Dr
Carlos Tamarit
(Technische Universität München)
25/09/2019, 16:30
Cosmology & Astroparticle Physics
High-scale axion models are sensitive to CMB isocurvature bounds, which are thought to rule out scenarios with an axion decay constant fA above 10^14 GeV. This would be incompatible with grand unification scenarios featuring an axion with fA related to the unification scale, which could otherwise be primary targets for future experiments like CASPER and ABRACADABRA. In view of the above, we...
Dr
Martin Vollmann
(TUM)
25/09/2019, 16:45
Cosmology & Astroparticle Physics
A particularly promising prediction of several wimp DM models is the quasi-monochromatic emission of gamma rays due to their pair-annihilation in e.g. the innermost part of the Milky Way. High energy gamma-ray fluxes due to such annihilation processes are naively suppressed by the inverse-squared dependence on the heavy DM mass and by the fact that the cross section is loop-suppressed....
Kai Urban
(TUM)
25/09/2019, 17:05
Cosmology & Astroparticle Physics
For heavy electroweak dark matter, the resummation of large quantum corrections due to long-range potentials (the "Sommerfeld effect") is crucial in determining the precise annihilation cross-section. In this talk, I will consider the one-loop correction to the potential which provides the leading non-relativistic correction to the Sommerfeld effect in the case of wino or wino-like dark matter...
Mr
Tobias Binder
(Kavli IPMU)
25/09/2019, 17:20
Cosmology & Astroparticle Physics
The thermal decoupling description of multi-TeV scale dark matter (and co-annihilating partners) is reconsidered. In several works it has been pointed out that the inclusion of quantum mechanical effects in the computation of the thermal relic abundance is in certain cases required in order to make a precise determination of the upper bound on the DM mass. One of these quantum mechanical...
Dr
Stefan Vogl
(Max-Planck-Institut für Kernphysik)
25/09/2019, 17:35
Cosmology & Astroparticle Physics
Chemical equilibrium is a commonly made assumption in the freeze-out calculation of coannihilating dark matter. We explore the possible failure of this assumption and find a new conversion-driven freeze-out mechanism. Considering a representative simplified model inspired by supersymmetry with a neutralino- and sbottom-like particle we find regions in parameter space with very small couplings...
Dr
Giorgio Arcadi
(University of Rome 3)
25/09/2019, 17:55
Cosmology & Astroparticle Physics
We ilustrate an accurate numerical Analysis of the scenario of real scalar dark matter with negligible coupling with the SM states. Assuming that the DM is produced during inflation and can reach at least kinetic Equilibrium due to its self-coupling, we illustrate a fully relativistic analysis of dark matter evolution, thermalization conditions and different freeze– out regimes, including the...
Mr
Marco Hufnagel
(DESY Hamburg)
25/09/2019, 18:10
Cosmology & Astroparticle Physics
Meta-stable dark sector particles decaying into electrons or photons may non-trivially change the Hubble rate, lead to entropy injection into the thermal bath of Standard Model particles and may also photodisintegrate light nuclei formed in the early universe. We study generic constraints from Big Bang Nucleosynthesis on such a setup, with a particular emphasis on MeV-scale particles which are...
