Quasiclassical Methods

Quasiclassical Methods PDF Author: Jeffrey Rauch
Publisher: Springer Science & Business Media
ISBN: 146121940X
Category : Mathematics
Languages : en
Pages : 236

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Book Description
This IMA Volume in Mathematics and its Applications QUASICLASSICAL METHODS is based on the proceedings of a very successful one-week workshop with the same title, which was an integral part of the 1994-1995 IMA program on "Waves and Scattering." We would like to thank Jeffrey Rauch and Barry Simon for their excellent work as organizers of the meeting. We also take this opportunity to thank the National Science Foun dation (NSF), the Army Research Office (ARO) and the Office of Naval Research (ONR), whose financial support made the workshop possible. A vner Friedman Robert Gulliver v PREFACE There are a large number of problems where qualitative features of a partial differential equation in an appropriate regime are determined by the behavior of an associated ordinary differential equation. The example which gives the area its name is the limit of quantum mechanical Hamil tonians (Schrodinger operators) as Planck's constant h goes to zero, which is determined by the corresponding classical mechanical system. A sec ond example is linear wave equations with highly oscillatory initial data. The solutions are described by geometric optics whose centerpiece are rays which are solutions of ordinary differential equations analogous to the clas sical mechanics equations in the example above. Much recent work has concerned with understanding terms beyond the leading term determined by the quasi classical limit. Two examples of this involve Weyl asymptotics and the large-Z limit of atomic Hamiltonians, both areas of current research.

Quasiclassical Methods

Quasiclassical Methods PDF Author: Jeffrey Rauch
Publisher: Springer Science & Business Media
ISBN: 146121940X
Category : Mathematics
Languages : en
Pages : 236

Get Book Here

Book Description
This IMA Volume in Mathematics and its Applications QUASICLASSICAL METHODS is based on the proceedings of a very successful one-week workshop with the same title, which was an integral part of the 1994-1995 IMA program on "Waves and Scattering." We would like to thank Jeffrey Rauch and Barry Simon for their excellent work as organizers of the meeting. We also take this opportunity to thank the National Science Foun dation (NSF), the Army Research Office (ARO) and the Office of Naval Research (ONR), whose financial support made the workshop possible. A vner Friedman Robert Gulliver v PREFACE There are a large number of problems where qualitative features of a partial differential equation in an appropriate regime are determined by the behavior of an associated ordinary differential equation. The example which gives the area its name is the limit of quantum mechanical Hamil tonians (Schrodinger operators) as Planck's constant h goes to zero, which is determined by the corresponding classical mechanical system. A sec ond example is linear wave equations with highly oscillatory initial data. The solutions are described by geometric optics whose centerpiece are rays which are solutions of ordinary differential equations analogous to the clas sical mechanics equations in the example above. Much recent work has concerned with understanding terms beyond the leading term determined by the quasi classical limit. Two examples of this involve Weyl asymptotics and the large-Z limit of atomic Hamiltonians, both areas of current research.

Group Theoretical Methods in Physics

Group Theoretical Methods in Physics PDF Author: M. A. Markov
Publisher: CRC Press
ISBN: 9783718602452
Category : Science
Languages : en
Pages : 746

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Book Description


Modern Methods for Multidimensional Dynamics Computations in Chemistry

Modern Methods for Multidimensional Dynamics Computations in Chemistry PDF Author: Donald Leo Thompson
Publisher: World Scientific
ISBN: 9789810233426
Category : Science
Languages : en
Pages : 764

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Book Description
This volume describes many of the key practical theoretical techniques that have been developed to treat chemical dynamics problems in many-atom systems. It contains thorough treatments of fundamental theory and prescriptions for performing computations. The selection of methods, ranging from gas phase bimolecular reactions to complex processes in condensed phases, reflects the breadth of the field.The book is an excellent reference for proven and accepted methods as well as for theoretical approaches that are still being developed. It is appropriate for graduate students and other ?novices? who wish to begin working in chemical dynamics as well as active researchers who wish to acquire a wider knowledge of the field.

Theory of Nonequilibrium Superconductivity

Theory of Nonequilibrium Superconductivity PDF Author: N. B. Kopnin
Publisher: Oxford University Press
ISBN: 9780198507888
Category : Science
Languages : en
Pages : 716

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Book Description
This text deals with the behaviour of superconductors in external fields varying in time, and with transport phenomena in superconductors.

Qualitative Methods In Quantum Theory

Qualitative Methods In Quantum Theory PDF Author: Migdal
Publisher: CRC Press
ISBN: 0429977573
Category : Science
Languages : en
Pages : 242

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Book Description
This unique book, written by a leading Soviet theorist, is not a textbook of quantum mechanics but rather a compendium of the "tricks of the trade"-the methods that all practicing theoretical physicists use but few have set down in writing.

Quantum Computation and Quantum Information Theory

Quantum Computation and Quantum Information Theory PDF Author: Anton Zeilinger
Publisher: World Scientific
ISBN: 9789810248185
Category : Computers
Languages : en
Pages : 540

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Book Description
Quantum information theory has revolutionised our view on the true nature of information and has led to such intriguing topics as teleportation and quantum computation. The field - by its very nature strongly interdisciplinary, with deep roots in the foundations both of quantum mechanics and of information theory and computer science - has become a major subject for scientists working in fields as diverse as quantum optics, superconductivity or information theory, all the way to computer engineers.

Differential Operators and Spectral Theory

Differential Operators and Spectral Theory PDF Author: M. Sh Birman
Publisher: American Mathematical Soc.
ISBN: 9780821813874
Category : Mathematics
Languages : en
Pages : 348

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Book Description
This volume contains a collection of original papers in mathematical physics, spectral theory and differential equations. The papers are dedicated to the outstanding mathematician, Professor M Sh Birman, on the occasion of his 70th birthday. Contributing authors are leading specialists and close professional coleagues of Birman. The main topics discussed are spectral and scattering theory of differential operators , trace formulas, and boundary value problems for PDEs. Several papers are devoted to the magnetic Schrodinger operator, which is within Birman's current scopeof interests and recently has been studied extensively. Included is a detailed survey of his mathematical work and an updated list of his publications. This book is aimed at graduate students and specialists in the above-mentioned branches of mathematics and theoretical physicists. The biographical section will be of interest to readers concerned with the scientific activities of Birman and the history of those branches of analysis and spectral theory where his contributions were important and often decisive.

Vibrational-Rotational Excitations in Nonlinear Molecular Systems

Vibrational-Rotational Excitations in Nonlinear Molecular Systems PDF Author: Alexander A. Ovchinnikov
Publisher: Springer Science & Business Media
ISBN: 1461513170
Category : Science
Languages : en
Pages : 361

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Book Description
"If there would be no God ~ then what a staff-captain am I?" ~ said one of the characters in a novel by Dostoevskii. In a similar way we can exclaim: "If there would be no nonlinearity ~ than what physics would that be'?". Really, the most interesting and exciting effects are described by non linear equations, and vanish in the linear approximation. For example, the general theory of relativity by A.Einstein comes to mind first - one of the most beautiful physical theories, which is in fact essentially nonlinear. Next, the phase transitions crystal ~ liquid and liquid ~ gas are due to the anhar monicity of inter-particle interactions, to dissociation and infinite motion. Similarly, transitions into the superconducting state or the superftuid would be impossible with purely harmonic interaction potentials. Another bril liant achievement in nonlinear physics was the construction of a laser and the subsequent development of nonlinear optics. The latter describes the in teraction of the matter with light of super-high intensity, when multi-quanta intra-molecular transitions become essential. Last, we should note here the very beautiful mathematical theory ~ the theory of catastrophes. Its subject is the study of invariant general properties of multi-dimensional surfaces in the vicinity of bifurcation points with respect to continuous transformations.

Theory of Quantum Transport at Nanoscale

Theory of Quantum Transport at Nanoscale PDF Author: Dmitry Ryndyk
Publisher: Springer
ISBN: 3319240889
Category : Science
Languages : en
Pages : 251

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Book Description
This book is an introduction to a rapidly developing field of modern theoretical physics – the theory of quantum transport at nanoscale. The theoretical methods considered in the book are in the basis of our understanding of charge, spin and heat transport in nanostructures and nanostructured materials and are widely used in nanoelectronics, molecular electronics, spin-dependent electronics (spintronics) and bio-electronics. The book is based on lectures for graduate and post-graduate students at the University of Regensburg and the Technische Universität Dresden (TU Dresden). The first part is devoted to the basic concepts of quantum transport: Landauer-Büttiker method and matrix Green function formalism for coherent transport, Tunneling (Transfer) Hamiltonian and master equation methods for tunneling, Coulomb blockade, vibrons and polarons. The results in this part are obtained as possible without sophisticated techniques, such as nonequilibrium Green functions, which are considered in detail in the second part. A general introduction into the nonequilibrium Green function theory is given. The approach based on the equation-of-motion technique, as well as more sophisticated one based on the Dyson-Keldysh diagrammatic technique are presented. The main attention is paid to the theoretical methods able to describe the nonequilibrium (at finite voltage) electron transport through interacting nanosystems, specifically the correlation effects due to electron-electron and electron-vibron interactions.

Atom - Molecule Collision Theory

Atom - Molecule Collision Theory PDF Author: Richard Barry Bernstein
Publisher: Springer Science & Business Media
ISBN: 1461329132
Category : Science
Languages : en
Pages : 785

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Book Description
The broad field of molecular collisions is one of considerable current interest, one in which there is a great deal of research activity, both experi mental and theoretical. This is probably because elastic, inelastic, and reactive intermolecular collisions are of central importance in many of the fundamental processes of chemistry and physics. One small area of this field, namely atom-molecule collisions, is now beginning to be "understood" from first principles. Although the more general subject of the collisions of polyatomic molecules is of great im portance and intrinsic interest, it is still too complex from the viewpoint of theoretical understanding. However, for atoms and simple molecules the essential theory is well developed, and computational methods are sufficiently advanced that calculations can now be favorably compared with experimental results. This "coming together" of the subject (and, incidentally, of physicists and chemists !), though still in an early stage, signals that the time is ripe for an appraisal and review of the theoretical basis of atom-molecule collisions. It is especially important for the experimentalist in the field to have a working knowledge of the theory and computational methods required to describe the experimentally observable behavior of the system. By now many of the alternative theoretical approaches and computational procedures have been tested and intercompared. More-or-Iess optimal methods for dealing with each aspect are emerging. In many cases working equations, even schematic algorithms, have been developed, with assumptions and caveats delineated.