Speaker
Dr
Pavel Buividovich
(Regensburg University)
Description
I present a general framework for constructing Diagrammatic Monte-Carlo algorithms for large-N quantum field theories, which is based on the stochastic solution of the full untruncated hierarchy of Schwinger-Dyson equations and is an extension of the approach proposed in arXiv:1104.3459, arXiv:1009.4033. The algorithms are capable of constructing both weak- or strong-coupling expansions which are convergent at large N and asymptotic 1/N expansions. We illustrate the application of the algorithm on the examples of the planar phi^4 theory, U(N) sigma model and strong-coupling QCD in the Veneziano limit at finite density. In the latter cases of lattice field theories with U(N) degrees of freedom, simulations in the weak-coupling regime are hindered by a sign problem. We discuss possible ways to overcome these problems, e.g. using the "bold" diagrammatic Monte-Carlo.
Primary author
Dr
Pavel Buividovich
(Regensburg University)