What's the dark matter made of? Do we have any idea of the kind of particle that should constitute ~85% of the matter content of the Universe? In this talk, I...
The First Billion Years project: birthplaces of direct collapse black holes
We investigate the environment in which direct-collapse black holes may form by analysing a cosmological, hydrodynamical simulation that is part of the First...
The First Billion Years project: the impact of stellar radiation on the co-evolution of Populations II and III
With the first metal enrichment by Population III (Pop III) supernovae (SNe), the formation of the first metal-enriched, Pop II stars becomes possible. In turn...
Twenty years ago, no one convincingly knew the age or the size of theUniverse to within a factor of two. Ten years ago, everyone agreed onthose same two numbers...
The imprint of cosmological hydrogen recombination lines on the power spectrum of the CMB
We explore the imprint of the cosmological hydrogen recombination lines on the power spectrum of the cosmic microwave background (CMB). In particular, we focus...
The Metallicity of Pregalactic Globular Clusters: The Observational Consequences of the First Stars
We explore a scenario in which metal-poor globular clusters (GCs) are enriched by the first supernovae in the universe. If the first stars in a 107 Msolar dark...
The primordial abundance of 4He, YP, is one of the hottest themes in present-day astronomy, mostly due to its cosmological relevance. The disagreement between...
The primordial helium abundance and the number of neutrino families
Based on observations of HII regions and on the new computations of the recombination coefficients of the HeI lines by Porter el al. we obtain a primordial...
The Pristine survey - III. Spectroscopic confirmation of an efficient search for extremely metal-poor stars
The Pristine survey is a narrow-band, photometric survey focused around the wavelength region of the Ca II H&K absorption lines, designed to efficiently search...