The author presents in detail a new non-perturbative approach to the
fermionic many-body problem, improving the bosonization technique and
generalizing it to dimensions d1 via functional integration and
Hubbard--Stratonovich transformations. In Part I he clearly illustrates
the approximations and limitations inherent in higher-dimensional
bosonization and derives the precise relation with diagrammatic
perturbation theory. He shows how the non-linear terms in the energy
dispersion can be systematically included into bosonization in arbitrary
d, so that in d1 the curvature of the Fermi surface can be taken
into account. Part II gives applications to problems of physical
interest. The book addresses researchers and graduate students in
theoretical condensed matter physics.