#### Alladi Ramakrishnan Hall

#### Universal features of left-right entanglement entropy

#### Shouvik Datta

##### IISc, Bangaluru

*We show the presence of universal features in the entanglement entropy of regularized boundary states for (1+1)-d conformal field theories on a circle when the reduced density matrix is obtained by tracing over right/left-moving modes. We derive a general formula for the left-right entanglement entropy in terms of the central charge and the modular S matrix of the theory. When the state is chosen to be an Ishibashi state, this measure of entanglement is shown to reproduce the spatial entanglement entropy of a (2+1)-d topological quantum field theory. This result is consistent with expectations from the TQFT/CFT correspondence.*

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