2017年度のセミナー

Date/Place Apr. 18th(Tue.) 15:30-16:30 / H711
Name Tsukasa Tada(RIKEN)
Title The use of unconventional quantizations for CFT(Slides)
Abstract It is conventionally thought that different time foliations for the quantum field theory lead merely physically equivalent quantizations. Therefore, one may choose whichever time-foliation that suits one's purpose best. There is a caveat, though. In the case of conformal field theories, there exists a singular time-foliation which corresponds to the vanishing point of the Casimir operator, or the “light-cone” for the inherent SL(2, R) symmetry. We show that this singular time-foliation for 2d CFT yields continuous Virasoro algebra implying the continuous spectrum for the system. The phenomenon known as the sine-square deformation in the study of quantum many body systems can be understood in this context. Further, we argue the change of the time foliation poses a very useful perspective on the nature of conformal field theories.

 

Date/Place Apr. 11th(Tue.) 15:30-16:30 / H711
Name Tokiro Numasawa(Osaka University)
Title Projection measurements in CFTs and their gravity duals(Slides)
Abstract In this paper we analyze three quantum operations in two dimensional conformal field theories (CFTs): local projection measurements, creations of partial entanglement between two CFTs, and swapping of subsystems between two CFTs. We also give their holographic duals and study time evolutions of entanglement entropy.

 

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