Eur. Phys. J. C (2020) 80: 483
https://doi.org/10.1140/epjc/s10052-020-7958-y

Regular Article - Theoretical Physics

Hydrostatic equilibrium configurations of neutron stars in a non-minimal geometry-matter coupling theory of gravity

¹ Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraíba, 12244-000, São José dos Campos, SP, Brazil
² Departamento de Física, Instituto Tecnológico de Aeronáutica, São José dos Campos, SP, 12228-900, Brazil
³ Universidade de São Paulo, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, R. do Matão 1226, Cidade Universitária, São Paulo, 05508-090, SP, Brazil

^* e-mail: geanderson.araujo.carvalho@gmail.com

Received: 1 November 2019
Accepted: 23 April 2020
Published online: 29 May 2020

Abstract

In this work we analyze hydrostatic equilibrium configurations of neutron stars in a non-minimal geometry-matter coupling (GMC) theory of gravity. We begin with the derivation of the hydrostatic equilibrium equations for the f(R, L) gravity theory, where R and L are the Ricci scalar and Lagrangian of matter, respectively. We assume , with constant. To describe matter inside neutron stars we assume a relativistic polytropic equation of state , with being the energy density, K and being constants. We also consider the more realistic equation of state (EoS) known as SLy4, which is a Skyrme type one based on effective nuclear interaction. We show that in this theory it is possible to reach the mass of massive pulsars, such as PSR J2215 + 5135, for both equations of state. Also, results for mass-radius relation in GMC gravity are strongly dependent on the stiffness of the EoS.