Schedule

14.00 : Fabio Riccioni (INFN, Rome)
Title : On defect branes and U-folds

14.45 : David Vergara (Universidad Nacional Autónoma de México, Mexico)
Title : Hidden Gauge Symmetry in Holomorphic Models

15:30 : Coffee, tea & cookies.

16.00 : Joaquim Gomis (Universitat de Barcelona, Spain)
Title : Canonical Realization of BMS Symmetry

16.45 : Fabrizio Rompineve (University of Heidelberg, Germany)
Title: Large Field Inflation and the Weak Gravity Conjecture

17.30 : Drinks

Abstracts

Fabio Riccioni: We review the classification of defect branes in maximal supergravity theories in various dimensions. Focusing in particular on the defect branes in eight dimensions, we analyse them as solutions of the compactified ten-dimensional IIB theory. Some of these solutions are not globally well-defined, because the metric in the internal space and the ten-dimensional dilaton are not single-valued. Such configurations are in general known as U-folds. Finally, we discuss the relation between some of these branes and a T-duality family of fluxes that has been recently classified.

David Vergara: We study the effect of a hidden gauge symmetry on complex holomorphic systems. For this purpose, we show that intrinsically any holomorphic system has this gauge symmetry. We establish that this symmetry is related to the Cauchy–Riemann equations, in the sense that the associated constraint is a first class constraint only in the case that the potential be holomorphic. As a consequence of this gauge symmetry on the complex space, we can fix the gauge condition in several ways and project from the complex phase-space to real phase space. Different projections are gauge related on the complex phase-space but are not directly related on the real physical phase-space. We also introduce this symmetry in the case of field theory.

Joaquim Gomis: We study the canonical realization of BMS symmetry for a free massive scalar field. We will construct an invariant scalar product for the generalized momenta. As a consequence we will introduce a quadratic Casimir with the supertranslations.

Fabrizio Rompineve: Waiting for the final observational verdict, there has recently been a lot of theoretical effort in constraining the realisation of Large Field Inflation in Quantum Gravity. In particular, no-go arguments based on the Weak Gravity Conjecture (WGC) have been proposed. In this talk, we first review the WGC and its recent applications to models of Axion Inflation. We then present a new model of large field inflation along a winding trajectory in the field space of two axionic fields, where the "axions"  originate from the complex structure moduli sector of a Calabi-Yau 3-fold at large complex structure. Istantonic corrections to the geometry generate an inflaton potential which realises Natural Inflation. We discuss the consequences of the WGC on our setup. Interestingly, our construction seems to realise a known loophole of recent no-go arguments: it is therefore a candidate for a model of large field inflation in string theory, compatible with the mild form of the WGC.