Discrete cosmological models in the Brans-Dicke theory of gravity
Discrete cosmological models in the Brans-Dicke theory of gravity
复制标题
布兰斯-迪克引力理论中的离散宇宙学模型
DOI：
10.1088/1361-6382/ab329e
复制
发表时间：
2019
影响因子：
3.5
通讯作者：
Durk J
中科院分区：
文献类型：
--
作者：
Durk J
我们考虑了在引力标量张量理论中建立非齐次宇宙模型的问题。这首先将这些理论的场方程分成约束方程和演化方程，然后通过确定约束的精确解来进行。我们找到了与包含规则点状质量阵列的宇宙学模型的初始数据相对应的几何的精确、封闭形式的表达式。这些解扩展了最近应用于爱因斯坦方程的类似方法，并提供了足够的初始条件来执行演化方程的数值积分。我们用我们的新解研究了由引力标量张量理论支配的宇宙中的不均匀性的影响，包括牛顿常数所允许的空间不均匀性。最后，我们将我们的解与一般相对论解进行了比较，并研究了改变标量自由度和张量自由度之间的耦合常数对解的影响。
We consider the problem of building inhomogeneous cosmological models in scalar-tensor theories of gravity. This starts by splitting the field equations of these theories into constraint and evolution equations, and then proceeds by identifying exact solutions to the constraints. We find exact, closed form expressions for geometries that correspond to the initial data for cosmological models containing regular arrays of point-like masses. These solutions extend similar methods that have recently been applied to Einstein's equations, and provides sufficient initial conditions to perform numerical integration of the evolution equations. We use our new solutions to study the effects of inhomogeneity in cosmologies governed by scalar-tensor theories of gravity, including the spatial inhomogeneity allowed in Newton's constant. Finally, we compare our solutions to their general relativistic counterparts, and investigate the effect of changing the coupling constant between the scalar and tensor degrees of freedom.