1709.01278
Implications for the missing low-mass galaxies (satellites) problem from cosmic shear
Jimenez, Verde, Kitching
The number of observed dwarf galaxies, with DM mass <~1e11 Msun in the MW or the Andromeda galaxy does not agree with predictions from the successful LCDM paradigm. To alleviate this problem there has been a conjecture that there may be suppression of DM clustering on very small scales. However, the abundance of DM haloes outside the immediate neighborhood (The Local Group) does seem to agree with the expected abundance from the LCDM paradigm. Here, make the link between these problems and observations of WL cosmic shear, pointing out that cosmic shear can make significant statements about missing satellites problem in a statistical way. As an example and pedagogical application, use the recently measured small-scale matter PS from a spherical-Bessel analysis of current cosmic shear data that constrains the suppression of power on small-scales and thus indirectly estimates, on average, the abundance of DM haloes. In this example application find, on average, in a local region of ~Gpc^3 there is no significant small-scale power suppression implying that suppression of small-scale power is not a viable solution to the 'missing satellites problem' or, alternatively, that there is no 'missing satellite problem' for DM masses >5e9 Msun. Further analysis of current and future WL surveys will provide details on the power spectrum at scales much smaller than k>10 h/Mpc corresponding roughly to masses M<1e9 Msun.
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