引力子质量对中子星I-Q关系的修正

近年来,研究发现中子星的转动惯量I和四极矩Q存在着一个关系式,即I-Q关系.而且,该关系式不依赖于中子星内部的物态方程,与引力理论相关.因此,对该关系式的研究可用来检验引力理论.de Rham-GabadadzeTolley(dRGT)massive gravity是一种自洽的引力子静止质量不为零的修正引力理论,是目前国际引力理论研究的热点.本论文主要基于该修正引力理论,在慢速旋转近似下,利用多方指数n=0的物态方程,计算了dRGT massive gravity中牛顿极限下的I-Q关系.我们将dRGT massive gravity与爱因斯坦引力中的I-Q关系进行比较,发现引力子质量不会影响I与Q的平方之间无量纲化后的正比关系,但会改变其比例系数.

I-Q relation of neutron star affected by massive graviton

Recently,it has been found that there is a relationship between the moment of inertia I and gravitational quadrupole moment Q of a neutron star,which is well-known as the I-Q relation of a neutron star.Specifically,the I-Q relation is found to be independent of the state equation of matter inside a neutron star and is only related to gravitational theories.Therefore,this I-Q relation can be used to test gravitational theories.The dRGT massive gravity is a well-defined modified gravity with massive graviton,which has attracted considerable attention.In this study,we mainly investigate the I-Q relation of a neutron star affected by massive graviton in the dRGT massive gravity.By focusing on a slow rotational neutron star,and using the state equation of matter inside the star with n=0 case in the polytropic process,we analytically obtain the I-Q relation under the Newtonian limit of neutron stars in the dRGT massive gravity.We compare our results with those in Einstein gravity,and obtain that the I-Q relation still holds in the presence of massive graviton.However,the proportional coefficient of the I-Q relation is dependent on the graviton mass parameter m.