Open FRW universes and self-acceleration from nonlinear massive gravity
Open FRW universes and self-acceleration from nonlinear massive gravity
复制标题
DOI：
10.1088/1475-7516/2011/11/030
复制
发表时间：
2011-09
影响因子：
6.4
通讯作者：
A. Gumrukcuoglu;Chunshan Lin;S. Mukohyama
中科院分区：
文献类型：
--
作者：
A. Gumrukcuoglu;Chunshan Lin;S. Mukohyama
在最近提出的具有洛伦兹不变质量项的非线性质量引力的背景下，我们研究了由任意物质源驱动的开放Friedmann-Robertson-Walker(FRW)宇宙。虽然平坦的FRW解最近被证明是不存在的，但这一证明并不延伸到开放宇宙。我们找到了Stuckelberg标量运动方程的三个独立的解分支。其中一个分支不允许任何非平凡的FRW宇宙论，就像在之前的禁止结果中一样。另一方面，另外两个分支都允许一般开放的FRW宇宙，由弗里德曼方程控制，具有物质源、标准曲率项和有效的宇宙学常数Λ±=c±mG_2。这里，mg是引力子质量，+和-代表两个分支，c±是由理论的两个无量纲参数确定的常数。由于具有足够小的曲率常数的开放的FRW宇宙可以近似于平坦的FRW宇宙，但不存在完全平坦的FRW解，所以该理论在平坦的FRW极限处表现出不连续性。
In the context of a recently proposed nonlinear massive gravity with Lorentz-invariant mass terms, we investigate open Friedmann-Robertson-Walker (FRW) universes driven by arbitrary matter source. While the flat FRW solutions were recently shown to be absent, the proof does not extend to the open universes. We find three independent branches of solutions to the equations of motion for the Stuckelberg scalars. One of the branches does not allow any nontrivial FRW cosmologies, as in the previous no-go result. On the other hand, both of the other two branches allow general open FRW universes governed by the Friedmann equation with the matter source, the standard curvature term and an effective cosmological constant Λ± = c±mg2. Here, mg is the graviton mass, + and - represent the two branches, and c± are constants determined by the two dimensionless parameters of the theory. Since an open FRW universe with a sufficiently small curvature constant can approximate a flat FRW universe but there is no exactly flat FRW solution, the theory exhibits a discontinuity at the flat FRW limit.