2015/11/30 by Difu Shi, C. M. Baugh, Carlton M. Baugh
Physics and Astronomy · #Astrophysics #Baryon acoustic oscillations #Black Holes and Theoretical Physics #COSMIC cancer database #Classical mechanics #Cold dark matter #Cosmic background radiation #Cosmic microwave background #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Lambda-CDM model #Matter power spectrum #Physical cosmology #Physics #Quantum mechanics #Quintessence #Redshift #Scalar field #Spectral density #Theoretical physics #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stw882
12 pages, 12 figures, Published in MNRAS after minor correction
openalex publication_date 2016/04/15 · arxiv created 2017/05/01 · arxiv updated 2017/05/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Early dark energy (EDE) models are a class of quintessence dark energy with a dynamically evolving scalar field which display a small but non-negligible amount of dark energy at the epoch of matter-radiation equality. Compared with a cosmological constant, the presence of dark energy at early times changes the cosmic expansion history and consequently the shape of the linear theory power spectrum and potentially other observables. We constrain the cosmological parameters in the EDE cosmology using recent measurements of the cosmic microwave background and baryon acoustic oscillations. The best-fitting models favour no EDE; here we consider extreme examples which are in mild tension with current observations in order to explore the observational consequences of a maximally allowed amount of EDE. We study the non-linear evolution of cosmic structure in EDE cosmologies using large-volume N-body simulations. Many large-scale structure statistics are found to be very similar between the Λ cold dark matter (ΛCDM) and EDE models. We find that EDE cosmologies predict fewer massive haloes in comparison to ΛCDM, particularly at high redshifts. The most promising way to distinguish EDE from ΛCDM is to measure the power spectrum on large scales, where differences of up to 15 per cent are expected.