Cosmology
Various research activities are conducted at the DFA, covering various aspects of cosmology. Some of these are outlined below.
The dark universe: dark matter and dark energy
Faculty: Antonino Del Popolo,Andrei A. Mesinger,Giuseppe Puglisi
Only ~5% of the Universe is ordinary matter; the rest is dark matter (~27%) and dark energy (~68%), both still unknown. The presence of Dark matter is indirectly inferred from its gravitational effects as well as the Cosmic Microwave Background, while Dark energy explains the observed accelerated expansion of our Universe. However, we still do not understand the nature of either components. In Catania we are working on observable signatures of the dark sector, throughout cosmic time.
The primordial Universe
Faculty: Giuseppe Puglisi
The Cosmic Microwave Background (CMB) is the earliest observable image of the Universe, about 380,000 years after the Big Bang. The tiny fluctuations in the CMB represents the link between the largest structures we observe today and the Big Bang. In fact, they were produced as quantum fluctuations 1e-34 s after the Big Bang (when the Universe was 1e-28 times the size it is today). What physical mechanism produced them? We are not very sure yet! But the next-generation of ground and space-based CMB observatories will surely answer some of these fundamental questions.
The dawn of the first galaxies
Faculty: Andrei A. Mesinger
Sometime after the Big Bang, primordial gas condensed into the first stars and galaxies. These earliest structures are too distant and too faint to be seen directly, and yet they had a transformative impact on our Universe. Their light permeated space in complex patterns, eventually heating and ionizing almost every atom in the Universe, culminating in its final phase change: the Epoch of Reionization. We know almost nothing about this mysterious “Cosmic Dawn”. Luckily, current and upcoming telescopes are starting to provide datasets of unmatched scientific potential. In Catania we are interpreting these observations with state-of-the-art simulations and cutting-edge data analysis, in order to learn about galaxy formation and fundamental physics.
Tracing the Universe's Chemical DNA
Faculty: Fiorenzo Vincenzo
The elements and molecules that we see in nearby and distant galaxies are a result of generations of star formation, evolution, and death. As such, their abundances can tell us about long-dead stellar populations. We use large astronomical datasets combined with theoretical approaches to study chemical abundances in stars and galaxies, linking them to their physical properties. Our work focuses on the origins of elements, the processes shaping galaxy formation and evolution across different cosmic environments, and the internal mechanisms affecting stellar surface abundances.
Machine learning for Cosmology
Faculty: Andrei A. Mesinger,Giuseppe Puglisi
Machine learning has become an important tool in cosmology, enabling the analysis of large and complex datasets from simulations and observations. If properly trained, neural networks can detect patterns that are difficult to capture with traditional methods, as well as speed up complex calculations by orders of magnitude. Researchers in Catania are developing cutting-edge machine learning tools to make simulations more efficient, extract more information from data, and interpret data in ways never before thought possible.
