Polar Quasinormal Modes of Neutron Stars in Massive Scalar-Tensor Theories

Frontiers in Physics

Jose Luis Blázquez-Salcedo ¹  Vincent Preut ²  Fech Scen Khoo ²  Jutta Kunz ² 

[1] Departamento de Física Teórica II and IPARCOS, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain;Institute of Physics, University of Oldenburg, Oldenburg, Germany;

关键词: relativistic stars - structure and stability;    modified theories of gravity;    gravitational waves;    neutron star;    quasinormal modes;   

DOI  :  10.3389/fphy.2021.741427

来源: DOAJ

【 摘 要 】

We study polar quasinormal modes of relativistic stars in scalar-tensor theories, where we include a massive gravitational scalar field and employ the standard Brans-Dicke coupling function. For the potential of the scalar field we consider a simple mass term as well as a potential associated with R2 gravity. The presence of the scalar field makes the spectrum of quasinormal modes much richer than the spectrum in General Relativity. We here investigate radial modes (l = 0) and quadrupole modes (l = 2). The general relativistic l = 0 normal modes turn into quasinormal modes in scalar-tensor theories, that are able to propagate outside of the stars. In addition to the pressure-led modes new scalar-led ϕ-modes arise. We analyze the dependence of the quasinormal mode frequencies and decay times on the scalar field mass.

【 授权许可】

Unknown