[Paper Review] Gravitational-wave detectors as particle-physics laboratories: Constraining scalar interactions with boson-star binaries

Costantino Pacilio, Massimo Vaglio+2 more|arXiv (Cornell University)|Jul 10, 2020

Atomic and Subatomic Physics Research4 citations

TL;DR

This paper presents the first coherent waveform model for boson star binaries with quartic self-interactions, incorporating spin-induced quadrupole and tidal deformability effects via a single coupling constant. It demonstrates that future detectors like the Einstein Telescope and LISA will provide strong, complementary constraints on bosonic self-interactions, while current instruments offer only marginal sensitivity.

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 LISA can provide strong, complementary bounds on bosonic self-interactions, while the constraining power of current detectors is marginal.

Motivation & Objective

• To develop a coherent waveform model for boson star binaries with quartic self-interactions to enable precision gravitational-wave astronomy.
• To incorporate spin-induced quadrupolar and tidal deformability effects in terms of masses, spins, and a single coupling constant.
• To assess the constraining power of current and future gravitational-wave detectors on scalar field coupling constants.
• To explore the potential of boson star mergers as probes of fundamental physics beyond the Standard Model.
• To provide a theoretical framework for testing scalar field theories using gravitational-wave data from future observatories.

Proposed method

• Construct a waveform model that coherently includes both spin-induced quadrupole moments and tidal deformability in boson star binaries.
• Parameterize the scalar field theory using a single quartic self-interaction coupling constant, reducing complexity while preserving physical relevance.
• Model the inspiral dynamics using effective field theory techniques to describe the internal structure of boson stars.
• Integrate the waveform model into likelihood-based parameter estimation pipelines for gravitational-wave data analysis.
• Simulate signal-to-noise ratios and Fisher information matrix projections for future detectors like LISA and the Einstein Telescope.
• Compare the expected constraints on the coupling constant across different detector sensitivities and observation bands.

Experimental results

Research questions

• RQ1 How can the tidal and spin-induced quadrupole effects in boson star binaries be coherently modeled in a gravitational-wave waveform?
• RQ2 What is the sensitivity of current and future gravitational-wave detectors to the scalar self-coupling constant in boson star systems?
• RQ3 To what extent can boson star mergers constrain the parameters of scalar field theories beyond general relativity?
• RQ4 How do the constraints from LISA and the Einstein Telescope compare in their ability to probe bosonic self-interactions?
• RQ5 What is the role of the single coupling constant in determining the observable signatures of boson star coalescences?

Key findings

• The first coherent waveform model for boson star binaries with quartic self-interactions has been successfully developed, incorporating both spin-induced quadrupole and tidal deformability effects.
• Future detectors such as the Einstein Telescope and LISA are expected to provide strong, complementary bounds on the scalar self-coupling constant.
• Current-generation gravitational-wave detectors like LIGO and Virgo have marginal constraining power on bosonic self-interactions due to limited sensitivity at relevant frequencies.
• The inclusion of spin-induced quadrupole moments significantly enhances the detectability and parameter estimation accuracy of boson star signals.
• The waveform model enables precise inference of the scalar coupling constant through matched filtering techniques in future observations.
• The study establishes a direct link between gravitational-wave observations and fundamental scalar field theories, opening a new avenue for particle physics constraints.