Toward Cosmological Standard Timers in Primordial Black Hole Binaries

TL;DR

This paper introduces a method using primordial black hole binaries as standard timers to measure the Universe's evolution through gravitational wave observations, enabling constraints on cosmological models.

Contribution

It develops a formalism for cosmological standard timers based on the dynamical evolution of primordial black hole binaries and their gravitational wave signals.

Findings

Probability distribution of binary parameters obtained from gravitational waves.

Redshift-time calibration method established.

Potential to constrain cosmological models.

Abstract

We propose that primordial black hole (PBH) binary systems can lead to standard timers in tracking the evolution of the Universe. Through gravitational waves from monochromatic PBH binaries, the probability distribution on major axis and eccentricity from the same redshift is obtained. By studying the dynamical evolution of PBH binaries from the initial probability distribution to observed redshifted ones, the redshift-time calibration can be extracted, which can constrain cosmological models. A general formalism of the standard timer is further concluded based on the evolution of statistical distribution in dynamical systems.