This modern introduction to operator theory on spaces with indefinite
inner product discusses the geometry and the spectral theory of linear
operators on these spaces, the deep interplay with complex analysis, and
applications to interpolation problems. The text covers the key results
from the last four decades in a readable way with full proofs provided
throughout. Step by step, the reader is guided through the intricate
geometry and topology of spaces with indefinite inner product, before
progressing to a presentation of the geometry and spectral theory on
these spaces. The author carefully highlights where difficulties arise
and what tools are available to overcome them. With generous background
material included in the appendices, this text is an excellent resource
for researchers in operator theory, functional analysis, and related
areas as well as for graduate students.