Seminário de Teoria Quântica do Campo Topológica  

06/12/2007, 15:30 — 16:30 — Sala P3.10, Pavilhão de Matemática
Ugo Bruzzo, International School for Advanced Studies (SISSA), Trieste

Instantons and framed bundles on rational surfaces

The talk concerns a correspondence between framed instantons on the one-point compactification of an affine complex surface $X$, and framed holomorphic bundles on a projective completion of $X$. This correspondence is known for $X$ the affine plane (Donaldson) and $X$ the affine plane blown up at a point (King). After reviewing these cases, I will discuss possible generalizations (basically, when the projective completion is a rational surface). I will also spend some words on instanton countings on these surfaces. Physically this corresponds to studying the Nekrasov partition function for topological super Yang-Mills theories on $X$.