This book is intended to give a systematic presentation of perturbation theory for linear
operators. It is hoped that the book will be useful to students as well as to mature scientists …

Quantum mechanical N-body systems with dilatation analytic interactions are investigated.
Absence of continuous singular part for the Hamiltonians is proved together with the …

We study a class of symmetric relatively compact perturbations satisfying analyticity
conditions with respect to the dilatation group in R n. Absence of continuous singular part for …

We study a mathematical model for an epidemic spreading in an age-structured population
with age-dependent transmission coefficient. We formulate the model as an abstract Cauchy …

1. Introduction. In this paper we study a boundary condition for the wave equation occurring
in theoretical acoustics. The initial value problem in a bounded domain is solved by …

Since the early part of the twentieth century, the use of integral equations has developed into
a range of tools for the study of partial differential equations. This includes the use of single …

The fields of photonics and phononics encompass the fundamental science of light and
sound propagation and interactions in complex structures, as well as its technological …

In this section we introduce some notations, formulate some properties of the potentials of
the single and double layers, and discuss the integral equations for solving the exterior …

We discuss the foundations and state-of-the-art of the method of analytical regularization
(MAR)(also called the semi-inversion method). This is a collective name for a family of …

A collisionless plasma is described by the Vlasov‐Poisson equations. The BGK equilibria
were proposed in 1957 as the simplest spatially‐dependent equilibria. Since that time the …