Gravitational-wave detectors as particle-physics laboratories: Constraining scalar interactions with a coherent inspiral model of boson-star binaries

TL;DR

This paper develops a new gravitational-wave waveform model for boson-star binaries with scalar interactions, enabling future detectors to better constrain fundamental scalar field couplings.

Contribution

It introduces the first coherent inspiral waveform model for boson stars with quartic interactions, including spin and tidal effects, to improve constraints on scalar field theories.

Findings

Future GW detectors can significantly constrain bosonic self-interactions.

Current detectors have limited ability to constrain these interactions.

The model incorporates spin-induced quadrupolar and tidal effects coherently.

Abstract

Gravitational-wave (GW) detections of binary neutron star coalescences play a crucial role to constrain the microscopic interaction of matter at ultrahigh density. Similarly, if boson stars exist in the universe their coalescence can be used to constrain the fundamental coupling constants of a scalar field theory. We develop the first coherent waveform model for the inspiral of boson stars with quartic interactions. The waveform includes coherently spin-induced quadrupolar and tidal-deformability contributions in terms of the masses and spins of the binary and of a single coupling constant of the theory. We show that future instruments such as the Einstein Telescope and the Laser Interferometer Space Antenna can provide strong complementary bounds on bosonic self-interactions, while the constraining power of current detectors is marginal.