Towards a C-theorem in defect CFT
Towards a C-theorem in defect CFT
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DOI:
10.1007/jhep01(2019)039
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发表时间:
2018-10
影响因子:
5.4
通讯作者:
Nozomu Kobayashi;T. Nishioka;Y. Sato;Kento Watanabe
中科院分区:
文献类型:
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作者:
Nozomu Kobayashi;T. Nishioka;Y. Sato;Kento Watanabe
We explore a C-theorem in defect conformal field theories (DCFTs) that unify all the known conjectures and theorems until now. We examine as a candidate C-function the additional contributions from conformal defects to the sphere free energy and the entanglement entropy across a sphere in a number of examples including holographic models. We find the two quantities are equivalent, when suitably regularized, for codimension-one defects (or boundaries), but differ by a universal constant term otherwise. Moreover, we find in a few field theoretic examples that the sphere free energy decreases but the entanglement entropy increases along a certain renormalization group (RG) flow triggered by a defect localized perturbation which is assumed to have a trivial IR fixed point without defects. We hence propose a C-theorem in DCFTs stating that the increment of the regularized sphere free energy due to the defect does not increase under any defect RG flow. We also provide a proof of our proposal in several holographic models of defect RG flows.