标题： 在高维宇宙学中可见空间的绝热膨胀 显示英文标题

标题： On the adiabatic expansion of the visible space in a higher-dimensional Cosmology

摘要： 在具有各向同性可见空间和内部空间以及多完美流体物质的高维宇宙学背景下，我们研究了在存在时间依赖内部空间的情况下，可见外部空间绝热膨胀的条件。 该分析基于在额外维度存在的情况下对四维应力-能量张量的重新解释。 这修改了可见宇宙的通常绝热能量守恒定律，导致一种新的宇宙学演化类型，该类型包括四维中的大尺度熵产生。 显示英文摘要

摘要： In the context of higher-dimensional cosmologies with isotropic visible and internal space and multi-perfect fluid matter, we study the conditions under which adiabatic expansion of the visoble external space is possible, when a time-dependent internal space is present. The analysis is based on a reinterpretation of the four-dimensional stress-energy tensor in the presence of the extra dimensions. This modifies the usual adiabatic energy conservation laws for the visible Universe, leading to a new type of cosmological evolution which includes large-scale entropy production in four dimensions.