952 research outputs found
Three-Body Losses in Trapped Bose-Einstein Condensed Gases
A time-dependent Kohn-Sham (KS)-like equation for N bosons in a trap is
generalized for the case of inelastic collisions. We derive adiabatic equations
which are used to calculate the nonlinear dynamics of the Bose-Einstein
condensate (BEC) and non-mean field corrections due to the three-body
recombination. We find that the calculated corrections are about 13 times
larger for 3D trapped dilute bose gases and about 7 times larger for 1D trapped
weakly interacting bose gases when compared with the corresponding corrections
for the ground state energy and for the collective frequencies.Comment: 11 pages, 2 figure
Cold Bose Gases near Feshbach Resonances
The lowest order constrained variational method [Phys. Rev. Lett. 88, 210403
(2002)] has been generalized for a dilute (in the sense that the range of
interatomic potential is small compared with inter-particle spacing) uniform
gas of bosons near the Feshbach resonance using the multi-channel zero-range
potential model. The method has been applied to Na (F=1, m_F=1) atoms near the
G Feshbach resonance. It is shown that at high densities, there are
significant differences between our results for the real part of energy per
particle and the one-channel zero-range potential approximation. We point out
the possibility of stabilization of the uniform con densate for the case of
negative scattering length.Comment: Revised version of cond-mat/0212196. Added Eqs. (21,22) and
references for section
Modeling of the Earth's gravity field using the New Global Earth Model (NEWGEM)
Traditionally, the global gravity field was described by representations based on the spherical harmonics (SH) expansion of the geopotential. The SH expansion coefficients were determined by fitting the Earth's gravity data as measured by many different methods including the use of artificial satellites. As gravity data have accumulated with increasingly better accuracies, more of the higher order SH expansion coefficients were determined. The SH representation is useful for describing the gravity field exterior to the Earth but is theoretically invalid on the Earth's surface and in the Earth's interior. A new global Earth model (NEWGEM) (KIM, 1987 and 1988a) was recently proposed to provide a unified description of the Earth's gravity field inside, on, and outside the Earth's surface using the Earth's mass density profile as deduced from seismic studies, elevation and bathymetric information, and local and global gravity data. Using NEWGEM, it is possible to determine the constraints on the mass distribution of the Earth imposed by gravity, topography, and seismic data. NEWGEM is useful in investigating a variety of geophysical phenomena. It is currently being utilized to develop a geophysical interpretation of Kaula's rule. The zeroth order NEWGEM is being used to numerically integrate spherical harmonic expansion coefficients and simultaneously determine the contribution of each layer in the model to a given coefficient. The numerically determined SH expansion coefficients are also being used to test the validity of SH expansions at the surface of the Earth by comparing the resulting SH expansion gravity model with exact calculations of the gravity at the Earth's surface
Theoretical analysis and reaction mechanisms for experimental results of hydrogen-nickel systems
Theoretical analysis and reaction mechanisms will be presented for anomalous heat effect (AHE) observed for hydrogen-Nickel systems, using a generalized conventional theory which are based on the optical theorem formulation of low-energy nuclear reactions (OTF-LENRs) and also based on generalization of the theory of Bose-Einstein condensation nuclear fusion
(BECNF) in micro/nano-scale metal particles
Separable Structure of Many-Body Ground-State Wave Function
We have investigated a general structure of the ground-state wave function
for the Schr\"odinger equation for identical interacting particles (bosons
or fermions) confined in a harmonic anisotropic trap in the limit of large .
It is shown that the ground-state wave function can be written in a separable
form. As an example of its applications, this form is used to obtain the
ground-state wave function describing collective dynamics for trapped
bosons interacting via contact forces.Comment: J. Phys. B: At. Mol. Opt. Phys. 33 (2000) (accepted for publication
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