Roger Nussbaum – författare

In the past several decades the classical Perron-Frobenius theory for nonnegative matrices has been extended to obtain remarkably precise and beautiful results for classes of nonlinear maps. This nonlinear Perron-Frobenius theory has found significant uses in computer science, mathematical biology, game theory and the study of dynamical systems. This is the first comprehensive and unified introduction to nonlinear Perron-Frobenius theory suitable for graduate students and researchers entering the field for the first time. It acquaints the reader with recent developments and provides a guide to challenging open problems. To enhance accessibility, the focus is on finite dimensional nonlinear Perron-Frobenius theory, but pointers are provided to infinite dimensional results. Prerequisites are little more than basic real analysis and topology.

The volume contains the texts of four courses, given bythe authors at a summer school that sought to present thestate of the art in the growing field of topological methodsin the theory of o.d.e. (in finite and infinitedimension),and to provide a forum for discussion of the wide variety ofmathematical tools which are involved. The topics coveredrange from the extensions of the Lefschetz fixed point andthe fixed point index on ANR''s, to the theory of parity ofone-parameter families of Fredholm operators, and from thetheory of coincidence degree for mappings on Banach spacesto homotopy methods for continuation principles.CONTENTS: P. Fitzpatrick: The parity as an invariant fordetecting bifurcation of the zeroes of one parameterfamilies of nonlinear Fredholm maps.- M. Martelli:Continuation principles and boundary value problems.- J.Mawhin: Topological degree and boundary value problems fornonlinear differential equations.- R.D. Nussbaum: The fixedpoint index and fixed point theorems.