Dark matter equation of state through cosmic history

0502007 - FZÚ 2019 RIV US eng J - Journal Article
Kopp, Michael - Skordis, Constantinos - Thomas, D.B. - Ilić, Stephane
Dark matter equation of state through cosmic history.
Physical Review Letters. Roč. 120, č. 22 (2018), s. 1-6, č. článku 221102. ISSN 0031-9007. E-ISSN 1079-7114
EU Projects: European Commission(XE) 617656 - THEMODS
Institutional support: RVO:68378271
Keywords : cosmic background radiation * cosmological model * parameter space * constituent * history * baryon
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 9.227, year: 2018

Cold dark matter is a crucial constituent of the current concordance cosmological model. Having a vanishing equation of state (EOS), its energy density scales with the inverse cosmic volume and is thus uniquely described by a single number, its present abundance. We test the inverse cosmic volume law for dark matter (DM) by allowing its EOS to vary independently in eight redshift bins in the range z=105 and z=0. We use the latest measurements of the cosmic microwave background radiation from the Planck satellite and supplement them with baryon acoustic oscillation (BAO) data from the 6dF and SDSS-III BOSS surveys and with the Hubble Space Telescope (HST) key project data. We find no evidence for nonzero EOS in any of the eight redshift bins. With Planck data alone, the DM abundance is most strongly constrained around matter-radiation equality ωgeq=0.1193-0.0035+0.0036 (95% C.L.), whereas its present-day value is more weakly constrained: ωg(0)=0.16-0.10+0.12 (95% C.L.).
Permanent Link: http://hdl.handle.net/11104/0293970