Properties of gauge theories from D branes

by Paolo Di Vecchia (NORDITA)

Tuesday 11 Oct 2005, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

We will consider D branes having less supersymmetric and non-conformal gauge theories living on their world-volume and by constructing their corresponding classical solutions and using some gauge/gravity relations we will derive some perturbative properties of these gauge theories as the beta-function and the chiral anomaly. We will show that this is a consequence of the absence of threshold corrections to the gauge coupling constants. Then we will show that, if the classical solution is regular everywhere, we can also derive non-perturbative properties such as the gaugino condensate. In the last part of this seminar we will consider D branes having on their world-volume non-supersymmetric gauge theories such as the so-called "orientifold field theories" and we will show that in these cases the classical solution reproduces the correct gauge coupling constant only for a large number of colours (N -> infinity), while the theta-angle is correctly given for any value of N.