论文标题
物质耦合在修饰的重力中的一致性
Consistency of matter coupling in modified gravity
论文作者
论文摘要
当重力拉格朗日具有堕落结构以避免Ostrogragradsky Ghost的问题时，重力理论中的物质耦合是一个非平凡的问题。最近，该问题是针对广义的Disfryal Horndeski类中的玻色物质领域解决的，迄今为止，这是通过对Horndeski理论进行可逆变形转换的更高衍生性不形式转换而获得的最普通的无鬼标量理论。在本文中，我们阐明了典型的异形Horndeski理论中典型物质耦合的一致性。我们开发了与广义的非正式转化相关的四元转换定律，以查看它如何影响费米子耦合。我们发现，费米子耦合的一致性需要在玻感案例所需的条件下额外的条件。结果，我们确定了广义的霍格德斯基类的一个子类，该类允许对普通物质字段（包括标准模型颗粒）的一致耦合。
Matter coupling in modified gravity theories is a nontrivial issue when the gravitational Lagrangian possesses a degeneracy structure to avoid the problem of the Ostrogradsky ghost. Recently, this issue was addressed for bosonic matter fields in the generalized disformal Horndeski class, which is so far the most general class of ghost-free scalar-tensor theories obtained by performing a higher-derivative generalization of invertible disformal transformations on Horndeski theories. In this paper, we clarify the consistency of fermionic matter coupling in the generalized disformal Horndeski theories. We develop the transformation law for the tetrad associated with the generalized disformal transformation to see how it affects the fermionic matter coupling. We find that the consistency of the fermionic matter coupling requires an additional condition on top of the one required for the bosonic case. As a result, we identify a subclass of the generalized disformal Horndeski class which allows for consistent coupling of ordinary matter fields, including the standard model particles.
