title: Applying the variational principle to (1+1)-dimensional quantum field theories.
abstract: We extend the recently introduced continuous matrix product state variational class to the setting of (1+1)-dimensional relativistic quantum field theories. This allows one to overcome the difficulties highlighted by Feynman concerning the application of the variational procedure to relativistic theories, and provides a new way to regularize quantum field theories. A fermionic version of the continuous matrix product state is introduced which is manifestly free of fermion doubling and sign problems. We illustrate the power of the formalism by studying the momentum occupation for free massive Dirac fermions and the chiral symmetry breaking in the Gross-Neveu model.
authors.affiliation: Ghent University, Department of Physics and Astronomy, Krijgslaan 281-S9, B-9000 Ghent, Belgium.
authors.forename: Jutho
authors.initials: J
authors.lastname: Haegeman
authors.forename: J Ignacio
authors.initials: JI
authors.lastname: Cirac
authors.forename: Tobias J
authors.initials: TJ
authors.lastname: Osborne
authors.forename: Henri
authors.initials: H
authors.lastname: Verschelde
authors.forename: Frank
authors.initials: F
authors.lastname: Verstraete