Graviton mass generation in in-spiraling DNS

TL;DR

This paper proposes a mechanism where scalarization in inspiraling double neutron star systems can generate a variable mass for gravitons, depending on the system's properties, with potential observational implications.

Contribution

It introduces a novel scalarization-based mechanism for graviton mass generation in binary neutron star systems, linking graviton mass to source properties and binary separation.

Findings

Graviton mass depends on the properties of scalarized neutron star binaries.

Effective graviton masses are estimated to be around 10^{-23} eV/c^2.

More massive gravitons are emitted from closer, higher-frequency binaries.

Abstract

We point out that a spontaneous scalarized inspiring double neutron star (DNS) system can provide us a natural laboratory to investigate the generation mechanism of masses for gravitons. Because of the appearance of a gravitational scalar background field, with small fluctuations, converged by iterative interplay of the mass dimensional external scalar fields, the binary system suffers from a spontaneous Lorentz symmetry breaking. The two scalarized NSs dip in a Higgs-like gravitational scalar potential, where the massless scalar background fluctuation field plays the role of Higgs field. Consequently, the gravitational scalar background field becomes massive. The radiated gravitons, propagating in a Yukawa-corrected potential, acquire a scalar-background-dependent mass term, in a massive-scalar-field-mediated way. We demonstrate that the mass of gravitons depends on intrinsic properties of the sources, which is not a certain value. The background-dependent masses for gravitons from scalarized orbital shrinking DNS is variable with the compactness of two components, as well as the separation of the binary. We get the effective masses for gravitons radiated from 8 detected DNS binaries with more precise mass measurements in our galaxy, whose values appear to be of the order of $10^{-23} ev/c^2$. It is found that more massive gravitons radiate from more closer DNS system, consisting with the higher-frequency gravitational waves from closer binaries.