12 citations · 26 across the 7 of their papers we have counts for
10 papers
On Kippenhahn curves and higher-rank numerical ranges of some matrices
Natália Bebiano, Joáo da Providéncia, Ilya M. Spitkovsky
The higher rank numerical ranges of generic matrices are described in terms of the components of their Kippenhahn curves. Cases of tridiagonal (in particular, reciprocal) 2-periodi…
Kippenhahn curves of some tridiagonal matrices
Natália Bebiano, Joáo da Providéncia, Ilya M. Spitkovsky +1
Tridiagonal matrices with constant main diagonal and reciprocal pairs of off-diagonal entries are considered. Conditions for such matrices with sizes up to 6-by-6 to have elliptica…
A quantum system with a non-Hermitian Hamiltonian
Natália Bebiano, João da Providência, S. Nishiyama +1
The relevance in Physics of non-Hermitian operators with real eigenvalues is being widely recognized not only in quantum mechanics but also in other areas, such as quantum optics,…
Towards non-Hermitian quantum statistical thermodynamics
Natália Bebiano, João da Providência, João P. da Providência
Non-Hermitian Hamiltonians possessing a discrete real spectrum motivated a remarkable research activity in quantum physics and new insights have emerged. In this paper we formulate…
Fermionic model with a non-Hermitian Hamiltonian
Natália Bebiano, João da Providência, Seiya Nishiyama +1
This paper deals with the mathematical spectral analysis and physical interpretation of a fermionic system described by a non-Hermitian Hamiltonian possessing real eigenvalues. A s…
Non self-adjoint operators with real spectra and extensions of quantum mechanics
N. Bebiano, J. da Providência
In this article, we review the general quantum mechanical setting associated to a non self-adjoint Hamiltonian with real spectrum. Spectral properties of the Hamiltonian of a simpl…
Inequalities in Rényi's quantum thermodynamics
Natália Bebiano, João da Providência, João Pinheiro da Providência
A theory of thermodynamics has been recently formulated and derived on the basis of Rényi entropy and its relative versions. In this framework, we define the concepts of partition…
Spectral analysis of a selected non self-adjoint Hamiltonian in an infinite dimensional Hilbert space
Natalia Bebiano, Joao da Providencia, Joao P. da Providencia
The so-called equation of motion method is useful to obtain the explicit form of the eigenvectors and eigenvalues of certain non self-adjoint bosonic Hamiltonians with real eigenva…
Direct and inverse spectral problems for a class of non-selfadjoint band matrices
Natalia Bebiano, Mikhail Tyaglov
The spectral properties of a class of band matrices are investigated. The reconstruction of matrices of this special class from given spectral data is also studied. Necessary and s…
Non Hermitian Operators with Real Spectrum in Quantum Mechanics
João da Providência, Natália Bebiano, João Pinheiro da Providência
Examples are given of non-Hermitian Hamiltonian operators which have a real spectrum. Some of the investigated operators are expressed in terms of the generators of the Weil-Heisen…