Quantum field theory and supersymmetry
Field Theory
Topics studied in the group include: conformal and topological theories with boundary, in particular their geometrical aspects and applications (K. Gawedzki), supersymmetric field theories, in particular supergravity, YangMills theory with extended supersymmetry, lowdimensional theories (F. Delduc, M. Magro, H. Samtleben).
String Theory
String theory is a theory to describe nature at the smallest length scales. It replaces the concept of pointlike elementary particles or local fields by extended stringlike objects. It is at the heart of the unification of the different fundamental interactions and has had tremendous impact on our understanding of quantum field theories, gravitational interactions and geometry. Many research activities of our group are centered around various aspects and applications of this theory.
Conformal Field Theory
There has been a constant progress in twodimensional quantum field theory stimulated by the applications to classical and quantum statistical mechanics, condensed matter and string theory. We have developed an original geometric approach to the WZW sigma models of conformal field theory, based on the geometry of gerbes and gerbe modules that permits to tackle the global aspects of conformal sigma models.
Supersymmetry
Supersymmetry is a symmetry that exchanges bosonic and fermionic degrees of freedom. It plays a prominent role in string theory and for the understanding of the structure of divergencies in quantum field theories. In particular, we study supersymmetric theories in low dimensions, including models of superconformal quantum mechanics.
Supergravity
At low energies and after compactification of the extra dimensions, string theory is described by effective field theories that combine gravity, supersymmetry and gauge symmetry, socalled gauged supergravities. Our research focusses on the construction and classification of these theories in various spacetime dimensions and their applications to (nongeometric) flux compactifications. Modern developments in generalized and exceptional geometry provide powerful tools for the study of string compactifications.
AdS / CFT correspondence
The AdS / CFT correspondence is a conjectured holographic duality between particular fourdimensional superconformal gauge theories (CFT) and string theory on Antide Sitter (AdS) backgrounds. A well established example is the maximally supersymmetric case for which the gauge theory is N=4 super YangMills theory. The integrability of the underlying models plays a key role in this correspondence. We investigate the algebraic properties underlying the classical integrability of the relevant nonlinear sigmamodels. Modern developments include the construction of integrable deformations of these sigmamodels.
Selected Publications

GreenSchwarz Mechanism for String Dualities, C. Eloy, O. Hohm, and H. Samtleben, Phys. Rev. Lett. 124, 091601 (2020). [arXiv:1912.01700]

Integrable coupled sigmamodels, F. Delduc, S. Lacroix, M. Magro, and B. Vicedo, Phys. Rev. Lett. 122, 041601 (2019). [arXiv:1811.12316]

Exceptional Form of D=11 Supergravity, O. Hohm and H. Samtleben, Phys. Rev. Lett. 111, 231601 (2013). [arXiv:1308.1673]

Consistent Type IIB Reductions to Maximal 5D Supergravity, A. Baguet, O. Hohm and H. Samtleben, Phys. Rev. D 92, 065004 (2015). [arXiv:1506.01385]

Integrable deformation of the AdS_{5} x S^{5 }superstring action, F. Delduc, M. Magro and B. Vicedo, Phys. Rev. Lett. 112, 051601 (2014). [arXiv:1309.5850]