Axial quasi-normal modes of neutron stars in $R^2$ gravity

Abstract

In the present paper the axial quasi-normal modes of neutron stars in $f(R)$ gravity are examined using a large set of equations of state. The numerical calculations are made using two different approaches -- performing time evolution of the perturbation equations and solving the time-independent representation of the equations as a boundary value problem. According to the results the mode frequencies and the damping times decrease with the increase of the free parameter of the theory in comparison to the pure general relativistic case. While the frequencies deviate significantly from Einstein's theory for all realistic neutron star masses (say above $1M_{\odot }$), the damping times reach non-negligible differences only for the more massive models. We have constructed as well universal (equation of state independent) gravitational wave asteroseismology relations involving the frequencies and the damping times. It turns out that the equation of state independence is preserved using the same normalization as in pure general relativity and the qualitative differences of the phenomenological relations with respect to Einstein's theory of gravity can be large for large values of the free parameter in $f(R)$ gravity.

20 pages, 8 Figures

References in corpus (19)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• Multi-messenger Observations of a Binary Neutron Star Merger
• GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence
• GW170608: Observation of a 19-solar-mass Binary Black Hole Coalescence
• Swope Supernova Survey 2017a (SSS17a), the Optical Counterpart to a Gravitational Wave Source
• Constraints on a phenomenologically parameterized neutron-star equation of state
• New constraints on radii and tidal deformabilities of neutron stars from GW170817
• Extreme Gravity Tests with Gravitational Waves from Compact Binary Coalescences: (II) Ringdown
• Extreme Gravity Tests with Gravitational Waves from Compact Binary Coalescences: (I) Inspiral-Merger
• Quasi-Normal Modes and Gravitational Wave Astronomy
• Slowly rotating neutron and strange stars in $R^2$ gravity
• Rapidly rotating neutron stars in $R$-squared gravity
• On the 1/c Expansion of f(R) Gravity
• Neutron star mergers as a probe of modifications of general relativity with finite-range scalar forces
• Scalarization of neutron stars with realistic equations of state
• Axial quasinormal modes of static neutron stars in the nonminimal derivative coupling sector of Horndeski gravity: spectrum and universal relations for realistic equations of state
• Axial Quasi-Normal Modes of Scalarized Neutron Stars with Realistic Equations of State

Cited by in corpus (18)

• Spinning and excited black holes in Einstein-scalar-Gauss-Bonnet theory
• Radial oscillations and stability of compact stars in $f(R,T)=R+2\beta T$ gravity
• Anisotropic quark stars in $R^2$ gravity
• Quasinormal modes of compact objects in alternative theories of gravity
• Ultra long lived quasinormal modes of neutron stars in massive scalar-tensor gravity
• Axial quasi-normal modes of scalarized neutron stars with massive self-interacting scalar field
• Strongest constraint in $f(R)=R+\alpha R^2$ gravity: stellar stability
• Polar Quasinormal Modes of Neutron Stars in Massive Scalar-Tensor Theories
• Oscillation dynamics of scalarized neutron stars
• On the Inverse Spectrum Problem of Neutron Stars
• Nonlinear dynamics of oscillating neutron stars in scalar-tensor gravity
• Reconstruction of the neutron star equation of state from $w$-quasinormal modes spectra with a piecewise polytropic meshing and refinement method
• Compact Objects in Alternative Gravities
• Universal relations for quasinormal modes of neutron stars in $R^2$ gravity
• The effect of pressure anisotropy on quark stars structure in the Starobinsky model
• Normal and Quasinormal Modes of Holographic Multiquark Star
• Axial perturbations of neutron stars with shift symmetric conformal coupling
• Axial $w$-modes of anisotropic neutron stars