Diffusion equations with degenerate nonlinear source terms arise in many different applications, e.g., in the theory of epidemics, in models of cortical spreading depression, and in models of evaporation and condensation in porous media. In this paper, we consider a generalization of these models to a system of n coupled diffusion equations with identical nonlinear source terms. We determine si...

We have observed the Bose-Einstein condensation of an atomic gas in the (quasi)uniform three-dimensional potential of an optical box trap. Condensation is seen in the bimodal momentum distribution and the anisotropic time-of-flight expansion of the condensate. The critical temperature agrees with the theoretical prediction for a uniform Bose gas. The momentum distribution of a noncondensed quan...

During the VOCALS campaign spaceborne satellite observations showed that travelling gravity wave packets, generated by geostrophic adjustment, resulted in perturbations to marine boundary layer (MBL) clouds over the southeast Pacific Ocean (SEP). Often, these perturbations were reversible in that passage of the wave resulted in the clouds becoming brighter (in the wave crest), then darker (in t...

We examine the occurrence of Bose-Einstein condensation in both nonrelativistic and relativistic systems with no self-interactions in a general setting. A simple condition for the occurrence of Bose-Einstein condensation is given. We show that condensation can occur only if q ≥ 3, where q is the dimension associated with the continuous part of the eigenvalue spectrum of the Hamiltonian for nonr...

The system of shock wave-induced vapor condensation in uids of large heat capacity has been investigated theoretically. The wave structure is governed by diierences in the time scales associated with various relaxation mechanisms and their coupling to the macroscopic ow. In the low to moderate Mach number range, the viscous and heat-conducting forces are localized within a discontinuous forerun...

We study a multi-functional device for cold atoms consisting of three-terminal ring circuit pierced by synthetic magnetic flux, where the can be continuous or discretized. The flux controls atomic current through via Aharonov-Bohm effect. Our shows flux-induced transition reflections from an Andreev-like negative density to positive density. Further, direct into specific output ports, realizing...