Moment of Inertia for Axisymmetric Neutron Stars in the Standard-Model Extension

Abstract

We develop a consistent approach to calculate the moment of inertia (MOI) for axisymmetric neutron stars (NSs) in the Lorentz-violating Standard-Model Extension (SME) framework. To our knowledge, this is the first relativistic MOI calculation for axisymmetric NSs in a Lorentz-violating gravity theory other than deformed, rotating NSs in the General Relativity. Under Lorentz violation, there is a specific direction in the spacetime and NSs get stretched or compressed along that direction. When a NS is spinning stationarily along this direction, a conserved angular momentum and the concept of MOI are well defined. In the SME framework, we calculate the partial differential equation governing the rotation and solve it numerically with the finite element method to get the MOI for axisymmetric NSs caused by Lorentz violation. Besides, we study an approximate case where the correction to the MOI is regarded solely from the deformation of the NS and compare it with its counterpart in the Newtonian gravity. Our formalism and the numerical method can be extended to other theories of gravity for static axisymmetric NSs.

9 pages, 3 figures; accepted by PRD

References in corpus (31)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Shapiro delay measurement of a two solar mass neutron star
• The Confrontation between General Relativity and Experiment
• Neutron Star Observations: Prognosis for Equation of State Constraints
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• Tests of general relativity from timing the double pulsar
• Signals for Lorentz Violation in Post-Newtonian Gravity
• Models of Pulsar Glitches
• Strong-field Gravity Tests with the Double Pulsar
• Modelling magnetically deformed neutron stars
• Detection of 107 glitches in 36 southern pulsars
• I-Love-Q, Spontaneously: Slowly Rotating Neutron Stars in Scalar-Tensor Theories
• Slowly rotating neutron and strange stars in $R^2$ gravity
• Short-range gravity and Lorentz violation
• Tests of local Lorentz invariance violation of gravity in the standard model extension with pulsars
• Magnetically-driven crustquakes in neutron stars
• Static spherical vacuum solutions in the bumblebee gravity model
• Stellar and substellar objects in modified gravity
• Constraining the dense matter equation-of-state with radio pulsars
• New pulsar limit on local Lorentz invariance violation of gravity in the standard-model extension
• Lorentz Symmetry Violations from Matter-Gravity Couplings with Lunar Laser Ranging
• Combined search for anisotropic birefringence in the gravitational-wave transient catalog GWTC-1
• Combined Search for a Lorentz-Violating Force in Short-Range Gravity Varying as the Inverse Sixth Power of Distance
• Bayesian inference of quark star equation of state using the NICER PSR J0030+0451 data
• Neutron stars as extreme laboratories for gravity tests
• Testing the Gravitational Weak Equivalence Principle in the Standard-Model Extension with Binary Pulsars
• Degeneracy in Studying the Supranuclear Equation of State and Modified Gravity with Neutron Stars
• Signature of Lorentz Violation in Continuous Gravitational-Wave Spectra of Ellipsoidal Neutron Stars
• Precession of spheroids under Lorentz violation and observational consequences for neutron stars
• Pulsar Glitch in a Strangeon Star Model. III. The recovery
• Tests of conservation laws in post-Newtonian gravity with binary pulsars

Cited by in corpus (4)

• New limits on the local Lorentz invariance violation of gravity in the Standard-Model Extension with pulsars
• Scaling and universality in strange quark stars
• Precise constraint on properties of neutron stars through new universal relations and astronomical observations
• Inferring neutron-star Love-Q relations from gravitational waves in the hierarchical Bayesian framework