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arXiv 2108.10364gr-qcastro-ph.CO
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变色龙屏蔽依赖于NFW晕的形状和结构

Chameleon Screening Depends on the Shape and Structure of NFW Halos

Andrius Tamosiunas, Chad Briddon, Clare Burrage, Weiguang Cui, Adam Moss

摘要:

变色龙引力是一个例子,它在宇宙学尺度上产生了有趣的现象学,同时拥有一个屏蔽机制,使其能够避免太阳系的限制。这种模型导致非线性场方程,其只能在简单的高度对称系统中解析求解。本文用有限元方法研究了变色龙屏蔽标量-张量理论的运动方程。更具体地说,我们解决了球形和三轴NFW集群大小的晕场方程。这使得一个详细的调查之间的关系NFW浓度和维里质量参数和变色龙加速度的幅度,在维里半径测量。此外,我们还研究了晕三轴性对变色龙加速度的影响。我们专注于参数空间区域,仍然允许的观测约束。我们发现,给定我们的数据集,在维里半径的变色龙到NFW加速比的最大允许值是$\sim 10^{-7}$。这一结果有力地表明,变色龙模型仍然允许的观测约束不会导致任何可测量的影响星系团规模。尽管如此,我们也发现,有一个直接的关系之间的NFW潜力和变色龙NFW加速比维里半径。类似地,在NFW浓度、维里质量和维里半径处的加速度比之间存在直接的(然而复杂得多的)关系。最后,我们发现,三轴度引入额外的方向效应的加速度测量。这些效应结合在一起可能会被用于未来对第五种力量的观测研究。

英文摘要:

Chameleon gravity is an example of a model that gives rise to interesting phenomenology on cosmological scales while simultaneously possessing a screening mechanism, allowing it to avoid solar system constraints. Such models result in non-linear field equations, which can be solved analytically only in simple highly symmetric systems. In this work we study the equation of motion of a scalar-tensor theory with chameleon screening using the finite element method. More specifically, we solve the field equation for spherical and triaxial NFW cluster-sized halos. This allows a detailed investigation of the relationship between the NFW concentration and the virial mass parameters and the magnitude of the chameleon acceleration, as measured at the virial radius. In addition, we investigate the effects on the chameleon acceleration due to halo triaxiality. We focus on the parameter space regions that are still allowed by the observational constraints. We find that given our dataset, the largest allowed value for the chameleon-to-NFW acceleration ratio at the virial radius is $\sim 10^{-7}$. This result strongly indicates that the chameleon models that are still allowed by the observational constraints would not lead to any measurable effects on galaxy cluster scales. Nonetheless, we also find that there is a direct relationship between the NFW potential and the chameleon-to-NFW acceleration ratio at the virial radius. Similarly, there is a direct (yet a much more complicated) relationship between the NFW concentration, the virial mass and the acceleration ratios at the virial radius. Finally, we find that triaxiality introduces extra directional effects on the acceleration measurements. These effects in combination could potentially be used in future observational searches for fifth forces.

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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