论文标题
恢复良好的重力的扩展
An Expansion of Well Tempered Gravity
论文作者
论文摘要
面对宇宙学中两个近乎棘手的问题时 - 如何消除原始的宇宙恒定问题以及如何参数化的重力来解释当前的宇宙加速度 - 我们可以通过对抗来取得进展。通过退化标量场动力学到宇宙学常数的良好纠正的解决方案也将不同的Horndeski重力术语涉及，使其对立。我们得出了动力学项$ k $与轮换对称理论的编织项$ g_3 $之间的连接（包括运行的普朗克质量$ g_4 $），从而将以前的关于单次或二项式依赖性的工作扩展到了任意有限程度的多项式。我们还展示了无限系列扩展的示例。对于这些“黄金”重力理论，这种对立条件大大减少了测试对宇宙学观察的修饰的重力所需的参数数量。
When faced with two nigh intractable problems in cosmology -- how to remove the original cosmological constant problem and how to parametrize modified gravity to explain current cosmic acceleration -- we can make progress by counterposing them. The well tempered solution to the cosmological constant through degenerate scalar field dynamics also relates disparate Horndeski gravity terms, making them contrapuntal. We derive the connection between the kinetic term $K$ and braiding term $G_3$ for shift symmetric theories (including the running Planck mass $G_4$), extending previous work on monomial or binomial dependence to polynomials of arbitrary finite degree. We also exhibit an example for an infinite series expansion. This contrapuntal condition greatly reduces the number of parameters needed to test modified gravity against cosmological observations, for these "golden" theories of gravity.
