Entanglement Entropy via Double Cone Regularization

This paper proposes an alternative regularization method for handling the ultraviolet behavior of entanglement entropy. Utilizing an $i\epsilon$ prescription in the Euclidean double cone geometry, it accurately reproduces the universal behavior of entanglement entropy. The method is demonstrated in the free boson theory in arbitrary dimensions and two-dimensional conformal field theories. The findings highlight the effectiveness of the $i\epsilon$ regularization method in addressing ultraviolet issues in quantum field theory and gravity, suggesting potential applications to other calculable quantities.
Comment: 5 pages and 1 figure. Added acknowledgement for v2, Published version v3 including minor corrections and improvements