Abstract
When an interface connects two CFTs, the entanglement entropy between the two CFTs is determined by a quantity called the effective central charge. The effective central charge does not have a simple form in terms of the central charges of the two CFTs, but intricately depends on the transmissive properties of the interface.
In this article, we examine universal properties of the effective central charge. We first clarify how the effective central charge appears when considering general subsystems of the interface CFT. Then using this result and ideas used in the proof of the c-theorem, we provide a universal upper bound on the effective central charge.
In past studies, the effective central charge was defined only in two dimensions. We propose an analogue of the effective central charge in general dimensions possessing similar universal properties as in two dimensions.
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Acknowledgments
We thank Constantin Bachas, Horacio Casini, and Gonzalo Torroba for useful discussions. AK, HS, and MW are supported in part by the U.S. Department of Energy under Grant No. DE-SC0022021 and a grant from the Simons Foundation (Grant 651440, AK). The work by YK and HO is supported in part by the U.S. Department of Energy, Office of Science, Office of High Energy Physics, under Award Number DE-SC0011632. In addition, YK is supported by the Brinson Prize Fellowship at Caltech. HO is supported in part by the Simons Investigator Award (MP-SIP-00005259), the World Premier International Research Center Initiative, MEXT, Japan, and JSPS Grants-in-Aid for Scientific Research 20K03965 and 23K03379. This work was performed in part at the Aspen Center for Physics, which is supported by NSF grant PHY-1607611.
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Karch, A., Kusuki, Y., Ooguri, H. et al. Universality of effective central charge in interface CFTs. J. High Energ. Phys. 2023, 126 (2023). https://doi.org/10.1007/JHEP11(2023)126
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DOI: https://doi.org/10.1007/JHEP11(2023)126