引力的因果修正及其观测界限
Causal Modifications of Gravity and Their Observational Bounds
摘要：
由于广义相对论是唯一的无质量自旋2粒子在大距离的理论，最合理的方法有重大的修改是引入一个或多个轻标量介导一个新的长程力。大多数现有的标量研究都引用了在短距离内表现出某种“屏蔽”的模型，以隐藏太阳系测试中的力。然而，众所周知，这样的修改也表现出超亮度，这可以被解释为一种非因果关系。在这项工作中，我们探讨明确的亚光速和因果标量场模型。特别是，我们研究了一个共形耦合标量$ϕ$，与一个小的耦合，以遵守太阳系的边界，和一个非正则的动力学项$K(X)$（$X=(\partialϕ)^2/2$），遵守所有的subluminality约束，是双曲的。我们认为$K(X)$是规范的小$X$，但超出一些非线性规模进入一个新的缩放制度的权力$p$，与$1/2<p<1$（DBI动力学项是限制$p=1/2$和规范标量是$p=1$）。与屏蔽（和超光速）相反，这种新的力量在高密度（和亚光速）的体系中变得越来越重要。然后，我们转向分布式环境，为这种新的相互作用设定界限。我们计算的约束条件，如赫尔斯-泰勒的二进制系统中的进动，我们计算修正中子星流体静力平衡，我们计算功率辐射，张量模式的修正和新的标量模式，这可能是重要的合并。
英文摘要：
Since general relativity is the unique theory of massless spin 2 particles at large distances, the most reasonable way to have significant modifications is to introduce one or more light scalars that mediate a new long-range force. Most existing studies of such scalars invoke models that exhibit some kind of "screening" at short distances to hide the force from solar system tests. However, as is well known, such modifications also exhibit superluminality, which can be interpreted as a form of acausality. In this work we explore explicitly subluminal and causal scalar field models. In particular, we study a conformally coupled scalar $ϕ$, with a small coupling to matter to obey solar system bounds, and a non-canonical kinetic term $K(X)$ ($X=(\partialϕ)^2/2$) that obeys all subluminality constraints and is hyperbolic. We consider $K(X)$ that is canonical for small $X$, but beyond some nonlinear scale enters a new scaling regime of power $p$, with $1/2<p<1$ (the DBI kinetic term is the limit $p=1/2$ and a canonical scalar is $p=1$). As opposed to screening (and superluminality), this new force becomes more and more important in the regime of high densities (and subluminality). We then turn to the densest environments to put bounds on this new interaction. We compute constraints from precession in binary systems such as Hulse-Taylor, we compute corrections to neutron star hydrostatic equilibrium, and we compute power in radiation, both tensor mode corrections and the new scalar mode, which can be important during mergers.
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。
