-01-01
This chapter presents the basic principles of cluster dynamics as a particular case of mesoscopic rate theory models developed to investigate fuel behaviour under irradiation such as in UO 2 . It is shown that as this method simulates the evolution of the concentration of every type of point or aggregated defect in a grain of material. It produces rich information that sheds light on the mechanisms involved in microstructure evolution and gas behaviour that are not accessible through conventional models but yet can provide for improvements in those models. Cluster dynamics parameters are mainly the energetic values governing the basic evolution mechanisms of the material (diffusion, trapping and thermal resolution). In this sense, the model has a general applicability to very different operational situations (irradiation, ion-beam implantation, annealing) provided that they rely on the same basic mechanisms, without requiring additional data fitting, as is required for more empirical conventional models. This technique, when applied to krypton implanted and annealed samples, yields a precise interpretation of the release curves and helps assess migration mechanisms and the krypton diffusion coefficient, for which data is very difficult to obtain due to the low solubility of the gas. (authors)
MACCIA, ELIZABETH S.; AND OTHERS
AN ANNOTATED BIBLIOGRAPHY OF 20 ITEMS AND A DISCUSSION OF ITS SIGNIFICANCE WAS PRESENTED TO DESCRIBE CURRENT UTILIZATION OF SUBJECT THEORIES IN THE CONSTRUCTION OF AN EDUCATIONAL THEORY. ALSO, A THEORY MODEL WAS USED TO DEMONSTRATE CONSTRUCTION OF A SCIENTIFIC EDUCATIONAL THEORY. THE THEORY MODEL INCORPORATED SET THEORY (S), INFORMATION THEORY…
Müller, Gert; Sacks, Gerald
1990-01-01
These proceedings contain research and survey papers from many subfields of recursion theory, with emphasis on degree theory, in particular the development of frameworks for current techniques in this field. Other topics covered include computational complexity theory, generalized recursion theory, proof theoretic questions in recursion theory, and recursive mathematics.
K-theory and representation theory
International Nuclear Information System (INIS)
Kuku, A.O.
2003-01-01
This contribution includes K-theory of orders, group-rings and modules over EI categories, equivariant higher algebraic K-theory for finite, profinite and compact Lie group actions together with their relative generalisations and applications
Gravity, general relativity theory and alternative theories
International Nuclear Information System (INIS)
Zel'dovich, Ya.B.; Grishchuk, L.P.; Moskovskij Gosudarstvennyj Univ.
1986-01-01
The main steps in plotting the current gravitation theory and some prospects of its subsequent development are reviewed. The attention is concentrated on a comparison of the relativistic gravitational field with other physical fields. Two equivalent formulations of the general relativity (GR) - geometrical and field-theoretical - are considered in detail. It is shown that some theories of gravity constructed as the field theories at a flat background space-time are in fact just different formulations of GR and not alternative theories
Generalizability theory and item response theory
Glas, Cornelis A.W.; Eggen, T.J.H.M.; Veldkamp, B.P.
2012-01-01
Item response theory is usually applied to items with a selected-response format, such as multiple choice items, whereas generalizability theory is usually applied to constructed-response tasks assessed by raters. However, in many situations, raters may use rating scales consisting of items with a selected-response format. This chapter presents a short overview of how item response theory and generalizability theory were integrated to model such assessments. Further, the precision of the esti...
Becker, Katrin; Becker, Melanie; Schwarz, John H.
String theory is one of the most exciting and challenging areas of modern theoretical physics. This book guides the reader from the basics of string theory to recent developments. It introduces the basics of perturbative string theory, world-sheet supersymmetry, space-time supersymmetry, conformal field theory and the heterotic string, before describing modern developments, including D-branes, string dualities and M-theory. It then covers string geometry and flux compactifications, applications to cosmology and particle physics, black holes in string theory and M-theory, and the microscopic origin of black-hole entropy. It concludes with Matrix theory, the AdS/CFT duality and its generalizations. This book is ideal for graduate students and researchers in modern string theory, and will make an excellent textbook for a one-year course on string theory. It contains over 120 exercises with solutions, and over 200 homework problems with solutions available on a password protected website for lecturers at www.cambridge.org/9780521860697. Comprehensive coverage of topics from basics of string theory to recent developments Ideal textbook for a one-year course in string theory Includes over 100 exercises with solutions Contains over 200 homework problems with solutions available to lecturers on-line
International Nuclear Information System (INIS)
Bergmann, P.G.
1980-01-01
A problem of construction of the unitary field theory is discussed. The preconditions of the theory are briefly described. The main attention is paid to the geometrical interpretation of physical fields. The meaning of the conceptions of diversity and exfoliation is elucidated. Two unitary field theories are described: the Weyl conformic geometry and Calitzy five-dimensioned theory. It is proposed to consider supersymmetrical theories as a new approach to the problem of a unitary field theory. It is noted that the supergravitational theories are really unitary theories, since the fields figuring there do not assume invariant expansion
Boley, Bruno A
1997-01-01
Highly regarded text presents detailed discussion of fundamental aspects of theory, background, problems with detailed solutions. Basics of thermoelasticity, heat transfer theory, thermal stress analysis, more. 1985 edition.
International Nuclear Information System (INIS)
Marciano, W.J.
1984-12-01
The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references
Jardine, John F
2015-01-01
This monograph on the homotopy theory of topologized diagrams of spaces and spectra gives an expert account of a subject at the foundation of motivic homotopy theory and the theory of topological modular forms in stable homotopy theory. Beginning with an introduction to the homotopy theory of simplicial sets and topos theory, the book covers core topics such as the unstable homotopy theory of simplicial presheaves and sheaves, localized theories, cocycles, descent theory, non-abelian cohomology, stacks, and local stable homotopy theory. A detailed treatment of the formalism of the subject is interwoven with explanations of the motivation, development, and nuances of ideas and results. The coherence of the abstract theory is elucidated through the use of widely applicable tools, such as Barr's theorem on Boolean localization, model structures on the category of simplicial presheaves on a site, and cocycle categories. A wealth of concrete examples convey the vitality and importance of the subject in topology, n...
Rationality, Theory Acceptance and Decision Theory
Directory of Open Access Journals (Sweden)
J. Nicolas Kaufmann
1998-06-01
Full Text Available Following Kuhn's main thesis according to which theory revision and acceptance is always paradigm relative, I propose to outline some possible consequences of such a view. First, asking the question in what sense Bayesian decision theory could serve as the appropriate (normative theory of rationality examined from the point of view of the epistemology of theory acceptance, I argue that Bayesianism leads to a narrow conception of theory acceptance. Second, regarding the different types of theory revision, i.e. expansion, contraction, replacement and residuals shifts, I extract from Kuhn's view a series of indications showing that theory replacement cannot be rationalized within the framework of Bayesian decision theory, not even within a more sophisticated version of that model. Third, and finally, I will point to the need for a more comprehensive model of rationality than the Bayesian expected utility maximization model, the need for a model which could better deal with the different aspects of theory replacement. I will show that Kuhn's distinction between normal and revolutionary science gives us several hints for a more adequate theory of rationality in science. I will also show that Kuhn is not in a position to fully articulate his main ideas and that he well be confronted with a serious problem concerning collective choice of a paradigm.
From chaos to unification: U theory vs. M theory
International Nuclear Information System (INIS)
Ye, Fred Y.
2009-01-01
A unified physical theory called U theory, that is different from M theory, is defined and characterized. U theory, which includes spinor and twistor theory, loop quantum gravity, causal dynamical triangulations, E-infinity unification theory, and Clifford-Finslerian unifications, is based on physical tradition and experimental foundations. In contrast, M theory pays more attention to mathematical forms. While M theory is characterized by supersymmetry string theory, U theory is characterized by non-supersymmetry unified field theory.
Contemporary theories of democracy
Directory of Open Access Journals (Sweden)
Mladenović Ivan
2008-01-01
Full Text Available The aim of this paper is two-fold: first, to analyze several contemporary theories of democracy, and secondly, to propose a theoretical framework for further investigations based on analyzed theories. The following four theories will be analyzed: pluralism, social choice theory, deliberative democracy and participatory democracy.
Moschovakis, YN
1987-01-01
Now available in paperback, this monograph is a self-contained exposition of the main results and methods of descriptive set theory. It develops all the necessary background material from logic and recursion theory, and treats both classical descriptive set theory and the effective theory developed by logicians.
't Hooft, Gerardus; Witten, Edward
2005-01-01
In his later years, Einstein sought a unified theory that would extend general relativity and provide an alternative to quantum theory. There is now talk of a "theory of everything"; fifty years after his death, how close are we to such a theory? (3 pages)
de Bruin, B.P.
2005-01-01
Game theory is the mathematical study of strategy and conflict. It has wide applications in economics, political science, sociology, and, to some extent, in philosophy. Where rational choice theory or decision theory is concerned with individual agents facing games against nature, game theory deals
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
The basic ideas of game theory were originated from the problems of maximum and minimum given by J.Yon Neumann in 1928. Later, wars accelerated the study of game theory, there are many developments that contributed to the advancement of game theory, many problems of optimum appeared in economic development process. Scientists applied mathematic methods to studying game theory to make the theory more profound and perfect. The axiomatic structure of game theory was nearly complete in 1944. The path of the development of game theory started from finite to infinite, from two players to many players, from expressing gains with quantity to showing the ending of game theory with abstract result, and from certainty problems to random problems. Thus development of game theory is closely related to the economic development. In recent years, the research on the non-differentiability of Shapley value posed by Belgian Mertens is one of the advanced studies in game theory.
Nonrelativistic superstring theories
International Nuclear Information System (INIS)
Kim, Bom Soo
2007-01-01
We construct a supersymmetric version of the critical nonrelativistic bosonic string theory [B. S. Kim, Phys. Rev. D 76, 106007 (2007).] with its manifest global symmetry. We introduce the anticommuting bc conformal field theory (CFT) which is the super partner of the βγ CFT. The conformal weights of the b and c fields are both 1/2. The action of the fermionic sector can be transformed into that of the relativistic superstring theory. We explicitly quantize the theory with manifest SO(8) symmetry and find that the spectrum is similar to that of type IIB superstring theory. There is one notable difference: the fermions are nonchiral. We further consider noncritical generalizations of the supersymmetric theory using the superspace formulation. There is an infinite range of possible string theories similar to the supercritical string theories. We comment on the connection between the critical nonrelativistic string theory and the lightlike linear dilaton theory
Nonrelativistic closed string theory
International Nuclear Information System (INIS)
Gomis, Jaume; Ooguri, Hirosi
2001-01-01
We construct a Galilean invariant nongravitational closed string theory whose excitations satisfy a nonrelativistic dispersion relation. This theory can be obtained by taking a consistent low energy limit of any of the conventional string theories, including the heterotic string. We give a finite first order worldsheet Hamiltonian for this theory and show that this string theory has a sensible perturbative expansion, interesting high energy behavior of scattering amplitudes and a Hagedorn transition of the thermal ensemble. The strong coupling duals of the Galilean superstring theories are considered and are shown to be described by an eleven-dimensional Galilean invariant theory of light membrane fluctuations. A new class of Galilean invariant nongravitational theories of light-brane excitations are obtained. We exhibit dual formulations of the strong coupling limits of these Galilean invariant theories and show that they exhibit many of the conventional dualities of M theory in a nonrelativistic setting
Gauge theory loop operators and Liouville theory
International Nuclear Information System (INIS)
Drukker, Nadav; Teschner, Joerg
2009-10-01
We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S 4 - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)
Identity theory and personality theory: mutual relevance.
Stryker, Sheldon
2007-12-01
Some personality psychologists have found a structural symbolic interactionist frame and identity theory relevant to their work. This frame and theory, developed in sociology, are first reviewed. Emphasized in the review are a multiple identity conception of self, identities as internalized expectations derived from roles embedded in organized networks of social interaction, and a view of social structures as facilitators in bringing people into networks or constraints in keeping them out, subsequently, attention turns to a discussion of the mutual relevance of structural symbolic interactionism/identity theory and personality theory, looking to extensions of the current literature on these topics.
Towards a theory of spacetime theories
Schiemann, Gregor; Scholz, Erhard
2017-01-01
This contributed volume is the result of a July 2010 workshop at the University of Wuppertal Interdisciplinary Centre for Science and Technology Studies which brought together world-wide experts from physics, philosophy and history, in order to address a set of questions first posed in the 1950s: How do we compare spacetime theories? How do we judge, objectively, which is the “best” theory? Is there even a unique answer to this question? The goal of the workshop, and of this book, is to contribute to the development of a meta-theory of spacetime theories. Such a meta-theory would reveal insights about specific spacetime theories by distilling their essential similarities and differences, deliver a framework for a class of theories that could be helpful as a blueprint to build other meta-theories, and provide a higher level viewpoint for judging which theory most accurately describes nature. But rather than drawing a map in broad strokes, the focus is on particularly rich regions in the “space of spaceti...
Gauge theory loop operators and Liouville theory
Energy Technology Data Exchange (ETDEWEB)
Drukker, Nadav [Humboldt Univ. Berlin (Germany). Inst. fuer Physik; Gomis, Jaume; Okuda, Takuda [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Teschner, Joerg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2009-10-15
We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S{sup 4} - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)
DEFF Research Database (Denmark)
Andersen, Jack
2015-01-01
Purpose To provide a small overview of genre theory and its associated concepts and to show how genre theory has had its antecedents in certain parts of the social sciences and not in the humanities. Findings The chapter argues that the explanatory force of genre theory may be explained with its...... emphasis on everyday genres, de facto genres. Originality/value By providing an overview of genre theory, the chapter demonstrates the wealth and richness of forms of explanations in genre theory....
Conlon, Joseph
2016-01-01
Is string theory a fraud or one of the great scientific advances? Why do so many physicists work on string theory if it cannot be tested? This book provides insight into why such a theory, with little direct experimental support, plays such a prominent role in theoretical physics. The book gives a modern and accurate account of string theory and science, explaining what string theory is, why it is regarded as so promising, and why it is hard to test.
Teaching Theory X and Theory Y in Organizational Communication
Noland, Carey
2014-01-01
The purpose of the activity described here is to integrate McGregor's Theory X and Theory Y into a group application: design a syllabus that embodies either Theory X or Theory Y tenets. Students should be able to differentiate between Theory X and Theory Y, create a syllabus based on Theory X or Theory Y tenets, evaluate the different syllabi…
Direction: unified theory of interactions
International Nuclear Information System (INIS)
Valko, P.
1987-01-01
Briefly characterized are the individual theories, namely, the general relativity theory, the Kaluza-Klein theory, the Weyl theory, the unified theory of electromagnetic and weak interactions, the supergravity theory, and the superstring theory. The history is recalled of efforts aimed at creating a unified theory of interactions, and future prospects are outlined. (M.D.). 2 figs
Building theory through design
DEFF Research Database (Denmark)
Markussen, Thomas
2017-01-01
This chapter deals with a fundamental matter of concern in research through design: how can design work lead to the building of new theory? Controversy exists about the balance between theory and design work in research through design. While some researchers see theory production as the scientific...... hallmark of this type of research, others argue for design work being the primary achievement, with theory serving the auxiliary function of inspiring new designs. This paper demonstrates how design work and theory can be appreciated as two equally important outcomes of research through design. To set...... the scene, it starts out by briefly examining ideas on this issue presented in existing research literature. Hereafter, it introduces three basic forms in which design work can lead to theory that is referred to as extending theories, scaffolding theories and blending theories. Finally, it is discussed how...
Generalizability Theory and Classical Test Theory
Brennan, Robert L.
2011-01-01
Broadly conceived, reliability involves quantifying the consistencies and inconsistencies in observed scores. Generalizability theory, or G theory, is particularly well suited to addressing such matters in that it enables an investigator to quantify and distinguish the sources of inconsistencies in observed scores that arise, or could arise, over…
Generalizability theory and item response theory
Glas, Cornelis A.W.; Eggen, T.J.H.M.; Veldkamp, B.P.
2012-01-01
Item response theory is usually applied to items with a selected-response format, such as multiple choice items, whereas generalizability theory is usually applied to constructed-response tasks assessed by raters. However, in many situations, raters may use rating scales consisting of items with a
International Nuclear Information System (INIS)
Kaku, M.
1987-01-01
In this article, the authors summarize the rapid progress in constructing string field theory actions, such as the development of the covariant BRST theory. They also present the newer geometric formulation of string field theory, from which the BRST theory and the older light cone theory can be derived from first principles. This geometric formulation allows us to derive the complete field theory of strings from two geometric principles, in the same way that general relativity and Yang-Mills theory can be derived from two principles based on global and local symmetry. The geometric formalism therefore reduces string field theory to a problem of finding an invariant under a new local gauge group they call the universal string group (USG). Thus, string field theory is the gauge theory of the universal string group in much the same way that Yang-Mills theory is the gauge theory of SU(N). The geometric formulation places superstring theory on the same rigorous group theoretical level as general relativity and gauge theory
Effective quantum field theories
International Nuclear Information System (INIS)
Georgi, H.M.
1993-01-01
The most appropriate description of particle interactions in the language of quantum field theory depends on the energy at which the interactions are studied; the description is in terms of an ''effective field theory'' that contains explicit reference only to those particles that are actually important at the energy being studied. The various themes of the article are: local quantum field theory, quantum electrodynamics, new physics, dimensional parameters and renormalizability, socio-dynamics of particle theory, spontaneously broken gauge theories, scale dependence, grand unified and effective field theories. 2 figs
Directory of Open Access Journals (Sweden)
Vivian B. Martin, Ph.D.
2005-03-01
Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.
Schürmann, Michael
2008-01-01
This volume contains the revised and completed notes of lectures given at the school "Quantum Potential Theory: Structure and Applications to Physics," held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald from February 26 to March 10, 2007. Quantum potential theory studies noncommutative (or quantum) analogs of classical potential theory. These lectures provide an introduction to this theory, concentrating on probabilistic potential theory and it quantum analogs, i.e. quantum Markov processes and semigroups, quantum random walks, Dirichlet forms on C* and von Neumann algebras, and boundary theory. Applications to quantum physics, in particular the filtering problem in quantum optics, are also presented.
Historicizing affordance theory
DEFF Research Database (Denmark)
Pedersen, Sofie; Bang, Jytte Susanne
2017-01-01
The aim of this article is to discuss how mutually enriching points from both affordance theory and cultural-historical activity theory can promote theoretical ideas which may prove useful as analytical tools for the study of human life and human development. There are two issues that need...... to be overcome in order to explore the potentials of James Gibson’s affordance theory: it does not sufficiently theorize (a) development and (b) society. We claim that Gibson’s affordance theory still needs to be brought beyond “the axiom of immediacy.” Ambivalences in Gibson’s affordance theory...... societal character of affordance theory....
Cooney, Adeline
2011-01-01
This paper explores ways to enhance and demonstrate rigour in a grounded theory study. Grounded theory is sometimes criticised for a lack of rigour. Beck (1993) identified credibility, auditability and fittingness as the main standards of rigour for qualitative research methods. These criteria were evaluated for applicability to a Straussian grounded theory study and expanded or refocused where necessary. The author uses a Straussian grounded theory study (Cooney, In press) to examine how the revised criteria can be applied when conducting a grounded theory study. Strauss and Corbin (1998b) criteria for judging the adequacy of a grounded theory were examined in the context of the wider literature examining rigour in qualitative research studies in general and grounded theory studies in particular. A literature search for 'rigour' and 'grounded theory' was carried out to support this analysis. Criteria are suggested for enhancing and demonstrating the rigour of a Straussian grounded theory study. These include: cross-checking emerging concepts against participants' meanings, asking experts if the theory 'fit' their experiences, and recording detailed memos outlining all analytical and sampling decisions. IMPLICATIONS FOR RESEARCH PRACTICE: The criteria identified have been expressed as questions to enable novice researchers to audit the extent to which they are demonstrating rigour when writing up their studies. However, it should not be forgotten that rigour is built into the grounded theory method through the inductive-deductive cycle of theory generation. Care in applying the grounded theory methodology correctly is the single most important factor in ensuring rigour.
Theories of Career Development. A Comparison of the Theories.
Osipow, Samuel H.
These seven theories of career development are examined in previous chapters: (1) Roe's personality theory, (2) Holland's career typology theory, (3) the Ginzberg, Ginsburg, Axelrod, and Herma Theory, (4) psychoanalytic conceptions, (5) Super's developmental self-concept theory, (6) other personality theories, and (7) social systems theories.…
Supersymmetric gauge theories from string theory
International Nuclear Information System (INIS)
Metzger, St.
2005-12-01
This thesis presents various ways to construct four-dimensional quantum field theories from string theory. In a first part we study the generation of a supersymmetric Yang-Mills theory, coupled to an adjoint chiral superfield, from type IIB string theory on non-compact Calabi-Yau manifolds, with D-branes wrapping certain sub-cycles. Properties of the gauge theory are then mapped to the geometric structure of the Calabi-Yau space. Even if the Calabi-Yau geometry is too complicated to evaluate the geometric integrals explicitly, one can then always use matrix model perturbation theory to calculate the effective superpotential. The second part of this work covers the generation of four-dimensional super-symmetric gauge theories, carrying several important characteristic features of the standard model, from compactifications of eleven-dimensional supergravity on G 2 -manifolds. If the latter contain conical singularities, chiral fermions are present in the four-dimensional gauge theory, which potentially lead to anomalies. We show that, locally at each singularity, these anomalies are cancelled by the non-invariance of the classical action through a mechanism called 'anomaly inflow'. Unfortunately, no explicit metric of a compact G 2 -manifold is known. Here we construct families of metrics on compact weak G 2 -manifolds, which contain two conical singularities. Weak G 2 -manifolds have properties that are similar to the ones of proper G 2 -manifolds, and hence the explicit examples might be useful to better understand the generic situation. Finally, we reconsider the relation between eleven-dimensional supergravity and the E 8 x E 8 -heterotic string. This is done by carefully studying the anomalies that appear if the supergravity theory is formulated on a ten-manifold times the interval. Again we find that the anomalies cancel locally at the boundaries of the interval through anomaly inflow, provided one suitably modifies the classical action. (author)
Henneaux, Marc; Vasiliev, Mikhail A
2017-01-01
Symmetries play a fundamental role in physics. Non-Abelian gauge symmetries are the symmetries behind theories for massless spin-1 particles, while the reparametrization symmetry is behind Einstein's gravity theory for massless spin-2 particles. In supersymmetric theories these particles can be connected also to massless fermionic particles. Does Nature stop at spin-2 or can there also be massless higher spin theories. In the past strong indications have been given that such theories do not exist. However, in recent times ways to evade those constraints have been found and higher spin gauge theories have been constructed. With the advent of the AdS/CFT duality correspondence even stronger indications have been given that higher spin gauge theories play an important role in fundamental physics. All these issues were discussed at an international workshop in Singapore in November 2015 where the leading scientists in the field participated. This volume presents an up-to-date, detailed overview of the theories i...
Covariant Noncommutative Field Theory
Energy Technology Data Exchange (ETDEWEB)
Estrada-Jimenez, S [Licenciaturas en Fisica y en Matematicas, Facultad de Ingenieria, Universidad Autonoma de Chiapas Calle 4a Ote. Nte. 1428, Tuxtla Gutierrez, Chiapas (Mexico); Garcia-Compean, H [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN P.O. Box 14-740, 07000 Mexico D.F., Mexico and Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Monterrey Via del Conocimiento 201, Parque de Investigacion e Innovacion Tecnologica (PIIT) Autopista nueva al Aeropuerto km 9.5, Lote 1, Manzana 29, cp. 66600 Apodaca Nuevo Leon (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato P.O. Box E-143, 37150 Leon Gto. (Mexico); Ramirez, C [Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000 Puebla (Mexico)
2008-07-02
The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced.
Zielenkiewicz, Wojciech
2004-01-01
The purpose of this book is to give a comprehensive description of the theoretical fundamentals of calorimetry. The considerations are based on the relations deduced from the laws and general equations of heat exchange theory and steering theory.
Covariant Noncommutative Field Theory
International Nuclear Information System (INIS)
Estrada-Jimenez, S.; Garcia-Compean, H.; Obregon, O.; Ramirez, C.
2008-01-01
The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced
Stabilizing bottomless action theories
International Nuclear Information System (INIS)
Greensite, J.; Halpern, M.B.
1983-12-01
The authors show how to construct the Euclidean quantum theory corresponding to classical actions which are unbounded from below. The method preserves the classical limit, the large-N limit, and the perturbative expansion of the unstabilized theories. (Auth.)
Algebraic conformal field theory
International Nuclear Information System (INIS)
Fuchs, J.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica
1991-11-01
Many conformal field theory features are special versions of structures which are present in arbitrary 2-dimensional quantum field theories. So it makes sense to describe 2-dimensional conformal field theories in context of algebraic theory of superselection sectors. While most of the results of the algebraic theory are rather abstract, conformal field theories offer the possibility to work out many formulae explicitly. In particular, one can construct the full algebra A-bar of global observables and the endomorphisms of A-bar which represent the superselection sectors. Some explicit results are presented for the level 1 so(N) WZW theories; the algebra A-bar is found to be the enveloping algebra of a Lie algebra L-bar which is an extension of the chiral symmetry algebra of the WZW theory. (author). 21 refs., 6 figs
Rothbart, Andrea
2012-01-01
An imaginative introduction to number theory and abstract algebra, this unique approach employs a pair of fictional characters whose dialogues explain theories and demonstrate applications in terms of football scoring, chess moves, and more.
Economic theories of dictatorship
Alexandre Debs
2010-01-01
This article reviews recent advances in economic theories of dictatorships and their lessons for the political stability and economic performance of dictatorships. It reflects on the general usefulness of economic theories of dictatorship, with an application to foreign relations.
International Nuclear Information System (INIS)
Elliott, J.A.
1993-01-01
Plasma kinetic theory is discussed and a comparison made with the kinetic theory of gases. The plasma is described by a modified set of fluid equations and it is shown how these fluid equations can be derived. (UK)
Indian Academy of Sciences (India)
strongly motivate a detailed search for inflation within string theory, although it has ... between string theory and observations provides a strong incentive for ..... sonably be expected to arise for any system having very many degrees of freedom.
International Nuclear Information System (INIS)
Bonara, L.; Cotta-Ramusino, P.; Rinaldi, M.
1987-01-01
It is well-known that type I and heterotic superstring theories have a zero mass spectrum which correspond to the field content of N=1 supergravity theory coupled to supersymmetric Yang-Mills theory in 10-D. The authors study the field theory ''per se'', in the hope that simple consistency requirements will determine the theory completely once one knows the field content inherited from string theory. The simplest consistency requirements are: N=1 supersymmetry; and absence of chiral anomalies. This is what the authors discuss in this paper here leaving undetermined the question of the range of validity of the resulting field theory. As is known, a model of N=1 supergravity (SUGRA) coupled to supersymmetric Yang-Mills (SYM) theory was known in the form given by Chapline and Manton. The coupling of SUGRA to SYM was determined by the definition of the ''field strength'' 3-form H in this paper
Introduction to percolation theory
Stauffer, Dietrich
1991-01-01
Percolation theory deals with clustering, criticallity, diffusion, fractals, phase transitions and disordered systems. This book covers the basic theory for the graduate, and also professionals dealing with it for the first time
DEFF Research Database (Denmark)
Clemmensen, Torkil; Kaptelinin, Victor; Nardi, Bonnie
2016-01-01
different ways of using activity theory: (1) analysing unique features, principles, and problematic aspects of the theory; (2) identifying domain-specific requirements for new theoretical tools; (3) developing new conceptual accounts of issues in the field of HCI; (4) guiding and supporting empirical...... analyses of HCI phenomena; and (5) providing new design illustrations, claims, and guidelines. We conclude that HCI researchers are not only users of imported theory, but also theory-makers who adapt and develop theory for different purposes.......This paper reports a study of the use of activity theory in human–computer interaction (HCI) research. We analyse activity theory in HCI since its first appearance about 25 years ago. Through an analysis and meta-synthesis of 109 selected HCI activity theory papers, we created a taxonomy of 5...
International Nuclear Information System (INIS)
Partovi, M.H.
1982-01-01
From a generalization of the covariant derivative, nonlocal gauge theories are developed. These theories enjoy local gauge invariance and associated Ward identities, a corresponding locally conserved current, and a locally conserved energy-momentum tensor, with the Ward identities implying the masslessness of the gauge field as in local theories. Their ultraviolet behavior allows the presence as well as the absence of the Adler-Bell-Jackiw anomaly, the latter in analogy with lattice theories
International Nuclear Information System (INIS)
Douglas, Michael R.; Nekrasov, Nikita A.
2001-01-01
This article reviews the generalization of field theory to space-time with noncommuting coordinates, starting with the basics and covering most of the active directions of research. Such theories are now known to emerge from limits of M theory and string theory and to describe quantum Hall states. In the last few years they have been studied intensively, and many qualitatively new phenomena have been discovered, on both the classical and the quantum level
International Nuclear Information System (INIS)
Adler, S.L.; Wilczek, F.
1993-11-01
Areas of emphasis include acceleration algorithms for the Monte Carlo analysis of lattice field and gauge theories, quaternionic generalizations of complex quantum mechanics and field theory, application of the renormalization group to the QCD phase transition, the quantum Hall effect, and black holes. Other work involved string theory, statistical properties of energy levels in integrable quantum systems, baryon asymmetry and the electroweak phase transition, anisotropies of the cosmic microwave background, and theory of superconductors
1990-02-21
LIDS-P-1953 Multiscale System Theory Albert Benveniste IRISA-INRIA, Campus de Beaulieu 35042 RENNES CEDEX, FRANCE Ramine Nikoukhah INRIA...TITLE AND SUBTITLE Multiscale System Theory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...the development of a corresponding system theory and a theory of stochastic processes and their estimation. The research presented in this and several
Philosophical theories of probability
Gillies, Donald
2000-01-01
The Twentieth Century has seen a dramatic rise in the use of probability and statistics in almost all fields of research. This has stimulated many new philosophical ideas on probability. Philosophical Theories of Probability is the first book to present a clear, comprehensive and systematic account of these various theories and to explain how they relate to one another. Gillies also offers a distinctive version of the propensity theory of probability, and the intersubjective interpretation, which develops the subjective theory.
Davis, Philip W.
This volume explores objectively the essential characteristic of nine twentieth-century linguistic theories with the theoretical variant for discussion based on one closely representative of work within a given approach or usually associated with the name of the theory. First, the theory of Ferdinand de Saussure is discussed based on his book,…
Constructivist Grounded Theory?
Directory of Open Access Journals (Sweden)
Barney G. Glaser, PhD, Hon. PhD
2012-06-01
Full Text Available AbstractI refer to and use as scholarly inspiration Charmaz’s excellent article on constructivist grounded theory as a tool of getting to the fundamental issues on why grounded theory is not constructivist. I show that constructivist data, if it exists at all, is a very, very small part of the data that grounded theory uses.
Maasland, E.
2012-01-01
Auction theory is a branch of game theory that considers human behavior in auction markets and the ensuing market outcomes. It is also successfully used as a tool to design real-life auctions. This thesis contains five essays addressing a variety of topics within the realm of auction theory. The
International Nuclear Information System (INIS)
Prasad, R.
1975-01-01
Results of researches into Unified Field Theory over the past seven years are presented. The subject is dealt with in chapters entitled: the choice of affine connection, algebraic properties of the vector fields, field laws obtained from the affine connection based on the path integral method, application to quantum theory and cosmology, interpretation of physical theory in terms of geometry. (U.K.)
Missinne, Leo E.; Wilcox, Victoria
This paper discusses the life, theories, and therapeutic techniques of psychotherapist, Viktor E. Frankl. A brief biography of Frankl is included discussing the relationship of his early experiences as a physician to his theory of personality. Frankl's theory focusing on man's need for meaning and emphasizing the spiritual dimension in each human…
Rajendran, Gnanathusharan; Mitchell, Peter
2007-01-01
This article considers three theories of autism: The Theory of Mind Deficit, Executive Dysfunction and the Weak Central Coherence accounts. It outlines each along with studies relevant to their emergence, their expansion, their limitations and their possible integration. Furthermore, consideration is given to any implication from the theories in…
International Nuclear Information System (INIS)
Mack, G.
1982-01-01
After a description of a pure Yang-Mills theory on a lattice, the author considers a three-dimensional pure U(1) lattice gauge theory. Thereafter he discusses the exact relation between lattice gauge theories with the gauge groups SU(2) and SO(3). Finally he presents Monte Carlo data on phase transitions in SU(2) and SO(3) lattice gauge models. (HSI)
Onderstal, A.M.
2002-01-01
This thesis is a collection of six papers in auction theory, with several economic applications, both to real life auctions and to other economic phenomena. In the introduction to the thesis, Onderstal argues why auction theory is an important branch of economic theory, and discusses several
Vazzana, Anthony; Garth, David
2007-01-01
One of the oldest branches of mathematics, number theory is a vast field devoted to studying the properties of whole numbers. Offering a flexible format for a one- or two-semester course, Introduction to Number Theory uses worked examples, numerous exercises, and two popular software packages to describe a diverse array of number theory topics.
Reflections on Activity Theory
Bakhurst, David
2009-01-01
It is sometimes suggested that activity theory represents the most important legacy of Soviet philosophy and psychology. But what exactly "is" activity theory? The canonical account in the West is given by Engestrom, who identifies three stages in the theory's development: from Vygotsky's insights, through Leontiev's articulation of the…
Superspace conformal field theory
Energy Technology Data Exchange (ETDEWEB)
Quella, Thomas [Koeln Univ. (Germany). Inst. fuer Theoretische Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2013-07-15
Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.
Superspace conformal field theory
International Nuclear Information System (INIS)
Quella, Thomas
2013-07-01
Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.
International Nuclear Information System (INIS)
Kikkawa, Keiji; Nakanishi, Noboru; Nariai, Hidekazu
1983-01-01
These proceedings contain the articles presented at the named symposium. They deal with geometrical aspects of gauge theory and gravitation, special problems in gauge theories, quantum field theory in curved space-time, quantum gravity, supersymmetry including supergravity, and grand unification. See hints under the relevant topics. (HSI)
Constructor theory of probability
2016-01-01
Unitary quantum theory, having no Born Rule, is non-probabilistic. Hence the notorious problem of reconciling it with the unpredictability and appearance of stochasticity in quantum measurements. Generalizing and improving upon the so-called ‘decision-theoretic approach’, I shall recast that problem in the recently proposed constructor theory of information—where quantum theory is represented as one of a class of superinformation theories, which are local, non-probabilistic theories conforming to certain constructor-theoretic conditions. I prove that the unpredictability of measurement outcomes (to which constructor theory gives an exact meaning) necessarily arises in superinformation theories. Then I explain how the appearance of stochasticity in (finitely many) repeated measurements can arise under superinformation theories. And I establish sufficient conditions for a superinformation theory to inform decisions (made under it) as if it were probabilistic, via a Deutsch–Wallace-type argument—thus defining a class of decision-supporting superinformation theories. This broadens the domain of applicability of that argument to cover constructor-theory compliant theories. In addition, in this version some of the argument's assumptions, previously construed as merely decision-theoretic, follow from physical properties expressed by constructor-theoretic principles. PMID:27616914
Schmidt, Ulrich; Zank, Horst
2010-01-01
In previous models of (cumulative) prospect theory reference-dependence of preferences is imposed beforehand and the location of the reference point is exogenously determined. This paper provides an axiomatization of a new specification of cumulative prospect theory, termed endogenous prospect theory, where reference-dependence is derived from preference conditions and a unique reference point arises endogenously.
Sharpening Intertemporal Prospect Theory
Pushpa, Rathie; Carlos, Radavelli; Sergio, Da Silva
2006-01-01
Prospect theory [4] of risky choices has been extended to encompass intertemporal choices [6]. Presentation of intertemporal prospect theory suffers from minor mistakes, however [2]. To clarify the theory we restate it and show further mistakes in current presentations ([6], [2]) of value and discount functions.
Gauge theories as theories of spontaneous breakdown
International Nuclear Information System (INIS)
Ivanov, E.A.; Ogievetsky, V.I.
1976-01-01
Any gauge theory is proved to arise from spontaneous breakdown of symmetry under certain infinite parameter group, the corresponding gauge field being the Goldstone field by which this breakdown is accompanied
Theory and context / Theory in context
DEFF Research Database (Denmark)
Glaveanu, Vlad Petre
2014-01-01
trans-disciplinary manner. Consideration needs to be given as well to connected scholarship focusing on imagination, innova-tion, and improvisation. Last but not least, an expanded the-ory of context cannot ignore the institutional context of doing research on creativity. Creativity scholars are facing......It is debatable whether the psychology of creativity is a field in crisis or not. There are clear signs of increased fragmenta-tion and a scarcity of integrative efforts, but is this necessari-ly bad? Do we need more comprehensive theories of creativ-ity and a return to old epistemological...... questions? This de-pends on how one understands theory. Against a view of theoretical work as aiming towards generality, universality, uniformity, completeness, and singularity, I advocate for a dynamic perspective in which theory is plural, multifaceted, and contextual. Far from ‘waiting for the Messiah...
Invariant Theory (IT) & Standard Monomial Theory (SMT)
Indian Academy of Sciences (India)
2013-07-06
Jul 6, 2013 ... Why invariant theory? (continued). Now imagine algebraic calculations being made, with the two different sets of co-ordinates, about something of geometrical or physical interest concerning the configuration of points, ...
Whitham modulation theory for (2 + 1)-dimensional equations of Kadomtsev–Petviashvili type
Ablowitz, Mark J.; Biondini, Gino; Rumanov, Igor
2018-05-01
Whitham modulation theory for certain two-dimensional evolution equations of Kadomtsev–Petviashvili (KP) type is presented. Three specific examples are considered in detail: the KP equation, the two-dimensional Benjamin–Ono (2DBO) equation and a modified KP (m2KP) equation. A unified derivation is also provided. In the case of the m2KP equation, the corresponding Whitham modulation system exhibits features different from the other two. The approach presented here does not require integrability of the original evolution equation. Indeed, while the KP equation is known to be a completely integrable equation, the 2DBO equation and the m2KP equation are not known to be integrable. In each of the cases considered, the Whitham modulation system obtained consists of five first-order quasilinear partial differential equations. The Riemann problem (i.e. the analogue of the Gurevich–Pitaevskii problem) for the one-dimensional reduction of the m2KP equation is studied. For the m2KP equation, the system of modulation equations is used to analyze the linear stability of traveling wave solutions.
Otsuka, Fumiko; Matsukiyo, Shuichi; Kis, Arpad; Nakanishi, Kento; Hada, Tohru
2018-02-01
Field-aligned diffusion of energetic ions in the Earth’s foreshock is investigated by using the quasi-linear theory (QLT) and test particle simulation. Non-propagating MHD turbulence in the solar wind rest frame is assumed to be purely transverse with respect to the background field. We use a turbulence model based on a multi-power-law spectrum including an intense peak that corresponds to upstream ULF waves resonantly generated by the field-aligned beam (FAB). The presence of the ULF peak produces a concave shape of the diffusion coefficient when it is plotted versus the ion energy. The QLT including the effect of the ULF wave explains the simulation result well, when the energy density of the turbulent magnetic field is 1% of that of the background magnetic field and the power-law index of the wave spectrum is less than 2. The numerically obtained e-folding distances from 10 to 32 keV ions match with the observational values in the event discussed in the companion paper, which contains an intense ULF peak in the spectra generated by the FAB. Evolution of the power spectrum of the ULF waves when approaching the shock significantly affects the energy dependence of the e-folding distance.
Irvine, J M
1972-01-01
Nuclear Structure Theory provides a guide to nuclear structure theory. The book is comprised of 23 chapters that are organized into four parts; each part covers an aspect of nuclear structure theory. In the first part, the text discusses the experimentally observed phenomena, which nuclear structure theories need to look into and detail the information that supports those theories. The second part of the book deals with the phenomenological nucleon-nucleon potentials derived from phase shift analysis of nucleon-nucleon scattering. Part III talks about the phenomenological parameters used to de
Measure and integration theory
Burckel, Robert B
2001-01-01
This book gives a straightforward introduction to the field as it is nowadays required in many branches of analysis and especially in probability theory. The first three chapters (Measure Theory, Integration Theory, Product Measures) basically follow the clear and approved exposition given in the author's earlier book on ""Probability Theory and Measure Theory"". Special emphasis is laid on a complete discussion of the transformation of measures and integration with respect to the product measure, convergence theorems, parameter depending integrals, as well as the Radon-Nikodym theorem. The fi
Kilmister, Clive William
1970-01-01
Special Theory of Relativity provides a discussion of the special theory of relativity. Special relativity is not, like other scientific theories, a statement about the matter that forms the physical world, but has the form of a condition that the explicit physical theories must satisfy. It is thus a form of description, playing to some extent the role of the grammar of physics, prescribing which combinations of theoretical statements are admissible as descriptions of the physical world. Thus, to describe it, one needs also to describe those specific theories and to say how much they are limit
Variational Transition State Theory
Energy Technology Data Exchange (ETDEWEB)
Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)
2016-09-29
This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.
Bollobas, Bela
2004-01-01
The ever-expanding field of extremal graph theory encompasses a diverse array of problem-solving methods, including applications to economics, computer science, and optimization theory. This volume, based on a series of lectures delivered to graduate students at the University of Cambridge, presents a concise yet comprehensive treatment of extremal graph theory.Unlike most graph theory treatises, this text features complete proofs for almost all of its results. Further insights into theory are provided by the numerous exercises of varying degrees of difficulty that accompany each chapter. A
Introduction to spectral theory
Levitan, B M
1975-01-01
This monograph is devoted to the spectral theory of the Sturm- Liouville operator and to the spectral theory of the Dirac system. In addition, some results are given for nth order ordinary differential operators. Those parts of this book which concern nth order operators can serve as simply an introduction to this domain, which at the present time has already had time to become very broad. For the convenience of the reader who is not familar with abstract spectral theory, the authors have inserted a chapter (Chapter 13) in which they discuss this theory, concisely and in the main without proofs, and indicate various connections with the spectral theory of differential operators.
Barron, E N
2013-01-01
An exciting new edition of the popular introduction to game theory and its applications The thoroughly expanded Second Edition presents a unique, hands-on approach to game theory. While most books on the subject are too abstract or too basic for mathematicians, Game Theory: An Introduction, Second Edition offers a blend of theory and applications, allowing readers to use theory and software to create and analyze real-world decision-making models. With a rigorous, yet accessible, treatment of mathematics, the book focuses on results that can be used to
Prest, M
1988-01-01
In recent years the interplay between model theory and other branches of mathematics has led to many deep and intriguing results. In this, the first book on the topic, the theme is the interplay between model theory and the theory of modules. The book is intended to be a self-contained introduction to the subject and introduces the requisite model theory and module theory as it is needed. Dr Prest develops the basic ideas concerning what can be said about modules using the information which may be expressed in a first-order language. Later chapters discuss stability-theoretic aspects of module
International Nuclear Information System (INIS)
Lucha, W.; Neufeld, H.
1986-01-01
We investigate the relation between finiteness of a four-dimensional quantum field theory and global supersymmetry. To this end we consider the most general quantum field theory and analyse the finiteness conditions resulting from the requirement of the absence of divergent contributions to the renormalizations of the parameters of the theory. In addition to the gauge bosons, both fermions and scalar bosons turn out to be a necessary ingredient in a non-trivial finite gauge theory. In all cases discussed, the supersymmetric theory restricted by two well-known constraints on the dimensionless couplings proves to be the unique solution of the finiteness conditions. (Author)
International Nuclear Information System (INIS)
Eloranta, E.
2003-11-01
The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)
International Nuclear Information System (INIS)
Crisan, M.
1988-01-01
This book discusses the most important aspects of the theory. The phenomenological model is followed by the microscopic theory of superconductivity, in which modern formalism of the many-body theory is used to treat most important problems such as superconducting alloys, coexistence of superconductivity with the magnetic order, and superconductivity in quasi-one-dimensional systems. It concludes with a discussion on models for exotic and high temperature superconductivity. Its main aim is to review, as complete as possible, the theory of superconductivity from classical models and methods up to the 1987 results on high temperature superconductivity. Contents: Phenomenological Theory of Superconductivity; Microscopic Theory of Superconductivity; Theory of Superconducting Alloys; Superconductors in a Magnetic Field; Superconductivity and Magnetic Order; Superconductivity in Quasi-One-Dimensional Systems; and Non-Conventional Superconductivity
International Nuclear Information System (INIS)
Yilmaz, H.
1975-01-01
Schwinger's source theory is applied to the problem of gravitation and its quantization. It is shown that within the framework of a flat-space the source theory implementation leads to a violation of probability. To avoid the difficulty one must introduce a curved space-time hence the source concept may be said to necessitate the transition to a curved-space theory of gravitation. It is further shown that the curved-space theory of gravitation implied by the source theory is not equivalent to the conventional Einstein theory. The source concept leads to a different theory where the gravitational field has a stress-energy tensor t/sup nu//sub mu/ which contributes to geometric curvatures
Introduction to representation theory
Etingof, Pavel; Hensel, Sebastian; Liu, Tiankai; Schwendner, Alex
2011-01-01
Very roughly speaking, representation theory studies symmetry in linear spaces. It is a beautiful mathematical subject which has many applications, ranging from number theory and combinatorics to geometry, probability theory, quantum mechanics, and quantum field theory. The goal of this book is to give a "holistic" introduction to representation theory, presenting it as a unified subject which studies representations of associative algebras and treating the representation theories of groups, Lie algebras, and quivers as special cases. Using this approach, the book covers a number of standard topics in the representation theories of these structures. Theoretical material in the book is supplemented by many problems and exercises which touch upon a lot of additional topics; the more difficult exercises are provided with hints. The book is designed as a textbook for advanced undergraduate and beginning graduate students. It should be accessible to students with a strong background in linear algebra and a basic k...
[Introduction to grounded theory].
Wang, Shou-Yu; Windsor, Carol; Yates, Patsy
2012-02-01
Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.
Niederreiter, Harald
2015-01-01
This textbook effectively builds a bridge from basic number theory to recent advances in applied number theory. It presents the first unified account of the four major areas of application where number theory plays a fundamental role, namely cryptography, coding theory, quasi-Monte Carlo methods, and pseudorandom number generation, allowing the authors to delineate the manifold links and interrelations between these areas. Number theory, which Carl-Friedrich Gauss famously dubbed the queen of mathematics, has always been considered a very beautiful field of mathematics, producing lovely results and elegant proofs. While only very few real-life applications were known in the past, today number theory can be found in everyday life: in supermarket bar code scanners, in our cars’ GPS systems, in online banking, etc. Starting with a brief introductory course on number theory in Chapter 1, which makes the book more accessible for undergraduates, the authors describe the four main application areas in Chapters...
Computational invariant theory
Derksen, Harm
2015-01-01
This book is about the computational aspects of invariant theory. Of central interest is the question how the invariant ring of a given group action can be calculated. Algorithms for this purpose form the main pillars around which the book is built. There are two introductory chapters, one on Gröbner basis methods and one on the basic concepts of invariant theory, which prepare the ground for the algorithms. Then algorithms for computing invariants of finite and reductive groups are discussed. Particular emphasis lies on interrelations between structural properties of invariant rings and computational methods. Finally, the book contains a chapter on applications of invariant theory, covering fields as disparate as graph theory, coding theory, dynamical systems, and computer vision. The book is intended for postgraduate students as well as researchers in geometry, computer algebra, and, of course, invariant theory. The text is enriched with numerous explicit examples which illustrate the theory and should be ...
DEFF Research Database (Denmark)
Wæver, Ole
2011-01-01
theory is found to ‘act politically’ through three structural features that systematically shape the political effects of using the theory. The article further discusses – on the basis of the preceding articles in the special issue – three emerging debates around securitization theory: ethics......This article outlines three ways of analysing the ‘politics of securitization’, emphasizing an often-overlooked form of politics practised through theory design. The structure and nature of a theory can have systematic political implications. Analysis of this ‘politics of securitization......’ is distinct from both the study of political practices of securitization and explorations of competing concepts of politics among security theories. It means tracking what kinds of analysis the theory can produce and whether such analysis systematically impacts real-life political struggles. Securitization...
Nuclear matter from chiral effective field theory
International Nuclear Information System (INIS)
Drischler, Christian
2017-01-01
Nuclear matter is an ideal theoretical system that provides key insights into the physics of different length scales. While recent ab initio calculations of medium-mass to heavy nuclei have demonstrated that realistic saturation properties in infinite matter are crucial for reproducing experimental binding energies and charge radii, the nuclear-matter equation of state allows tight constraints on key quantities of neutron stars. In the present thesis we take advantage of both aspects. Chiral effective field theory (EFT) with pion and nucleon degrees of freedom has become the modern low-energy approach to nuclear forces based on the symmetries of quantum chromodynamics, the fundamental theory of strong interactions. The systematic chiral expansion enables improvable calculations associated with theoretical uncertainty estimates. In recent years, chiral many-body forces were derived up to high orders, allowing consistent calculations including all many-body contributions at next-to-next-to-next-to-leading order (N 3 LO). Many further advances have driven the construction of novel chiral potentials with different regularization schemes. Here, we develop advanced methods for microscopic calculations of the equation of state of homogeneous nuclear matter with arbitrary proton-to-neutron ratio at zero temperature. Specifically, we push the limits of many-body perturbation theory (MBPT) considerations to high orders in the chiral and in the many-body expansion. To address the challenging inclusion of three-body forces, we introduce a new partial-wave method for normal ordering that generalizes the treatment of these contributions. We show improved predictions for the neutron-matter equation of state with consistent N 3 LO nucleon-nucleon (NN) plus three-nucleon (3N) potentials using MBPT up to third order and self-consistent Green's function theory. The latter also provides nonperturbative benchmarks for the many-body convergence. In addition, we extend the normal
Nuclear matter from chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Drischler, Christian
2017-11-15
Nuclear matter is an ideal theoretical system that provides key insights into the physics of different length scales. While recent ab initio calculations of medium-mass to heavy nuclei have demonstrated that realistic saturation properties in infinite matter are crucial for reproducing experimental binding energies and charge radii, the nuclear-matter equation of state allows tight constraints on key quantities of neutron stars. In the present thesis we take advantage of both aspects. Chiral effective field theory (EFT) with pion and nucleon degrees of freedom has become the modern low-energy approach to nuclear forces based on the symmetries of quantum chromodynamics, the fundamental theory of strong interactions. The systematic chiral expansion enables improvable calculations associated with theoretical uncertainty estimates. In recent years, chiral many-body forces were derived up to high orders, allowing consistent calculations including all many-body contributions at next-to-next-to-next-to-leading order (N{sup 3}LO). Many further advances have driven the construction of novel chiral potentials with different regularization schemes. Here, we develop advanced methods for microscopic calculations of the equation of state of homogeneous nuclear matter with arbitrary proton-to-neutron ratio at zero temperature. Specifically, we push the limits of many-body perturbation theory (MBPT) considerations to high orders in the chiral and in the many-body expansion. To address the challenging inclusion of three-body forces, we introduce a new partial-wave method for normal ordering that generalizes the treatment of these contributions. We show improved predictions for the neutron-matter equation of state with consistent N{sup 3}LO nucleon-nucleon (NN) plus three-nucleon (3N) potentials using MBPT up to third order and self-consistent Green's function theory. The latter also provides nonperturbative benchmarks for the many-body convergence. In addition, we extend the
Microcanonical quantum field theory
International Nuclear Information System (INIS)
Strominger, A.
1983-01-01
Euclidean quantum field theory is equivalent to the equilibrium statistical mechanics of classical fields in 4+1 dimensions at temperature h. It is well known in statistical mechanics that the theory of systems at fixed temperature is embedded within the more general and fundamental theory of systems at fixed energy. We therefore develop, in precise analogy, a fixed action (macrocanonical) formulation of quantum field theory. For the case of ordinary renormalizable field theories, we show (with one exception) that the microcanonical is entirely equivalent to the canonical formulation. That is, for some particular fixed value of the total action, the Green's functions of the microcanonical theory are equal, in the bulk limit, to those of the canonical theory. The microcanonical perturbation expansion is developed in some detail for lambdaphi 4 . The particular value of the action for which the two formulations are equivalent can be calculated to all orders in perturbation theory. We prove, using Lehmann's Theorem, that this value is one-half Planck unit per degree of freedom, if fermionic degrees of freedom are counted negatively. This is the 4+1 dimensional analog of the equipartition theorem. The one exception to this is supersymmetric theories. A microcanonical formulation exists if and only if supersymmetry is broken. In statistical mechanics and in field theory there are systems for which the canonical description is pathological, but the microcanonical is not. An example of such a field theory is found in one dimension. A semiclassical expansion of the microcanonical theory is well defined, while an expansion of the canonical theory is hoplessly divergent
Franklin, Joel
2017-01-01
Classical field theory, which concerns the generation and interaction of fields, is a logical precursor to quantum field theory, and can be used to describe phenomena such as gravity and electromagnetism. Written for advanced undergraduates, and appropriate for graduate level classes, this book provides a comprehensive introduction to field theories, with a focus on their relativistic structural elements. Such structural notions enable a deeper understanding of Maxwell's equations, which lie at the heart of electromagnetism, and can also be applied to modern variants such as Chern–Simons and Born–Infeld. The structure of field theories and their physical predictions are illustrated with compelling examples, making this book perfect as a text in a dedicated field theory course, for self-study, or as a reference for those interested in classical field theory, advanced electromagnetism, or general relativity. Demonstrating a modern approach to model building, this text is also ideal for students of theoretic...
Algebraic quantum field theory
International Nuclear Information System (INIS)
Foroutan, A.
1996-12-01
The basic assumption that the complete information relevant for a relativistic, local quantum theory is contained in the net structure of the local observables of this theory results first of all in a concise formulation of the algebraic structure of the superselection theory and an intrinsic formulation of charge composition, charge conjugation and the statistics of an algebraic quantum field theory. In a next step, the locality of massive particles together with their spectral properties are wed for the formulation of a selection criterion which opens the access to the massive, non-abelian quantum gauge theories. The role of the electric charge as a superselection rule results in the introduction of charge classes which in term lead to a set of quantum states with optimum localization properties. Finally, the asymptotic observables of quantum electrodynamics are investigated within the framework of algebraic quantum field theory. (author)
Children's theories of motivation.
Gurland, Suzanne T; Glowacky, Victoria C
2011-09-01
To investigate children's theories of motivation, we asked 166 children (8-12 years of age) to rate the effect of various motivational strategies on task interest, over the short and long terms, in activities described as appealing or unappealing. Children viewed the rewards strategy as resulting in greatest interest except when implemented over the long term for appealing activities. Individual difference analyses revealed that some children held operant theories of motivation, in which rewards were central, and others held hybrid theories, in which rewards were key, but some allowance was made for interest to be self-sustaining in the absence of inducements. Children's theories predicted their academic self-regulation. Their theories are discussed relative to an expert theory of motivation. Copyright © 2011 Elsevier Inc. All rights reserved.
DEFF Research Database (Denmark)
Zander, Pär Ola
2014-01-01
theory. The paper concludes that Baudrillard's arguments for abandoning Marxism altogether are problematic and led him away from developing a more finished theory of value. This is unfortunate because it remains a project that may yield interesting insights even in contemporary social theory, not least......Jean Baudrillard outlined a theory of value in his early writings that built on, but also criticized, Marxist concepts of use value and exchange value. In this paper, I use a close reading to delineate the diachronic transition of Baudrillard's writings toward anti-Marxism and (allegedly......) postmodernism, with specific focus on his value theory, in order to understand his own reasons for abandoning his previous position. I then follow the marginal stream of scholars who are making use of the early Baudrillard. I find his value theory promising but still a mere sketch rather than an actual general...
DEFF Research Database (Denmark)
Birkedal, Lars; Bizjak, Aleš; Clouston, Ranald
2016-01-01
This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of program logics, and for programming and reasoning...... with coinductive types. We wish to implement GDTT with decidable type-checking, while still supporting non-trivial equality proofs that reason about the extensions of guarded recursive constructions. CTT is a variation of Martin-L\\"of type theory in which the identity type is replaced by abstract paths between...... terms. CTT provides a computational interpretation of functional extensionality, is conjectured to have decidable type checking, and has an implemented type-checker. Our new type theory, called guarded cubical type theory, provides a computational interpretation of extensionality for guarded recursive...
Karlin, Anna R
2016-01-01
This book presents a rigorous introduction to the mathematics of game theory without losing sight of the joy of the subject. This is done by focusing on theoretical highlights (e.g., at least six Nobel Prize winning results are developed from scratch) and by presenting exciting connections of game theory to other fields, such as computer science, economics, social choice, biology, and learning theory. Both classical topics, such as zero-sum games, and modern topics, such as sponsored search auctions, are covered. Along the way, beautiful mathematical tools used in game theory are introduced, including convexity, fixed-point theorems, and probabilistic arguments. The book is appropriate for a first course in game theory at either the undergraduate or graduate level, whether in mathematics, economics, computer science, or statistics. Game theory's influence is felt in a wide range of disciplines, and the authors deliver masterfully on the challenge of presenting both the breadth and coherence of its underlying ...
International Nuclear Information System (INIS)
Combes, J.M.
1980-10-01
A complementary approach to the time dependent scattering theory for one-body Schroedinger operators is presented. The stationary theory is concerned with objects of quantum theory like scattering waves and amplitudes. In the more recent abstract stationary theory some generalized form of the Lippman-Schwinger equation plays the basic role. Solving this equation leads to a linear map between generalized eigenfunctions of the perturbed and unperturbed operators. This map is the section at fixed energy of the wave-operator from the time dependent theory. Although the radiation condition does not appears explicitely in this formulation it can be shown to hold a posteriori in a variety of situations thus restoring the link with physical theories
Quantum theory without reduction
International Nuclear Information System (INIS)
Cini, Marcello; Levy-Leblond, J.-M.
1990-01-01
Quantum theory offers a strange, and perhaps unique, case in the history of science. Although research into its roots has provided important results in recent years, the debate goes on. Some theorists argue that quantum theory is weakened by the inclusion of the so called 'reduction of the state vector' in its foundations. Quantum Theory without Reduction presents arguments in favour of quantum theory as a consistent and complete theory without this reduction, and which is capable of explaining all known features of the measurement problem. This collection of invited contributions defines and explores different aspects of this issue, bringing an old debate into a new perspective, and leading to a more satisfying consensus about quantum theory. (author)
DEFF Research Database (Denmark)
Birkedal, Lars; Bizjak, Aleš; Clouston, Ranald
2016-01-01
This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of program logics, and for programming and reasoning...... with coinductive types. We wish to implement GDTT with decidable type checking, while still supporting non-trivial equality proofs that reason about the extensions of guarded recursive constructions. CTT is a variation of Martin-L\\"of type theory in which the identity type is replaced by abstract paths between...... terms. CTT provides a computational interpretation of functional extensionality, enjoys canonicity for the natural numbers type, and is conjectured to support decidable type-checking. Our new type theory, guarded cubical type theory (GCTT), provides a computational interpretation of extensionality...
DEFF Research Database (Denmark)
Balle, Søren Hattesen
This paper takes its starting point in a short poem by Wallace Stevens from 1917, which incidentally bears the title “Theory”. The poem can be read as a parable of theory, i.e., as something literally ’thrown beside’ theory (cf. OED: “...“). In the philosophical tradition this is also how the style of theory has been figured, that is to say: as something that is incidental to it or just happens to be around as so much paraphernalia. In my reading of Stevens’ poem I shall argue that this is exactly the position from which Stevens takes off when he assumes...... the task of writing a personified portrait of theory. Theory emerges as always beside(s) itself in what constitutes its style, but the poem also suggests that theory’s style is what gives theory both its power and its contingency. Figured as a duchess Theoria is only capable of retaining her power...
Supersymmetric gauge field theories
International Nuclear Information System (INIS)
Slavnov, A.A.
1976-01-01
The paper is dealing with the role of supersymmetric gauge theories in the quantum field theory. Methods of manipulating the theories as well as possibilities of their application in elementary particle physics are presented. In particular, the necessity is explained of a theory in which there is symmetry between Fermi and Bose fields, in other words, of the supersymmetric gauge theory for construction of a scheme for the Higgs particle connecting parameters of scalar mesons with those of the rest fields. The mechanism of supersymmetry breaking is discussed which makes it possible to remain the symmetric procedure of renormalization intact. The above mechanism of spontaneous symmetry breaking is applied to demonstrate possibilities of constructing models of weak and electromagnetic interactions which would be acceptable from the point of view of experiments. It is noted that the supersymmetric gauge theories represent a natural technique for description of vector-like models
DEFF Research Database (Denmark)
Javadi, Hossein; Forouzbakhsh, Farshid; Daei Kasmaei, Hamed
2016-01-01
There are various theories in physics, but nature is unique. This is not nature's problem that we have various theories; nature obeys simple and unique law. We should improve our theories. Universal constancy of the speed of light undergoes the question whether the limit on the light speed...... is the mechanism of increasing in the photon energy that causes increase in its frequency growth? So, in CPH theory (Creative particles of Higgs Theory), it has been attempted to scrutinize the interface between classical mechanics, relativity and quantum mechanics through a novel approach to the established...... physical events. Emphasizing on these phenomena and presenting the relation between photon's energy and frequency, CPH Theory is to draw attention on the importance of constancy of speed in relation to the mass structure which will be scrutinized in reviewing relativistic Newton's second law. The results...
International Nuclear Information System (INIS)
Creutz, M.
1983-04-01
In the last few years lattice gauge theory has become the primary tool for the study of nonperturbative phenomena in gauge theories. The lattice serves as an ultraviolet cutoff, rendering the theory well defined and amenable to numerical and analytical work. Of course, as with any cutoff, at the end of a calculation one must consider the limit of vanishing lattice spacing in order to draw conclusions on the physical continuum limit theory. The lattice has the advantage over other regulators that it is not tied to the Feynman expansion. This opens the possibility of other approximation schemes than conventional perturbation theory. Thus Wilson used a high temperature expansion to demonstrate confinement in the strong coupling limit. Monte Carlo simulations have dominated the research in lattice gauge theory for the last four years, giving first principle calculations of nonperturbative parameters characterizing the continuum limit. Some of the recent results with lattice calculations are reviewed
Effective quantum field theories
International Nuclear Information System (INIS)
Georgi, H.M.
1989-01-01
Certain dimensional parameters play a crucial role in the understanding of weak and strong interactions based on SU(2) x U(1) and SU(3) symmetry group theories and of grand unified theories (GUT's) based on SU(5). These parameters are the confinement scale of quantum chromodynamics and the breaking scales of SU(2) x U(1) and SU(5). The concepts of effective quantum field theories and renormalisability are discussed with reference to the economics and ethics of research. (U.K.)
International Nuclear Information System (INIS)
Kiefer, C.
2004-01-01
The following topics are dealt with: Particles and waves, the superposition principle and probability interpretation, the uncertainty relation, spin, the Schroedinger equation, wave functions, symmetries, the hydrogen atom, atoms with many electrons, Schroedinger's cat and the Einstein-podolsky-Rosen problem, the Bell inequalities, the classical limit, quantum systems in the electromagnetic field, solids and quantum liquids, quantum information, quantum field theory, quantum theory and gravitation, the mathematical formalism of quantum theory. (HSI)
Chartrand, Gary
1984-01-01
Graph theory is used today in the physical sciences, social sciences, computer science, and other areas. Introductory Graph Theory presents a nontechnical introduction to this exciting field in a clear, lively, and informative style. Author Gary Chartrand covers the important elementary topics of graph theory and its applications. In addition, he presents a large variety of proofs designed to strengthen mathematical techniques and offers challenging opportunities to have fun with mathematics. Ten major topics - profusely illustrated - include: Mathematical Models, Elementary Concepts of Grap
Introduction to superstring theory
International Nuclear Information System (INIS)
Nunez, Carmen
2009-01-01
This is a very basic introduction to the AdS/CFT correspondence. The first lecture motivates the duality between gauge theories and gravity/string theories. The next two lectures introduce the bosonic and supersymmetric string theories. The fourth lecture is devoted to study Dp-branes and finally, in the fifth lecture I discuss the two worlds: N=4 SYM in 3+1 flat dimensions and type IIB superstrings in AdS 5 x S5. (author)
Operational Shock Complexity Theory
2005-05-26
Theory : Recommendations For The National Strategy To Defeat Terrorism.” Student Issue Paper, Center for Strategic Leadership , US Army War College, July...Lens of Complexity Theory : Recommendations For The National Strategy To Defeat Terrorism.” (Student Issue Paper, Center for Strategic Leadership , US...planners managed to cause confusion in the enemy’s internal model by operating in an unexpected manner. 140 Glenn E. James, “Chaos Theory : The
1991-02-01
theory orients command leadership for the enormous task of managing organizations in our environment fraught with volatility, uncertainty...performance and organizational ethics. A THEORY OF MANAGEMENT BACKGROUND BASIC MANAGEMENT BEHAVIORAL Definitions FUNCTIONS ASPECTS History Planning Leadership ...the best way to manage in their theory of managerial leadership . To them, the 9,9 position on their model, "is acknowledged by managers as the
Introduction to superstring theory
Energy Technology Data Exchange (ETDEWEB)
Nunez, Carmen [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina)], e-mail: carmen@iafe.uba.ar
2009-07-01
This is a very basic introduction to the AdS/CFT correspondence. The first lecture motivates the duality between gauge theories and gravity/string theories. The next two lectures introduce the bosonic and supersymmetric string theories. The fourth lecture is devoted to study Dp-branes and finally, in the fifth lecture I discuss the two worlds: N=4 SYM in 3+1 flat dimensions and type IIB superstrings in AdS{sub 5} x S5. (author)
International Nuclear Information System (INIS)
Petronzio, R.
1992-01-01
Lattice gauge theories are about fifteen years old and I will report on the present status of the field without making the elementary introduction that can be found in the proceedings of the last two conferences. The talk covers briefly the following subjects: the determination of α s , the status of spectroscopy, heavy quark physics and in particular the calculation of their hadronic weak matrix elements, high temperature QCD, non perturbative Higgs bounds, chiral theories on the lattice and induced theories
International Nuclear Information System (INIS)
Kim, Jong Deuk
2000-02-01
This book is composed of 8 chapters. It tells what interfacial phenomenon is by showing interfacial energy, characteristic of interface and system of interface from chapter 1. It also introduces interfacial energy and structure theory, molecular structure and orientation theory, and interfacial electricity phenomenon theory in the following 3 chapters. It still goes on by introducing super molecule cluster, disequilibrium dispersion, and surface and film through 3 chapters. And the last chapter is about colloid and application of interface.
International Nuclear Information System (INIS)
Schmutzer, E.
1979-01-01
Issued on the occasion of Albert Einstein's 100th birthday the book deals topically with the special and general relativity theory. The latest experiments to confirm the relativity theory are described and the historical development of the theory is presented in detail. Emphasis is given to the disclosure of deep insights into the nature of matter. Of interest to experts in physical and natural sciences and to mathematicians
Advanced Tokamak Stability Theory
Zheng, Linjin
2015-03-01
The intention of this book is to introduce advanced tokamak stability theory. We start with the derivation of the Grad-Shafranov equation and the construction of various toroidal flux coordinates. An analytical tokamak equilibrium theory is presented to demonstrate the Shafranov shift and how the toroidal hoop force can be balanced by the application of a vertical magnetic field in tokamaks. In addition to advanced theories, this book also discusses the intuitive physics pictures for various experimentally observed phenomena.
DEFF Research Database (Denmark)
Hagedorn, Claudia
2017-01-01
I discuss different theories of leptonic flavor and their capability of describing the features of the lepton sector, namely charged lepton masses, neutrino masses, lepton mixing angles and leptonic (low and high energy) CP phases. In particular, I show examples of theories with an abelian flavor...... symmetry G_f, with a non-abelian G_f as well as theories with non-abelian G_f and CP....
Theory of particle interactions
International Nuclear Information System (INIS)
Belokurov, V.V.; Shirkov, D.V.
1986-01-01
Development and modern state of the theory of elementary particle interactions is described. The main aim of the paper is to give a picture of quantum field theory development in the form easily available for physicists not occupied in this field of science. Besides the outline of chronological development of main representations, the description of renormalization and renorm-groups, gauge theories, models of electro-weak interactions and quantum chromodynamics, the latest investigations related to joining all interactions and supersymmetries is given
Dijkgraaf, R; Verlinde, Herman L
1997-01-01
Via compactification on a circle, the matrix model of M-theory proposed by Banks et al suggests a concrete identification between the large N limit of two-dimensional N=8 supersymmetric Yang-Mills theory and type IIA string theory. In this paper we collect evidence that supports this identification. We explicitly identify the perturbative string states and their interactions, and describe the appearance of D-particle and D-membrane states.
International Nuclear Information System (INIS)
Ryder, L.H.
1985-01-01
This introduction to the ideas and techniques of quantum field theory presents the material as simply as possible and is designed for graduate research students. After a brief survey of particle physics, the quantum theory of scalar and spinor fields and then of gauge fields, is developed. The emphasis throughout is on functional methods, which have played a large part in modern field theory. The book concludes with a bridge survey of ''topological'' objects in field theory and assumes a knowledge of quantum mechanics and special relativity
Games, theory and applications
Thomas, L C
2011-01-01
Anyone with a knowledge of basic mathematics will find this an accessible and informative introduction to game theory. It opens with the theory of two-person zero-sum games, two-person non-zero sum games, and n-person games, at a level between nonmathematical introductory books and technical mathematical game theory books. Succeeding sections focus on a variety of applications - including introductory explanations of gaming and meta games - that offer nonspecialists information about new areas of game theory at a comprehensible level. Numerous exercises appear with full solutions, in addition
Empirical comparison of theories
International Nuclear Information System (INIS)
Opp, K.D.; Wippler, R.
1990-01-01
The book represents the first, comprehensive attempt to take an empirical approach for comparative assessment of theories in sociology. The aims, problems, and advantages of the empirical approach are discussed in detail, and the three theories selected for the purpose of this work are explained. Their comparative assessment is performed within the framework of several research projects, which among other subjects also investigate the social aspects of the protest against nuclear power plants. The theories analysed in this context are the theory of mental incongruities and that of the benefit, and their efficiency in explaining protest behaviour is compared. (orig./HSCH) [de
Mandl, Franz
2010-01-01
Following on from the successful first (1984) and revised (1993) editions, this extended and revised text is designed as a short and simple introduction to quantum field theory for final year physics students and for postgraduate students beginning research in theoretical and experimental particle physics. The three main objectives of the book are to: Explain the basic physics and formalism of quantum field theory To make the reader proficient in theory calculations using Feynman diagrams To introduce the reader to gauge theories, which play a central role in elementary particle physic
WORKSHOP: Thermal field theory
Energy Technology Data Exchange (ETDEWEB)
Anon.
1989-04-15
The early history of the Universe is a crucial testing ground for theories of elementary particles. Speculative ideas about the constituents of matter and their interactions are reinforced if they are consistent with what we suppose happened near the beginning of time and discarded if they are not. The cosmological consequences of these theories are usually deduced using a general statistical approach called thermal field theory. Thus, 75 physicists from thirteen countries met in Cleveland, Ohio, last October for the first 'Workshop on Thermal Field Theories and their Applications'.
Cappell, Sylvain; Rosenberg, Jonathan
2014-01-01
Surgery theory, the basis for the classification theory of manifolds, is now about forty years old. The sixtieth birthday (on December 14, 1996) of C.T.C. Wall, a leading member of the subject''s founding generation, led the editors of this volume to reflect on the extraordinary accomplishments of surgery theory as well as its current enormously varied interactions with algebra, analysis, and geometry. Workers in many of these areas have often lamented the lack of a single source surveying surgery theory and its applications. Because no one person could write such a survey, the editors ask
Cappell, Sylvain; Rosenberg, Jonathan
2014-01-01
Surgery theory, the basis for the classification theory of manifolds, is now about forty years old. There have been some extraordinary accomplishments in that time, which have led to enormously varied interactions with algebra, analysis, and geometry. Workers in many of these areas have often lamented the lack of a single source that surveys surgery theory and its applications. Indeed, no one person could write such a survey. The sixtieth birthday of C. T. C. Wall, one of the leaders of the founding generation of surgery theory, provided an opportunity to rectify the situation and produce a
Enderton, Herbert B
1977-01-01
This is an introductory undergraduate textbook in set theory. In mathematics these days, essentially everything is a set. Some knowledge of set theory is necessary part of the background everyone needs for further study of mathematics. It is also possible to study set theory for its own interest--it is a subject with intruiging results anout simple objects. This book starts with material that nobody can do without. There is no end to what can be learned of set theory, but here is a beginning.
Generalized etale cohomology theories
Jardine, John F
1997-01-01
A generalized etale cohomology theory is a theory which is represented by a presheaf of spectra on an etale site for an algebraic variety, in analogy with the way an ordinary spectrum represents a cohomology theory for spaces. Examples include etale cohomology and etale K-theory. This book gives new and complete proofs of both Thomason's descent theorem for Bott periodic K-theory and the Nisnevich descent theorem. In doing so, it exposes most of the major ideas of the homotopy theory of presheaves of spectra, and generalized etale homology theories in particular. The treatment includes, for the purpose of adequately dealing with cup product structures, a development of stable homotopy theory for n-fold spectra, which is then promoted to the level of presheaves of n-fold spectra. This book should be of interest to all researchers working in fields related to algebraic K-theory. The techniques presented here are essentially combinatorial, and hence algebraic. An extensive background in traditional stable hom...
International Nuclear Information System (INIS)
Oblow, E.M.; Perey, F.G.
1984-01-01
A comprehensive rigorous theory is developed for screening sensitivity coefficients in largescale modeling applications. The theory uses Bayesian inference and group theory to establish a probabilistic framework for solving an underdetermined system of linear equations. The underdetermined problem is directly related to statistical screening sensitivity theory as developed in recent years. Several examples of the new approach to screening are worked out in detail and comparisons are made with statistical approaches to the problem. The drawbacks of these latter methods are discussed at some length
Dwivedi, Yogesh K; Schneberger, Scott L
2011-01-01
The overall mission of this book is to provide a comprehensive understanding and coverage of the various theories and models used in IS research. Specifically, it aims to focus on the following key objectives: To describe the various theories and models applicable to studying IS/IT management issues. To outline and describe, for each of the various theories and models, independent and dependent constructs, reference discipline/originating area, originating author(s), seminal articles, level of analysis (i.e. firm, individual, industry) and links with other theories. To provide a critical revie
International Nuclear Information System (INIS)
Krasnikov, N.V.
1987-01-01
Nonlocal gauge theories including gravity are considered. It is shown that the introduction of the additional nonlocal interaction makes γ 5 -anomalous theories meaningful. The introduction of such interaction leads to macrocausal unitary theory, which describes the interaction of massive vector fields with fermion fields. It is shown that nonlocal gauge theories with nonlocal scale Λ nl ≤(1-10) TeV can solve the gauge hierarchy problem. An example of nonlinear grand unified gauge model in which topologically nontrivial finite energy monopole solutions are absent is found
Consistent classical supergravity theories
International Nuclear Information System (INIS)
Muller, M.
1989-01-01
This book offers a presentation of both conformal and Poincare supergravity. The consistent four-dimensional supergravity theories are classified. The formulae needed for further modelling are included
Goethe, Johann Wolfgang von
2006-01-01
The wavelength theory of light and color had been firmly established by the time the great German poet published his Theory of Colours in 1810. Nevertheless, Goethe believed that the theory derived from a fundamental error, in which an incidental result was mistaken for a elemental principle. Far from affecting a knowledge of physics, he maintained that such a background would inhibit understanding. The conclusions Goethe draws here rest entirely upon his personal observations.This volume does not have to be studied to be appreciated. The author's subjective theory of colors permits him to spe
DEFF Research Database (Denmark)
Hastings, Gerard; Brown, Abraham; Anker, Thomas Boysen
2010-01-01
influence this positioning (Social Cognitive Theory and Social Norms) and; (iii) what offerings might encourage them to change their behaviour – or, those in a position to do so, to make the social context more conducive to change (Exchange Theory). Moreover, the chapter outlines how social marketers might......The chapter looks at three important theories which help social marketers to think more systematically about the key questions they need to address: (i) how does the target group or population feel about a particular behaviour (Stages of Change Theory); (ii) what social and contextual factors...... benefit from a social epistemological approach....
International Nuclear Information System (INIS)
Deshpande, N.G.
1980-01-01
By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given
DEFF Research Database (Denmark)
Galle, Per
2006-01-01
aware of, I demonstrate how 'insidious inconsistency ' may infect design theory if we ignore this admonition. As a possible remedy, I propose a method by which the philosophy of design may develop sound methaphysical foundations ('worldviews') for design theory - and obtain philosophical insights......I suspect that the growing 'body' of design theory may be infected by more inconsistency than is justifiable by genuine disagreement among design researchers. Taking my clue from Peirce, who argued that theory inevitably rests on basics metaphysical assumptions that theorists ought to be critically...
Dynasting Theory: Lessons in learning grounded theory
Directory of Open Access Journals (Sweden)
Johnben Teik-Cheok Loy, MBA, MTS, Ph.D.
2011-06-01
Full Text Available This article captures the key learning lessons gleaned from the author’s experience learning and developing a grounded theory for his doctoral dissertation using the classic methodology as conceived by Barney Glaser. The theory was developed through data gathered on founders and successors of Malaysian Chinese family-own businesses. The main concern for Malaysian Chinese family businesses emerged as dynasting . the building, maintaining, and growing the power and resources of the business within the family lineage. The core category emerged as dynasting across cultures, where founders and successors struggle to transition from traditional Chinese to hybrid cultural and modernized forms of family business from one generation to the next. The key learning lessons were categorized under five headings: (a sorting through different versions of grounded theory, (b educating and managing research stakeholders, (c embracing experiential learning, (d discovering the core category: grounded intuition, and (e recognizing limitations and possibilities.Keywords: grounded theory, learning, dynasting, family business, Chinese
Kontextualisierung von Queer Theory Contextualizing Queer Theory
Directory of Open Access Journals (Sweden)
Anna Voigt
2008-03-01
Full Text Available Christine M. Klapeer legt in diesem Einführungsband dar, aus welchen politischen und theoretischen Kontexten heraus sich ‚queer‘ zu einem Begriff mit besonderem politischem und theoretischem Gehalt entwickelt hat. Wesentlich zielt sie dabei auf eine kritische Kontextualisierung von „queer theory”. Die Autorin geht zunächst auf das Gay Liberation Movement ein, grenzt die Queer Theory vom Poststrukturalismus, von feministischen Theorien und den Lesbian and Gay Studies ab, beleuchtet Eckpunkte queeren Denkens und zeichnet schließlich die Entwicklungen in Österreich sowohl politisch-rechtlich als auch bewegungsgeschichtlich und in der Wissenschaftslandschaft nach.Christine M. Klapeer’s introductory volume demonstrates the manner in which ‘queer’ grew out of various political and theoretical contexts to become a term with special political and theoretical content. She focuses primarily on a critical contextualization of “queer theory.” The author begins by approaching the Gay Liberation Movement and then distinguishes Queer Theory from poststructuralism, from feminist theories, and from Lesbian and Gay Studies. She continues on to illuminate the key aspects of queer thought and concludes by sketching the development in Austria in terms of politics and the law, the history of movements, and within the landscape of knowledge.
[Topics in field theory and string theory
International Nuclear Information System (INIS)
1990-01-01
In the past year, I have continued to investigate the relations between conformal field theories and lattice statistical mechanical models, and in particular have been studying two dimensional models coupled to quantum gravity. I have continued as well to consider possible extension of these results to higher dimensions and potential applications in other contexts
Kinetic theory and simulation of multi-species plasmas in tokamaks excited with ICRF microwaves
International Nuclear Information System (INIS)
Kerbel, G.D.; McCoy, M.G.
1984-01-01
This paper presents a description of a bounce-averaged Fokker-Planck quasilinear model for the kinetic description of tokamak plasmas. The non-linear collision and quasilinear resonant diffusion operators are represented in a form conducive to numerical solution with specific attention to the treatment of the boundary layer separating trapped and passing orbit regions of velocity space. The numerical techniques employed are detailed in so far as they constitute significant departure from those used in the conventional uniform magnetic field case. Examples are given to illustrate the combined effects of collisional and resonant diffusion
Theory of nonlinear interaction of particles and waves in an inverse plasma maser. Part 1
International Nuclear Information System (INIS)
Krivitsky, V.S.; Vladimirov, S.V.
1991-01-01
An expression is obtained for the collision integral describing the simultaneous interaction of plasma particles with resonant and non-resonant waves. It is shown that this collision integral is determined by two processes: a 'direct' nonlinear interaction of particles and waves, and the influence of the non-stationary of the system. The expression for the nonlinear collision integral is found to be quite different from the expression for a quasi-linear collision integral; in particular, the nonlinear integral contains higher-order derivatives of the distribution function with respect to momentum than the quasi-linear one. (author)
Trubitsyn, A G
2012-01-01
In attempts to develop a means of life prolongation the humankind has created more than three hundred theories of the aging; each of them offers the original cause of aging. However, none of them has given practical result by now. The majority of the theories have now only historical interest. There are several different theories that are mainly under consideration currently. They are based on reliable, proven evidence: the free radical theory, the protein error theory, the replicative senescence theory, the theory of reparation weakening, the immunological theory, several versions of neuroendocrinal theories, and programmed aging theory. The theory presented here is based on conception that the life as the phenomenon represents many of the interconnected physical and chemical processes propelled by energy of the mitochondrial bioenergetical machine. Gradual degradation of all vital processes is caused by the programmed decrease in level of bioenergetics. This theory unites all existing theories of aging constructed on authentic facts: it is shown, that such fundamental phenomena accompanying aging process as the increase in level of reactive oxygen species (ROS), the decrease in the general level of protein synthesis, the limitation of cellular dividing (Haiflick limit), decrease in efficiency of reparation mechanisms are caused by bioenergetics attenuation. Each of these phenomena in turn generates a number of harmful secondary processes. Any of the theories bases on one of these destructive phenomena or their combination. Hence, each of them describes one of sides of process of the aging initially caused by programmed decrease of level of bioenergetics. This united theory gives the chance to understand the nature of aging clock and explains a phenomenon of increase in longevity at the condition of food restriction. Failures of attempts to develop means from aging are explained by that the manipulations with the separate secondary phenomena of attenuation of
Revisiting the theory of the evolution of pick-up ion distributions: magnetic or adiabatic cooling?
Directory of Open Access Journals (Sweden)
H. J. Fahr
2007-01-01
Full Text Available We study the phasespace behaviour of heliospheric pick-up ions after the time of their injection as newly created ions into the solar wind bulk flow from either charge exchange or photoionization of interplanetary neutral atoms. As interaction with the ambient MHD wave fields we allow for rapid pitch angle diffusion, but for the beginning of this paper we shall neglect the effect of quasilinear or nonlinear energy diffusion (Fermi-2 acceleration induced by counterflowing ambient waves. In the up-to-now literature connected with the convection of pick-up ions by the solar wind only adiabatic cooling of these ions is considered which in the solar wind frame takes care of filling the gap between the injection energy and energies of the thermal bulk of solar wind ions. Here we reinvestigate the basics of the theory behind this assumption of adiabatic pick-up ion reactions and correlated predictions derived from it. We then compare it with the new assumption of a pure magnetic cooling of pick-up ions simply resulting from their being convected in an interplanetary magnetic field which decreases in magnitude with increase of solar distance. We compare the results for pick-up ion distribution functions derived along both ways and can point out essential differences of observational and diagnostic relevance. Furthermore we then include stochastic acceleration processes by wave-particle interactions. As we can show, magnetic cooling in conjunction with diffusive acceleration by wave-particle interaction allows for an unbroken power law with the unique power index γ=−5 beginning from lowest velocities up to highest energy particles of about 100 KeV which just marginally can be in resonance with magnetoacoustic turbulences. Consequences for the resulting pick-up ion pressures are also analysed.
Revisiting the theory of the evolution of pick-up ion distributions: magnetic or adiabatic cooling?
Directory of Open Access Journals (Sweden)
H. J. Fahr
2008-01-01
Full Text Available We study the phasespace behaviour of heliospheric pick-up ions after the time of their injection as newly created ions into the solar wind bulk flow from either charge exchange or photoionization of interplanetary neutral atoms. As interaction with the ambient MHD wave fields we allow for rapid pitch angle diffusion, but for the beginning of this paper we shall neglect the effect of quasilinear or nonlinear energy diffusion (Fermi-2 acceleration induced by counterflowing ambient waves. In the up-to-now literature connected with the convection of pick-up ions by the solar wind only adiabatic cooling of these ions is considered which in the solar wind frame takes care of filling the gap between the injection energy and energies of the thermal bulk of solar wind ions. Here we reinvestigate the basics of the theory behind this assumption of adiabatic pick-up ion reactions and correlated predictions derived from it. We then compare it with the new assumption of a pure magnetic cooling of pick-up ions simply resulting from their being convected in an interplanetary magnetic field which decreases in magnitude with increase of solar distance. We compare the results for pick-up ion distribution functions derived along both ways and can point out essential differences of observational and diagnostic relevance. Furthermore we then include stochastic acceleration processes by wave-particle interactions. As we can show, magnetic cooling in conjunction with diffusive acceleration by wave-particle interaction allows for an unbroken power law with the unique power index γ=−5 beginning from lowest velocities up to highest energy particles of about 100 KeV which just marginally can be in resonance with magnetoacoustic turbulences. Consequences for the resulting pick-up ion pressures are also analysed.
2003-01-01
With the start of next year, CERN's Theory Division and Experimental Physics Division will merge to form the new Department of Physics. The Bulletin looks back at an era, has a closer a look at what the Theory Division is and what makes it so special.
Braidotti, R.
2016-01-01
This essay proposes a genealogical cartography of the emergence of a posthuman turn in critical theory, including feminist theory, based on the convergence of posthumanism with post-anthropocentrism. The former critiques the universalist posture of the idea of ‘Man’ as the alleged ‘measure of all
Nuclear theory progress report
International Nuclear Information System (INIS)
1991-01-01
This report discusses research performed at University of Washington in nuclear theory. Some of the topics discussed are: nuclear astrophysics; symmetry; time reversal invariance; quark matter; superallowed beta decay; exclusive reactions; nuclear probes; soliton model; relativistic heavy ion collisions; supernova explosions; neutrino processes in dense matter; field theories; weak interaction physics; and nuclear structure
Hyperfunction quantum field theory
International Nuclear Information System (INIS)
Nagamachi, S.; Mugibayashi, N.
1976-01-01
The quantum field theory in terms of Fourier hyperfunctions is constructed. The test function space for hyperfunctions does not contain C infinitely functios with compact support. In spite of this defect the support concept of H-valued Fourier hyperfunctions allows to formulate the locality axiom for hyperfunction quantum field theory. (orig.) [de
Rexhepi, Jevdet; Torres, Carlos Alberto
2011-01-01
This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments…
Stefanovich, Eugene
2018-01-01
This book introduces notation, terminology, and basic ideas of relativistic quantum theories. The discussion proceeds systematically from the principle of relativity and postulates of quantum logics to the construction of Poincaré invariant few-particle models of interaction and scattering. It is the first of three volumes formulating a consistent relativistic quantum theory of interacting charged particles.
Science and information theory
Brillouin, Léon
1962-01-01
A classic source for exploring the connections between information theory and physics, this text is geared toward upper-level undergraduates and graduate students. The author, a giant of 20th-century mathematics, applies the principles of information theory to a variety of issues, including Maxwell's demon, thermodynamics, and measurement problems. 1962 edition.
International Nuclear Information System (INIS)
Haxton, W.; Bertsch, G.; Henley, E.M.
1993-01-01
This report briefly discussion the following programs of the Institute for Nuclear Theory: fundamental interactions in nuclei; strangeness in hadrons and nuclei; microscopic nuclear structure theory; nuclear physics in atoms and molecules; phenomenology and lattice QCD; and large amplitude collective motion
Mayer, William V.
In this paper the author examines the question of whether evolution is a theory or a dogma. He refutes the contention that there is a monolithic scientific conspiracy to present evolution as dogma and suggests that his own presentation might be more appropriately entitled "Creationism: Theory or Dogma." (PEB)
Sadovskii, Michael V
2013-01-01
This book discusses the main concepts of the Standard Model of elementary particles in a compact and straightforward way. The work illustrates the unity of modern theoretical physics by combining approaches and concepts of the quantum field theory and modern condensed matter theory. The inductive approach allows a deep understanding of ideas and methods used for solving problems in this field.
International Nuclear Information System (INIS)
Yuille, A.L.
1980-11-01
Topics in the Yang-Mills theories of strong interactions and the quantum theories of gravity are examined, using the path integral approach, including; Yang-Mills instantons in curved spacetimes, Israel-Wilson metrics, Kaehler spacetimes, instantons and anti-instantons. (U.K.)
Introduction to gauge theories
International Nuclear Information System (INIS)
Wit, B. de
1983-01-01
In these lectures we present the key ingredients of theories with local gauge invariance. We introduce gauge invariance as a starting point for the construction of a certain class of field theories, both for abelian and nonabelian gauge groups. General implications of gauge invariance are discussed, and we outline in detail how gauge fields can acquire masses in a spontaneous fashion. (orig./HSI)
Ritter, Simone; Rietzschel, Eric; Zedelius, Claire; Müller, Barbara; Schooler, Jonathan
2017-01-01
Creativity is of great appeal and importance to people, and they strive to understand creativity by developing lay theories. Such lay theories about creativity concern, for example, the characteristics of creative persons, such as the ‘mad genius’ idea, or environmental factors that contribute to
Shor, Mikhael
2003-01-01
States making game theory relevant and accessible to students is challenging. Describes the primary goal of GameTheory.net is to provide interactive teaching tools. Indicates the site strives to unite educators from economics, political and computer science, and ecology by providing a repository of lecture notes and tests for courses using…
Supersymmetric and supergravity theories
International Nuclear Information System (INIS)
Pernici, M.
1986-01-01
The author addressed problems in Kaluza-Klein supergravity, in supersymmetric theories and in string theories. They constructed the following supergravity theories in higher dimensions: the maximal gauged supergravities in five and seven dimensions, both related to the respective ungauged theory, though the latter cannot be obtained by putting the coupling constant of the gauged version to zero (gauge discontinuity); the ten-dimensional N = 2 non-chiral and the six-dimensional N = 4 supergravities, through trivial dimensional reduction of higher dimensional theories. They studied the Kaluza-Klein compactifications of the seven-dimensional supergravity theories and of the ten-dimensional, N = 2 non-chiral supergravity. They obtained the non-compact gaugings and the critical points of the potential of the maximal gauged supergravity in seven dimensions. They computed the non-abelian chiral anomaly in super Yang-Mills theories, using a variation of the Fujikawa method. The covariant action of the SU(2) spinning string is obtained together with its extension to non-linear sigma models. A covariant action for the free open spinning string field theory is constructed by analyzing the BRST transformations
International Nuclear Information System (INIS)
Hasegawa, Akira.
1975-04-01
A new theory of aurora formation is presented based on Alfven wave-electron interaction. The theory explains consistently 1) the electron acceleration process, 2) the formation of auroral layers and 3) the long wave formation in the longitudinal direction. (auth.)
Swan, R G
1968-01-01
From the Introduction: "These notes are taken from a course on algebraic K-theory [given] at the University of Chicago in 1967. They also include some material from an earlier course on abelian categories, elaborating certain parts of Gabriel's thesis. The results on K-theory are mostly of a very general nature."
J. de Haan (Hans)
2010-01-01
textabstractThis thesis is a treatise on a theory for societal transitions: pillar theory. Societal transitions are complex processes taking place in complex systems, large-scale, long-term processes in which societal systems radically change the way they are composed and function. Since we all are
Gauge theory and renormalization
Hooft, G. 't
1996-01-01
Early developments leading to renormalizable non-Abelian gauge theories for the weak, electromagnetic and strong interactions, are discussed from a personal viewpoint. They drastically improved our view of the role of field theory, symmetry and topology, as well as other branches of mathematics, in
String perturbation theory diverges
International Nuclear Information System (INIS)
Gross, D.J.; Periwal, V.
1988-01-01
We prove that perturbation theory for the bosonic string diverges for arbitrary values of the coupling constant and is not Borel summable. This divergence is independent of the existence of the infinities that occur in the theory due to the presence of tachyons and dilaton tadpoles. We discuss the physical implications of such a divergence
Instantaneous stochastic perturbation theory
International Nuclear Information System (INIS)
Lüscher, Martin
2015-01-01
A form of stochastic perturbation theory is described, where the representative stochastic fields are generated instantaneously rather than through a Markov process. The correctness of the procedure is established to all orders of the expansion and for a wide class of field theories that includes all common formulations of lattice QCD.
Suppes, Patrick
1972-01-01
This clear and well-developed approach to axiomatic set theory is geared toward upper-level undergraduates and graduate students. It examines the basic paradoxes and history of set theory and advanced topics such as relations and functions, equipollence, finite sets and cardinal numbers, rational and real numbers, and other subjects. 1960 edition.
Minimalism and Optimality Theory
Broekhuis, H.; Woolford, E.; den Dikken, M.
2013-01-01
This article discusses the relation between the minimalist program (MP) and optimality theory (OT) and will show that, contrary to popular belief, MP and OT are not inherently incompatible or competing frameworks/theories. Instead, we will show (i) that the two can well be seen as complementary
CERN. Geneva. Audiovisual Unit
2002-01-01
I will present a simple and non-technical overview of string theory, aimed for non-experts who like to get some idea what string theory is about. Besides introductory material, I intend to cover also some of the more recent developments.
Introductory photoemission theory
International Nuclear Information System (INIS)
Arai, Hiroko; Fujikawa, Takashi
2010-01-01
An introductory review is presented on the basis of many-body scattering theory. Some fundamental aspects of photoemission theory are discussed in detail. A few applications are also discussed; photoelectron diffraction, depth distribution function and multi-atom resonant photoemission are also discussed briefly. (author)
Developments in perturbation theory
International Nuclear Information System (INIS)
Greenspan, E.
1976-01-01
Included are sections dealing with perturbation expressions for reactivity, methods for the calculation of perturbed fluxes, integral transport theory formulations for reactivity, generalized perturbation theory, sensitivity and optimization studies, multigroup calculations of bilinear functionals, and solution of inhomogeneous Boltzmann equations with singular operators
French Theory's American Adventures
Cusset, Francois
2008-01-01
In this article, the author discusses how it is simply too late to be still speaking about French theory and its role in the intellectual life of the United States today. It seems to many observers that the gap between real-life politics and theory's guerrillas is much too wide already, after 30 years of academic fever, for the two worlds to even…
History, Theory, and Education
Rury, John L.
2011-01-01
In this article, the author discusses the question of theory as it may pertain to the history of education, with particular attention to the United States. Historians, like everyone else, have little choice regarding the use of theory; to one extent or another they must. The question is how much and to what end. The author aims to consider the…
Jackendoff, Ray
2017-01-01
Formal theories of mental representation have receded from the importance they had in the early days of cognitive science. I argue that such theories are crucial in any mental domain, not just for their own sake, but to guide experimental inquiry, as well as to integrate the domain into the mind as a whole. To illustrate the criteria of adequacy…
Sexual Murderers' Implicit Theories
Beech, Anthony; Fisher, Dawn; Ward, Tony
2005-01-01
Interviews with 28 sexual murderers were subjected to grounded theory analysis. Five implicit theories (ITs) were identified: dangerous world, male sex drive is uncontrollable, entitlement, women as sexual objects, and women as unknowable. These ITs were found to be identical to those identified in the literature as being present in rapists. The…
Documentary and Cognitive Theory
DEFF Research Database (Denmark)
Bondebjerg, Ib
2014-01-01
This article deals with the benefits of using cognitive theory in documentary film studies. The article outlines general aspects of cognitive theory in humanities and social science, however the main focus is on the role of narrative, visual style and emotional dimensions of different types...
Implicit Theories of Persuasion.
Roskos-Ewoldsen, David R.
1997-01-01
Explores whether individuals have implicit theories of persuasion. Examines how persuasive strategies are cognitively represented--identifies types of tactics in attitude change and social acceptability of persuasive strategies. Finds implicit theories of persuasion reflect the audience's familiarity with the topic. Finds also that implicit…
International Nuclear Information System (INIS)
Lawden, D.F.
1985-01-01
The book on elements of relativity theory is intended for final year school students or as an early university course in mathematical physics. Special principle of relativity, lorentz transformation, velocity transformations, relativistic mechanics, and general theory of relativity, are all discussed. (U.K.)
DEFF Research Database (Denmark)
Michelsen, Aage U.
2004-01-01
Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process.......Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process....
Towards Extended Vantage Theory
Glaz, Adam
2010-01-01
The applicability of Vantage Theory (VT), a model of (colour) categorization, to linguistic data largely depends on the modifications and adaptations of the model for the purpose. An attempt to do so proposed here, called Extended Vantage Theory (EVT), slightly reformulates the VT conception of vantage by capitalizing on some of the entailments of…
Governance and organizational theory
Directory of Open Access Journals (Sweden)
Carlos E. Quintero Castellanos
2017-07-01
Full Text Available The objective of this essay is to propose a way to link the theoretical body that has been weaved around governance and organizational theory. For this, a critical exposition is done about what is the theoretical core of governance, the opportunity areas are identified for the link of this theory with organizational theory. The essay concludes with a proposal for the organizational analysis of administrations in governance. The essay addresses with five sections. The first one is the introduction. In the second one, I present a synthesis of the governance in its current use. In the next one are presented the work lines of the good governance. In the fourth part, I show the organizational and managerial limits in the governance theory. The last part develops the harmonization proposal for the governance and organizational theories.
Chartrand, Gary; Rosen, Kenneth H
2008-01-01
Beginning with the origin of the four color problem in 1852, the field of graph colorings has developed into one of the most popular areas of graph theory. Introducing graph theory with a coloring theme, Chromatic Graph Theory explores connections between major topics in graph theory and graph colorings as well as emerging topics. This self-contained book first presents various fundamentals of graph theory that lie outside of graph colorings, including basic terminology and results, trees and connectivity, Eulerian and Hamiltonian graphs, matchings and factorizations, and graph embeddings. The remainder of the text deals exclusively with graph colorings. It covers vertex colorings and bounds for the chromatic number, vertex colorings of graphs embedded on surfaces, and a variety of restricted vertex colorings. The authors also describe edge colorings, monochromatic and rainbow edge colorings, complete vertex colorings, several distinguishing vertex and edge colorings, and many distance-related vertex coloring...
Quantal density functional theory
Sahni, Viraht
2016-01-01
This book deals with quantal density functional theory (QDFT) which is a time-dependent local effective potential theory of the electronic structure of matter. The treated time-independent QDFT constitutes a special case. In the 2nd edition, the theory is extended to include the presence of external magnetostatic fields. The theory is a description of matter based on the ‘quantal Newtonian’ first and second laws which is in terms of “classical” fields that pervade all space, and their quantal sources. The fields, which are explicitly defined, are separately representative of electron correlations due to the Pauli exclusion principle, Coulomb repulsion, correlation-kinetic, correlation-current-density, and correlation-magnetic effects. The book further describes Schrödinger theory from the new physical perspective of fields and quantal sources. It also describes traditional Hohenberg-Kohn-Sham DFT, and explains via QDFT the physics underlying the various energy functionals and functional derivatives o...
International Nuclear Information System (INIS)
Francaviglia, M.
1990-01-01
Although general relativity is a well-established discipline the theory deserves efforts aimed at producing alternative or more general frameworks for investigating the classical properties of gravity. These are either devoted to producing alternative viewpoints or interpretations of standard general relativity, or at constructing, discussing and proposing experimental tests for alternative descriptions of the dynamics of the gravitational field and its interaction (or unification) with external matter fields. Classical alternative theories of gravitation can roughly classified as follows; theories based on a still 4-dimensional picture, under the assumption that the dynamics of the gravitational field is more complicated than Einstein's and theories based on higher-dimensional pictures. This leads to supergravity and strings which are not included here. Theories based on higher-dimensional pictures on the assumption that space-time is replaced by a higher-dimensional manifold. Papers on these classifications are reviewed. (author)
DEFF Research Database (Denmark)
Pais, Alexandre; Valero, Paola
2014-01-01
What is the place of social theory in mathematics education research, and what is it for? This special issue of Educational Studies in Mathematics offers insights on what could be the role of some sociological theories in a field that has historically privileged learning theories coming from...... from a “socio-cultural” approach to learning and rather deploy sociological theories in the analysis of mathematics education practices. In this commentary paper, we will point to what we see to be the contributions of these papers to the field. We will do so by highlighting issues that run through...... the six papers. We will try to synthetize what we think are the benchmarks of the social approach to mathematics education that they propose. We will also take a critical stance and indicate some possible extensions of the use of social theory that are not addressed in this special issue but nonetheless...
Silva, C E
2007-01-01
This book is an introduction to basic concepts in ergodic theory such as recurrence, ergodicity, the ergodic theorem, mixing, and weak mixing. It does not assume knowledge of measure theory; all the results needed from measure theory are presented from scratch. In particular, the book includes a detailed construction of the Lebesgue measure on the real line and an introduction to measure spaces up to the Carathéodory extension theorem. It also develops the Lebesgue theory of integration, including the dominated convergence theorem and an introduction to the Lebesgue L^pspaces. Several examples of a dynamical system are developed in detail to illustrate various dynamical concepts. These include in particular the baker's transformation, irrational rotations, the dyadic odometer, the Hajian-Kakutani transformation, the Gauss transformation, and the Chacón transformation. There is a detailed discussion of cutting and stacking transformations in ergodic theory. The book includes several exercises and some open q...
Directory of Open Access Journals (Sweden)
Dr. Alvita Nathaniel, DSN, APRN, BC
2005-06-01
Full Text Available The Grounded Theory Perspective III: Theoretical Coding, Barney G. Glaser (Sociology Press, 2005. Not intended for a beginner, this book further defi nes, describes, and explicates the classic grounded theory (GT method. Perspective III lays out various facets of theoretical coding as Glaser meticulously distinguishes classic GT from other subsequent methods. Developed many years after Glaser’s classic GT, these methods, particularly as described by Strauss and Corbin, adopt the grounded theory name and engender ongoing confusion about the very premises of grounded theory. Glaser distinguishes between classic GT and the adscititious methods in his writings, referring to remodeled grounded theory and its offshoots as Qualitative Data Analysis (QDA models.
Nonlocal continuum field theories
2002-01-01
Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...
Translation Theory 'Translated'
DEFF Research Database (Denmark)
Wæraas, Arild; Nielsen, Jeppe
2016-01-01
Translation theory has proved to be a versatile analytical lens used by scholars working from different traditions. On the basis of a systematic literature review, this study adds to our understanding of the ‘translations’ of translation theory by identifying the distinguishing features of the most...... common theoretical approaches to translation within the organization and management discipline: actor-network theory, knowledge-based theory, and Scandinavian institutionalism. Although each of these approaches already has borne much fruit in research, the literature is diverse and somewhat fragmented......, but also overlapping. We discuss the ways in which the three versions of translation theory may be combined and enrich each other so as to inform future research, thereby offering a more complete understanding of translation in and across organizational settings....
Statistical theory and inference
Olive, David J
2014-01-01
This text is for a one semester graduate course in statistical theory and covers minimal and complete sufficient statistics, maximum likelihood estimators, method of moments, bias and mean square error, uniform minimum variance estimators and the Cramer-Rao lower bound, an introduction to large sample theory, likelihood ratio tests and uniformly most powerful tests and the Neyman Pearson Lemma. A major goal of this text is to make these topics much more accessible to students by using the theory of exponential families. Exponential families, indicator functions and the support of the distribution are used throughout the text to simplify the theory. More than 50 ``brand name" distributions are used to illustrate the theory with many examples of exponential families, maximum likelihood estimators and uniformly minimum variance unbiased estimators. There are many homework problems with over 30 pages of solutions.
International Nuclear Information System (INIS)
Gross, D.J.
1985-01-01
String theories offer a way of realizing the potential of supersymmetry, Kaluza-Klein and much more. They represent a radical departure from ordinary quantum field theory, but in the direction of increased symmetry and structure. They are based on an enormous increase in the number of degrees of freedom, since in addition to fermionic coordinates and extra dimensions, the basic entities are extended one dimensional objects instead of points. Correspondingly the symmetry group is greatly enlarged, in a way that we are only beginning to comprehend. At the very least this extended symmetry contains the largest group of symmetries that can be contemplated within the framework of point field theories-those of ten-dimensional supergravity and super Yang-Mills theory. Types of string theories and the phenomenology to be expected from them are reviewed
Energy Technology Data Exchange (ETDEWEB)
Bergshoeff, Eric A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University,Stony Brook, NY 11794-3636 (United States); Penas, Victor A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)
2016-06-06
We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for “exotic' dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.
International Nuclear Information System (INIS)
Callen, J.D.; Dory, R.A.; Aghevli, R.
1977-01-01
The progress during the past year is organized by group efforts and divided into five major areas. The basic tokamak areas and the sections in which their work is summarized are: magnetohydrodynamic (MHD) theory, kinetic theory, and transport simulation. The ELMO Bumpy Torus (EBT) theory work has its own research projects on MHD theory, kinetic theory, and transport simulation. In the plasma engineering area, relevant research work is further developed and synthesized into models that are used in the design of advanced fusion systems--The Next Step (TNS), demonstration fusion reactor (Demo), EBT ignition test, etc. Specific plasma engineering projects on providing the TNS physics basis and the development of the EBT reactor study are discussed. The computing support activities during the past year are summarized
Theory X and Theory Y in the Organizational Structure.
Barry, Thomas J.
This document defines contrasting assumptions about the labor force--theory X and theory Y--and shows how they apply to the pyramid organizational structure, examines the assumptions of the two theories, and finally, based on a survey and individual interviews, proposes a merger of theories X and Y to produce theory Z. Organizational structures…
Bastin, Ted
2009-07-01
List of participants; Preface; Part I. Introduction: 1. The function of the colloquium - editorial; 2. The conceptual problem of quantum theory from the experimentalist's point of view O. R. Frisch; Part II. Niels Bohr and Complementarity: The Place of the Classical Language: 3. The Copenhagen interpretation C. F. von Weizsäcker; 4. On Bohr's views concerning the quantum theory D. Bohm; Part III. The Measurement Problem: 5. Quantal observation in statistical interpretation H. J. Groenewold; 6. Macroscopic physics, quantum mechanics and quantum theory of measurement G. M. Prosperi; 7. Comment on the Daneri-Loinger-Prosperi quantum theory of measurement Jeffrey Bub; 8. The phenomenology of observation and explanation in quantum theory J. H. M. Whiteman; 9. Measurement theory and complex systems M. A. Garstens; Part IV. New Directions within Quantum Theory: What does the Quantum Theoretical Formalism Really Tell Us?: 10. On the role of hidden variables in the fundamental structure of physics D. Bohm; 11. Beyond what? Discussion: space-time order within existing quantum theory C. W. Kilmister; 12. Definability and measurability in quantum theory Yakir Aharonov and Aage Petersen; 13. The bootstrap idea and the foundations of quantum theory Geoffrey F. Chew; Part V. A Fresh Start?: 14. Angular momentum: an approach to combinatorial space-time Roger Penrose; 15. A note on discreteness, phase space and cohomology theory B. J. Hiley; 16. Cohomology of observations R. H. Atkin; 17. The origin of half-integral spin in a discrete physical space Ted Bastin; Part VI. Philosophical Papers: 18. The unity of physics C. F. von Weizsäcker; 19. A philosophical obstacle to the rise of new theories in microphysics Mario Bunge; 20. The incompleteness of quantum mechanics or the emperor's missing clothes H. R. Post; 21. How does a particle get from A to B?; Ted Bastin; 22. Informational generalization of entropy in physics Jerome Rothstein; 23. Can life explain quantum mechanics? H. H
Benchmarks with diffusion theory and transport theory
International Nuclear Information System (INIS)
Cunha Menezes Filho, A. da; Souza, A.L. de.
1984-01-01
The multiplication factor and some spectral indices for five critical assemblies (ZPR-6-7, ZPR-3-11, GODIVA, BIG-TEN and FLATTOP) are calculated by Diffusion and Transport Theory, with group constants generated by MC 2 (for diffusion calculations) and by NJOY (for transport calculations). The discrepancies encountered in the ZPR-6-7 spectra, can be tracked to the large differences in the elastic cross section for Iron, calculated by MC 2 and NJOY. (Author) [pt
Anomalous gauge theories revisited
International Nuclear Information System (INIS)
Matsui, Kosuke; Suzuki, Hiroshi
2005-01-01
A possible formulation of chiral gauge theories with an anomalous fermion content is re-examined in light of the lattice framework based on the Ginsparg-Wilson relation. It is shown that the fermion sector of a wide class of anomalous non-abelian theories cannot consistently be formulated within this lattice framework. In particular, in 4 dimension, all anomalous non-abelian theories are included in this class. Anomalous abelian chiral gauge theories cannot be formulated with compact U(1) link variables, while a non-compact formulation is possible at least for the vacuum sector in the space of lattice gauge fields. Our conclusion is not applied to effective low-energy theories with an anomalous fermion content which are obtained from an underlying anomaly-free theory by sending the mass of some of fermions to infinity. For theories with an anomalous fermion content in which the anomaly is cancelled by the Green-Schwarz mechanism, a possibility of a consistent lattice formulation is not clear. (author)
Energy Technology Data Exchange (ETDEWEB)
Svozil, K. [Univ. of Technology, Vienna (Austria)
1995-11-01
Inasmuch as physical theories are formalizable, set theory provides a framework for theoretical physics. Four speculations about the relevance of set theoretical modeling for physics are presented: the role of transcendental set theory (i) in chaos theory, (ii) for paradoxical decompositions of solid three-dimensional objects, (iii) in the theory of effective computability (Church-Turing thesis) related to the possible {open_quotes}solution of supertasks,{close_quotes} and (iv) for weak solutions. Several approaches to set theory and their advantages and disadvantages for physical applications are discussed: Cantorian {open_quotes}naive{close_quotes} (i.e., nonaxiomatic) set theory, contructivism, and operationalism. In the author`s opinion, an attitude, of {open_quotes}suspended attention{close_quotes} (a term borrowed from psychoanalysis) seems most promising for progress. Physical and set theoretical entities must be operationalized wherever possible. At the same time, physicists should be open to {open_quotes}bizarre{close_quotes} or {open_quotes}mindboggling{close_quotes} new formalisms, which need not be operationalizable or testable at the time of their creation, but which may successfully lead to novel fields of phenomenology and technology.
International Nuclear Information System (INIS)
Souza, Manoelito M. de
1997-01-01
We discuss the physical meaning and the geometric interpretation of implementation in classical field theories. The origin of infinities and other inconsistencies in field theories is traced to fields defined with support on the light cone; a finite and consistent field theory requires a light-cone generator as the field support. Then, we introduce a classical field theory with support on the light cone generators. It results on a description of discrete (point-like) interactions in terms of localized particle-like fields. We find the propagators of these particle-like fields and discuss their physical meaning, properties and consequences. They are conformally invariant, singularity-free, and describing a manifestly covariant (1 + 1)-dimensional dynamics in a (3 = 1) spacetime. Remarkably this conformal symmetry remains even for the propagation of a massive field in four spacetime dimensions. We apply this formalism to Classical electrodynamics and to the General Relativity Theory. The standard formalism with its distributed fields is retrieved in terms of spacetime average of the discrete field. Singularities are the by-products of the averaging process. This new formalism enlighten the meaning and the problem of field theory, and may allow a softer transition to a quantum theory. (author)
International Nuclear Information System (INIS)
Aref'eva, I.Ya.; Slavnov, A.A.
1981-01-01
This lecture is devoted to the discussion of gauge field theory permitting from the single point of view to describe all the interactions of elementary particles. The authors used electrodynamics and the Einstein theory of gravity to search for a renormgroup fixing a form of Lagrangian. It is shown that the gauge invariance added with the requirement of the minimum number of arbitraries in Lagrangian fixes unambigously the form of the electromagnetic interaction. The generalization of this construction for more complicate charge spaces results in the Yang-Mills theory. The interaction form in this theory is fixed with the relativity principle in the charge space. A quantum scheme of the Yang-Mills fields through the explicit separation of true dynamic variables is suggested. A comfortable relativistically invariant diagram technique for the calculation of a producing potential for the Green functions is described. The Ward generalized identities have been obtained and a procedure of the elimination of ultraviolet and infrared divergencies has been accomplished. Within the framework of QCD (quantum-chromodynamic) the phenomenon of the asymptotic freedom being the most successful prediction of the gauge theory of strong interactions was described. Working methods with QCD outside the framework of the perturbation theory have been described from a coupling constant. QCD is represented as a single theory possessing both the asymptotical freedom and the freedom retaining quarks [ru
Energy Technology Data Exchange (ETDEWEB)
Chen, Jing-Yuan, E-mail: chjy@uchicago.edu [Kadanoff Center for Theoretical Physics, University of Chicago, Chicago, IL 60637 (United States); Stanford Institute for Theoretical Physics, Stanford University, CA 94305 (United States); Son, Dam Thanh, E-mail: dtson@uchicago.edu [Kadanoff Center for Theoretical Physics, University of Chicago, Chicago, IL 60637 (United States)
2017-02-15
We develop an extension of the Landau Fermi liquid theory to systems of interacting fermions with non-trivial Berry curvature. We propose a kinetic equation and a constitutive relation for the electromagnetic current that together encode the linear response of such systems to external electromagnetic perturbations, to leading and next-to-leading orders in the expansion over the frequency and wave number of the perturbations. We analyze the Feynman diagrams in a large class of interacting quantum field theories and show that, after summing up all orders in perturbation theory, the current–current correlator exactly matches with the result obtained from the kinetic theory. - Highlights: • We extend Landau’s kinetic theory of Fermi liquid to incorporate Berry phase. • Berry phase effects in Fermi liquid take exactly the same form as in Fermi gas. • There is a new “emergent electric dipole” contribution to the anomalous Hall effect. • Our kinetic theory is matched to field theory to all orders in Feynman diagrams.
Axiomatic conformal field theory
International Nuclear Information System (INIS)
Gaberdiel, M.R.; Goddard, P.
2000-01-01
A new rigourous approach to conformal field theory is presented. The basic objects are families of complex-valued amplitudes, which define a meromorphic conformal field theory (or chiral algebra) and which lead naturally to the definition of topological vector spaces, between which vertex operators act as continuous operators. In fact, in order to develop the theory, Moebius invariance rather than full conformal invariance is required but it is shown that every Moebius theory can be extended to a conformal theory by the construction of a Virasoro field. In this approach, a representation of a conformal field theory is naturally defined in terms of a family of amplitudes with appropriate analytic properties. It is shown that these amplitudes can also be derived from a suitable collection of states in the meromorphic theory. Zhu's algebra then appears naturally as the algebra of conditions which states defining highest weight representations must satisfy. The relationship of the representations of Zhu's algebra to the classification of highest weight representations is explained. (orig.)
Bollobás, Béla
1998-01-01
The time has now come when graph theory should be part of the education of every serious student of mathematics and computer science, both for its own sake and to enhance the appreciation of mathematics as a whole. This book is an in-depth account of graph theory, written with such a student in mind; it reflects the current state of the subject and emphasizes connections with other branches of pure mathematics. The volume grew out of the author's earlier book, Graph Theory -- An Introductory Course, but its length is well over twice that of its predecessor, allowing it to reveal many exciting new developments in the subject. Recognizing that graph theory is one of several courses competing for the attention of a student, the book contains extensive descriptive passages designed to convey the flavor of the subject and to arouse interest. In addition to a modern treatment of the classical areas of graph theory such as coloring, matching, extremal theory, and algebraic graph theory, the book presents a detailed ...
Quaternionic quantum field theory
International Nuclear Information System (INIS)
Adler, S.L.
1986-01-01
In this paper the author describes a new kind of quantum mechanics or quantum field theory based on quaternions. Quaternionic quantum mechanics has a Schrodinger equation, a Dirac transformation theory, and a functional integral. Quaternionic quantum mechanics does not seem to have (except in the complex quantum mechanics specialization): A correspondence principle, and beyond this a commuting tensor product, asymptotic states, an S-matrix, a canonical formalism, coherent states or a Euclidean continuation. A new kind of quantum mechanics exists. There are many interesting formal questions to study, which should enable one to decide whether quaternionic quantum field theory is relevant for particle physics
Cohn, Harvey
1980-01-01
""A very stimulating book ... in a class by itself."" - American Mathematical MonthlyAdvanced students, mathematicians and number theorists will welcome this stimulating treatment of advanced number theory, which approaches the complex topic of algebraic number theory from a historical standpoint, taking pains to show the reader how concepts, definitions and theories have evolved during the last two centuries. Moreover, the book abounds with numerical examples and more concrete, specific theorems than are found in most contemporary treatments of the subject.The book is divided into three parts
DEFF Research Database (Denmark)
Knudsen, Thorbjørn
2003-01-01
principles of variation, continuity and selection, it is argued that economic selection theory should mimic the causal structure of neo-Darwinian theory. Two of the most influential explanations of economic evolution, Alchian's and Nelson and Winter's, are used to illustrate how this could be achieved.......The present article provides a minimal description of the causal structure of economic selection theory and outlines how the internal selection dynamics of business organisations can be reconciled with selection in competitive markets. In addition to generic similarity in terms of the Darwinian...
Anthropology and social theory
DEFF Research Database (Denmark)
Thomassen, Bjørn
2013-01-01
This article argues that anthropology may represent untapped perspectives of relevance to social theory. The article starts by critically reviewing how anthropology has come to serve as the ‘Other’ in various branches of social theory, from Marx and Durkheim to Parsons to Habermas, engaged...... in a hopeless project of positing ‘primitive’ or ‘traditional’ society as the opposite of modernity. In contemporary debates, it is becoming increasingly recognized that social theory needs history, back to the axial age and beyond. The possible role of anthropology in theorizing modernity receives far less...
Theories of information behavior
Erdelez, Sandra; McKechnie, Lynne
2005-01-01
This unique book presents authoritative overviews of more than 70 conceptual frameworks for understanding how people seek, manage, share, and use information in different contexts. A practical and readable reference to both well-established and newly proposed theories of information behavior, the book includes contributions from 85 scholars from 10 countries. Each theory description covers origins, propositions, methodological implications, usage, links to related conceptual frameworks, and listings of authoritative primary and secondary references. The introductory chapters explain key concepts, theory–method connections, and the process of theory development.
International Nuclear Information System (INIS)
Ecker, G.
1996-06-01
After a general introduction to the structure of effective field theories, the main ingredients of chiral perturbation theory are reviewed. Applications include the light quark mass ratios and pion-pion scattering to two-loop accuracy. In the pion-nucleon system, the linear σ model is contrasted with chiral perturbation theory. The heavy-nucleon expansion is used to construct the effective pion-nucleon Lagrangian to third order in the low-energy expansion, with applications to nucleon Compton scattering. (author)
Fraïssé, R
2011-01-01
The first part of this book concerns the present state of the theory of chains (= total or linear orderings), in connection with some refinements of Ramsey's theorem, due to Galvin and Nash-Williams. This leads to the fundamental Laver's embeddability theorem for scattered chains, using Nash-Williams' better quasi-orderings, barriers and forerunning.The second part (chapters 9 to 12) extends to general relations the main notions and results from order-type theory. An important connection appears with permutation theory (Cameron, Pouzet, Livingstone and Wagner) and with logics (existence criter
DEFF Research Database (Denmark)
Dindler, Christian; Dalsgaard, Peter
2014-01-01
We present the notion of ‘bridging concepts’ as a particular form of intermediary knowledge in HCI research, residing between theory and practice. We argue that bridging concepts address the challenge of facilitating exchange between theory and practice in HCI, and we compare it to other....... These constituents specify how bridging concepts, as a form of knowledge, are accountable to both theory and practice. We present an analysis of the concept of ‘peepholes’ as an example of a bridging concept aimed at spurring user curiosity and engagement....
International Nuclear Information System (INIS)
Cohen-Tannoudji, G.
1990-01-01
This paper is devoted to a review of the connections between quantumchromodynamics (QCD) and string theories. One reviews the phenomenological models leading to string pictures in non perturbative QCD and the string effects, related to soft gluon coherence, which arise in perturbative QCD. One tries to build a string theory which goes to QCD at the zero slope limit. A specific model, based on superstring theories is shown to agree with QCD four point amplitudes at the Born approximation and with one loop corrections. One shows how this approach can provide a theoretical framework to account for the phenomenological property of parton-hadron duality
Unitary unified field theories
International Nuclear Information System (INIS)
Sudarshan, E.C.G.
1976-01-01
This is an informal exposition of some recent developments. Starting with an examination of the universality of electromagnetic and weak interactions, the attempts at their unification are outlined. The theory of unitary renormalizable self-coupled vector mesons with dynamical sources is formulated for a general group. With masses introduced as variable parameters it is shown that the theory so defined is indeed unitary. Diagrammatic rules are developed in terms of a chosen set of fictitious particles. A number of special examples are outlined including a theory with strongly interacting vector and axial vector mesons and weak mesons. Applications to weak interactions of strange particles is briefly outlined. (Auth.)
Menasco, William
2005-01-01
This book is a survey of current topics in the mathematical theory of knots. For a mathematician, a knot is a closed loop in 3-dimensional space: imagine knotting an extension cord and then closing it up by inserting its plug into its outlet. Knot theory is of central importance in pure and applied mathematics, as it stands at a crossroads of topology, combinatorics, algebra, mathematical physics and biochemistry.* Survey of mathematical knot theory* Articles by leading world authorities* Clear exposition, not over-technical* Accessible to readers with undergraduate background in mathematics
Quantum electronics basic theory
Fain, V M; Sanders, J H
1969-01-01
Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai
1978-11-01
R 2. GOVT A $ SION NO. 3 RIEqLPýIVT’S.;TALOG NUMBER r/ 4. TITLE (and wbiFflT, -L M4 1 , FEEDBACK SYSTEM THEORY ~r Inter in- 6. PERFORMING ORG. REPORT...ANNUAL REPORT FEEDBACK SYSTEM THEORY AFOSR GRANT NO. 76-2946B Air Force Office of Scientific Research for year ending October 31, 1978 79 02 08 L|I...re less stringent than in other synthesis techniques which cannot handle significant parameter uncertainty. _I FEEDBACK SYSTEM THEORY 1. Introduction
Irreversible processes kinetic theory
Brush, Stephen G
2013-01-01
Kinetic Theory, Volume 2: Irreversible Processes deals with the kinetic theory of gases and the irreversible processes they undergo. It includes the two papers by James Clerk Maxwell and Ludwig Boltzmann in which the basic equations for transport processes in gases are formulated, together with the first derivation of Boltzmann's ""H-theorem"" and a discussion of this theorem, along with the problem of irreversibility.Comprised of 10 chapters, this volume begins with an introduction to the fundamental nature of heat and of gases, along with Boltzmann's work on the kinetic theory of gases and s
Iwaniec, Henryk
2004-01-01
Analytic Number Theory distinguishes itself by the variety of tools it uses to establish results, many of which belong to the mainstream of arithmetic. One of the main attractions of analytic number theory is the vast diversity of concepts and methods it includes. The main goal of the book is to show the scope of the theory, both in classical and modern directions, and to exhibit its wealth and prospects, its beautiful theorems and powerful techniques. The book is written with graduate students in mind, and the authors tried to balance between clarity, completeness, and generality. The exercis
International Nuclear Information System (INIS)
Pokorski, S.
1987-01-01
Quantum field theory forms the present theoretical framework for the understanding of the fundamental interactions of particle physics. This book examines gauge theories and their symmetries with an emphasis on their physical and technical aspects. The author discusses field-theoretical techniques and encourages the reader to perform many of the calculations presented. This book includes a brief introduction to perturbation theory, the renormalization programme, and the use of the renormalization group equation. Several topics of current research interest are covered, including chiral symmetry and its breaking, anomalies, and low energy effective lagrangians and some basics of supersymmetry
Finite temperature field theory
Das, Ashok
1997-01-01
This book discusses all three formalisms used in the study of finite temperature field theory, namely the imaginary time formalism, the closed time formalism and thermofield dynamics. Applications of the formalisms are worked out in detail. Gauge field theories and symmetry restoration at finite temperature are among the practical examples discussed in depth. The question of gauge dependence of the effective potential and the Nielsen identities are explained. The nonrestoration of some symmetries at high temperature (such as supersymmetry) and theories on nonsimply connected space-times are al
Interpolating string field theories
International Nuclear Information System (INIS)
Zwiebach, B.
1992-01-01
This paper reports that a minimal area problem imposing different length conditions on open and closed curves is shown to define a one-parameter family of covariant open-closed quantum string field theories. These interpolate from a recently proposed factorizable open-closed theory up to an extended version of Witten's open string field theory capable of incorporating on shell closed strings. The string diagrams of the latter define a new decomposition of the moduli spaces of Riemann surfaces with punctures and boundaries based on quadratic differentials with both first order and second order poles
Hansen, Jean-Pierre
1986-01-01
This book gives a comprehensive and up-to-date treatment of the theory of ""simple"" liquids. The new second edition has been rearranged and considerably expanded to give a balanced account both of basic theory and of the advances of the past decade. It presents the main ideas of modern liquid state theory in a way that is both pedagogical and self-contained. The book should be accessible to graduate students and research workers, both experimentalists and theorists, who have a good background in elementary mechanics.Key Features* Compares theoretical deductions with experimental r
Rewriting the Opportunity Theory
DEFF Research Database (Denmark)
Korsgaard, Steffen T.
The aim of this paper is to further the discussion of opportunity theory by discussing its ontological and epistemological underpinnings, which have been neglected in previous discussions. The idea that opportunities have an objective component is critically examined drawing on insights from soci...... constructionism. It is argued that opportunity theory needs to be rewritten.......The aim of this paper is to further the discussion of opportunity theory by discussing its ontological and epistemological underpinnings, which have been neglected in previous discussions. The idea that opportunities have an objective component is critically examined drawing on insights from social...
Wu Ta You
1962-01-01
This volume addresses the broad formal aspects and applications of the quantum theory of scattering in atomic and nuclear collisions. An encyclopedic source of pioneering work, it serves as a text for students and a reference for professionals in the fields of chemistry, physics, and astrophysics. The self-contained treatment begins with the general theory of scattering of a particle by a central field. Subsequent chapters explore particle scattering by a non-central field, collisions between composite particles, the time-dependent theory of scattering, and nuclear reactions. An examinati
Eves, Howard
1980-01-01
The usefulness of matrix theory as a tool in disciplines ranging from quantum mechanics to psychometrics is widely recognized, and courses in matrix theory are increasingly a standard part of the undergraduate curriculum.This outstanding text offers an unusual introduction to matrix theory at the undergraduate level. Unlike most texts dealing with the topic, which tend to remain on an abstract level, Dr. Eves' book employs a concrete elementary approach, avoiding abstraction until the final chapter. This practical method renders the text especially accessible to students of physics, engineeri
Introduction: Critical Visual Theory
Directory of Open Access Journals (Sweden)
Peter Ludes
2014-03-01
Full Text Available The studies selected for publication in this special issue on Critical Visual Theory can be divided into three thematic groups: (1 image making as power making, (2 commodification and recanonization, and (3 approaches to critical visual theory. The approaches to critical visual theory adopted by the authors of this issue may be subsumed under the following headings (3.1 critical visual discourse and visual memes in general and Anonymous visual discourse in particular, (3.2 collective memory and gendered gaze, and (3.3 visual capitalism, global north and south.
Introduction to gauge field theory
International Nuclear Information System (INIS)
Bailin, David; Love, Alexander
1986-01-01
The book is intended as an introduction to gauge field theory for the postgraduate student of theoretical particle physics. The topics discussed in the book include: path integrals, classical and quantum field theory, scattering amplitudes, feynman rules, renormalisation, gauge field theories, spontaneous symmetry breaking, grand unified theory, and field theories at finite temperature. (UK)
To theory of gravitational interaction
Minkevich, A. V.
2008-01-01
Some principal problems of general relativity theory and attempts of their solution are discussed. The Poincare gauge theory of gravity as natural generalization of Einsteinian gravitation theory is considered. The changes of gravitational interaction in the frame of this theory leading to the solution of principal problems of general relativity theory are analyzed.
Herstein, IN
2011-01-01
S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.
M-Theory and Maximally Supersymmetric Gauge Theories
Lambert, Neil
2012-01-01
In this informal review for non-specalists we discuss the construction of maximally supersymmetric gauge theories that arise on the worldvolumes branes in String Theory and M-Theory. Particular focus is made on the relatively recent construction of M2-brane worldvolume theories. In a formal sense, the existence of these quantum field theories can be viewed as predictions of M-Theory. Their construction is therefore a reinforcement of the ideas underlying String Theory and M-Theory. We also briefly discuss the six-dimensional conformal field theory that is expected to arise on M5-branes. The construction of this theory is not only an important open problem for M-Theory but also a significant challenge to our current understanding of quantum field theory more generally.
Yang-Mills theory - a string theory in disguise
International Nuclear Information System (INIS)
Foerster, D.
1979-01-01
An examination of the Schwinger-Dyson equations of U(N) lattice Yang-Mills theory shows that this theory is exactly equivalent to a theory of strings that interact with one another only through their topology. (Auth.)
Drawing Out Theory: Art and the Teaching of Political Theory.
Miller, Char R.
2000-01-01
Discusses how to use art in introductory political theory courses. Provides examples of incorporating art to teach political theory, such as examining Machiavelli's "The Prince" and Michelangelo's "David" to understand Florentine (Florence, Italy) political theory. (CMK)
Kuang, Zhen-Bang
2014-01-01
Theory of Electroelasticity analyzes the stress, strain, electric field and electric displacement in electroelastic structures such as sensors, actuators and other smart materials and structures. This book also describes new theories such as the physical variational principle and the inertial entropy theory. It differs from the traditional method by using the physical variational principle to derive the governing equations of the piezoelectric material, whereas the Maxwell stress is obtained automatically. By using the inertial entropy theory, the temperature wave equation is obtained very easily. The book is intended for scientists, researchers and engineers in the areas of mechanics, physics, smart material and control engineering as well as mechanical, aeronautical and civil engineering, etc. Zhen-Bang Kuang is a professor at Shanghai Jiao Tong University.
Testing strong interaction theories
International Nuclear Information System (INIS)
Ellis, J.
1979-01-01
The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)
International Nuclear Information System (INIS)
Adler, S.L.; Wilczek, F.
1992-11-01
Members of the Institute have worked on a number of problems including the following: acceleration algorithms for the Monte Carlo analysis of lattice field, and gauge and spin theories, based on changes of variables specific to lattices of dimension 2 ell ; construction of quaternionic generalizations of complex quantum mechanics and field theory; wave functions for paired Hall states; black hole quantum mechanics; generalized target-space duality in curved string backgrounds; gauge symnmetry algebra of the N = 2 string; two-dimensional quantum gravity and associated string theories; organizing principles from which the signal processing of neural networks in the retina and cortex can be deduced; integrable systems of KdV type; and a theory for Kondo insulators
Gunter, Helen M.
2013-01-01
This article reports on a seminar by the Critical Educational Policy and Leadership Research Interest Group in June 2012. The article reports on the papers and our engagement with the need to use theory to develop descriptions and understandings.
Close, Frank
2017-01-01
Physicist Frank Close takes the reader to the frontiers of science in a vividly told investigation of revolutionary science and enterprise from the seventeenth century to the present. He looks at what has been meant by theories of everything, explores the scientific breakthroughs they have allowed, and shows the far-reaching effects they have had on crucial aspects of life and belief. Theories of everything, he argues, can be described as those which draw on all relevant branches of knowledge to explain everything known about the universe. Such accounts may reign supreme for centuries. Then, often as a result of the advances they themselves have enabled, a new discovery is made which the current theory cannot explain. A new theory is needed which inspiration, sometimes, supplies. Moving from Isaac Newton's work on gravity and motion in the seventeenth century to thermodynamics and James Clerk Maxwell's laws of electromagnetism in the nineteenth to Max Planck's and Paul Dirac's quantum physics in the twentiet...
Theory of fundamental interactions
International Nuclear Information System (INIS)
Pestov, A.B.
1992-01-01
In the present article the theory of fundamental interactions is derived in a systematic way from the first principles. In the developed theory there is no separation between space-time and internal gauge space. Main equations for basic fields are derived. In is shown that the theory satisfies the correspondence principle and gives rise to new notions in the considered region. In particular, the conclusion is made about the existence of particles which are characterized not only by the mass, spin, charge but also by the moment of inertia. These are rotating particles, the particles which represent the notion of the rigid body on the microscopical level and give the key for understanding strong interactions. The main concepts and dynamical laws for these particles are formulated. The basic principles of the theory may be examined experimentally not in the distant future. 29 refs
Kirschner, Paul A.; Kirschner, Femke; Paas, Fred
2010-01-01
Kirschner, P. A., Kirschner, F. C., & Paas, F. (2009). Cognitive load theory. In E. M. Anderman & L. H. Anderman (Eds.). Psychology of classroom learning: An encyclopedia, Volume 1, a-j (pp. 205-209). Detroit, MI: Macmillan Reference.
International Nuclear Information System (INIS)
Gaisser, T.K.; Shafi, Q.; Barr, S.M.; Seckel, D.; Rusjan, E.; Fletcher, R.S.
1991-01-01
This report discusses research of professor at Bartol research institute in the following general areas: particle phenomenology and non-accelerator physics; particle physics and cosmology; theories with higher symmetry; and particle astrophysics and cosmology
Theory of gravitational interactions
Gasperini, Maurizio
2017-01-01
This is the second edition of a well-received book that is a modern, self-contained introduction to the theory of gravitational interactions. The new edition includes more details on gravitational waves of cosmological origin, the so-called brane world scenario, and gravitational time-delay effects. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field, while the second, more advanced part discusses the deep analogies (and differences) between a geometric theory of gravity and the “gauge” theories of the other fundamental interactions. This fills a gap within the traditional approach to general relativity which usually leaves students puzzled about the role of gravity. The required notions of differential geometry are reduced to the minimum, allowing room for aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational inter...
DEFF Research Database (Denmark)
Rijkhoff, Jan
2010-01-01
This paper argues that grammatical theorizing and linguistic typologizing must go hand in hand and that rare typological features play a central role in the interaction of typology and theory. The paper is organized as follows. Section 2 discusses a sampling method that (compared to other samplin...... Functional (Discourse) Grammar and sections 4 and 5 are concerned with the crucial role of rara both in theory driven data collection and in data driven theory building.......This paper argues that grammatical theorizing and linguistic typologizing must go hand in hand and that rare typological features play a central role in the interaction of typology and theory. The paper is organized as follows. Section 2 discusses a sampling method that (compared to other sampling...
Elasticity theory and applications
Saada, Adel S; Hartnett, James P; Hughes, William F
2013-01-01
Elasticity: Theory and Applications reviews the theory and applications of elasticity. The book is divided into three parts. The first part is concerned with the kinematics of continuous media; the second part focuses on the analysis of stress; and the third part considers the theory of elasticity and its applications to engineering problems. This book consists of 18 chapters; the first of which deals with the kinematics of continuous media. The basic definitions and the operations of matrix algebra are presented in the next chapter, followed by a discussion on the linear transformation of points. The study of finite and linear strains gradually introduces the reader to the tensor concept. Orthogonal curvilinear coordinates are examined in detail, along with the similarities between stress and strain. The chapters that follow cover torsion; the three-dimensional theory of linear elasticity and the requirements for the solution of elasticity problems; the method of potentials; and topics related to cylinders, ...
DEFF Research Database (Denmark)
Schindler, Samuel
2013-01-01
light bending in 1919 by Eddington and others) to show that TDRs are used by scientists to resolve data conflicts. I argue that the rationality of the practices which employ TDRs can be saved if the independent support of the theories driving TDRs is construed in a particular way.......The thesis of theory-ladenness of observations, in its various guises, is widely considered as either ill-conceived or harmless to the rationality of science. The latter view rests partly on the work of the proponents of New Experimentalism who have argued, among other things, that experimental...... practices are efficient in guarding against any epistemological threat posed by theory-ladenness. In this paper I show that one can generate a thesis of theory-ladenness for experimental practices from an influential New Experimentalist account. The notion I introduce for this purpose is the concept...