Entanglement entropy for a Dirac fermion in three dimensions: Vertex contribution.

H. CASINI; M. HUERTA; L LEITAO

NUCLEAR PHYSICS B

ELSEVIER SCIENCE BV

Año: 2009 vol. 814 p. 594 - 609

0550-3213

 In three dimensions there is a logarithmically divergent contribution to the entanglement entropy which is due to the vertices located at the boundary of the region considered. In this work we find the corresponding universal coefficient for a free Dirac field, and extend a previous work in which the scalar case was treated. The problem is equivalent to find the conformal anomaly in three dimensional space where multiplicative boundary conditions for the field are imposed on a plane angular sector. As an intermediate step of the calculation we compute the trace of the Green function of a massive Dirac field in a two dimensional sphere with boundary conditions imposed on a segment of a great circle.