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arXiv 1808.04038math.AP
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玻色-爱因斯坦粒子的空间齐次玻尔兹曼方程:强收敛到平衡态的速率

The Spatially Homogeneous Boltzmann Equation for Bose-Einstein Particles: Rate of Strong Convergence to Equilibrium

Shuzhe Cai, Xuguang Lu

AI总结:

研究玻色-爱因斯坦粒子空间齐次玻尔兹曼方程的强收敛速率,证明低温下凝聚收敛并给出任意温度的代数收敛速率。

摘要:

本文是我们此前关于玻色-爱因斯坦粒子空间齐次玻尔兹曼方程研究工作的延续,该方程的量子碰撞核包含硬球模型。我们研究的解$F_t$满足质量、动量和能量守恒,且当$t\to\infty$时至少弱收敛到平衡态$F_{\rm be}$;已证明至少对于径向对称的非奇异初值,这类解是存在的,而在低温情形下,$F_t$必须为正博雷尔测度。本文取得的新进展如下:我们证明,对于所有径向对称的非奇异初值$F_0$,低温下$F_t(\{0\})$会随时间推移长时间收敛到玻色-爱因斯坦凝聚态$F_{\rm be}(\{0\})$。这一结果直接意味着解会随时间长时间强收敛到平衡态。我们还得到了任意温度下强收敛的代数速率。我们的证明基于熵控制、熵耗散的维拉尼不等式、为克服正下界缺失而构造的解与固定正函数之间的合适时变凸组合、三次碰撞积分的凸正性,以及用于获取凝聚正下界的迭代技巧。

英文摘要:

The paper is a continuation of our previous work on the spatially homogeneous Boltzmann equation for Bose-Einstein particles with quantum collision kernel that includes the hard sphere model. Solutions $F_t$ under consideration that conserve the mass, momentum, and energy and converge at least weakly to equilibrium $F_{\rm be}$ as $t\to\infty$ have been proven to exist at least for radially symmetric and non-singular initial data, and for the case of low temperature, $F_t$ have to be positive Borel measures. The new progress is as follows: we prove that the long time convergence of $F_t(\{0\})$ to the Bose-Einstein condensation $F_{\rm be}(\{0\})$ for low temperature holds for all radially symmetric and non-singular initial data $F_0$. This immediately implies the long time strong convergence to equilibrium. We also obtain an algebraic rate of the strong convergence for arbitrary temperature. Our proofs are based on the entropy control, Villani's inequality for the entropy dissipation, a suitable time-dependent convex combination between the solution and a fixed positive function (in order to overcome the lack of positive lower bound), the convex-positivity of the cubic collision integral, and an iteration technique for obtaining a positive lower bound of condensation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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