Relativistic Mean Field Model with Short-Range Correlations for Neutron Stars: Rotation in General Relativity and Stationary Structure in f(T) Gravity

• Grant number: 25/15506-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2025
• End date: November 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - General Physics
• Principal Investigator: Jose Carlos Neves de Araujo
• Grantee: Everson Henrique Rodrigues
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). São José dos Campos , SP, Brazil

Abstract

This project investigates neutron stars - extremely dense objects that serve as natural laboratories for testing fundamental physics theories, including modified gravity and nuclear physics effects. Focusing on relativistic mean-field (RMF) models, the proposal aims to incorporate short-range correlations (SRCs) into a realistic equation of state (EoS) within the context of modified gravity, specifically f(T) gravity. In modeling stellar matter, we will include SRCs in a hadronic RMF model for the core of the star, connecting it to a polytropic model for the outer crust and the BPS model for the surface layer.The inclusion of SRCs is expected to increase the maximum mass of neutron stars, as they tend to make the EoS stiffer. Through this study, we aim to introduce the effects of SRCs into f(T) gravity for the first time. By numerically integrating the field equations for the chosen EoS and solving the modified TOV equations in f(T) gravity, we will generate mass-radius diagrams for neutron stars. From these diagrams, we expect to identify configurations that could be classified as intermediate-mass objects (IMOs) within the f(T) relativistic framework.We will also explore the SRC-affected EoS in rotating stars to investigate how rotation impacts astrophysical and nuclear properties within the framework of general relativity, laying the foundation for future studies of rotation in f(T) gravity. The rotation analysis will be conducted using a non-perturbative, self-consistent field method. All results will be compared with observational constraints from gravitational wave interferometers and space telescopes such as NICER.