论文标题
触电引力模型中的幽灵不稳定与均等违规
Ghost instability in the teleparallel gravity model with parity violations
论文作者
论文摘要
在本文中，我们考虑了触发性重力框架内违反重力模型的平均值。均衡违规是由标量场与标量不变剂的耦合引起的，标量不变剂在扭曲张量中是奇偶校验和二次的耦合。总的来说，有两个这样的独立不变式，其中一个是Nieh-Yan密度。通过研究该模型的宇宙学扰动，我们发现它通常遭受标量和矢量扰动中幽灵不稳定的困难。但是，在特殊情况下，只有与Nieh-Yan密度的耦合存在，该模型是无幽灵的，并且还原为Nieh-Yan修饰的远程引力模型。我们还通过研究Minkowski背景周围的扰动来分析幽灵不稳定性的严重性。
In this paper we consider the parity violating gravity model within the framework of teleparallel gravity. The parity violations are caused by the couplings of a scalar field to the scalar invariants which are parity-odd and quadratic in the torsion tensor. Totally there are two such type independent invariants, and one of them is the Nieh-Yan density. Through investigations on the cosmological perturbations of this model, we find that in general it suffers from the difficulties of ghost instability in the scalar and vector perturbations. But in the special case only the coupling to the Nieh-Yan density exists, this model is ghost free and reduces to the Nieh-Yan modified Teleparallel Gravity model. We also analyze the severity of the ghost instability by studying the perturbations around the Minkowski background.
