On the Regularity of the Composition of Diffeomorphisms

On the Regularity of the Composition of Diffeomorphisms PDF Author: H. Inci
Publisher: American Mathematical Soc.
ISBN: 0821887416
Category : Mathematics
Languages : en
Pages : 72

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Book Description
For M a closed manifold or the Euclidean space Rn we present a detailed proof of regularity properties of the composition of Hs-regular diffeomorphisms of M for s > 12dim⁡M+1.

On the Regularity of the Composition of Diffeomorphisms

On the Regularity of the Composition of Diffeomorphisms PDF Author: H. Inci
Publisher: American Mathematical Soc.
ISBN: 0821887416
Category : Mathematics
Languages : en
Pages : 72

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Book Description
For M a closed manifold or the Euclidean space Rn we present a detailed proof of regularity properties of the composition of Hs-regular diffeomorphisms of M for s > 12dim⁡M+1.

Relative Equilibria in the 3-Dimensional Curved $n$-Body Problem

Relative Equilibria in the 3-Dimensional Curved $n$-Body Problem PDF Author: Florin Diacu
Publisher: American Mathematical Soc.
ISBN: 0821891367
Category : Mathematics
Languages : en
Pages : 92

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Book Description
Considers the 3 -dimensional gravitational n -body problem, n32 , in spaces of constant Gaussian curvature k10 , i.e. on spheres S 3 ?1 , for ?>0 , and on hyperbolic manifolds H 3 ?1, for ?

Nonlinear Stability of Ekman Boundary Layers in Rotating Stratified Fluids

Nonlinear Stability of Ekman Boundary Layers in Rotating Stratified Fluids PDF Author: Hajime Koba
Publisher: American Mathematical Soc.
ISBN: 0821891332
Category : Mathematics
Languages : en
Pages : 142

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Book Description
A stationary solution of the rotating Navier-Stokes equations with a boundary condition is called an Ekman boundary layer. This book constructs stationary solutions of the rotating Navier-Stokes-Boussinesq equations with stratification effects in the case when the rotating axis is not necessarily perpendicular to the horizon. The author calls such stationary solutions Ekman layers. This book shows the existence of a weak solution to an Ekman perturbed system, which satisfies the strong energy inequality. Moreover, the author discusses the uniqueness of weak solutions and computes the decay rate of weak solutions with respect to time under some assumptions on the Ekman layers and the physical parameters. The author also shows that there exists a unique global-in-time strong solution of the perturbed system when the initial datum is sufficiently small. Comparing a weak solution satisfying the strong energy inequality with the strong solution implies that the weak solution is smooth with respect to time when time is sufficiently large.

Stochastic Flows in the Brownian Web and Net

Stochastic Flows in the Brownian Web and Net PDF Author: Emmanuel Schertzer
Publisher: American Mathematical Soc.
ISBN: 0821890883
Category : Mathematics
Languages : en
Pages : 172

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Book Description
It is known that certain one-dimensional nearest-neighbor random walks in i.i.d. random space-time environments have diffusive scaling limits. Here, in the continuum limit, the random environment is represented by a `stochastic flow of kernels', which is a collection of random kernels that can be loosely interpreted as the transition probabilities of a Markov process in a random environment. The theory of stochastic flows of kernels was first developed by Le Jan and Raimond, who showed that each such flow is characterized by its -point motions. The authors' work focuses on a class of stochastic flows of kernels with Brownian -point motions which, after their inventors, will be called Howitt-Warren flows. The authors' main result gives a graphical construction of general Howitt-Warren flows, where the underlying random environment takes on the form of a suitably marked Brownian web. This extends earlier work of Howitt and Warren who showed that a special case, the so-called "erosion flow", can be constructed from two coupled "sticky Brownian webs". The authors' construction for general Howitt-Warren flows is based on a Poisson marking procedure developed by Newman, Ravishankar and Schertzer for the Brownian web. Alternatively, the authors show that a special subclass of the Howitt-Warren flows can be constructed as random flows of mass in a Brownian net, introduced by Sun and Swart. Using these constructions, the authors prove some new results for the Howitt-Warren flows.

A Complete Classification of the Isolated Singularities for Nonlinear Elliptic Equations with Inverse Square Potentials

A Complete Classification of the Isolated Singularities for Nonlinear Elliptic Equations with Inverse Square Potentials PDF Author: Florica C. Cîrstea
Publisher: American Mathematical Soc.
ISBN: 0821890220
Category : Mathematics
Languages : en
Pages : 97

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Book Description
In particular, for b = 1 and λ = 0, we find a sharp condition on h such that the origin is a removable singularity for all non-negative solutions of [[eqref]]one, thus addressing an open question of Vázquez and Véron.

Large Deviations for Additive Functionals of Markov Chains

Large Deviations for Additive Functionals of Markov Chains PDF Author: Alejandro D. de Acosta
Publisher: American Mathematical Soc.
ISBN: 0821890891
Category : Mathematics
Languages : en
Pages : 120

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Book Description


Near Soliton Evolution for Equivariant Schrodinger Maps in Two Spatial Dimensions

Near Soliton Evolution for Equivariant Schrodinger Maps in Two Spatial Dimensions PDF Author: Ioan Bejenaru
Publisher: American Mathematical Soc.
ISBN: 0821892150
Category : Mathematics
Languages : en
Pages : 120

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Book Description
The authors consider the Schrödinger Map equation in 2+1 dimensions, with values into \mathbb{S}^2. This admits a lowest energy steady state Q, namely the stereographic projection, which extends to a two dimensional family of steady states by scaling and rotation. The authors prove that Q is unstable in the energy space \dot H^1. However, in the process of proving this they also show that within the equivariant class Q is stable in a stronger topology X \subset \dot H^1.

Spectra of Symmetrized Shuffling Operators

Spectra of Symmetrized Shuffling Operators PDF Author: Victor Reiner
Publisher: American Mathematical Soc.
ISBN: 0821890956
Category : Mathematics
Languages : en
Pages : 121

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Book Description
For a finite real reflection group W and a W -orbit O of flats in its reflection arrangement - or equivalently a conjugacy class of its parabolic subgroups - the authors introduce a statistic noninv O (w) on w in W that counts the number of O -noninversions of w . This generalises the classical (non-)inversion statistic for permutations w in the symmetric group S n. The authors then study the operator ? O of right-multiplication within the group algebra CW by the element that has noninv O (w) as its coefficient on w.

Structure and Regularity of Group Actions on One-Manifolds

Structure and Regularity of Group Actions on One-Manifolds PDF Author: Sang-hyun Kim
Publisher: Springer Nature
ISBN: 3030890066
Category : Mathematics
Languages : en
Pages : 323

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Book Description
This book presents the theory of optimal and critical regularities of groups of diffeomorphisms, from the classical work of Denjoy and Herman, up through recent advances. Beginning with an investigation of regularity phenomena for single diffeomorphisms, the book goes on to describes a circle of ideas surrounding Filipkiewicz's Theorem, which recovers the smooth structure of a manifold from its full diffeomorphism group. Topics covered include the simplicity of homeomorphism groups, differentiability of continuous Lie group actions, smooth conjugation of diffeomorphism groups, and the reconstruction of spaces from group actions. Various classical and modern tools are developed for controlling the dynamics of general finitely generated group actions on one-dimensional manifolds, subject to regularity bounds, including material on Thompson's group F, nilpotent groups, right-angled Artin groups, chain groups, finitely generated groups with prescribed critical regularities, and applications to foliation theory and the study of mapping class groups. The book will be of interest to researchers in geometric group theory.

Special Values of Automorphic Cohomology Classes

Special Values of Automorphic Cohomology Classes PDF Author: Mark Green
Publisher: American Mathematical Soc.
ISBN: 0821898574
Category : Mathematics
Languages : en
Pages : 158

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Book Description
The authors study the complex geometry and coherent cohomology of nonclassical Mumford-Tate domains and their quotients by discrete groups. Their focus throughout is on the domains which occur as open -orbits in the flag varieties for and , regarded as classifying spaces for Hodge structures of weight three. In the context provided by these basic examples, the authors formulate and illustrate the general method by which correspondence spaces give rise to Penrose transforms between the cohomologies of distinct such orbits with coefficients in homogeneous line bundles.