RESEARCH AREAS
Explore our research topics
OUR RESEARCH AREAS
Observational Cosmology
Astrophysics and cosmology both play a role in the ongoing research on the distribution of dark matter within galaxies. Observations and cosmological simulations come to contradictory conclusions, and only a full understanding of systematic effects both in astrophysical and cosmological methods of analysis can hope to solve this puzzle.
Large-Scale Structures
This topic encompasses the use of large-scale structures to constrain the underlying theory of gravity by use of the growth factor and power spectra data, mainly by SDSS and BOSS collaborations.
Gravitational Physics
Studies of extended theories of gravity may provide unexpected features of well-established gravitational configurations such as black holes or neutron stars, such as hairy black holes and stars with non-Schwarzschild exterior solution. Moreover the existence of wormholes and the avoidance of singularities are also topics of interest in the theoretical side of this line of research.
Gravitational Waves
The new open window to the Universe that recent detection of gravitational waves provides, is explored in order to constrain even further the different alternatives to Einsteinian gravity which are studied in the community, shedding for instance some light to the scale of inflation and the abundance of primordial black holes.
Inhomogeneous Cosmology
The possible effects of inhomogeneity (small scale and large scale) on cosmological dynamics and observations is a key unresolved issue, as inhomogeneity might seriously affect the interpretation of observations of distant supernovae as implying the existence of dark energy. This project looks both at the effects of averaging and back-reaction on cosmological dynamics and observations, and at ways that large-scale inhomogeneity (a violation of the Copernican Principle) can be observationally tested. The effect of inhomogeneity on cosmological observations is also being investigated, specifically to determine the detailed geometry of the cosmos directly from observations, exploring the nature and evolution of structures in cosmology, studying inhomogeneous solutions of Einstein’s field equations and their applications to cosmology. Establishing the degree of cosmic homogeneity/inhomogeneity by analysing the data without the assumption of homogeneity.
Modified Gravity and Dark Energy
The aim of this research programme is to provide a systematic way of constraining alternative theories of gravity and dark energy models based on both theoretical and observational considerations. An understanding of the cosmological dynamics in these theories is an important step in this investigation, as this will enable us to obtain the key features of the Cosmic Microwave Background spectrum and determine the structure formation scenario. Consequently, we are developing a new generation of tools, which will help us find constraints on the form of the actual theory of gravity. Studies of solutions for stars in modified gravity are also underway.
Relativistic Plasma Dynamics
The interface between GR and Plasma Physics in general and the coupling between gravitational waves and electromagnetic fields, expected to occur in extreme astrophysical environments in particular are being investigated. When a gravitational wave (GW) passes through a magnetic field, it vibrates the magnetic field lines, creating electromagnetic (EM) radiation. Although this effect has been known for some time it remains a relatively unexplored area of physics. Virtually all stars have a strong magnetic field threading through and surrounding them. This field becomes immensely strong as the field lines are compressed as the star collapses to a Black Hole or neutron star. At many points in their lifetimes highly dense objects are powerful generators of GW, making them prime candidates for regions of the universe where the EM-GW interaction takes place to a significant degree. Initial investigations of the EM-GW interaction have provided indications of the physical processes we might expect. However, these effects have not yet been studied in a strong gravitational field, the most promising place where such an interaction is likely to happen. Since plasma physics in strong gravitational fields is known to have an extraordinarily complex set of modes and instabilities, this area is a fascinating and beautiful area of interdisciplinary research.