We present a study of Dirac quantum fields in a four-dimensional de Sitter spacetime. The
theory is based on the requirement of precise analyticity properties of the waves and the …

We study quantum fields on spacetimes having a bifurcate Killing horizon by allowing the
possibility that left and right (ingoing and outgoing) modes have different temperatures. An …

We present a complete study of a family of tachyonic scalar fields living on the de Sitter
universe. We show that for an infinite set of discrete values of the negative squared mass …

Abstract We study the Sine-Gordon model with Minkowski signature in the framework of
perturbative algebraic quantum field theory. We calculate the vertex operator algebra …

Infrared singular variables which often enter in the formulation of models in quantum field
theory, many-body theory, and quantum statistical mechanics are described in terms of …

Experimental evidences and theoretical motivations lead to consider the curved space-time
relativity based on the de Sitter group SO 0 (1, 4) or Sp (2, 2) as an appealing substitute to …

We consider the simplest non-trivial local composite operators in the massless Sine-Gordon
model, which are∂ µϕ∂ νϕ and the stress tensor Tµν. We show that even in the finite …

In this paper we study hermitian kernels invariant under the action of a semigroup with
involution. We characterize those hermitian kernels that realize the given action by bounded …

The Buchholz'scattering theory of waves in two dimensional massless models suggests a
natural definition of a scattering amplitude. We compute such a scattering amplitude for …

We study by nonperturbative techniques a vector and axial-vector theory characterized by a
parameter which interpolates between pure vector and chiral Schwinger models. The main …