论文标题
关于变化的精细结构常数的广义理论
On Generalized Theories of Varying Fine Structure Constant
论文作者
论文摘要
我们使用一类标量扩展的重力理论，该理论可以推动当前的宇宙加速度，并适应精细结构常数$α$的轻度宇宙变化。动机来自Bekenstein，Sandvik，Barrow和Magueijo开发的老式理论。 $α$变化是由与带电物质相互作用的真实标量场引入的。我们基于宇宙当前物质密度的参数化执行宇宙学重建。通过使用马尔可夫链蒙特卡洛模拟将理论估计与JLA + OHD + BAO数据集进行比较，可以确保观察性一致性。对不同红移时$α$变化的参考，对雇用和尺寸光谱仪的分子吸收系的分析被认为是参考。讨论了两个例子。第一个探讨了与电荷物质相互作用的标量场的依赖性动力学耦合。第二个例子是广义的Brans-Dicke形式主义，其中$α$的变化符合有效的物质领域。这会产生牛顿常数$ g $和$α$的同时变化。这种变异的模式在宇宙扩张历史中可能具有至关重要的作用。
We work with a class of scalar extended theory of gravity that can drive the present cosmic acceleration as well as accommodate a mild cosmic variation of the fine structure constant $α$. The motivation comes from a vintage theory developed by Bekenstein, Sandvik, Barrow and Magueijo. The $α$ variation is introduced by a real scalar field interacting with charged matter. We execute a cosmological reconstruction based on a parametrization of the present matter density of the Universe. Observational consistency is ensured by comparing the theoretical estimates with JLA + OHD + BAO data sets, using a Markov chain Monte Carlo simulation. An analysis of molecular absorption lines from HIRES and UVES spectrographs is considered as a reference for the variation of $α$ at different redshifts. Two examples are discussed. The first explores a field-dependent kinetic coupling of the scalar field interacting with charged matter. The second example is a generalized Brans-Dicke formalism where the varying $α$ is fitted in as an effective matter field. This generates a simultaneous variation of the Newtonian constant $G$ and $α$. The pattern of this variation can have a crucial role in cosmic expansion history.
