A search for ultralight axions using precision cosmological data

作者：Hlozek, Renee; Grin, Daniel; Marsh, David J. E.^*; Ferreira, Pedro G.

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2015, 91(10): 103512.

DOI：10.1103/PhysRevD.91.103512

• DARK ENERGY SURVEY
• BARYON ACOUSTIC-OSCILLATIONS
• BACKGROUND POWER SPECTRUM
• HALO FORMATION
• SN 1987A
• MATTER
• GALAXIES
• PERTURBATIONS
• CONSTRAINTS
• SCALE

Ultralight axions (ULAs) with masses in the range 10(-33) eV <= m(a) <= 10(-20) eV are motivated by string theory and might contribute to either the dark-matter or dark-energy densities of the Universe. ULAs could suppress the growth of structure on small scales, lead to an altered integrated Sachs-Wolfe effect on cosmic microwave-background (CMB) anisotropies, and change the angular scale of the CMB acoustic peaks. In this work, cosmological observables over the full ULA mass range are computed and then used to search for evidence of ULAs using CMB data from theWilkinson Microwave Anisotropy Probe (WMAP), Planck satellite, Atacama Cosmology Telescope, and South Pole Telescope, as well as galaxy clustering data from the WiggleZ galaxy-redshift survey. In the mass range 10(-32) eV <= m(a) <= 10(-25.5) eV, the axion relic-density Omega(a) (relative to the total dark-matter relic density Omega(d)) must obey the constraints Omega(a)/Omega(d) <= 0.05 and Omega(a) h(2) <= 0.006 at 95% confidence. For m(a) greater than or similar to 10(-24) eV, ULAs are indistinguishable from standard cold dark matter on the length scales probed, and are thus allowed by these data. For m(a) less than or similar to 10(-32) eV, ULAs are allowed to compose a significant fraction of the dark energy.

• 出版日期2015-5-15