11 research outputs found
Kinetic Limit for Wave Propagation in a Random Medium
We study crystal dynamics in the harmonic approximation. The atomic masses
are weakly disordered, in the sense that their deviation from uniformity is of
order epsilon^(1/2). The dispersion relation is assumed to be a Morse function
and to suppress crossed recollisions. We then prove that in the limit epsilon
to 0 the disorder averaged Wigner function on the kinetic scale, time and space
of order epsilon^(-1), is governed by a linear Boltzmann equation.Comment: 71 pages, 3 figure
Spherical Spectral Synthesis and Two-Radius Theorems on Damek-Ricci Spaces
We prove that spherical spectral analysis and synthesis hold in Damek-Ricci
spaces and derive two-radius theorems
Geometry of entangled states
Geometric properties of the set of quantum entangled states are investigated.
We propose an explicit method to compute the dimension of local orbits for any
mixed state of the general K x M problem and characterize the set of
effectively different states (which cannot be related by local
transformations). Thus we generalize earlier results obtained for the simplest
2 x 2 system, which lead to a stratification of the 6D set of N=4 pure states.
We define the concept of absolutely separable states, for which all globally
equivalent states are separable.Comment: 16 latex pages, 4 figures in epsf, minor corrections, references
updated, to appear in Phys. Rev.