Paul Frederik Depta

TL;DR: In this article, a detailed evaluation of BBN bounds on the annihilation cross section of dark matter with a mass $1\,\text{MeV}, m_\chi \lesssim 1\, \text{GeV} was performed.

Abstract: Axion-like particles with masses in the keV-GeV range have a profound impact on the cosmological evolution of our Universe, in particular on the abundance of light elements produced during Big Bang Nucleosynthesis. The resulting limits are complementary to searches in the laboratory and provide valuable additional information regarding the validity of a given point in parameter space. A potential drawback is that altering the cosmological history may potentially weaken or even fully invalidate these bounds. The main objective of this article is therefore to evaluate the robustness of cosmological constraints on axion-like particles in the keV-GeV region, allowing for various additional effects which may weaken the bounds of the standard scenario. Employing the latest determinations of the primordial abundances as well as information from the cosmic microwave background we find that while bounds can indeed be weakened, very relevant robust constraints remain.

TL;DR: In this paper, the authors show that with large initial clustering the problem is exacerbated and constraints on primordial black hole dark matter become overwhelmingly strong, and that the effect of such clustering on the dark matter of a binary black hole merger becomes even stronger.

TL;DR: In this paper, the authors revise and update model-independent constraints from Big Bang Nucleosynthesis on MeV-scale particles which decay into photons and/or electron-positron pairs.

TL;DR: In this article, a detailed evaluation of BBN bounds on the annihilation cross section of dark matter with a mass $1\,\text{MeV}, m_\chi \lesssim 1\, \text{GeV} was performed.