On the semigroup generated by the renormalized Nelson Hamiltonian.

Abstract We consider the renormalized Nelson model at a fixed total momentum P : H ren (P) ; the Hamiltonian H ren (P) is defined through an infinite energy renormalization. We prove that e − β H ren (P) is positivity improving for all P ∈ R 3 and β > 0 in the Fock representation. [ABSTRACT FROM AUTHOR]