标题： 三维引力与非线性宇宙学 显示英文标题

标题： 3D gravity and non-linear cosmology

摘要： 通过引入一个关于标量曲率的非线性项$R$，测试了暗能量是否可能作为3D引力公式中的几何效应出现。我们研究了一个遵循非多态方程状态的宇宙流体（范德瓦尔斯方程），该方程用于构建源的能量-动量张量，表示在引力相互作用中与物质贡献相关的假想暴胀子。根据尺度因子、其加速度以及组分的能量密度随时间的变化，可以构建一个膨胀的3D宇宙的描述，随后是物质主导时期。对于较晚的时间，验证了在某些条件下，$R$中的非线性项可以产生旧的3D宇宙加速膨胀，其中普通物质由范德瓦尔斯组分的正压极限表示。 显示英文摘要

摘要： By the inclusion of an additional term, non-linear in the scalar curvature $R$, it is tested if dark energy could rise as a geometrical effect in 3D gravitational formulations. We investigate a cosmological fluid obeying a non-polytropic equation of state (the van der Waals equation) that is used to construct the energy-momentum tensor of the sources, representing the hypothetical inflaton in gravitational interaction with a matter contribution. Following the evolution in time of the scale factor, its acceleration, and the energy densities of constituents it is possible to construct the description of an inflationary 3D universe, followed by a matter dominated era. For later times it is verified that, under certain conditions, the non-linear term in $R$ can generate the old 3D universe in accelerated expansion, where the ordinary matter is represented by the barotropic limit of the van der Waals constituent.