The authors present a higher-order Godunov method for the solution of the twoand three-dimensional equations of ideal magnetohydrodynamics (MHD). This work is based both on a suitable operator-split approximation to the full multidimensional equations, and on a one-dimensional Riemann solver. TIlls Riemann solver is sufficiently robust to handle the nonstrictly hyperbolic nature of the MHD equa...

I review recent constraints on and claimed detections of a time-varying fine-structure constant α. Our results are consistent with no variation in α from the epoch of recombination to the present day, and restrict any such variation to be less than about 4%. The forthcoming MAP and Planck experiments will be able to break most of the currently existing degeneracies between α and other cosmologi...

‎By considering a degenerate $p(x)-$Laplacian equation‎, ‎a generalized compact embedding in weighted variable‎ ‎exponent Sobolev space is presented‎. ‎Multiplicity of positive solutions are discussed by applying fibering map approach for the‎ ‎corresponding Nehari manifold‎. 

A SU (4) ⊗ O(3) scheme for nonstrange baryons Abstract. We show that nonstrange baryon resonances can be classified according to multiplets of SU (4)⊗ O(3). We identify spectral regularities and degeneracies that allow us to predict the high spin spectrum from 2 to 3 GeV.

We present a microscopic index formula for the degeneracy of dyons in four-dimensional N = 4 string theory. This counting formula is manifestly symmetric under the duality group, and its asymptotic growth reproduces the macroscopic Bekenstein-Hawking entropy. We give a derivation of this result in terms of the type II five-brane compactified on K3, by assuming that its fluctuations are describe...

Hisakazu Minakata, Hiroshi Nunokawa, Stephen Parke 1 Department of Physics, Tokyo Metropolitan University 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan [email protected] 2 Instituto de F́ısica Teórica, Universidade Estadual Paulista Rua Pamplona 145, 01405-900 São Paulo, SP Brazil [email protected] 3 Theoretical Physics Department, Fermi National Accelerator Laboratory P.O.Box ...

We will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. The confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional Schrodinger equation. Excellent dependence is found between size effects, time relaxation and degenerate four wave mixi...

We will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. The confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional Schrodinger equation. Excellent dependence is found between size effects, time relaxation and degenerate four wave mixi...

We compute the boundary entropies for the allowed boundary conditions of the SU (2)-invariant principal chiral model at level k = 1. We used the reflection factors determined in ref.[27]. As a by-product we obtain some miscellaneous results such as the ground-state energy for mixed boundary conditions as well as the degeneracies of the Kondo model in the underscreened and exactly screened cases...

The spectrum of eigenenergies of a quantum integrable system whose hamil-tonian depends on a single parameter shows degeneracies (crossings) when the parameter varies. We derive a semiclassical expression for the density of crossings in the plane energy-parameter, that is the number of crossings per unit of energy and unit of parameter, in terms of classical periodic orbits. We compare the resu...