Toward a dynamical shift condition for unequal mass black hole binary simulations

TL;DR

This paper introduces a position-dependent shift damping condition for black hole binary simulations that improves stability in unequal mass cases without significantly affecting gravitational wave extraction.

Contribution

It proposes a novel, position-dependent damping parameter for moving puncture simulations, enhancing stability for unequal mass black hole binaries.

Findings

Stable evolutions with the new damping parameter

Minimal impact on gravitational wave signals

Improved handling of unequal mass binaries

Abstract

Moving puncture simulations of black hole binaries rely on a specific gauge choice that leads to approximately stationary coordinates near each black hole. Part of the shift condition is a damping parameter, which has to be properly chosen for stable evolutions. However, a constant damping parameter does not account for the difference in mass in unequal mass binaries. We introduce a position dependent shift damping that addresses this problem. Although the coordinates change, the changes in the extracted gravitational waves are small.