De Sitter宇宙的稳定性

该文研究了De Sitter宇宙的稳定性,通过计算引力波的扰动、尘埃物质的扰动以及宇宙常数的扰动,得到对于开与闭De Sitter宇宙都是稳定的．     

Kim黑洞熵与能斯特定理

从Kim时空背景下的Klein-Gordon方程出发,利用brick-wall方法计算标量场的自由能和熵.得到标量场的熵不仅与黑洞的外视界面积有关,而且也是内视界面积的函数.所得结论,当取某种近似时,可得到熵只与外视界面积成正比的关系.并且表明,用内外视界位置参量表达的熵,在黑洞辐射温度趋于绝对零度时,黑洞的熵也趋于零,它满足能斯特定理,可视为黑洞的普朗克绝对熵 关键词： brick-wall方法 黑洞熵 能斯特定理     

Entropic force between two horizons of dilaton black holes with a power-Maxwell field

In this paper,we consider(n+1)-dimensional topological dilaton de Sitter black holes with a powerMaxwell field as thermodynamic systems.The thermodynamic quantities corresponding to the black hole horizon and the cosmological horizon are interrelated.Therefore,the total entropy of the space-time should be the sum of the entropies of the black hole horizon and the cosmological horizon plus a correction term which is produced by the association of the two horizons.We analyze the entropic force produced by the correction term at given temperatures,which is affected by the parameters and dimensions of the space-time.It is shown that the change of entropic force with the position ratio of the two horizons in some regions is similar to that of the variation of the Lennard-Jones force with the position of particles.If the effect of entropic force is similar to that of the Lennard-Jones force,and other forces are absent,the motion of the cosmological horizon relative to the black hole horizon should have an oscillating process.The entropic force between the two horizons is probably one of the participants in driving the evolution of the universe.