Effective-action model for dynamical scalarization beyond the adiabatic approximation

TL;DR

This paper develops a comprehensive effective-action model to describe the full dynamical evolution of scalarization in compact binaries, including nonadiabatic effects and eccentric orbits, improving predictions for gravitational wave signals.

Contribution

It introduces a new effective-field-theory approach that captures nonadiabatic and eccentric effects in dynamical scalarization beyond the adiabatic approximation.

Findings

Scalarization onset prediction requires full dynamical modeling.

Nonadiabatic effects cause oscillatory behavior during phase transition.

Model enables more accurate gravitational wave predictions.

Abstract

In certain scalar-field extensions to general relativity, scalar charges can develop on compact objects in an inspiraling binary -- an effect known as dynamical scalarization. This effect can be modeled using effective-field-theory methods applied to the binary within the post-Newtonian approximation. Past analytic investigations focused on the adiabatic (or quasi-stationary) case for quasi-circular orbits. In this work, we explore the full dynamical evolution around the phase transition to the scalarized regime. This allows for generic (eccentric) orbits and to quantify nonadiabatic (e.g., oscillatory) behavior during the phase transition. We also find that even in the circular-orbit case, the onset of scalarization can only be predicted reliably when taking the full dynamics into account, i.e., the adiabatic approximation is not appropriate. Our results pave the way for accurate post-Newtonian predictions for dynamical scalarization effects in gravitational waves from compact binaries.