Joint Nordita-Uppsala Seminar: Entanglement C-functions of defects and interfaces in N=4 SYM

by Ronnie Rodgers (Nordita)

Wednesday 22 Oct 2025, 11:00 → 12:00 Europe/Stockholm

Å101130 (Uppsala Univeristy)

C-functions are quantities in quantum field theory (QFT) that monotonically decrease under renormalisation group flows, thus making quantitative the notion of reduction of degrees of freedom along the flow. One tool for defining C-functions and proving their monotonicity is using entanglement entropy. However there is no known entanglement C-function for bulk RG flows in QFTs with defects. I will present results for holographic entanglement entropy in N=4 supersymmetric Yang-Mills theory with a codimension-one defect or interface and with a bulk RG flow on one side of the defect. This setup is holographically dual to probe D5-branes in AdS5 x S5. Using these results I will test various candidate entanglement C-functions. I will show that the best candidate is indeed always smaller in the IR than in the UV, but not necessarily monotonic in between.