Assessing the potential of cluster edges as a standard ruler

TL;DR

This paper evaluates galaxy cluster edges as a promising standard ruler for cosmology, demonstrating their potential to constrain models beyond $\\Lambda$CDM and improve measurements of key parameters when combined with other probes.

Contribution

It provides a comprehensive assessment of cluster edges as a cosmological probe and explores their combined constraining power with other observational data.

Findings

Cluster edges can constrain dark energy equation of state about twice as precisely as supernovae.

Combining cluster edges with CMB yields 0.5% precision on H0.

Cluster edges improve constraints on cosmological parameters when combined with other probes.

Abstract

We assess comprehensively the potential of galaxy cluster edges as a standard ruler in measuring cosmological distances and probing exotic physics. Confronting five alternative cosmological models with cluster edges from the near future Dark Energy Spectroscopic Instrument survey, we conclude that cluster edges can serve as a promising probe to constrain models beyond $\Lambda$CDM. Especially, the constraining precision of equation of state of dark energy from cluster edges is just about two times larger than that from the Pantheon Type Ia supernovae sample. We find that the constraining power of cluster edges can be exhibited better by combining it with other probes. Combining cluster edges with cosmic microwave background, baryon acoustic oscillations, Type Ia supernovae, cosmic chronometers and simulated gravitational-wave events from the space-based Einstein Telescope, respectively, we constrain $\Lambda$CDM and find that the data combination of cosmic microwave background and cluster edges gives the best constraint on the Hubble constant $H_0$ with a $0.5\%$ precision and the matter density ratio $\Omega_m$ with a $1.6\%$ precision among these five pair datasets, and that the data combination of gravitational waves and cluster edges almost shares the same constraining power as that of Type Ia supernovae and cluster edges. We also give the most stringent constraint on $\Lambda$CDM by combining cluster edges with available cosmological data. With the help of other probes, galaxy cluster edges can give new insights on exotic physics better at cosmological scales.