Conformal Blocks and Negativity at Large Central Charge

TL;DR

This paper investigates entanglement negativity between two disjoint intervals in 1+1D CFT at large central charge, highlighting the role of conformal blocks and null descendants, with numerical and analytic comparisons.

Contribution

It introduces a numerical approach to compute negativity via conformal blocks and compares it with existing perturbative analytic methods.

Findings

Leading negativity behavior is governed by the logarithm of conformal blocks.

Null descendants significantly influence the negativity near the intervals.

Numerical results align with perturbative expansions in the cross-ratio.

Abstract

We consider entanglement negativity for two disjoint intervals in 1+1 dimensional CFT in the limit of large central charge. As the two intervals get close, the leading behavior of negativity is given by the logarithm of the conformal block where a set of approximately null descendants appears in the intermediate channel. We compute this quantity numerically and compare with existing analytic methods which provide perturbative expansion in powers of the cross-ratio.