We show rigorously that condensate fragmentation cannot occur in dilute Bose systems unless forced by exact specification of the values of conserved quantities. We also prove that, relatedly, the symmetric ground state of a dilute Bose gas with positive scattering length in a cylindrical trap is globally stable, and with negative scattering length locally stable, a result with nontrivial implic...

Naturally fractured reservoirs (NFR) represent an important percentage of worldwide hydrocarbon reserves and production. The performance naturally gas condensate would be more complicated regarding both rock fluid effects. In contrast to the dual-porosity model, dual-porosity/dual-permeability (dual-permeability) model is considered as a modified in which flow wellbore occurs through matrix fra...

We investigate the particle-number fluctuations of condensate due to collective excitations for trapped two-dimensional (2D) and quasi-2D Bose gases at low temperature. We show that the fluctuations of the condensate are proportional to the square of the total particle number of the system. For a quasi-2D Bose gas the fluctuations are also proportional to the square root of the trapping frequen...

The Changbei gas field, which initially exhibited high gas-production performance, is dominated by large-displacement horizontal wells. With the decrease in reservoir pressure, liquid loading well currently severe, and production has been rapidly decreasing. Thus, recognizing gas-well to maintain stable necessary. A method was established identify water source of field. First, formation condens...

We study the rotation of a 87Rb Bose-Einstein condensate confined in a quadratic plus quartic potential. This trap configuration allows one to increase the rotation frequency of the gas above the trap frequency. In such a fast rotation regime we observe a dramatic change in the appearance of the quantum gas. The vortices which were easily detectable for a slower rotation become much less visibl...

Influence of the damping on collective oscillations of a one-dimensional trapped Bose gas in the mean field regime has been studied. Using the phenomenological damping approach developed by L.P. Pitaevskii, modified variational equations for the parameters of the condensate wave function is derived. Analytical expressions for the condensate parameters in equilibrium state have been obtained. Bi...

We study the quantum and the mean-field Gross-Pitaevskii (GP) dynamics of a Bose-Einstein condensate gas confined in a toroidal trap. According to GP, if the interatomic interaction is attractive, the rotational states of the system can be dynamically stable or unstable depending on the strength of the mean-field energy. The full quantum analysis, however, reveals that the condensate is always ...