The Fokker-Planck formalism for closed bosonic strings by Nobuyuki Ishibashi

This is an online seminar series on string field theory (SFT) and related topics (worldsheet theory, string amplitudes, compactifications, homotopy algebras…) on Thursday every 2 weeks. Talks are 1.5 hours long: the recommended format is a general introduction of 30 min for students and non-specialists (especially before technical talks), followed by 1 hour of talk discussions intertwined. Abstract: Every Riemann surface with genus g and n punctures admits a hyperbolic metric, if 2 g - 2 n is greater than 0. Such a surface can be decomposed into pairs of pants whose boundaries are geodesics. We construct a string field theory for closed bosonic strings based on this pants decomposition. In order to do so, we derive a recursion relation satisfied by the off-shell amplitudes, using the Mirzakhani’s scheme for computing integrals over the moduli space of bordered Riemann surfaces. The recursion relation can be turned into a string field theory via the Fokker-Planck formalism. The Fokker-Planck Hamilto