collaborators

6 papers

astro-ph.CO2026

Fine-tuning in mixed Dark Matter models with Primordial Black Hole relics

Amirah Aljazaeri, Christian T. Byrnes

We investigate the fine-tuning of a tripartite dark matter (DM) scenario involving ultra-light primordial black holes (PBHs), whose evaporation before Big Bang Nucleosynthesis leav…

astro-ph.IM2026

aurel: A Python package for automatic relativistic calculations

Robyn L. Munoz, Christian T. Byrnes, Will J. Roper

\texttt{aurel} is an open-source Python package designed to \emph{au}tomatically calculate \emph{rel}ativistic quantities. It uses an efficient, flexible and user-friendly caching…

astro-ph.CO2025

Primordial black holes in Randall-Sundrum: Cosmological signatures

Itzi Aldecoa-Tamayo, Christian T. Byrnes, David Seery

We reconsider primordial black hole physics in Randall-Sundrum Type-II universes, focusing on constraints from cosmological and astrophysical observables. We pay particular attenti…

astro-ph.CO2025

Comprehensively Constraining Ultra-Light Primordial Black Holes Through Relic Formation and Early Mergers

Amirah Aljazaeri, Christian T. Byrnes

We investigate constraints on the least explored, smallest mass scales of primordial black holes (PBHs), which evaporate prior to Big Bang Nucleosynthesis (BBN). Our study examines…

astro-ph.CO2025

Curvaton in light of the ACT results

Christian T. Byrnes, Marina Cortês, Andrew R. Liddle

The latest results from the Atacama Cosmology Telescope Collaboration have moved the preferred perturbation spectral index closer towards one. We reanalyse constraints…

astro-ph.CO2025

Robust μ-distortion constraints on primordial supermassive black holes from cubic (gNL) non-Gaussian perturbations

Xavier Pritchard, Christian T. Byrnes, Julien Lesgourgues +1

We make the first calculation of the spectral distortion constraints on the primordial curvature power spectrum in the limit of large cubic non-Gaussianity. This calculation involv…