Neutron star pulse profile observations as extreme gravity probes

Abstract

The x-ray emission of hot spots on the surface of neutron stars is the prime target of the Neutron star Interior Composition Explorer (NICER). These x-ray pulse profiles not only encode information of the bulk properties of these stars, which teaches us about matter at supranuclear densities, but also about the spacetime curvature around them which teaches us about relativistic gravity. We explore the possibility of performing strong-gravity tests with NICER observations using a recently developed pulse profile model beyond general relativity. Our results suggest that NICER can place constraints on deviations from general relativity due to an additional scalar degree of freedom which are independent and competitive relative to constraints with binary pulsar observations.

7 pages, 3 figures. v2: updated title and new appendix

References in corpus (16)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• The Confrontation between General Relativity and Experiment
• Tests of general relativity from timing the double pulsar
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Dark Energy Camera Discovery of the Optical Counterpart
• The relativistic pulsar-white dwarf binary PSR J1738+0333 II. The most stringent test of scalar-tensor gravity
• Pulse profiles of millisecond pulsars and their Fourier amplitudes
• The Oblate Schwarzschild Approximation for Light Curves of Rapidly Rotating Neutron Stars
• The relativistic pulsar-white dwarf binary PSR J1738+0333 I. Mass determination and evolutionary history
• Observatory science with eXTP
• Thermal X-rays from Millisecond Pulsars: Constraining the Fundamental Properties of Neutron Stars
• Gravity and Scalar Fields
• Electromagnetism and hidden vector fields in modified gravity theories: spontaneous and induced vectorization
• On the possibility of setting a new constraint to scalar-tensor theories
• Pulse profiles from a pulsar in scalar-tensor gravity
• Modeling pulse profiles of accreting millisecond pulsars
• Scalar Charges and Scaling Relations in Massless Scalar-Tensor Theories

Cited by in corpus (9)

• Astrophysical and theoretical physics implications from multimessenger neutron star observations
• Spontaneous scalarization
• The surface of rapidly-rotating neutron stars: implications to neutron star parameter estimation
• Scalarized neutron stars in massive scalar-tensor gravity: X-ray pulsars and tidal deformability
• Light curves from highly compact neutron stars with spot size effect
• Compact Objects in Entangled Relativity
• Analytical expressions for pulse profile of neutron stars in plasma environments
• More than the sum of its parts: combining parameterized tests of extreme gravity
• Neutron stars as extreme gravity probes