2023 - SUMMER SEMESTER
Indian Institute of Science, Bangalore
Detecting low-mass primordial black holes as the dark matter candidate
Primordial black holes (PBHs) are one of the oldest and well-motivated dark matter candidates. PBHs can have a wide range in masses and their detection techniques vary (depending on their masses). I will be concentrating on the low-mass end of PBH masses (masses ~ 1016 g to 1018 g). I will discuss how one can detect the Hawking radiation from these objects. I will discuss the current constraints using various astrophysical observables like low-energy Galactic positrons, gamma-rays, and other observables. I will also discuss how near-future gamma-ray telescopes can discover low-mass PBH dark matter.
NLO Electric field correlators for the Dark Matter relic abundance
WIMPs at the TeV mass scale and above experience long-range force effects, which are known to play a crucial role for predicting the relic abundance precisely. One such effect is the existence of bound states in the spectrum. In the early Universe, they can form and subsequently decay through annihilation, leading to a further depletion of the total abundance. We review electroweakly charged dark matter and colored coannihilation scenarios as examples. To compute the formation of bound states at NLO (zero and finite temperature) in such scenarios, it turns out that the effort can be reduced to the evaluation of electric field correlators thanks to factorization. Our results for U(1) and SU(N) electric field correlators are presented, showing collinear finiteness and gauge invariance at NLO. Potential implications of enhanced bound-state formation rates due to the NLO effects are discussed.