Research in Astrophysics

Early Universe Physics

Early Universe is nowadays probed with unprecedented precision by Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) experiments. This poses severe challenges to our comprehension of the physical processes occurred in the Early Universe, as well as the nature of the Dark Cosmological Components. The SISSA Astrophysics group is directly involved in operating (Planck, Ebex) and planned CMB and LSS (Euclid) observations, according to the following main directions:

Formation and Evolution of galaxies and black holes

Our team aims at investigating the complex process leading to the formation and evolution of galaxy and supermassive black holes throughout the history of the Universe. To this purpose, we develop physical models to interpret and understand the wealth of current observations concerning galaxies, relic black holes, and active galactic nuclei over the whole electromagnetic spectrum. Our team is strongly involved in ongoing international scientific projects based on the Planck and Herschel space-observatories and on the development of the upcoming Euclid mission. Our main research topics include:

Dark Matter

Dark matter is a main protagonist in Cosmology. Its presence, proven by observations, implies the existence of physics yet undiscovered, moreover such a component is likely to rule the formation and the evolution of any Cosmological Structure. In galaxies, groups and clusters of glaxies, the observed ordinary baryonic matter, gas and stars, had, over the whole history of the Universe, a complex interplay with this invisible component. The detailed lines of research are:

Gravitation theory

Almost 100 years after Einstein introduced General Relativity, the theory still remains puzzling. Systems were gravity is strong, such as compact stars and black holes, and the phenomena taking place in their vicinity can provide new insight in both astrophysics and fundamental physics. The thorny issues of quantum gravity and potentially even classical deviations from General Relativity are most pertinent than ever. The gravity theory group at SISSA is active in the following directions:

High Energy Astrophysics

The formation and the evolution of extremely compact stellar objects and Black Holes in the Universe are signaled by exceptional phenomena such as production of particles accelerated to energies much higher than those reachable by the most powerful accelerators on Earth. Often these particles are collimated in extremely energetic jets. Extraordinary X-ray and gamma-ray luminosity is also associated with these objects. High Energy Astrophysics is devoted to study the extremely energetic phenomena occurring in the Universe, in order to understand these extraordinary cosmic settings and to test the fundamental physics at its frontiers.

Large Scale Structure

Present Large Scale Structure and Galaxy Cluster simulations in cosmology are compared with data from existing and planned (Euclid) surveys, allowing to gain unprecedented insight into the role of hydrodynamics, the main properties and dynamics of the Dark Matter and Dark Energy, as well as to constrain Gravity Modifications. The LSS group at SISSA is active in the following directions:

Stellar Structure and Evolution

Stellar evolution keeps a unique role for deciphering the visible properties of the universe, from the solar neighborhoods to the primeval galaxies. A new Renaissance for the stellar structure theory is approaching, due to the challenging results of asteroseismology, that are disclosing the invisible star's secrets. Our group is involved in the following research topics: