Pseudo-Hermitian Random Matrices (eBook)

This book is a comprehensive guide to pseudo-Hermitian random matrices, their properties, and their role in many models that are relevant to physical processes. The book starts by showing how the concept of pseudo-Hermiticity emerged from studies of PT-symmetric systems which aroused the interest of the random matrix theory community. The chapters that follow discuss the consequences of the pseudo-Hermitian condition to the eigen-decomposition of non-Hermitian matrices, and an investigation of pseudo-Hermitian random matrices in tridiagonal form, discussing the scenario with real eigenvalues, and the appearance of complex eigenvalues generated by unbound and non-positive metrics. Subsequently, the author introduces pseudo-Hermitian Gaussian matrices and their properties including characteristic polynomials, and statistical properties of their eigenvalues. Finally, in the last chapter, the time invariance of the metric is upended and a pseudo-Hermitian model with a time dependent metricis constructed to discuss the time evolution of entangled states.

Mauricio Porto Pato is a Senior Professor at the University of São Paulo with a large experience in the field of random matrices theory and applications. In the early 90's, in a collaboration with the nuclear physicist M. S. Hussein, he began a study of random matrices that resulted in the construction of an ensemble to be applied to a situation of partial conservation of a quantum number. The model was then, successfully, applied to the description of isospin data. In a collaboration with O. Bohigas, another important contribution of him to be highlighted, was the formalism to deal with missing levels in correlated spectra, a study that evolved from his work with the experimentalist G. E. Mitchell. About ten years ago, his interest moved from Hermitian to non-Hermitian operators and this led to his involvement with the studies of the class of pseudo-Hermitian matrices associated to PT-symmetric systems, that is, systems invariant under parity and time-reversal transformations. This investigation started with the introduction of the pseudo-Hermiticity condition in the sparse tridiagonal matrices of the so-called beta-ensembles of the random matrix theory. Next, the pseudo-Hermiticity condition was extended to the standard Gaussian matrices with the creation of the pseudo-Hermitian Gaussian ensembles. All this effort, along a decade, comprises about one dozen of works among articles and thesis.