06/12/2007, 15:30 — 16:30 — Room P3.10, Mathematics Building
Ugo Bruzzo, International School for Advanced Studies (SISSA), Trieste
Instantons and framed bundles on rational surfacesThe talk concerns a correspondence between framed instantons on the one-point compactification of an affine complex surface , and framed holomorphic bundles on a projective completion of . This correspondence is known for the affine plane (Donaldson) and 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 .