The mass-radius relation for neutron stars in $f(R)=R+\alpha R^2$ gravity: a comparison between purely metric and torsion formulations

Abstract

Within the framework of $f(R)=R+\alpha R^2$ gravity, we study realistic models of neutron stars, using equations of state compatible with the LIGO constraints. i.e. APR4, MPA1, SLy, and WW1. By numerically solving modified Tolman-Oppenheimer-Volkoff equations, we investigate the Mass--Radius relation in both metric and torsional $f(R)=R+\alpha R^2$ gravity models. In particular, we observe that torsion effects decrease the compactness and total mass of neutron star with respect to the General Relativity predictions, therefore mimicking the effects of a repulsive massive field. The opposite occurs in the metric theory, where mass and compactness increase with $\alpha$, thus inducing an excess of mass that overtakes the standard General Relativity limit. We also find that the sign of $\alpha$ must be reversed whether one considers the metric theory (positive) or torsion (negative) to avoid blowing up solutions. This could draw an easy test to either confirm or discard one or the other theory by determining the sign of parameter $\alpha$.

arXiv comment16 pages, accepted for publication in Phys. Rev. D

References in corpus (76)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
• Shapiro delay measurement of a two solar mass neutron star
• Extended Theories of Gravity
• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Is Cosmic Speed-Up Due to New Gravitational Physics?
• Modified gravity with negative and positive powers of the curvature: unification of the inflation and of the cosmic acceleration
• Laser Interferometer Space Antenna
• Curvature Quintessence
• Masses, Radii, and Equation of State of Neutron Stars
• A unified equation of state of dense matter and neutron star structure
• Beyond the Cosmological Standard Model
• The Cosmic Triangle: Revealing the State of the Universe
• Planck 2013 results. XXII. Constraints on inflation
• Gravity Probe B: Final Results of a Space Experiment to Test General Relativity
• Equation of state and neutron star properties constrained by nuclear physics and observation
• Palatini Approach to Modified Gravity: f(R) Theories and Beyond
• Hybrid stars that masquerade as neutron stars
• The Equation of State of Hot, Dense Matter and Neutron Stars
• GW170817: Joint Constraint on the Neutron Star Equation of State from Multimessenger Observations
• Scientific Objectives of Einstein Telescope
• Relativistic Mean-Field Theory and the High-Density Nuclear Equation of State
• Refined Neutron-Star Mass Determinations for Six Eclipsing X-Ray Pulsar Binaries
• The Lyman-alpha Forest Power Spectrum from the Sloan Digital Sky Survey
• Further stable neutron star models from f(R) gravity
• Measuring the neutron star equation of state with gravitational wave observations
• Cosmological reconstruction of realistic modified F(R) gravities
• Extended Gravity Cosmography
• Quintessence without scalar fields
• Black holes, cosmological solutions, future singularities, and their thermodynamical properties in modified gravity theories
• The Newtonian Limit of F(R) gravity
• The Mass-Radius relation for Neutron Stars in $f(R)$ gravity
• Extreme neutron stars from Extended Theories of Gravity
• A 2.1 Solar Mass Pulsar Measured by Relativistic Orbital Decay
• Maximal neutron star mass and the resolution of hyperon puzzle in modified gravity
• Constraining the Mass and Radius of Neutron Stars in Globular Clusters
• A f(R) gravity without cosmological constant
• Dark Matter from R^2-gravity
• Nonperturbative models of quark stars in $f(R)$ gravity
• Junction Conditions in f(R) Theories of Gravity
• Using Neutron Star Observations to Determine Crust Thicknesses, Moments of Inertia, and Tidal Deformabilities
• Nearly Starobinsky inflation from modified gravity
• Inflationary universe from perfect fluid and $F(R)$ gravity and its comparison with observational data
• The mass of the neutron star in Vela X-1
• On the evolution of density perturbations in f(R) theories of gravity
• Black Holes in Higher Derivative Gravity Theories
• On neutron stars in f(R) theories: small radii, large masses and large energy emitted in a merger
• Breakdown of I-Love-Q universality in rapidly rotating relativistic stars
• Charged spherically symmetric black holes in $f(R)$ gravity and their stability analysis
• Cluster Density Profiles as a Test of Modified Gravity
• f(R) Gravity with Torsion: The Metric-Affine Approach
• Covariant gauge-invariant perturbations in multifluid f(R) gravity
• The Imaginary Starobinsky Model
• Magnetic Neutron Stars in f(R) gravity
• On the 1/c Expansion of f(R) Gravity
• Frequency-Dependent Responses in 3rd Generation Gravitational-Wave Detectors
• Trace-anomaly driven inflation in modified gravity and the BICEP2 result
• F(R) cosmology in presence of a phantom fluid and its scalar-tensor counterpart:towards a unified precision model of the universe evolution
• The Cauchy problem for metric-affine f(R)-gravity in presence of perfect-fluid matter
• Tracking quintessence by cosmic shear - Constraints from VIRMOS-Descart and CFHTLS and future prospects
• Implications of the mass $M=2.17_{-0.10}^{+0.11}$M${}_{\odot }$ of PSR~J0740+6620 on the Equation of State of Super-Dense Neutron-Rich Nuclear Matter
• f(R) cosmology with torsion
• Large Scale Structure Constraints for a Class of f(R) Theories of Gravity
• A general solution in the Newtonian limit of f(R)- gravity
• f(R) gravity with torsion: a geometric approach within the J-bundles framework
• Twins: The Two Shortest Period Non-Interacting Double Degenerate White Dwarf Stars
• Metric-affine $f(R)$-gravity with torsion: an overview
• On the junction conditions in $f(R)$-gravity with torsion
• Testing metric-affine f(R)-gravity by relic scalar gravitational waves
• Black hole stability under odd-parity perturbations in Horndeski gravity
• Neutron star masses in $R^2$-gravity

Cited by in corpus (34)

• Stellar structure models in modified theories of gravity: lessons and challenges
• Extended Gravity Description for the GW190814 Supermassive Neutron Star
• Stable and self-consistent compact star models in teleparallel gravity
• Observational constraints on Myrzakulov gravity
• Supermassive Neutron Stars in Axion $F(R)$ Gravity
• Cosmological applications of Myrzakulov gravity
• Rotating Neutron Stars in F(R) Gravity with Axions
• Thermodynamic topology of topological black hole in $F(R)$-ModMax gravity's rainbow
• Effective interactions in Ricci-Based Gravity models below the non-metricity scale
• Effect of massive graviton on dark energy star structure
• Compact Star in General $F(R)$ Gravity: Inevitable Degeneracy Problem and Non-Integer Power Correction
• Dynamical system analysis of Myrzakulov gravity
• Maximum mass of an anisotropic compact object admitting the modified Chaplygin equation of state in Buchdahl-I metric
• Neutron Star in Covariant $f(Q)$ gravity
• Transit cosmological models in Myrzakulov F(R,T) gravity theory
• A critical discussion on the $H_0$ tension
• Revisiting compact star in $F(R)$ gravity: Roles of chameleon potential and energy conditions
• Compact stars in $f(T)=T+\xi T^{\beta }$ gravity
• Investigating dark energy by electromagnetic frequency shifts
• Generalized $R^p$-attractor Cosmology in the Jordan and Einstein Frames: New Type of Attractors and Revisiting Standard Jordan Frame $R^p$ Inflation
• Solving Tolman-Oppenheimer-Volkoff equations in f(T) gravity: a novel approach applied to some realistic equations of state
• Investigating dark energy by electromagnetic frequency shifts II: the Pantheon+ sample
• Compact stars in the Einstein dark energy model
• Extremely small stars in scalar-tensor gravity: when stellar radius is less than Schwarzschild one
• Compact star in noninteger power model of $f(R)$ gravity
• Signatures of strangeness in neutron star merger remnants
• Neutron Stars in f(R)-Gravity and Its Extension with a Scalar Axion Field
• Probing Strong Field $f(R)$ Gravity and Ultra-Dense Matter with the Structure and Thermal Evolution of Neutron Stars
• On the linear stability of polytropic fluid spheres in $R^2$ gravity
• Some exact relativistic star solutions in $f(R)$ gravity
• Non-metricity signatures on the Higgs boson signal strengths at the LHC
• Accelerating electrically charged ModMax black hole solutions in $F(R)$ gravity
• Mass-radius relation, moment of inertia, and tidal love numbers of anisotropic neutron stars in f (R,T) gravity
• Maximum mass limit of strange stars in quadratic curvature-matter coupled gravity