On the Virasoro six-point identity block and chaos
Tarek Anous, Felix M. Haehl
备注:
29 pages, 5 figures, v2 minor typos fixed, including corrected factors in the definition of $\tilde{T}$. Discussion on the symmetries of the blocks were updated. v3: typos fixed
We study six-point correlation functions in two dimensional conformal field theory, where the six operators are grouped in pairs with equal conformal dimension. Assuming large central charge $c$ and a sparse spectrum, the leading contribution to this correlation function is the six-point Virasoro identity block - corresponding to each distinct pair of operators fusing into the identity and its descendants. We call this the star channel. One particular term in the star channel identity block is the stress tensor $SL(2,\mathbb{R})$ (global) block, for which we derive an explicit expression. In the holographic context, this object corresponds to a direct measure of nonlinear effects in pure gravity. We calculate additional terms in the star channel identity block that contribute at the same order at large $c$ as the global block using the novel theory of reparametrizations, which extends the shadow operator formalism in a natural way. We investigate these blocks' relevance to quantum chaos in the form of six-point scrambling in an out-of time ordered correlator. Interestingly, the global block does not contribute to the scrambling mode of this correlator, implying that, to leading order, six-point scrambling is insensitive to the three-point graviton coupling in the bulk dual. Finally, we compare our findings with a different OPE channel, called the comb channel, and find the same result for the chaos exponent in this decomposition.
Virasoro Conformal Blocks and modular functor from Liouville CFT
Beijing International Center for Mathematical Research, Peking University(北京大学北京国际数学研究中心);Université Paris-Saclay, CNRS, Laboratoire de mathématiques d’Orsay(巴黎萨克雷大学,法国国家科学研究中心,奥赛数学实验室);University of Helsinki, Department of Mathematics and Statistics(赫尔辛基大学数学与统计系);Aix-Marseille University, Institut de Mathématiques de Marseille (I2M), and Institut Universitaire de France (IUF)(艾克斯-马赛大学,马赛数学研究所(I2M),法国大学研究院(IUF))