Assessing the potential of cluster edges as a standard ruler on constraining dark energy models

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 Λ CDM . In particular, the constraining precision of the equation of state of dark energy from cluster edges is just about 2 times as large as 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 the cosmic microwave background, baryon acoustic oscillations, type Ia supernovae, cosmic chronometers, and simulated gravitational-wave events from the space-based Einstein Telescope, we constrain Λ CDM and find that the data combination of the cosmic microwave background and cluster edges gives the best constraints on the Hubble constant H₀, with 0.5% precision, and the matter density ratio Ω_m, with 1.6% precision, among these five pair datasets, and that the data combination of gravitational waves and cluster edges shares almost the same constraining power as that of type Ia supernovae and cluster edges. We also give the most stringent constraint on Λ 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.