Event calendar file
State of the Universe
Title 1: Analytic covariance of the galaxy power spectrum ; Title 2: First astrophysical constraints on dark matter interactions with ordinary matter at low relative velocity
by Mr. Jay Wadekar (New York University)
Friday, January 3, 2020
from
to
(Asia/Kolkata)
at A304
at A304
| Description |
Abstract 1: A robust analysis of the covariance of the galaxy power spectrum is crucial for cosmological parameter estimation. The traditional process of obtaining the covariance involves simulating thousands of mocks. I will present an analytic approach for the covariance matrix which is more than four orders of magnitude faster than mocks. The dominance of shot noise at quasi-linear scales greatly simplifies the analytic approach and makes it useful for future surveys like DESI and Euclid. Abstract 2: I will present constraints on DM-ordinary matter interactions at v_{relative} ~ 17 km/s, by requiring that the heating/cooling due to DM interacting with gas in the Leo T dwarf galaxy not exceed the radiative cooling rate of the gas. This imposes strong limits on sub-GeV millicharged DM and also gives the strongest bounds to date on ultra-light hidden photon DM for the mass range 10-23 < mDM < 10-10 eV. |
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