Tensor-multi-scalar theories: relativistic stars and 3 + 1 decomposition
Tensor-multi-scalar theories: relativistic stars and 3 + 1 decomposition
复制标题
张量多标量理论：相对论星和 3 1 分解
DOI：
10.1088/0264-9381/32/20/204001
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发表时间：
2015
影响因子：
3.5
通讯作者：
U. Sperhake
中科院分区：
文献类型：
--
作者：
M. Horbatsch;Hector O. Silva;D. Gerosa;P. Pani;E. Berti;L. Gualtieri;U. Sperhake
引力理论与多个标量场耦合到度规和对方的一个自然的扩展研究单标量张量理论是有趣的现象学框架来描述偏离广义相对论在强场制度。在这些理论中，标量场的N元组在N维黎曼目标空间流形的坐标片中取值，该流形的性质不受弱场观测的约束。在这里，我们简单地介绍了一个非平凡的模型与两个标量场和一个最大对称的目标空间流形。在这个模型中，我们提出了一个初步的调查自发标量化的相对论，完美的流体恒星模型在球对称。我们发现，标量化阈值是由一个对称的标量物质耦合矩阵的特征值，并强标量恒星配置的属性还取决于目标空间的曲率半径。为了准备数值相对论模拟，我们还写下了一般张量多标量理论的场方程的3 + 1分解。
Gravitational theories with multiple scalar fields coupled to the metric and each other—a natural extension of the well studied single-scalar-tensor theories—are interesting phenomenological frameworks to describe deviations from general relativity in the strong-field regime. In these theories, the N-tuple of scalar fields takes values in a coordinate patch of an N-dimensional Riemannian target-space manifold whose properties are poorly constrained by weak-field observations. Here we introduce for simplicity a non-trivial model with two scalar fields and a maximally symmetric target-space manifold. Within this model we present a preliminary investigation of spontaneous scalarization for relativistic, perfect fluid stellar models in spherical symmetry. We find that the scalarization threshold is determined by the eigenvalues of a symmetric scalar-matter coupling matrix, and that the properties of strongly scalarized stellar configurations additionally depend on the target-space curvature radius. In preparation for numerical relativity simulations, we also write down the 3 + 1 decomposition of the field equations for generic tensor-multi-scalar theories.