413 research outputs found
Observational properties of cosmic gamma-ray bursts
A brief overview of the major observational results obtained in gamma-ray burst studies is presented. Also discussed is to what extent the thermonuclear model, which appears at present to be the most plausible, can account for the observed properties of the bursts. The investigation of gamma-ray bursts should cover observations of the time histories of events, energy spectra, and their variablility, source localization, and inspection of the localization regions during the active and quiescent phases of the source in other wavelengths, as well as, evaluation of the statistical distributions of the data obtained
Dephasing in two decoupled one-dimensional Bose-Einstein condensates and the subexponential decay of the interwell coherence
We provide a simple physical picture of the loss of coherence between two
coherently split one-dimensional Bose-Einstein condensates. The source of the
dephasing is identified with nonlinear corrections to the elementary excitation
energies in either of the two independent condensates. We retrieve the result
by Burkov, Lukin and Demler [Phys. Rev. Lett. 98, 200404 (2007)] on the
subexponential decay of the cocherence for the large time, however, the scaling
of the characteristic decoherence time differs.Comment: revtex4, no figure
Nonexponential motional damping of impurity atoms in Bose-Einstein condensates
We demonstrate that the damping of the motion of an impurity atom injected at
a supercritical velocity into a Bose-Einstein condensate can exhibit
appreciable deviation from the exponential law on time scales of s.Comment: revtex, 4 pages + 2 figures (epsi format
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