Entanglement entropy via double-cone regularization

This paper proposes an alternative regularization method for handling the ultraviolet behavior of entanglement entropy. Utilizing an <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>i</a:mi><a:mi>ε</a:mi></a:math> 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 <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>i</c:mi><c:mi>ε</c:mi></c:math> regularization method in addressing ultraviolet issues in quantum field theory and gravity, suggesting potential applications to other calculable quantities. Published by the American Physical Society 2024