Global Solutions for Small Nonlinear Long Range Perturbations of Two Dimensional Schrödinger Equations

Global Solutions for Small Nonlinear Long Range Perturbations of Two Dimensional Schrödinger Equations PDF

Author: Jean-Marc Delort

Publisher:

Published: 2002

Total Pages: 110

ISBN-13:

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Here the author presents the following: Let $Q_1, Q_2$ be two quadratic forms, and $u$ a local solution of the two-dimensional Schrodinger equation $(i\partial _t + \Delta )u = Q_1(u,\nabla _x u) + Q_2(\bar {u},\nabla _x \bar {u})$. He proves that if $Q_1$ and $Q_2$ do depend on the derivatives of $u$, and if the Cauchy datum is small enough and decaying enough at infinity, the solution exists for all times. The difficulty of the problem originates in the fact that the nonlinear perturbation is a long range one: This means that it can be written as the product of (a derivative of) $u$ and of a potential whose $L^\infty$ space-norm is not time integrable at infinity.

Strichartz Estimates for Schrödinger Equations with Variable Coefficients

Strichartz Estimates for Schrödinger Equations with Variable Coefficients PDF

Author: Luc Robbiano

Publisher:

Published: 2005

Total Pages: 222

ISBN-13:

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The authors prove the (local in time) Stricharz estimates (for the full range of parameters given by the scaling unless the end point) for asymptotically flat and non trapping perturbations of the flat Laplacian in $\mathbb {R} ^n$, $n\geq 2$. The main point of the proof, namely the dispersion estimate, is obtained in constructing a parametrix. The main tool for this construction is the use of the Fourier-Bros-Iagolnitzer (FBI) transform.

Mathematical Study of the Betaplane Model

Mathematical Study of the Betaplane Model PDF

Author: Isabelle Gallagher

Publisher:

Published: 2006

Total Pages: 132

ISBN-13:

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The authors are interested in a model of rotating fluids, describing the motion of the ocean in the equatorial zone. This model is known as the Saint-Venant, or shallow-water type system, to which a rotation term is added whose amplitude is linear with respect to the latitude; in particular it vanishes at the equator. After a physical introduction to the model, the authors describe the various waves involved and study in detail the resonances associated to those waves. They then exhibit the formal limit system (as the rotation becomes large), obtained as usual by filtering out the waves, and prove its wellposedness. Finally they prove three types of convergence results: a weak convergence result towards a linear, geostrophic equation, a strong convergence result of the filtered solutions towards the unique strong solution to the limit system, and a ``hybrid'' strong convergence result of the filtered solutions towards a weak solution to the limit system. In particular the authors obtain that there are no confined equatorial waves in the mean motion as the rotation becomes large.

Coefficient Systems and Supersingular Representations of GL2(F)

Coefficient Systems and Supersingular Representations of GL2(F) PDF

Author: Vytautas Paskunas

Publisher:

Published: 2004

Total Pages: 102

ISBN-13:

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Let $F$ be a non-Archimedean local field with the residual characteristic $p$. The author constructs a good number of smooth irreducible $\overline {\mathbf {F}}_p$-representations of $\mathrm {GL}_2(F)$, which are supersingular in the sense of Barthel and Livne. If $F=\mathbf {Q}_p$ then results of Breuil imply that our construction gives all the supersingular representations up to the twist by an unramified quasi-character. The author conjectures that this is true for an arbitrary $F$. The book is suitable for graduate students and research mathematicians interested in algebra and algebraic geometry.

On Mapping Properties of the General Relativistic Constraints Operator in Weighted Function Spaces, with Applications

On Mapping Properties of the General Relativistic Constraints Operator in Weighted Function Spaces, with Applications PDF

Author: Piotr T. Chruściel

Publisher:

Published: 2003

Total Pages: 118

ISBN-13:

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In this book, the authors prove perturbation and gluing results for solutions of the general relativistic constraints with controlled boundary behavior or asymptotic behavior. This is obtained by a study of the linearized equation in weighted spaces a la Corvino-Schoen. Among other methods, this can be used to prove existence of non-trivial asymptotically simple vacuum space-times. The book is suitable for graduate students and research mathematicians interested in analysis.

Spectral Properties of Self-similar Lattices and Iteration of Rational Maps

Spectral Properties of Self-similar Lattices and Iteration of Rational Maps PDF

Author: Christophe Sabot

Publisher:

Published: 2003

Total Pages: 118

ISBN-13:

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In this text, the author considers discrete Laplace operators defined on lattices based on finitely ramified self-similar sets and their continuous analogs defined on the self-similar sets. He focuses on the spectral properties of these operators. The basic example is the lattice based on the Sierpinski gasket. He introduces a new renormalization map that appears to be a rational map defined on a smooth projective variety. (More precisely, this variety is isomorphic to a product of three types of Grassmannians: complex Grassmannians, Lagrangian Grassmannian, and orthogonal Grassmannians.) He relates some characteristics of the dynamics of its iterates with some characteristics of the spectrum of the operator. Specifically, he gives an explicit formula for the density of states in terms of the Green current of the map, and he relates the indeterminacy points of the map with the so-called Neumann-Dirichlet eigenvalues which lead to eigenfunctions with compact support on the unbounded lattice. Depending on the asymptotic degree of the map, he can prove drastically different spectral properties of the operators. The formalism is valid for the general class of finitely ramified self-similar sets.