Cosmic Mach Number: a sensitive probe for the growth of structure
- Kavli Institute for Cosmology and Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom)
- Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ (United States)
- Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)
We investigate the potential power of the Cosmic Mach Number (CMN), which is the ratio between the mean velocity and the velocity dispersion of galaxies as a function of cosmic scales, to constrain cosmologies. We first measure the CMN from 4 catalogs of galaxy peculiar velocity surveys at low redshift (z element of [0.002,0.03]), and use them to contrast cosmological models. Overall, current data is consistent with the WMAP7 ΛCDM model. We find that the CMN is highly sensitive to the growth of structure on scales k element of [0.01,0.1] h/Mpc in Fourier space. Therefore, modified gravity models, and models with massive neutrinos, in which the structure growth generically deviates from that of the ΛCDM model in a scale-dependent way, can be well differentiated from the ΛCDM model by using future CMN data.
- OSTI ID:
- 22280010
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2012, Issue 06; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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