Date Mar 28, 2018, 1:30 pm – 1:30 pm Location PCTS Seminar Room Share on X Share on Facebook Share on LinkedIn Speaker Shiroman Prakash Affiliation Dayalbagh Educational Institute, Agra Presentation "A Review of Bifundamental Chern-Simons Theories and the M/N Expansion" Details Event Description In this talk we will review some results and conjectures about non-supersymmetric bifundamental $U(N)\timesU(M)$ Chern-Simons coupled to matter. It is an apparently unique feature of three-dimensions that one can easily define a variety of non-supersymmetric lines of conformal fixed points via the Chern-Simons kinetic term for a gauge field. An interesting class of conformal fixed points are those based on l $U(N)\timesU(M)$ gauge groups coupled to matter transforming as bifundamental representation, which can be thought of as non-supersymmetric generalizations of the ABJ(M) theories. When $M \ll N$ these theories are effectively vector models, and are solvable in the large $N$ limit. When $M=N$ the theories are effectively large $N$ matrix (or adjoint) models and cannot be solved at strong coupling. Perturbation theory in the parameter $M/N$ takes one away from the solvable large $N$ vector model towards the unsolvable (but more interesting) large $N$ matrix model. A holographic dual description, when $M \ll N$, would be a theory of higher spin gauge fields (with extra $U(M)$ indices), and the parameter $M/N$ plays the role of a gravitational 't Hooft coupling. We will review some of the few calculations in the $M/N$ expansion that have been carried out, show how the existence of some non-supersymmetric bifundamental CFT's can be ruled out, and point out various open problems in the field. We may briefly also discuss similar expansions for $U(N) \times O(D) \times U(M)$ tensor models.