Entanglement of self-interacting scalar fields in an expanding spacetime

¹ Departamento de Física, Universidade Federal de Minas Gerais, ICEX - P.O. BOX 702, 30.161-970, Belo Horizonte, MG, Brazil
² Departamento de Matemática, Universidade Federal de Ouro Preto, ICEB 35400-000 Campus Morro do Cruzeiro, Ouro Preto, MG, Brazil
³ Department of Mathematical Sciences, Centre for Particle Theory, Durham University South Road, Durham DH1 3LE, UK
⁴ Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela 64049-550, Teresina, PI, Brazil

Received: 3 June 2016
Accepted: 11 July 2016

Abstract

We evaluate self-interaction effects on the quantum correlations of field modes of opposite momenta for scalar theory in a two-dimensional asymptotically flat Robertson-Walker spacetime. Such correlations are encoded both in the von Neumann entropy defined through the reduced density matrix in one of the modes and in the covariance expressed in terms of the expectation value of the number operators for each mode in the evolved state. The entanglement between field modes carries information about the underlying spacetime evolution.