In contrast to the positive definite Helmholtz equation, the deceivingly similar looking
indefinite Helmholtz equation is difficult to solve using classical iterative methods. Simply …

State-of-the-art finite-element methods for time-harmonic acoustics governed by the
Helmholtz equation are reviewed. Four major current challenges in the field are specifically …

Many tasks in applied geosciences cannot be solved by single measurements, but require
the integration of geophysical, geotechnical and hydrological methods. Numerical …

" This engagingly written text provides a useful pedagogical introduction to an extensive
class of geometrical phenomena in the optics of polarization and phase, including simple …

In the last two decades, the field of inverse problems has certainly been one of the fastest
growing areas in applied mathematics. This growth has largely been driven by the needs of …

The purpose of this chapter is to provide a survey of our book by placing what we have to
say in a historical context. We obviously cannot give a complete account of inverse …

In the fourteen years since the second edition of this book appeared, linear integral
equations have continued to be an active area of mathematics and they have revealed more …

2 Introduction that the law of formation has been found. The corresponding direct problem is
to evaluate the sequence (an) given the law of formation. It is clear that such inverse …

Partial differential equations provide mathematical models of many important problems in
the physical sciences and engineering. This book treats one class of such equations …

Since the middle of the last century, computing power has increased sufficiently that the
direct numerical approximation of Maxwell's equations is now an increasingly important tool …