Programma 12 Aprile

Dualitā e brane (L. Girardello)

Giulio Bonelli (SISSA Trieste)

D-branes on partial resolutions and flavoured matrix models

We will first review a carefull derivation of a generalized Dijkgraaf-Vafa constuction on appropriate smooth non compact CYs built as total spaces of holomorphic vector bundles over the Riemann sphere. This will be done by calculating the relevant B-model topological open string field (holomorphic Chern-Simons) partition function and showing how it reduces step by step to the appropriate (multi-)matrix model. We will further consider the reduction on singular CYs obtained by adding singular points on the sphere. We show that these additional singularities trigger the appearence of a flavour-like structure in the matrix model. In the singular DV case, we obtain the Argurio-Campos-Ferretti-Heise matrix model which has been tested to generate the quantum superpotential for N=1 unitary SYM with flavour.


Roberto Casero

Towards the string dual of N=1 SCQD-like theories

Abstract: The inclusion of flavor degrees of freedom in the string/gauge correspondence is an interesting and relevant problem in view of the construction of a dual theory of QCD. After a general introduction, we obtain supergravity plus branes solutions which we argue to be related to 4d N=1 SQCD with a quartic superpotential. The geometries depend on the ratio Nf/Nc which can be kept of order one, present a good singularity at the origin and are weakly curved elsewhere. We support our field theory interpretation by studying a variety of features like R-symmetry breaking, instantons, Seiberg duality, running of couplings, Wilson loops.


Gianguido Dall'Agata

Non-Kaehler attracting manifolds.

Abstract: The black hole attractor mechanism can be extended to describe generic critical points of the potentials coming from flux compactifications of IIB string theory on a Calabi-Yau manifold. We show that these "new attractors" can be used also in relation to the landscape of non-Kaehler vacua emerging in heterotic compactifications. In this framework we provide a description of the selection mechanism of the internal manifold as an attracting point in the space of possible geometric deformations.


Pietro Fre

Compattificazioni della M Teoria su tori twistati, Coomologia di Chevalley, FDA ed un teorema No Go.

Abstract: Vi č molto interesse per le compattificazioni della M teoria con flussi su varietā con G strutture ed in particolare su varietā gruppali non semisemplici. Si cerca la relazione tra i flussi e le algebre di gauge che emergono in bassa dimensione. In questo contesto ha suscitato molto interesse la possibilitā che l'algebra di gauge in D=4 non sia una semplice algebra di Lie ma una Free Differential Algebra. Usando tecniche coomologiche ho stabilito le condizioni per cui questo possa accadere in caso di varietā gruppali ed usando teoremi classici di algebre di Lie ho dimostrato in collaborazione con Mario Trigiante che per semplici compattificazioni senza sorgenti estese non esistono compattificazioni con flussi non banali su tori twistati e tanto meno non banali FDA in D=4. Rimane aperta la possibilitā di ottenere simili situazioni tramite l'uso di sorgenti e fattori di warp. Tuttavia l'analisi coomologica va in questo caso completamente rifatta ab initio.


Dario Martelli

Sasaki-Einstein geometry and AdS/CFT

The AdS/CFT correspondence motivates the study of Sasaki-Einstein manifolds, and their associated non-compact Calabi-Yau varieties. I will discuss various aspects of the relevant geometry, and their relation to properties of the dual superconformal field theories. In particular, I will discuss the geometric counterpart of "a-maximization" in terms of an optimisation problem in the geometry. I will mainly focus on the case of toric geometries and field theories, but will also describe recent work that extends these results beyond the toric realm.


Michela Petrini

Gauge/gravity duals and Generalised Complex Geometry

Abstract: L'idea e' di discutere l'applicazione del formalismo della Geometria Complessa Generalizzata allo studio delle soluzioni di supergravita' duali a teorie di gauge. Questo permette di avere una migliore comprensione della geometria di tali soluzioni e di trovarne di nuove.