Four hints and test candidates of the local cosmic expansion

TL;DR

This paper investigates the local cosmic expansion's effect on binary pulsars, providing new observational evidence supporting the cosmic drag hypothesis and identifying test candidates for further study.

Contribution

It presents additional binary pulsar evidence for local cosmic expansion and calculates observable ranges for cosmic drag effects, proposing test candidates.

Findings

Support for scale-independent cosmic expansion from multiple binaries

Total anomaly of orbital decay measurements is about 3.6 sigma

Identification of six test candidates with predicted excess decay

Abstract

The expansion of the universe on short distance scales is a new frontier to investigate the dark energy. The excess orbital decay in binary pulsars may be related to acceleration by the local cosmic expansion, called the cosmic drag. Modern observations of two independent binaries (PSR B1534+12 and PSR B1913+16) support this interpretation and result in a scale-independent expansion with viscous uniformity, in which binary systems have a smaller expansion rate than the Hubble constant. This paper shows additional evidential binaries (PSR J1012-5307 and PSR J1906+0746), supporting the cosmic drag picture. The total anomaly of the conventional model is about $3.6\,\sigma$ including two evidential binaries reported before. In addition, an observable range of the cosmic drag has been calculated for typical models of both NS-NS binary and NS-WD binary. In this region, six test candidates are listed with predictions of the excess orbital decay.