PIRSA:17010055

Cores in Dwarf Galaxies from Fermi Repulsion

APA

Unwin, J. (2017). Cores in Dwarf Galaxies from Fermi Repulsion. Perimeter Institute for Theoretical Physics. https://pirsa.org/17010055

MLA

Unwin, James. Cores in Dwarf Galaxies from Fermi Repulsion. Perimeter Institute for Theoretical Physics, Jan. 31, 2017, https://pirsa.org/17010055

BibTex

          @misc{ scivideos_PIRSA:17010055,
            doi = {10.48660/17010055},
            url = {https://pirsa.org/17010055},
            author = {Unwin, James},
            keywords = {Particle Physics},
            language = {en},
            title = {Cores in Dwarf Galaxies from Fermi Repulsion},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2017},
            month = {jan},
            note = {PIRSA:17010055 see, \url{https://scivideos.org/pirsa/17010055}}
          }
          

James Unwin University of Illinois at Chicago

Talk numberPIRSA:17010055
Source RepositoryPIRSA
Collection

Abstract

Cold dark matter provides a remarkably good description of cosmology and astrophysics. However, observations connected with small scales might be in tension with this framework. In particular, structure formation simulations suggest that the density profiles of dwarf spheroidal galaxies should exhibit cusps, in contrast to observations. I will show that Fermi repulsion can explain the observed cored density profiles in dwarf galaxies for sub-keV fermionic dark matter.  While in conventional dark matter scenarios, such sub-keV thermal dark matter would be excluded by free streaming bounds, I will argue that these constraints are ameliorated in models with dark matter at lower temperature than conventional thermal scenarios. Finally, I will outline a class in which the dark matter typically has a lower temperature than the thermal expectation, dubbed Flooded Dark Matter, and discuss aspects of model building.