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Title: Long-lived light mediator to dark matter and primordial small scale spectrum

We calculate the early universe evolution of perturbations in the dark matter energy density in the context of simple dark sector models containing a GeV scale light mediator. We consider the case that the mediator is long-lived, with lifetime up to a second, and before decaying it temporarily dominates the energy density of the universe. We show that for primordial perturbations that enter the horizon around this period, the interplay between linear growth during matter domination and collisional damping can generically lead to a sharp peak in the spectrum of dark matter density perturbation. As a result, the population of the smallest DM halos gets enhanced. Possible implications of this scenario are discussed.
Authors:
 [1]
  1. Walter Burke Institute for Theoretical Physics,California Institute of Technology, Pasadena, CA 91125 (United States)
Publication Date:
OSTI Identifier:
22458434
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 05; Other Information: PUBLISHER-ID: JCAP05(2015)008; OAI: oai:repo.scoap3.org:10207; cc-by Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
Sponsoring Org:
SCOAP3, CERN, Geneva (Switzerland)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; DISTURBANCES; ENERGY DENSITY; GALACTIC EVOLUTION; GEV RANGE; NONLUMINOUS MATTER; SPECTRA; UNIVERSE; VISIBLE RADIATION