Thermodynamics second law and ω = −1 crossing(s) in interacting holographic dark energy model Abstract By the assumption that the thermodynamics second law is valid, we study the possibility of ω = −1 crossing in an interacting holographic dark energy model. We show that this crossing is possible provided we choose appropriate parameters for the system.

By using a second quantized formulation of level crossing, which does not assume adiabatic approximation, a convenient formula for geometric terms including offdiagonal terms is derived. The analysis of geometric phases is reduced to a simple diagonalization of the Hamiltonian in the present formulation. If one diagonalizes the geometric terms in the infinitesimal neighborhood of level crossing...

In a nucleonic propagation through conical crossings of electronic energy levels, the codimension two conical crossings are the simplest energy level crossings, which affect the Born– Oppenheimer approximation in the zeroth order term. The purpose of this paper is to develop the surface hopping method for the Schrödinger equation with conical crossings in the Eulerian formulation. The approach ...

In the framework of the seesaw mechanism with three heavy right-handed Majorana neutrinos and no Higgs triplets we carry out a systematic study of the structure of the right-handed neutrino sector. Using the current low-energy neutrino data as an input and assuming hierarchical Dirac-type neutrino masses mDi, we calculate the masses Mi and the mixing of the heavy neutrinos. We confront the infe...

Motivated by Heilmann and Lieb’s work [8], we discuss energy level crossings for the one-dimensional Hubbard model through the Bethe ansatz, constructing explicitly the degenerate eigenstates at the crossing points. After showing the existence of solutions for the Lieb–Wu equations with one-down spin, we solve them numerically and construct Bethe ansatz eigenstates. We thus verify all the level...

Two-dimensional PT-symmetric quantum-mechanical systems with the complex cubic potential V 12 = x 2 + y 2 + igxy 2 and the complex Hénon-Heiles potential V HH = x 2 + y 2 + ig xy 2 − x 3 /3 are investigated. Using numerical and perturbative methods, energy spectra are obtained to high levels. Although both potentials respect the PT symmetry, the complex energy eigenvalues appear when level cros...

We investigate the Josephson coupling between two superconductors mediated through an infinite U Anderson impurity, adapting a variational wavefunction approach which has proved successful for the Kondo model. Unlike the Kondo problem, however, a crossing of singlet and doublet state energies may be produced by varying the ratio of Kondo energy to superconducting gap, in agreement with recent w...

The primary all-trans --> 13-cis photoisomerization of retinal in bacteriorhodopsin has been investigated by means of quantum chemical and combined classical/quantum mechanical simulations employing the density matrix evolution method. Ab initio calculations on an analog of a protonated Schiff base of retinal in vacuo reveal two excited states S1 and S2, the potential surfaces of which intersec...

We demonstrate the level crossing phenomenon for fermions in the background field of the sphaleron barrier, by numerically determining the fermion eigenvalues along the minimal energy path from one vacuum to another. We assume that the fermions of a doublet are degenerate in mass, allowing for spherically symmetric ansätze for all of the fields, when the mixing angle dependence is neglected.