Nuclear & Particle Astrophysics

How does matter behave under extreme dense conditions?

This group studies matter at extreme large temperatures, as those occurring a few microseconds after the Big Bang, and focuses on understanding the physics of compact stellar objects from its tiniest constituents.

Back to the Big Bang: the thermal period of the universe

There are some few physical scenarios in the Universe with extreme high density and/or temperature matter conditions, much higher than in any terrestrial environment. These scenarios are challenging our current understanding of how matter behaves and interacts in these situations, and has attracted the interest of both large experimental and theoretical communities of nuclear and particle physics, as well as of astrophysicists and cosmologists.

The matter of the universe some few microseconds after the Big Bang was made up of a mixture or soup of quarks and gluons, the so called quark gluon plasma. Matter under extreme dense conditions can also be found in compact stars. Neutron stars are supposed to be composed by neutrons, protons and electrons, although they might also contain unconfined quark matter in their core. High-precision X-ray astronomy from future space missions, such as NICER (Neutron star Interior Composition ExploreR) or eXTP (enhanced X-ray Timing and Polarimetry Mission), is expected to offer precise measurements of masses and radii and, thus, help us in understanding the microscopic composition of neutron stars.

Focus

The research of the group of Nuclear and Particle Astrophysics aims at understanding the behaviour of matter under extreme density and/or matter conditions. We mainly focus on understanding the physics of compact stellar objects from its tiniest constituents, thus connecting present knowledge of the physics of subatomic particles at extreme conditions of densities with astrophysical observations.

Our topics of research include:

Equation of state of dense phases in compact stellar objects (which allows us to constrain the mass/ratio relation of the star), including the interplay of dense matter with dark matter
Transport properties inside neutron stars (which allows us to understand the behaviour of their hydrodynamical modes, rotational properties, and cooling)
Magnetic fields

We also study matter at extreme large temperatures, such as those occurring a few microseconds after the Big Bang. Our topics of research include:

The properties of quarks and hadrons in hot and dense matter,
Effective descriptions of the dynamics of the hot quark-gluon plasma, which are studied in present particle accelerators, such as the FAIR/GSI, LHC/CERN or RHIC/BNL.