Spacetime Curvature as a Probe of Exotic Core Phases in Neutron Stars within Modified Gravity
arXiv:2508.08866 · doi:10.1103/rjzl-pcr4
Abstract
In this study, we investigate the effect of Energy-Momentum Squared Gravity (EMSG) on the curvature of neutron stars (NSs) by using three relativistic mean-field (RMF) equations of state (EOSs) and three hadron-quark phase transition (HQPT) EOSs. Neutron stars, with their extreme densities and strong gravitational fields, provide an ideal laboratory for testing General Relativity (GR) in the high-curvature regime and for exploring possible deviations via modified gravity. EMSG extends GR by including nonlinear terms involving the energy-momentum tensor, characterized by a coupling parameter . We focus on the Kretschmann, Ricci, and Weyl curvature scalars, analyzing their dependence on baryon density and radial coordinate for varying values of . Our results indicate that EMSG can significantly alter the curvature profiles of neutron stars. In particular, the magnitude of both Weyl and Kretschmann scalars increases (decreases) for a positive (negative) EMSG parameter, with the former exhibiting a larger dependence. Similarly, the surface curvature (SC) is notably affected by . Interestingly, we further observe distinct discontinuities in the curvature profiles at hadron-quark phase transitions, especially in the soft and intermediate HQPT models. These signatures may provide observable imprints of exotic core phases in neutron stars.
Comments are welcome
References in corpus (25)
- GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
- Dynamics of dark energy
- Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
- Multi-messenger Observations of a Binary Neutron Star Merger
- f(R,T) gravity
- PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
- A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation
- A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
- Swope Supernova Survey 2017a (SSS17a), the Optical Counterpart to a Gravitational Wave Source
- Palatini Approach to Modified Gravity: f(R) Theories and Beyond
- f(R,L_m) gravity
- Extreme neutron stars from Extended Theories of Gravity
- Strong-field Gravity Tests with the Double Pulsar
- Energy-Momentum Squared Gravity
- I-Love-Q, Spontaneously: Slowly Rotating Neutron Stars in Scalar-Tensor Theories
- Gravitational wave lensing beyond general relativity: birefringence, echoes and shadows
- Black hole-neutron star mergers are unlikely multi-messenger sources
- Impacts of dark matter on the curvature of the neutron star
- Dense and Hot QCD at Strong Coupling
- A short gamma-ray burst from a proto-magnetar remnant
- Energy-Momentum Squared Gravity: A Brief Overview
- Relativistic structure of charged quark stars in energy-momentum squared gravity
- Weak field and slow motion limits in energy-momentum powered gravity
- Constraining the Surface Curvature of an Anisotropic Neutron Star
- Constraining the -mode oscillations frequency in Neutron Stars through Universal Relations in the realm of Energy-Momentum Squared Gravity