Wolfgang Arendt – författare

This textbook introduces the study of partial differential equations using both analytical and numerical methods. Throughout, three fundamental examples are studied with different tools: Poisson’s equation, the heat equation, and the wave equation on Euclidean domains.

This textbook introduces the study of partial differential equations using both analytical and numerical methods. Throughout, three fundamental examples are studied with different tools: Poisson’s equation, the heat equation, and the wave equation on Euclidean domains.

This volume develops the structural theory of one‑parameter semigroups of positive operators on ordered Banach spaces, addressing the fundamental problem of characterizing their generators, spectral properties, and asymptotic behavior. Such semigroups form a central analytical framework for models arising in partial differential equations, probability theory, ergodic theory, and mathematical physics.Since its first publication in 1986, the book has become a foundational reference, offering a rigorous and unified treatment of positivity, Banach lattices, and semigroup theory. The exposition covers Banach spaces, Banach lattices, C(X) spaces, and operator algebras, with a systematic focus on generator theory, spectral analysis, and long‑time behavior.This second edition preserves the original conceptual framework and organization while presenting the entire text in a fully revised and professionally typeset form. Misprints have been corrected, references updated, and a new chapter of notes surveys key developments of the past four decades, placing the original results in a modern context without compromising their historical coherence. The book remains an essential resource for researchers and advanced graduate students in operator theory and functional analysis.

This book is devoted to the study of evolution equations via form methods. The theory is presented both in the language of Kato, with densely defined forms, and that of Lions, in the spirit of Gelfand triples. The main object is the semigroup associated with a form, for which topics such as positivity, invariance of closed convex sets and the Trotter product formula are discussed.A wide range of applications is treated, for example, parabolic equations with various boundary conditions, the Stokes operator, the Dirichlet-to-Neumann operator, and non-autonomous semilinear parabolic equations.The book grew out of the Internet Seminar “Form Methods for Evolution Equations, and Applications” organized by the authors. Each of the 19 chapters is devoted to one particular subject and includes exercises. As a special feature, carefully placed “interludes” provide background results, all with complete proofs, to make the book fully self-contained.

This monograph gives a systematic account of the theory of vector-valued Laplace transforms, ranging from representation theory to Tauberian theorems. In parallel, the theory of linear Cauchy problems and semigroups of operators is developed completely in the spirit of Laplace transforms. Existence and uniqueness, regularity, approximation and above all asymptotic behaviour of solutions are studied. Diverse applications to partial differential equations are given. The book contains an introduction to the Bochner integral and several appendices on background material. It is addressed to students and researchers interested in evolution equations, Laplace and Fourier transforms, and functional analysis. The second edition contains detailed notes on the developments in the last decade. They include, for instance, a new characterization of well-posedness of abstract wave equations in Hilbert space due to M. Crouzeix. Moreover new quantitative results on asymptotic behaviour of Laplace transforms have been added. The references are updated and some errors have been corrected.

The present volume contains a collection of original research articles and expository contributions on recent developments in operator theory and its multifaceted applications. They cover a wide range of themes from the IWOTA 2010 conference held at the TU Berlin, Germany, including spectral theory, function spaces, mathematical system theory, evolution equations and semigroups, and differential and difference operators. The book encompasses new trends and various modern topics in operator theory, and serves as a useful source of information to mathematicians, scientists and engineers.

This monograph gives a systematic account of the theory of vector-valued Laplace transforms, ranging from representation theory to Tauberian theorems. In parallel, the theory of linear Cauchy problems and semigroups of operators is developed completely in the spirit of Laplace transforms. Existence and uniqueness, regularity, approximation and above all asymptotic behaviour of solutions are studied. Diverse applications to partial differential equations are given. The book contains an introduction to the Bochner integral and several appendices on background material. It is addressed to students and researchers interested in evolution equations, Laplace and Fourier transforms, and functional analysis. The second edition contains detailed notes on the developments in the last decade. They include, for instance, a new characterization of well-posedness of abstract wave equations in Hilbert space due to M. Crouzeix. Moreover new quantitative results on asymptotic behaviour of Laplace transforms have been added. The references are updated and some errors have been corrected.

The present volume contains a collection of original research articles and expository contributions on recent developments in operator theory and its multifaceted applications. They cover a wide range of themes from the IWOTA 2010 conference held at the TU Berlin, Germany, including spectral theory, function spaces, mathematical system theory, evolution equations and semigroups, and differential and difference operators. The book encompasses new trends and various modern topics in operator theory, and serves as a useful source of information to mathematicians, scientists and engineers.

This proceedings volume originates from a conference held in Herrnhut in June 2013. It provides unique insights into the power of abstract methods and techniques in dealing successfully with numerous applications stemming from classical analysis and mathematical physics. The book features diverse topics in the area of operator semigroups, including partial differential equations, martingale and Hilbert transforms, Banach and von Neumann algebras, Schrödinger operators, maximal regularity and Fourier multipliers, interpolation, operator-theoretical problems (concerning generation, perturbation and dilation, for example), and various qualitative and quantitative Tauberian theorems with a focus on transfinite induction and magics of Cantor.The last fifteen years have seen the dawn of a new era for semigroup theory with the emphasis on applications of abstract results, often unexpected and far removed from traditional ones. The aim of the conference was to bring together prominent experts in the field of modern semigroup theory, harmonic analysis, complex analysis and mathematical physics, and to present the lively interactions between all of those areas and beyond. In addition, the meeting honored the sixtieth anniversary of Prof C. J. K. Batty, whose scientific achievements are an impressive illustration of the conference goal. These proceedings present contributions by prominent scientists at this international conference, which became a landmark event.They will be a valuable and inspiring source of information for graduate students and established researchers.

Dieses Buch richtet sich an Studierende im Bachelor oder im ersten Master-Jahr sowohl in der (Wirtschafts-)Mathematik als auch in den Studiengängen Informatik, Physik und Ingenieurwissenschaften. Die 2.

Philippe Benilan was a most original and charismatic mathematician who had a deep and decisive impact on the theory of nonlinear evolution equations. The present volume is dedicated to him and contains research papers written by highly distinguished mathematicians. They are all related to Benilan's work and reflect the present state of this most active field. The contributions cover a wide range of nonlinear and linear equations. Special topics are Hamilton-Jacobi equations, the porous medium equation, reaction diffusion systems, integro-differential equations and visco-elasticity, maximal regularity for elliptic and parabolic equations, and the Ornstein-Uhlenbeck operator. Also in this volume, the legendary work of Benilan-Brezis on Thomas-Fermi theory is published for the first time.