#### Gravitation and Cosmology

General Relativity — Einstein’s theory of gravity — predicts many fascinating phenomena, such as black holes and gravitational waves, whose existence has spectacularly been confirmed recently. It also provides the basis to our understanding of the Universe and its evolution at the largest scales. The standard cosmological model has been developed into a very accurate theory of the dynamics of the Universe, both at the largest observable distances and back in time to almost its very beginning.
[+]

This progress has not only given us a remarkably detailed and accurate understanding of the cosmos, but, more excitingly, it has brought us face to face with new challenges at an even deeper level. Could the accelerated expansion of the Universe be due to a "dark energy" that permeates it with negative pressure? And what is the enigmatic dark matter that holds galaxies together and controls the formation of structure in the Universe? Do these mysteries point to new particle physics beyond the Standard Model, or are they instead harbingers of a failure of Einstein’s theory at large scales? Can the new gravitational wave astronomy help resolve these issues? How well do we understand the extreme distortion of space and time that occurs when two black holes collide? Will the gravitational waves generated in these collisions lead us to a new paradigm for these perplexing objects?

Indeed, we already know that Einstein's General Relativity theory is an incomplete theory. Its inconsistency with quantum mechanics requires the formulation of a new paradigm, a quantum theory of gravity, that allows us to understand the structure of spacetime at its most fundamental level. The most fruitful approach in this search has resulted from combining ideas from String Theory — a naturally quantized theory of gravity — together with tantalizing glimpses from the study of quantum black holes. The "holographic principle" has emerged as a powerful, though not yet fully understood, framework to overcome the limitations of conventional quantum field theory approaches to gravity. In a surprising turn of events, it has also given us a radical reformulation of some of the most difficult quantum systems (such as quark gluon plasmas) in terms of the "dual" physics of black holes in higher-dimensional spacetimes.

##### ICCUB Contribution

ICCUB researchers work in a broad spectrum of directions in gravitation and theoretical cosmology. Research is focused on: black holes in most of its aspects; inflationary models, cosmology of the early and present universe, and semiclassical gravity; holography in quantum gravity and the gauge/gravity correspondence.

##### Lines of Research

- Dark matter and dark energy in cosmology and in particle physics
- Quantum and semiclassical gravity
- Black holes: classical, quantum, stringy, astrophysical, and primordial
- Holographic principle in black holes and cosmology
- Inflation and the early universe

##### Members