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QUANTUM FIELD THEORY

Quantum Field Theory underlies our current understanding of all fundamental interactions and serves as a theoretical framework for the Standard Model of elementary particles, which describes the basic constituents of matter and forces among them in an economic and mathematically elegant way. The Standard Model has been tested to an unprecedented accuracy and makes highly accurate predictions for phenomena ranging from tiny quantum effects in electromagnetic processes to strong forces that keep atomic nuclei together.

Methods of Quantum Field Theory have many application beyond particle physics. Their utility in many-body physics has been recognized early on, and they now belong to the standard toolkit in Condensed-Matter Theory. Another area where Quantum Field Theory is becoming increasingly important is Cosmology. Many outstanding puzzles about the structure and history of the Universe, such as the existence of dark matter, an asymmetry between ordinary matter and anti-matter, and the origin of primordial inhomogeneities that eventually evolved into starts and galaxies are likely to find their solutions within the framework of Quantum Field Theory.

One feature that makes Quantum Field Theory so esthetically attractive, and at the same time powerfully predictive, is the prominent role of symmetries. Perhaps the most important symmetry principle from our modern point of view is gauge symmetry. The Standard Model of elementary particles is a gauge theory that encompasses the strong, electromagnetic and weak interactions. The discovery of the Higgs boson at the Large Hadron Collider reconfirmed the validity of the Standard Model up to the highest energies accessible on Earth.

Supersymmetry is another important principle that has played the key role in the developments in Quantum Field Theory in the last thirty years. Supersymmetry transforms particles bosons into fermions and, in a way, extends space-time by intrinsically quantum extra dimensions. Supersymmetry proved extremely useful in the strong-coupling domain of Quantum Field Theory. Strongly-coupled regime arises in Quantum Chromodynamics (QCD), the theory of strong interactions, at low energies, and in numerous condensed-matter systems. This regime is notoriously difficult to understand, but become comprehensible under the looking glass of supersymmetry. Supersymmetry has given us an insight into physics of strong interactions that cannot be studied by any other means and uncovered deep connections of Quantum Field Theory with String Theory and many areas of modern mathematics.

The High-Energy Physics group at Nordita explores different areas of Quantum Field Theory, ranging from its mathematical aspects to applications in particle phenomenology. Current activities are focussed on exact results in field theory at strong coupling, connections between Quantum Field Theory and String Theory, holographic duality, the physics of black holes, and on scattering amplitudes in gauge theories and quantum gravity.


This page was printed on 2024-03-29 from www.nordita.org/research/he/qft