Entanglement through conformal interfaces

We consider entanglement through permeable interfaces in the c=1 (1+1)-dimensional conformal field theory. We compute the partition functions with the interfaces inserted. By the replica trick, the entanglement entropy is obtained analytically. The entropy scales logarithmically with respect to the size of the system, similarly to the universal scaling of the ordinary entanglement entropy in (1+1)-dimensional conformal field theory. Its coefficient, however, is not constant but controlled by the permeability, the dependence on which is expressed through the dilogarithm function. The sub-leading term of the entropy counts the winding numbers, showing an analogy to the topological entanglement entropy which characterizes the topological order in (2+1)-dimensional systems.Comment: 14 pages, no figures; (v2) a reference added, minor changes; (v3) results and comments on special cases adde

Convex Functions and g-Rearrangements on Intervals

Article信州大学工学部紀要 66: 1-5 (1989)departmental bulletin pape

Decreasing Rearrangements of Non-Negative (C₀) Sequences and Some Extensions of Hardy-Littlewood-Pólya's Theorems

Article信州大学工学部紀要 49: 13-22 (1980)departmental bulletin pape

Average phase factor in the PNJL model

The average phase factor of the QCD determinant is evaluated at finite quark chemical potential ({\mu}_q) with the two-flavor version of the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model with the scalar-type eight-quark interaction. For {\mu}_q larger than half the pion mass at vacuum m_{\pi}, the average phase factor is finite only when the Polyakov loop is larger than 0.5, indicating that lattice QCD is feasible only in the deconfinement phase. A critical endpoint (CEP) lies in the region of the zero average phase factor. The scalar-type eight-quark interaction makes it shorter a relative distance of the CEP to the boundary of the region. For {\mu}_q < m_{\pi}/2, the PNJL model with dynamical mesonic fluctuations can reproduce lattice QCD data below the critical temperature.Comment: 8 pages, 6 figure

Describing the proper n-shape category by using non-continuous functions

In this paper, we describe the proper n-shape category by using non-continuous functions. Moreover, applying non-continuous homotopies, we show that the Cech expansion is a polyhedral expansion in the proper n-homotopy category