Triangle Seminars
Wednesday, 8 May 2019
Duality invariant cosmology to all orders in alpha prime
Olaf Hohm
(Humboldt, Berlin)
Abstract:
I discuss the higher-derivative \alpha' corrections
in the reduction to one dimension (cosmic time)
that is relevant for the dynamics of cosmological backgrounds.
In this setting string theory is known to be duality invariant
under O(d,d), which makes it possible to completely classify all
\alpha' corrections. I discuss some generic features of the
\alpha' completed Friedmann equations and show that there are
duality invariant theories that allow for de Sitter solutions
that are non-perturbative in \alpha', suggesting that string theory
may permit de Sitter vacua in this novel fashion.
I discuss the higher-derivative \alpha' corrections
in the reduction to one dimension (cosmic time)
that is relevant for the dynamics of cosmological backgrounds.
In this setting string theory is known to be duality invariant
under O(d,d), which makes it possible to completely classify all
\alpha' corrections. I discuss some generic features of the
\alpha' completed Friedmann equations and show that there are
duality invariant theories that allow for de Sitter solutions
that are non-perturbative in \alpha', suggesting that string theory
may permit de Sitter vacua in this novel fashion.
Posted by: IC
Thursday, 9 May 2019
Infrared enhancement of supersymmetry in four dimensions
Simone Giacomelli
(Oxford)
Abstract:
In this seminar I will discuss a recently-found class of RG flows in four dimensions exhibiting enhancement of supersymmetry in the infrared, which provides a lagrangian description of several strongly-coupled N=2 SCFTs. The procedure involves starting from a N=2 SCFT, coupling a chiral multiplet in the adjoint representation of the global symmetry to the moment map of the SCFT and turning on a nilpotent expectation value for this chiral. We show that, combining considerations based on 't Hooft anomaly matching and basic results about the N=2 superconformal algebra, it is possible to understand in detail the mechanism underlying this phenomenon and formulate a simple criterion for supersymmetry enhancement.
In this seminar I will discuss a recently-found class of RG flows in four dimensions exhibiting enhancement of supersymmetry in the infrared, which provides a lagrangian description of several strongly-coupled N=2 SCFTs. The procedure involves starting from a N=2 SCFT, coupling a chiral multiplet in the adjoint representation of the global symmetry to the moment map of the SCFT and turning on a nilpotent expectation value for this chiral. We show that, combining considerations based on 't Hooft anomaly matching and basic results about the N=2 superconformal algebra, it is possible to understand in detail the mechanism underlying this phenomenon and formulate a simple criterion for supersymmetry enhancement.
Posted by: QMW