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1. chinaXiv:201605.01011 [pdf]

A stochastic measure for eternal inflation

miao li; yi wang
Subjects: Physics >> The Physics of Elementary Particles and Fields

We use the?stochastic?approach to investigate?a?measure?for?slow roll?eternal?inflation. The probability?for?the universe to have?a?given Hubble radius can be calculated in this framework. In?a?solvable model, it is shown that the probability?for?the universe to evolve from?a?state with?a?smaller Hubble radius to one with?a?larger Hubble radius is dominated by the classical probability without the?stochastic?source, while the probability?for?the universe to evolve from?a?state with?a?larger Hubble radius to one with?a?smaller one is suppressed by exp(-Delta S), where the de Sitter entropy S arises naturally in this?stochasticapproach.

submitted time 2016-05-08 Hits577Downloads305 Comment 0

2. chinaXiv:201605.01003 [pdf]

Theoretical Analysis of Catalytic-sRNA-Mediated Gene Silencing

Yue Hao; fangliu xu; hualin shi
Subjects: Physics >> Interdisciplinary Physics and Related Areas of Science and Technology

Small regulatory RNA (sRNA) that acts by an antisense mechanism is critical for gene regulation at the posttranscriptional level. Recently, an Hfq-dependent sRNA named MicM, which is related to the regulation of outer membrane protein, was verified as a novel antisense sRNA due to its catalytic mode of regulation. Here we propose a simple kinetic model for the enzyme-like regulation mode of sRNA and study in detail the noise properties of the target gene under various recycling rates of the regulator. We predict that the recycling rate of sRNA and other relative parameters have significant influence on the noise strength of target expression. In comparison with the stoichiometric regulatory mode, a lesser fluctuation of target expression was observed near the threshold at which the transcription rates of both sRNA and target mRNA equal each other. We also found that the new mode is better in terms of rapid response to external signals. However, it needs more time to achieve target recovery if the stimulating signal disappears. Additionally, the obtained time evolution results of the MicM-ybfM interaction system based on our model are consistent with previous experimental results, serving as experimental evidence to back up our theoretical analysis. (C) 2010 Elsevier Ltd. All rights reserved.

submitted time 2016-05-08 Hits1497Downloads567 Comment 0

3. chinaXiv:201605.01001 [pdf]

Temperature-dependent frequency shifts in collective excitations of a Bose-Einstein condensate

Hualin Shi; Wei-Mou Zheng
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

By including the contribution of the thermal cloud in the Lagrangian of the condensate of a Bose gas, we extend the time-dependent variational method at zero temperature to study temperature-dependent low collective excitation modes. A Gaussian trial wave function of the condensate and a static distribution density of the thermal cloud are used and analytical expressions for temperature-dependent excitation frequencies obtained. Theoretical results are compared with measurements in the JILA and MIT experiments.

submitted time 2016-05-08 Hits1005Downloads381 Comment 0

4. chinaXiv:201605.00999 [pdf]

Thermodynamic Properties of a Trapped Interacting Bose Gas

Hualin Shi; Wei-Mou Zheng
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

A Bose gas in an external potential is studied by means of the local density approximation. Analytical results are derived for the thermodynamic properties of an ideal Bose gas in a generic power-law trapping potential, and their dependence on the mutual interaction of atoms in the case of a non-ideal Bose gas.

submitted time 2016-05-08 Hits996Downloads363 Comment 0

5. chinaXiv:201605.00997 [pdf]

The Energy of a Trappe Interacting Bose Gas

Hualin Shi; Wei-Mou Zheng
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

A Bose gas in an external potential is studied by means of the semiclassical approximation. Analytical results are derived for the energy of an interacting Bose gas in a generic power-law trapping potential. An expression for the chemical potential below the critical temperature is also obtained. The theoretical results are in agreement with a recent energy measurement.

submitted time 2016-05-08 Hits1023Downloads342 Comment 0

6. chinaXiv:201605.00996 [pdf]

Bose-Einstein condensation in an atomic gas with attractive interactions

Hualin Shi; Wei-Mou Zheng
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

A Bose gas in an external potential is studied by means of the semiclassical approximation. Analytical results are derived for the energy of an interacting Bose gas in a generic power-law trapping potential. An expression for the chemical potential below the critical temperature is also obtained. The theoretical results are in agreement with a recent energy measurement.

submitted time 2016-05-08 Hits941Downloads342 Comment 0

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