436 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Consejo Nacional de Investigaciones Científicas y TécnicasAR144 papers
- Universidad Nacional de La PlataAR72 papers
- Universidad de ColimaMX41 papers
- Centro Científico Tecnológico - La PlataAR40 papers
- Institute for Complex SystemsIT23 papers
- Sapienza University of RomeIT22 papers
- University of TrentoIT18 papers
- Centre National de la Recherche ScientifiqueFR13 papers
- Instituto de Fisica de Liquidos y Sistemas BiologicosAR13 papers
- University of MichiganUS12 papers
- Cornell UniversityUS11 papers
- University of CambridgeGB11 papers
10 papers · 1 filter
Weakly bound states in heterogeneous waveguides
Paolo Amore, Francisco M. Fernandez, Christoph P. Hofmann
We study the spectrum of the Helmholtz equation in a two-dimensional infinite waveguide, containing a weak heterogeneity localized at an internal point, and obeying Dirichlet bound…
Highly accurate calculation of the real and complex eigenvalues of one-dimensional anharmonic oscillators
Francisco M. Fernández, Javier Garcia
We draw attention on the fact that the Riccati-Padé method developed some time ago enables the accurate calculation of bound-state eigenvalues as well as of resonances embedded eit…
An intermediate state between the kagome-ice and the fully polarized state in DyTiO
S. A. Grigera, R. Borzi, D. G. Slobinsky +4
DyTiO is at present the cleanest example of a spin-ice material. Previous theoretical and experimental work on the first-order transition between the kagome-ice and the…
High order eigenvalues for the Helmholtz equation in complicated non-tensor domains through Richardson Extrapolation of second order finite differences
Paolo Amore, John P. Boyd, Francisco M. Fernandez +1
We apply second order finite difference to calculate the lowest eigenvalues of the Helmholtz equation, for complicated non-tensor domains in the plane, using different grids which…
Symmetric quadratic Hamiltonians with pseudo-Hermitian matrix representation
Francisco M Fernández
We prove that any symmetric Hamiltonian that is a quadratic function of the coordinates and momenta has a pseudo-Hermitian adjoint or regular matrix representation. The eigenvalues…
Three PT-symmetric Hamiltonians with completely different spectra
Francisco M. Fernández, Javier Garcia
We discuss three Hamiltonians, each with a central-field part and a PT-symmetric perturbation . When is the isotropic Harmonic oscillator the spectrum is real…
Highly accurate calculation of the resonances in the Stark effect in hydrogen
Francisco M Fernández, Javier Garcia
We obtained accurate resonances for the Stark effect in hydrogen by means of three independent methods. Two of them are based on complex rotation of the coordinates and diagonaliza…
On the symmetry of three identical interacting particles in a one-dimensional box
Paolo Amore, Francisco M. Fernández
We study a quantum-mechanical system of three particles in a one-dimensional box with two-particle harmonic interactions. The symmetry of the system is described by the point group…
Non-Hermitian Hamiltonians and similarity transformations
Francisco M. Fernández
We show that similarity (or equivalent) transformations enable one to construct non-Hermitian operators with real spectrum. In this way we can also prove and generalize the results…
Group theoretical analysis of a quantum-mechanical three-dimensional quartic anharmonic oscillator
Francisco M. Fernández
This paper illustrates the application of group theory to a quantum-mechanical three-dimensional quartic anharmonic oscillator with symmetry. It is shown that group theory…