Constraining Brans-Dicke Parameter Using Gravitational Radiation

TL;DR

This paper derives a theoretical constraint on the Brans-Dicke parameter by analyzing gravitational radiation from a neutron star orbiting a galactic center, using simplified Newtonian dynamics and scalar polarization calculations.

Contribution

It provides a novel, accessible method to constrain the Brans-Dicke parameter through gravitational radiation analysis in a simplified Newtonian framework.

Findings

Scalar polarization dominated by dipole radiation

Derived a new theoretical limit on the BD parameter

Method accessible to undergraduate students

Abstract

This article presents a theoretical limit on the Brans-Dicke (BD) parameter using a neutron star (NS) revolving around a galactic central engine.The assumption that the orbital radius is large enough allows to ignore strong curvature due to the central supermassive black hole (SMBH) and treat the problem with Newtonian dynamics. First, gravitational radiation polarizations are calculated in the BD theory. The scalar polarization, dominated by the dipole radiation, is then used to put a constraint on the BD parameter.The calculations are relatively simple and this makes it accessible to sophomore students.