Jonathan Cornell
(University of Cincinnati)
26/09/2018, 14:00
Cosmology & Astroparticle Physics
There is a long-standing discrepancy between the neutron lifetime measured from trapped neutrons versus those decaying in flight. In this talk, I will give an brief description of the experimental status of this puzzle and describe recent proposals to explain it by allowing the neutron to decay into hidden sector particles. In particular, I will focus on a scenario in which the neutron decays...
Dr
Rebecca Leane
(MIT)
26/09/2018, 14:20
Cosmology & Astroparticle Physics
The Galactic Center GeV excess is firmly detected. While there is statistical evidence suggesting the excess originates largely from point sources, its interpretation as a signal of annihilating dark matter has not been conclusively ruled out. We examine the degree to which assumptions about the diffuse modeling and source populations could affect non-Poissonian template fitting methods that...
Dr
Raghuveer Garani
(Universite Libre De Bruxelles)
26/09/2018, 14:40
Cosmology & Astroparticle Physics
If Dark Matter (DM) interacts with nucleons and/or electrons it can be trapped in celestial bodies. For a Neutron Star (NS), DM accumulating in the center could form a core which could further gravitationally collapse into a black hole. The requirement that such collapses do not occur gives constraints on the DM mass and interactions. Such phenomena crucially depends on the amount of DM that...
Mr
Sebastian Hoof
(Imperial College London)
26/09/2018, 15:00
Cosmology & Astroparticle Physics
One of the two possible scenarios for the Peccei-Quinn symmetry is to break before the end of inflation without being restored afterwards. In this case, the axion field is homogeneous across the observable universe and its initial field value is random. A Bayesian analysis of this scenario can quantify the well-known existence of “natural” values for the initial misalignment angle and axion...
Andreas Pargner
(Karlsruhe Insitute of Technology)
26/09/2018, 15:15
Cosmology & Astroparticle Physics
We present a semi-analytical method to calculate the average axion energy density as well as the power spectrum of density fluctuations when vacuum re-alignment happens after inflation. Furthermore, we develop a modified Press & Schechter approach, suitable to describe the collapse of non-linear density fluctuations during radiation domination. This allows us to make a prediction for the...
Dr
David Marsh
(University of Goettingen)
26/09/2018, 15:30
Cosmology & Astroparticle Physics
Antiferromagnetically doped topological insulators (A-TI) are among the candidates to host dynamical axion fields and axion-polaritons; weakly interacting quasiparticles that are analogous to the dark axion, a long sought after candidate dark matter particle. Here we demonstrate that using the axion quasiparticle and antiferromagnetic fluctuations in A-TI's in conjunction with low-noise...
