Download or read book Self Adjoint Extensions in Quantum Mechanics written by Springer and published by . This book was released on 2012-04-28 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self adjoint Extensions in Quantum Mechanics written by D.M. Gitman and published by Springer Science & Business Media. This book was released on 2012-04-27 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exposition is devoted to a consistent treatment of quantization problems, based on appealing to some nontrivial items of functional analysis concerning the theory of linear operators in Hilbert spaces. The authors begin by considering quantization problems in general, emphasizing the nontriviality of consistent operator construction by presenting paradoxes to the naive treatment. It then builds the necessary mathematical background following it by the theory of self-adjoint extensions. By considering several problems such as the one-dimensional Calogero problem, the Aharonov-Bohm problem, the problem of delta-like potentials and relativistic Coulomb problemIt then shows how quantization problems associated with correct definition of observables can be treated consistently for comparatively simple quantum-mechanical systems. In the end, related problems in quantum field theory are briefly introduced. This well-organized text is most suitable for students and post graduates interested in deepening their understanding of mathematical problems in quantum mechanics. However, scientists in mathematical and theoretical physics and mathematicians will also find it useful.
Download or read book Applications of Self Adjoint Extensions in Quantum Physics written by Pavel Exner and published by . This book was released on 2014-01-15 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self adjoint extensions and quantum mechanics written by Darren J. Platt and published by . This book was released on 2005 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self Adjoint Extension Schemes and Modern Applications to Quantum Hamiltonians written by Matteo Gallone and published by Springer Nature. This book was released on 2023-04-04 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces and discusses the self-adjoint extension problem for symmetric operators on Hilbert space. It presents the classical von Neumann and Krein–Vishik–Birman extension schemes both in their modern form and from a historical perspective, and provides a detailed analysis of a range of applications beyond the standard pedagogical examples (the latter are indexed in a final appendix for the reader’s convenience). Self-adjointness of operators on Hilbert space representing quantum observables, in particular quantum Hamiltonians, is required to ensure real-valued energy levels, unitary evolution and, more generally, a self-consistent theory. Physical heuristics often produce candidate Hamiltonians that are only symmetric: their extension to suitably larger domains of self-adjointness, when possible, amounts to declaring additional physical states the operator must act on in order to have a consistent physics, and distinct self-adjoint extensions describe different physics. Realising observables self-adjointly is the first fundamental problem of quantum-mechanical modelling. The discussed applications concern models of topical relevance in modern mathematical physics currently receiving new or renewed interest, in particular from the point of view of classifying self-adjoint realisations of certain Hamiltonians and studying their spectral and scattering properties. The analysis also addresses intermediate technical questions such as characterising the corresponding operator closures and adjoints. Applications include hydrogenoid Hamiltonians, Dirac–Coulomb Hamiltonians, models of geometric quantum confinement and transmission on degenerate Riemannian manifolds of Grushin type, and models of few-body quantum particles with zero-range interaction. Graduate students and non-expert readers will benefit from a preliminary mathematical chapter collecting all the necessary pre-requisites on symmetric and self-adjoint operators on Hilbert space (including the spectral theorem), and from a further appendix presenting the emergence from physical principles of the requirement of self-adjointness for observables in quantum mechanics.
Download or read book Applications of self adjoint extensions in quantum physics written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hilbert Space Operators in Quantum Physics written by Jirí Blank and published by Springer Science & Business Media. This book was released on 2008-09-24 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new edition of this book detailing the theory of linear-Hilbert space operators and their use in quantum physics contains two new chapters devoted to properties of quantum waveguides and quantum graphs. The bibliography contains 130 new items.
Download or read book Solvable Models in Quantum Mechanics written by Sergio Albeverio and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Next to the harmonic oscillator and the Coulomb potential the class of two-body models with point interactions is the only one where complete solutions are available. All mathematical and physical quantities can be calculated explicitly which makes this field of research important also for more complicated and realistic models in quantum mechanics. The detailed results allow their implementation in numerical codes to analyse properties of alloys, impurities, crystals and other features in solid state quantum physics. This monograph presents in a systematic way the mathematical approach and unifies results obtained in recent years. The student with a sound background in mathematics will get a deeper understanding of Schrödinger Operators and will see many examples which may eventually be used with profit in courses on quantum mechanics and solid state physics. The book has textbook potential in mathematical physics and is suitable for additional reading in various fields of theoretical quantum physics.
Download or read book Self adjoint Extensions to the Dirac Coulomb Hamiltonian written by Andrew Eric Brainerd and published by . This book was released on 2010 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Dirac equation is the relativistic generalization of the Schrödinger equation for spin 1/2 particles. It is written in the form -ihc -ihac OXIa+t' Omc 29 = ih-o (1.1) where V) is a four component Dirac spinor and the coefficients a and # are 4 x 4 matrices. Like the Schrödinger equation, the Dirac equation can be written as a time-independent eigenvalue equation H♯ = E* for a Hamiltonian operator H and energy eigenvalue E through separation of variables. The energy eigenvalues obtained by solving this equation must be real- one of the axioms of quantum mechanics is that physical observables, in this case energy, correspond to self-adjoint operators, in this case the Hamiltonian operator HI, acting on the Hilbert space 7H which describes the system in question. It can easily be shown that self-adjoint operators must have real eigenvalues. The reality of the energy eigenvalues becomes important when examining hydrogenic atoms using the Dirac equation. These atoms can be described by a Coulomb potential, V(r) = -Ze 2 /r, where Z is the number of protons in the nucleus and e is the elementary charge. When the nonrelativistic Schrodinger equation is solved for a Coulomb potential, the energy levels are given by the familiar Rydberg formula Z 2a 2mc2 1 En 2 2 (1.2) where Z is the number of protons in the atomic nucleus, a is the fine structure constant, m is the electron mass, c is the speed of light, and n a positive integer. Note that this formula assumes a stationary positive charge of infinite mass at the center of the atom, and that the energy levels for a more realistic model of an atom with a nucleus of finite mass M are given by replacing m with the reduced mass = mM/(m + M) in Eq. (1.2). When the Dirac equation in a Coulomb potential is used instead of the nonrelativistic Schrödinger equation, the energy levels are instead given by - 1/2 En, = mc2 1+ a2 (1.3) n' - j j +)2_ - 2Z2 where n' is a positive integer and j is the total angular momentum of the electron. The total angular momentum j can take on values in the range 1/2, 3/2 ..., n' - 1/2. The eigenvalues in Eq. (1.3) match those in Eq. (1.2) in the limit VZ 1, noting that in Eq. (1.2), a free electron is considered to have an energy of 0, while in Eq. (1.3), a free electron has energy mc2 . A problem arises with Eq. (1.3) when aZ j--. The quantity (j + 2- aZ 2 is imaginary, causing Eq. (1.3) to yield complex energy eigenvalues. Since the eigenvalues of a self-adjoint operator must all be real, this indicates that the Hamiltonian cannot be self-adjoint when aZ> j + 1. This issue raises two questions. The first is whether there is a physical explanation for the failure of Eq. (1.2) for large Z. The second is whether this problem can be addressed mathematically by defining a new, self-adjoint operator H., which is constructed from the old Hamiltonian H as a self-adjoint extension. In this thesis, I will answer both of these questions in the affirmative, relying and building upon work done by others on these questions. I will show how the failure of Eq. (1.2) can be motivated by physical considerations, and I will examine a family of self-adjoint extensions to the Dirac Coulomb Hamiltonian constructed using von Neumann's method of deficiency indices.
Download or read book Introduction To The Mathematical Structure Of Quantum Mechanics An A Short Course For Mathematicians 2nd Edition written by Franco Strocchi and published by World Scientific Publishing Company. This book was released on 2008-10-30 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second printing contains a critical discussion of Dirac derivation of canonical quantization, which is instead deduced from general geometric structures. This book arises out of the need for Quantum Mechanics (QM) to be part of the common education of mathematics students. The mathematical structure of QM is formulated in terms of the C*-algebra of observables, which is argued on the basis of the operational definition of measurements and the duality between states and observables, for a general physical system.The Dirac-von Neumann axioms are then derived. The description of states and observables as Hilbert space vectors and operators follows from the GNS and Gelfand-Naimark Theorems. The experimental existence of complementary observables for atomic systems is shown to imply the noncommutativity of the observable algebra, the distinctive feature of QM; for finite degrees of freedom, the Weyl algebra codifies the experimental complementarity of position and momentum (Heisenberg commutation relations) and Schrödinger QM follows from the von Neumann uniqueness theorem.The existence problem of the dynamics is related to the self-adjointness of the Hamiltonian and solved by the Kato-Rellich conditions on the potential, which also guarantee quantum stability for classically unbounded-below Hamiltonians. Examples are discussed which include the explanation of the discreteness of the atomic spectra.Because of the increasing interest in the relation between QM and stochastic processes, a final chapter is devoted to the functional integral approach (Feynman-Kac formula), to the formulation in terms of ground state correlations (the quantum mechanical analog of the Wightman functions) and their analytic continuation to imaginary time (Euclidean QM). The quantum particle on a circle is discussed in detail, as an example of the interplay between topology and functional integral, leading to the emergence of superselection rules and θ sectors.
Download or read book II Fourier Analysis Self Adjointness written by Michael Reed and published by Elsevier. This book was released on 1975 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Band 2.
Download or read book Application of Self adjoint Extensions to the Relativistic and Non relativistic Coulomb Problem written by Scott J. Beck and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Coulomb problem was one of the first successful applications of quantum theory and is a staple topic in textbooks. However there is an ambiguity in the solution to the problem that is seldom discussed in either textbooks or the literature. The ambiguity arises in the boundary conditions that must be applied at the origin where the Coulomb potential is singular. The textbook boundary condition is generally not the only one that is permissible or the one that is most appropriate. Here we revisit the question of boundary conditions using the mathematical method of self-adjoint extensions in context of modern realizations of the Coulomb problem in electrons on helium, Rydberg atoms and graphene. We determine the family of allowed boundary conditions for the non-relativistic Schr\"{o}dinger equation in one and three dimensions and the relativistic Dirac equation in two dimensions. The boundary conditions are found to break the classical SO$(4)$ Runge-Lenz symmetry of the non-relativistic Coulomb problem in three dimensions and to break scale invariance for the two dimensional Dirac problem. The symmetry breaking is analogous to the anomaly phenomenon in quantum field theory. Electrons on helium have been extensively studied for their potential use in quantum computing and as a laboratory for condensed matter physics. The trapped electrons provide a realization of the one dimensional non-relativistic Coulomb problem. Using the method of self-adjoint extensions we are able to reproduce the observed energy levels of electrons on helium which are known to deviate from the textbook Balmer formula. We also study the connection between the method of self-adjoint extensions and an older theoretical model introduced by Cole. Rydberg atoms have potential applications to atomic clocks and precision atomic experiments. They are hydrogen-like in that they have a single highly excited electron that orbits a small positively charged core. We compare the observed spectrum of several species of Rydberg atoms to the predictions of the Coulomb model with self-adjoint extension and to the predictions of the more elaborate quantum defect model which is generally found to be more accurate. The motion of electrons on atomically flat sheets of graphene is governed by the massless Dirac equation. The effect of charged impurities on the electronic states of graphene has been studied using scanning probe microscopy. Here we use the method of self-adjoint extensions to analyze the scattering of electrons from the charged impurities; our results generalize prior theoretical work which considered only one of the family of possible boundary conditions.
Download or read book Mathematical Methods in Quantum Mechanics written by Gerald Teschl and published by American Mathematical Soc.. This book was released on 2009 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum mechanics and the theory of operators on Hilbert space have been deeply linked since their beginnings in the early twentieth century. States of a quantum system correspond to certain elements of the configuration space and observables correspond to certain operators on the space. This book is a brief, but self-contained, introduction to the mathematical methods of quantum mechanics, with a view towards applications to Schrodinger operators. Part 1 of the book is a concise introduction to the spectral theory of unbounded operators. Only those topics that will be needed for later applications are covered. The spectral theorem is a central topic in this approach and is introduced at an early stage. Part 2 starts with the free Schrodinger equation and computes the free resolvent and time evolution. Position, momentum, and angular momentum are discussed via algebraic methods. Various mathematical methods are developed, which are then used to compute the spectrum of the hydrogen atom. Further topics include the nondegeneracy of the ground state, spectra of atoms, and scattering theory. This book serves as a self-contained introduction to spectral theory of unbounded operators in Hilbert space with full proofs and minimal prerequisites: Only a solid knowledge of advanced calculus and a one-semester introduction to complex analysis are required. In particular, no functional analysis and no Lebesgue integration theory are assumed. It develops the mathematical tools necessary to prove some key results in nonrelativistic quantum mechanics. Mathematical Methods in Quantum Mechanics is intended for beginning graduate students in both mathematics and physics and provides a solid foundation for reading more advanced books and current research literature. It is well suited for self-study and includes numerous exercises (many with hints).
Download or read book Unbounded Self adjoint Operators on Hilbert Space written by Konrad Schmüdgen and published by Springer Science & Business Media. This book was released on 2012-07-09 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a graduate text on unbounded self-adjoint operators on Hilbert space and their spectral theory with the emphasis on applications in mathematical physics (especially, Schrödinger operators) and analysis (Dirichlet and Neumann Laplacians, Sturm-Liouville operators, Hamburger moment problem) . Among others, a number of advanced special topics are treated on a text book level accompanied by numerous illustrating examples and exercises. The main themes of the book are the following: - Spectral integrals and spectral decompositions of self-adjoint and normal operators - Perturbations of self-adjointness and of spectra of self-adjoint operators - Forms and operators - Self-adjoint extension theory :boundary triplets, Krein-Birman-Vishik theory of positive self-adjoint extension
Download or read book Nonrelativistic Quantum Mechanics written by Anton Z. Capri and published by World Scientific. This book was released on 2002 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main unique feature of this book is its discussion of Hilbert space and rigged Hilbert space. Suitable for advanced undergraduate students as well as graduate students.
Download or read book From Micro to Macro Quantum Systems written by K. Kong Wan and published by World Scientific. This book was released on 2006 with total page 709 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional quantum theory has a very rigid structure, making it difficult to accommodate new properties emerging from novel systems. This book presents a flexible and unified theory for physical systems, from micro and macro quantum to classical. This is achieved by incorporating superselection rules and maximal symmetric operators into the theory. The resulting theory is applicable to classical, microscopic quantum and non-orthodox mixed quantum systems of which macroscopic quantum systems are examples. A unified formalism also greatly facilitates the discussion of interactions between these systems. A scheme of quantization by parts is introduced, based on the mathematics of selfadjoint and maximal symmetric extensions of symmetric operators, to describe point interactions. The results are applied to treat superconducting quantum circuits in various configurations.This book also discusses various topics of interest such as the asymptotic treatment of quantum state preparation and quantum measurement, local observables and local values, Schrdinger's cat states in superconducting systems, and a path space formulation of quantum mechanics.This self-contained book is complete with a review of relevant geometric and operator theories, for example, vector fields and operators, symmetric operators and their maximal symmetric extensions, direct integrals of Hilbert spaces and operators.
Download or read book Classical and Quantum Physics written by G. Marmo and published by Springer Nature. This book was released on 2019-10-26 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings is based on the interdisciplinary workshop held in Madrid, 5-9 March 2018, dedicated to Alberto Ibort on his 60th birthday. Alberto has great and significantly contributed to many fields of mathematics and physics, always with highly original and innovative ideas.Most of Albertos’s scientific activity has been motivated by geometric ideas, concepts and tools that are deeply related to the framework of classical dynamics and quantum mechanics.Let us mention some of the fields of expertise of Alberto Ibort:Geometric Mechanics; Constrained Systems; Variational Principles; Multisymplectic structures for field theories; Super manifolds; Inverse problem for Bosonic and Fermionic systems; Quantum Groups, Integrable systems, BRST Symmetries; Implicit differential equations; Yang-Mills Theories; BiHamiltonian Systems; Topology Change and Quantum Boundary Conditions; Classical and Quantum Control; Orthogonal Polynomials; Quantum Field Theory and Noncommutative Spaces; Classical and Quantum Tomography; Quantum Mechanics on phase space; Wigner-Weyl formalism; Lie-Jordan Algebras, Classical and Quantum; Quantum-to-Classical transition; Contraction of Associative Algebras; contact geometry, among many others.In each contribution, one may find not only technical novelties but also completely new way of looking at the considered problems. Even an experienced reader, reading Alberto's contributions on his field of expertise, will find new perspectives on the considered topic.His enthusiasm is happily contagious, for this reason he has had, and still has, very bright students wishing to elaborate their PhD thesis under his guidance.What is more impressive, is the broad list of rather different topics on which he has contributed.
