论文标题
额外标量
Superluminality in DHOST theory with extra scalar
论文作者
论文摘要
我们认为DHOST IA理论与最小耦合到重力的附加常规标量场在重力上相互作用。在宇宙学背景的线性扰动水平上，我们发现在存在缓慢滚动的额外标量场的情况下，其中一种模式通常以超光速度传播。该结果对于任何稳定的宇宙学背景都是有效的。我们确定了缺乏这种超纤维特性的DONOST IA理论的子类，所有模式都可能在透明上传播（sub）。我们讨论了对相互作用的DHOST IA理论的可能影响。
We consider DHOST Ia theory interacting gravitationally with an additional conventional scalar field minimally coupled to gravity. At the linearized level of perturbations about cosmological background, we find that in the presence of a slowly rolling extra scalar field, one of the modes generically propagates at superluminal speed. This result is valid for any stable cosmological background. We identify a subclass of DHOST Ia theories in which this superluminality property is absent, and all modes may propagate (sub)luminally. We discuss possible implications for the interacting DHOST Ia theories.
