473 research outputs found
Acceleration-induced nonlocality: kinetic memory versus dynamic memory
The characteristics of the memory of accelerated motion in Minkowski
spacetime are discussed within the framework of the nonlocal theory of
accelerated observers. Two types of memory are distinguished: kinetic and
dynamic. We show that only kinetic memory is acceptable, since dynamic memory
leads to divergences for nonuniform accelerated motion.Comment: LaTeX file, 6 PS figures, 34 page
Transport of the repulsive Bose-Einstein condensate in a double-well trap: interaction impact and relation to Josephson effect
Two aspects of the transport of the repulsive Bose-Einstein condensate (BEC)
in a double-well trap are inspected: impact of the interatomic interaction and
analogy to the Josephson effect. The analysis employs a numerical solution of
3D time-dependent Gross-Pitaevskii equation for a total order parameter
covering all the trap. The population transfer is driven by a time-dependent
shift of a barrier separating the left and right wells. Sharp and soft profiles
of the barrier velocity are tested. Evolution of the relevant characteristics,
involving phase differences and currents, is inspected. It is shown that the
repulsive interaction substantially supports the transfer making it possible i)
in a wide velocity interval and ii) three orders of magnitude faster than in
the ideal BEC. The transport can be approximately treated as the d.c. Josephson
effect. A dual origin of the critical barrier velocity (break of adiabatic
following and d.c.-a.c. transition) is discussed. Following the calculations,
robustness of the transport (d.c.) crucially depends on the interaction and
barrier velocity profile. Only soft profiles which minimize undesirable dipole
oscillations are acceptable.Comment: 10 pages, 8 figures, accepted by Laser Physis. arXiv admin note: text
overlap with arXiv:1312.2750 The replaced version has a few corrections and
additional reference
APPLICATIONS OF A FULLY VARIATIONAL METHOD FOR SOLVING ZERO ORDER THOMAS-FERMI EQUATIONS
We present some results obtained in a Thomas-Fermi calculation without restriction of the variational space. We compare them to those obtained with trial functions and to the results of the mean field approximation, in the case of the equation of state of hot dense matter
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