Turnaround density as a probe of the cosmological constant
Abstract
Spherical collapse predicts that a single value of the turnaround density, meaning the average matter density within the scale on which a structure detaches from the Hubble flow, characterizes all cosmic structures at the same redshift. It was recently shown by Korkidis et al. that this feature persists in complex non-spherical galaxy clusters that have been identified in N-body simulations. Here we show that the low-redshift evolution of the turnaround density constrains the cosmological parameters and it can be used to derive a local constraint on ΩΛ, 0 alone, independent of Ωm, 0. The turnaround density thus offers a promising new method for exploiting upcoming large cosmological datasets.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 2020
- DOI:
- 10.1051/0004-6361/201937358
- arXiv:
- arXiv:2004.04395
- Bibcode:
- 2020A&A...638L...8P
- Keywords:
-
- cosmological parameters;
- large-scale structure of Universe;
- galaxies: clusters: general;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 5 pages, 3 figures, submitted to A&