Gravitational-Wave Constraints on R2 Gravity
Abstract
Gravitational waves from compact binary coalescences provide a unique opportunity to test general relativity in the strong-field regime. Quadratic f(R)=R+aR2 gravity is among the simplest higher-curvature extensions of general relativity and introduces a massive scalar degree of freedom whose finite interaction range can modify compact-binary dynamics and gravitational-wave emission. We map this theory onto the effective-field-theory waveform for generic massive scalar-tensor gravity, obtaining a theory-specific inspiral phase correction governed by the single coupling parameter a. Using Bayesian analyses of the binary-neutron-star events GW170817 and GW190425, we obtain a combined constraint on the quadratic-curvature coupling of a≲6.2×106 m2 at 90% credibility, corresponding to a lower bound on the scalar mass of ms≳3.2×10−11 eV. This constitutes the strongest astrophysical constraint on the quadratic-curvature coupling, improving the previous best bound by approximately five orders of magnitude and demonstrating the sensitivity of binary-neutron-star inspirals to finite-range scalar interactions in the strong-field regime.
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BibTeX
@misc{gupta2026gravitationalwave,
title = {{Gravitational-Wave Constraints on $R^2$ Gravity}},
author = {Pawan Kumar Gupta and Laura Sagunski},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.06902},
eprint = {2611.06902},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.06902},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Gravitational-Wave Constraints on R^2 Gravity
AU - Pawan Kumar Gupta
AU - Laura Sagunski
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2611.06902
UR - https://arxiv.org/abs/2611.06902
AB - Gravitational waves from compact binary coalescences provide a unique opportunity to test general relativity in the strong-field regime. Quadratic f(R)=R+aR^2 gravity is among the simplest higher-curvature extensions of general relativity and introduces a massive scalar degree of freedom whose finite interaction range can modify compact-binary dynamics and gravitational-wave emission. We map this theory onto the effective-field-theory waveform for generic massive scalar-tensor gravity, obtaining a theory-specific inspiral phase correction governed by the single coupling parameter a. Using Bayesian analyses of the binary-neutron-star events GW170817 and GW190425, we obtain a combined constraint on the quadratic-curvature coupling of a≲6.2×10^6 m^2 at 90% credibility, corresponding to a lower bound on the scalar mass of m_s≳3.2×10^−11 eV. This constitutes the strongest astrophysical constraint on the quadratic-curvature coupling, improving the previous best bound by approximately five orders of magnitude and demonstrating the sensitivity of binary-neutron-star inspirals to finite-range scalar interactions in the strong-field regime.
ER -