Download or read book Twisted Pseudodifferential Calculus and Application to the Quantum Evolution of Molecules written by AndrŽ Martinez and published by American Mathematical Soc.. This book was released on 2009-06-05 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors construct an abstract pseudodifferential calculus with operator-valued symbol, suitable for the treatment of Coulomb-type interactions, and they apply it to the study of the quantum evolution of molecules in the Born-Oppenheimer approximation, in the case of the electronic Hamiltonian admitting a local gap in its spectrum. In particular, they show that the molecular evolution can be reduced to the one of a system of smooth semiclassical operators, the symbol of which can be computed explicitely. In addition, they study the propagation of certain wave packets up to long time values of Ehrenfest order.

Download or read book Effective Hamiltonians for Constrained Quantum Systems written by Jakob Wachsmuth and published by American Mathematical Soc.. This book was released on 2014-06-05 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors consider the time-dependent Schrödinger equation on a Riemannian manifold with a potential that localizes a certain subspace of states close to a fixed submanifold . When the authors scale the potential in the directions normal to by a parameter , the solutions concentrate in an -neighborhood of . This situation occurs for example in quantum wave guides and for the motion of nuclei in electronic potential surfaces in quantum molecular dynamics. The authors derive an effective Schrödinger equation on the submanifold and show that its solutions, suitably lifted to , approximate the solutions of the original equation on up to errors of order at time . Furthermore, the authors prove that the eigenvalues of the corresponding effective Hamiltonian below a certain energy coincide up to errors of order with those of the full Hamiltonian under reasonable conditions.

Download or read book Center Manifolds for Semilinear Equations with Non Dense Domain and Applications to Hopf Bifurcation in Age Structured Models written by Pierre Magal and published by American Mathematical Soc.. This book was released on 2009 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several types of differential equations, such as delay differential equations, age-structure models in population dynamics, evolution equations with boundary conditions, can be written as semilinear Cauchy problems with an operator which is not densely defined in its domain. The goal of this paper is to develop a center manifold theory for semilinear Cauchy problems with non-dense domain. Using Liapunov-Perron method and following the techniques of Vanderbauwhede et al. in treating infinite dimensional systems, the authors study the existence and smoothness of center manifolds for semilinear Cauchy problems with non-dense domain. As an application, they use the center manifold theorem to establish a Hopf bifurcation theorem for age structured models.

Download or read book Microlocal Methods in Mathematical Physics and Global Analysis written by Daniel Grieser and published by Springer Science & Business Media. This book was released on 2012-12-13 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microlocal analysis is a field of mathematics that was invented in the mid-20th century for the detailed investigation of problems from partial differential equations, which incorporated and made rigorous many ideas that originated in physics. Since then it has grown to a powerful machine which is used in global analysis, spectral theory, mathematical physics and other fields, and its further development is a lively area of current mathematical research. In this book extended abstracts of the conference 'Microlocal Methods in Mathematical Physics and Global Analysis', which was held at the University of Tübingen from the 14th to the 18th of June 2011, are collected.​

Download or read book Unfolding CR Singularities written by Adam Coffman and published by American Mathematical Soc.. This book was released on 2010 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 205, number 962 (first of 5 numbers)."

Download or read book Operator Theory on Noncommutative Domains written by Gelu Popescu and published by American Mathematical Soc.. This book was released on 2010 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 205, number 964 (third of 5 numbers)."

Download or read book Approximate Homotopy of Homomorphisms from C X into a Simple C Algebra written by Huaxin Lin and published by American Mathematical Soc.. This book was released on 2010 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 205, number 963 (second of 5 numbers)."

Download or read book On a Conjecture of E M Stein on the Hilbert Transform on Vector Fields written by Michael Thoreau Lacey and published by American Mathematical Soc.. This book was released on 2010 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 205, number 965 (fourth of 5 numbers)."

Download or read book Banach Algebras on Semigroups and on Their Compactifications written by Harold G. Dales and published by American Mathematical Soc.. This book was released on 2010 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 205, number 966 (end of volume)."

Download or read book Lyapunov Exponents and Invariant Manifolds for Random Dynamical Systems in a Banach Space written by Zeng Lian and published by American Mathematical Soc.. This book was released on 2010 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors study the Lyapunov exponents and their associated invariant subspaces for infinite dimensional random dynamical systems in a Banach space, which are generated by, for example, stochastic or random partial differential equations. The authors prove a multiplicative ergodic theorem and then use this theorem to establish the stable and unstable manifold theorem for nonuniformly hyperbolic random invariant sets.

Download or read book Ergodicity Stabilization and Singular Perturbations for Bellman Isaacs Equations written by Olivier Alvarez and published by American Mathematical Soc.. This book was released on 2010 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 204, number 960 (fourth of 5 numbers)."

Download or read book Robin Functions for Complex Manifolds and Applications written by Kang-Tae Kim and published by American Mathematical Soc.. This book was released on 2011 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Volume 209, number 984 (third of 5 numbers)."

Download or read book Non Divergence Equations Structured on Hormander Vector Fields Heat Kernels and Harnack Inequalities written by Marco Bramanti and published by American Mathematical Soc.. This book was released on 2010 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: "March 2010, Volume 204, number 961 (end of volume)."

Download or read book Small Divisor Problem in the Theory of Three Dimensional Water Gravity Waves written by GŽrard Iooss and published by American Mathematical Soc.. This book was released on 2009-06-05 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors consider doubly-periodic travelling waves at the surface of an infinitely deep perfect fluid, only subjected to gravity $g$ and resulting from the nonlinear interaction of two simply periodic travelling waves making an angle $2\theta$ between them. Denoting by $\mu =gL/c^{2}$ the dimensionless bifurcation parameter ( $L$ is the wave length along the direction of the travelling wave and $c$ is the velocity of the wave), bifurcation occurs for $\mu = \cos \theta$. For non-resonant cases, we first give a large family of formal three-dimensional gravity travelling waves, in the form of an expansion in powers of the amplitudes of two basic travelling waves. ``Diamond waves'' are a particular case of such waves, when they are symmetric with respect to the direction of propagation. The main object of the paper is the proof of existence of such symmetric waves having the above mentioned asymptotic expansion. Due to the occurence of small divisors, the main difficulty is the inversion of the linearized operator at a non trivial point, for applying the Nash Moser theorem. This operator is the sum of a second order differentiation along a certain direction, and an integro-differential operator of first order, both depending periodically of coordinates. It is shown that for almost all angles $\theta$, the 3-dimensional travelling waves bifurcate for a set of ``good'' values of the bifurcation parameter having asymptotically a full measure near the bifurcation curve in the parameter plane $(\theta,\mu ).$

Download or read book Unitary Invariants in Multivariable Operator Theory written by Gelu Popescu and published by American Mathematical Soc.. This book was released on 2009-06-05 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper concerns unitary invariants for $n$-tuples $T:=(T_1,\ldots, T_n)$ of (not necessarily commuting) bounded linear operators on Hilbert spaces. The author introduces a notion of joint numerical radius and works out its basic properties. Multivariable versions of Berger's dilation theorem, Berger-Kato-Stampfli mapping theorem, and Schwarz's lemma from complex analysis are obtained. The author studies the joint (spatial) numerical range of $T$ in connection with several unitary invariants for $n$-tuples of operators such as: right joint spectrum, joint numerical radius, euclidean operator radius, and joint spectral radius. He also proves an analogue of Toeplitz-Hausdorff theorem on the convexity of the spatial numerical range of an operator on a Hilbert space, for the joint numerical range of operators in the noncommutative analytic Toeplitz algebra $F_n^\infty$.

Download or read book Uniqueness and Stability in Determining a Rigid Inclusion in an Elastic Body written by Antonino Morassi and published by American Mathematical Soc.. This book was released on 2009-06-05 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors consider the inverse problem of determining a rigid inclusion inside an isotropic elastic body $\Omega$, from a single measurement of traction and displacement taken on the boundary of $\Omega$. For this severely ill-posed problem they prove uniqueness and a conditional stability estimate of log-log type.

Download or read book The Minimal Polynomials of Unipotent Elements in Irreducible Representations of the Classical Groups in Odd Characteristic written by Irina D. Suprunenko and published by American Mathematical Soc.. This book was released on 2009-06-05 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The minimal polynomials of the images of unipotent elements in irreducible rational representations of the classical algebraic groups over fields of odd characteristic are found. These polynomials have the form $(t-1)^d$ and hence are completely determined by their degrees. In positive characteristic the degree of such polynomial cannot exceed the order of a relevant element. It occurs that for each unipotent element the degree of its minimal polynomial in an irreducible representation is equal to the order of this element provided the highest weight of the representation is large enough with respect to the ground field characteristic. On the other hand, classes of unipotent elements for which in every nontrivial representation the degree of the minimal polynomial is equal to the order of the element are indicated. In the general case the problem of computing the minimal polynomial of the image of a given element of order $p^s$ in a fixed irreducible representation of a classical group over a field of characteristic $p>2$ can be reduced to a similar problem for certain $s$ unipotent elements and a certain irreducible representation of some semisimple group over the field of complex numbers. For the latter problem an explicit algorithm is given. Results of explicit computations for groups of small ranks are contained in Tables I-XII. The article may be regarded as a contribution to the programme of extending the fundamental results of Hall and Higman (1956) on the minimal polynomials from $p$-solvable linear groups to semisimple groups.