PINAMONTI , Nicola

We prove local existence of solutions of a functional renormalisation group equation for the effective action of an interacting quantum field theory, when a suitable local potential approximation is considered. To obtain this equation in a Lorentzian setting a quantum state for the theory is selected and a regulator consisting in a mass is...

We analyze the relative entropy of certain KMS states for scalar self-interacting quantum field theories over Minkowski backgrounds that have been recently constructed by Fredenhagen and Lindner (Commun Math Phys 332:895, 2014) in the framework of perturbative algebraic quantum field theory. The definition we are using is a generalization of...

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We construct states describing Bose–Einstein condensates at finite temperature for a relativistic massive complex scalar field with ||4-interaction. We start with the linearized theory over a classical condensate and construct interacting fields by perturbation theory. Using the concept of thermal masses, equilibrium states at finite...

For any number h such that ℏ:=h/2π is irrational and any skew-symmetric, non-degenerate bilinear form σ:ℤ2g×ℤ2g→ℤ, let be hg,σ be the twisted group ∗-algebra ℂ[ℤ2g] and consider the ergodic group of ∗-automorphisms of hg,σ induced by the action of the symplectic group Sp(ℤ2g,σ). We show that the only Sp(ℤ2g,σ)-invariant state on hg,σ is the...

We analyze the stability properties shown by KMS states for interacting massive scalar fields propagating over Minkowski spacetime, recently constructed in the framework of perturbative algebraic quantum field theories by Fredenhagen and Lindner (Commun Math Phys 332:895, 2014). In particular, we prove the validity of the return to equilibrium...