Explores genericity of approximation in various categories and presents many applications, including spectral multiplicity and properties of the maximal spectral type. This book contains a treatment of various constructions of cohomological nature with an emphasis on obtaining asymptotic behavior from approximate pictures at different time scales.

Differential Galois theory studies solutions of differential equations over a differential base field. In much the same way that ordinary Galois theory is the theory of field extensions generated by solutions of (one variable) polynomial equations, differential Galois theory looks at the nature of the differential field extension generated by the solution of differential equations. An additional feature is that the corresponding differential Galois groups (of automorphisms of the extension fixing the base and commuting with the derivation) are algebraic groups. This book deals with the...

The theory of generalized analytic continuation studies continuations of meromorphic functions in situations where traditional theory says there is a natural boundary. This broader theory touches on a an array of topics in classical analysis, as described in this book. The authors use the strong analogy with the summability of divergent series to motivate the subject. In this vein, for instance, theorems can be described as being Abelian or Tauberian. The introductory overview carefully explains the history and context of the theory.

Moduli problems in algebraic geometry date back to Riemann's famous count of the $3g-3$ parameters needed to determine a curve of genus $g$. This book studies the moduli space of curves of the same equisingularity class. It considers the moduli problem fro

Recent developments in geometric measure theory and harmonic analysis have led to new and deep results concerning the regularity of the support of measures which behave asymptotically (for balls of small radius) as the Euclidean volume. A striking feature of these results is that they actually characterize flatness of the support in terms of the asymptotic behavior of the measure. Such characterizations have led to important new progress in the study of harmonic measure for non-smooth domains. This volume provides an up-to-date overview and an introduction to the research literature in this...

This self-contained book is a systematic introduction to smooth ergodic theory. The topics discussed include: the general (abstract) theory of Lyapunov exponents and its applications to the stability theory of differential equations; stable manifold theory; absolute continuity; and the ergodic theory of dynamical systems with nonzero Lyapunov exponents (including geodesic flows). The authors consider several nontrivial examples of dynamical systems with nonzero Lyapunov exponents to illustrate some basic methods and ideas of the theory. The reader needs a basic knowledge of real analysis,...

Dynkin's lecture on the application of probability theory to the theory of nonlinear partial differential equations shows that all positive solutions for a class on nonlinear elliptical equations in a domain are described in terms of their traces on the boundary of the domain. While here Dynkin's main problematic tool is the theory of superdiffusio

Image compression, the Navier-Stokes equations, and detection of gravitational waves are three seemingly unrelated scientific problems that, remarkably, can be studied from one perspective. The notion that unifies the three problems is that of oscillating patterns, which are present in many natural images, help to explain nonlinear equations, and are pivotal in studying chirps and frequency-modulated signals. The first chapter of this book considers image processing, more precisely algorithms of image compression and denoising. This research is motivated in particular by the standard for...

This book presents the first steps of a theory of confoliations designed to link geometry and topology of three-dimensional contact structures with the geometry and topology of codimension-one foliations on three-dimensional manifolds. Developing almost independently, these theories at first glance belonged to two different worlds: The theory of foliations is part of topology and dynamical systems, while contact geometry is the odd-dimensional brother of symplectic geometry. However, both theories have developed a number of striking similarities. Confoliations--which interpolate between...

This work is about the interplay of computational commutative algebra and the theory of convex polytopes. It centres around a special class of ideals in a polynomial ring: the class of toric ideals. They are characterized as those prime ideals that are generated by monomial differences or as the defining ideals of toric varieties (not necessarily normal). The interdisciplinary nature of the study of Grobner bases is reflected by the specific applications appearing in this book. These applications lie in the domains of integer programming and computational statistics. The mathematical tools...