Our understanding of the physical world at its most fundamental level relies strongly on the standard model of particle physics, which currently describes the interactions of elementary particles. This is a truly impressive theory since it encompasses length scales ranging from 10^{-17} cm to cosmological scales. The basic interactions explained in this model – electromagnetic, weak and strong – are responsible for all known fundamental physical phenomena. In order to connect our understanding of these interactions with observation, theoretical physicists use quantum field theory, a technical instrument which has produced definite predictions that have been tested with unprecedented precision over the previous decades. [+]

However, even though no significant deviation from this theory has yet been measured, the standard model leaves enough open questions so that it is generally accepted that this model cannot be an actual fundamental theory, but at most an intermediate (effective) one. Such questions include, for example, the reason why the masses of quarks show such spectacular differences. Moreover, we know from the fact that neutrinos mix and have non-zero masses that the standard model needs an extension, pointing to the possibility of a grand unified theory (GUT) at higher energies. The Higgs mechanism and a new state of matter, the quark gluon plasma, are two more unsolved problems for what theoretical particle physics is currently trying to give an explanation.

ICCUB activities cover an ample spectrum of the areas reported in the hep-th and quant-ph archives. [+]

String theory has inspired in recent times enormous activity in the gauge/string duality conjecture that allows a treatment for some strongly coupled theories in terms of a gravity dual. These techniques are being applied to the study of the quark-gluon plasma. In this domain of physics, techniques such as the gauge/string duality meet nuclear phenomenology and effective theories and there is substantial cross-fertilization.

Duality techniques are also applied to a variety of strongly coupled condensed matter systems and in problems of quantum information.

Supersymmetric field theories are studied seeking to understand the ultraviolet behavior of theories with extended supersymmetries and deriving exact results.

In another line, some theories of emergent gravity have been proposed. There are are also obvious connections with cosmology and the physics of black holes. Researchers in this group share many common interests with the Gravitation and Cosmology one.

The research in quantum information can be roughly divided into six topics: multiparticle entanglement; low energy properties of many-body quantum systems; quantum error correction; topological order; ultra-cold gases; and quantum simulation.

The quantum information researchers at the ICCUB are in close collaboration with some of the groups at ICFO.