The consequences for the brane cosmological evolution of energy exchange between the brane and the bulk are analyzed. A rich variety of brane cosmologies is obtained, depending on the precise mechanism of energy transfer, the equation of state of brane-matter and the spatial topology. An accelerating era is generically a feature of the solutions. Prepared for 36th International Symposium Ahrens...

In recent generalized Kohn-Sham (GKS) schemes for density functional theory (DFT) HartreeFock type exchange is important. In plane waves and grid approaches the high cost of exchange energy calculations makes these GKS considerably more expensive than Kohn-Sham DFT calculations. We develop a stochastic approach for speeding up the calculation of exchange for large systems. We show that stochast...

We revisit the problem of the three-soliton collisions in the weakly perturbed sine-Gordon equation and develop an effective three-particle model allowing us to explain many interesting features observed in numerical simulations of the soliton collisions. In particular, we explain why collisions between two kinks and one antikink are observed to be practically elastic or strongly inelastic depe...

The effects of weather are manifested in an organism-environment relationship through the mediu m of thermal or h eat exchange_ Meteorological param eters alone may be quite meaningless when used in interpreting animal responses because weather instruments do not respond to the thermal regime of the atmosphere in the same way that a living organism does _ Further, weather instruments are often ...

Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherica...

Pion double charge exchange ~DCX! on nuclear targets has been extensively studied, both experimentally and theoretically, throughout the last two decades. Because at least two nucleons must be involved in the process, the study of DCX is a natural tool for exploring nucleon-nucleon correlations. In the course of these studies at low energies, a prominent peak in the (p,p) cross section in the n...

Exchange energy is especially sensitive to the numerical representation selected. We compare three discretized exchange energy formulations for 3D numerical micromagnetics on rectangular grids. Explicit formulae are provided for both Neumann and Dirichlet boundary conditions. Results illustrate the convergence order of these methods as a function of discretization cell size and the effect of ce...

In this paper, we study Landau-Lifshitz equations of ferromagnetism with a total energy that does not include a so-called exchange energy. Many problems, including existence, stability, regularity and asymptotic behaviors, have been extensively studied for such equations of models with the exchange energy. Problems turn out quite different and challenging for Landau-Lifshitz equations of no-exc...

The equilibrium structure and exchange constants of CaMnO 3 and LaMnO 3 have been investigated using total energy unrestricted Hartree-Fock (UHF) and localised orbital configuration interaction (CI) calculations on the bulk compounds and Mn 2 O 14− 11 and Mn 2 O 16− 11 clusters. The predicted structure and exchange constants for CaMnO 3 are in reasonable agreement with estimates based on its Né...