Activity on Non-Equilibrium Quantum Field Theory and Cosmology

I focused my activity on Out-of-Equilibrium QFT on the analysis of electromagnetic signatures of non-equilibrium system. This has consequences not only in Heavy Ion physics but also in Cosmology, specifically on the problem of generation of magnetic fields during the first phases of the evolution of the Universe.

• [SQED] Non-Equilibrium Quantum Plasmas in Scalar QED: Photon Production, Magnetic and Debye Masses and Conductivity, D. Boyanovsky, H. J. De Vega, M. Simionato, hep-ph/9909259, 55pp. Published in Phys. Rev. D61: 085007, 2000. This was one of the first papers in the literature studying strongly out of equilibrium aspects of quantum electrodynamics. Here we studied possible signatures of strongly out of equilibrium processes, which eventually appear in Heavy Ions Collisions or in the Early Universe. Questions we have analized are the photo-production process, the dynamics of the electrical conductivity, and the generation of magnetic and electric mass for the photon in scalar QED, using the non-perturbative 1/N expansion.
• [M1] Magnetic Field Generation From Nonequilibrium Phase Transitions, D. Boyanovsky, M. Simionato, H.J. de Vega, hep-ph/0208272, 37pp. To be published in Phys. Rev. D In this paper we extend the analysis given in [SQED] focusing on the analysis of the magnetic field spectrum from strongly out of equilibrium phase transitions. The motivation is to apply this kind of analysis, here for semplicity developed in Minkowski space-time, to cosmological space-times, with the aim of understanding primordial magnetic fields generated during the early stages of evolution of the universe. With this in view, we study in detail the effect of the electrical conductivity on the generation of long wavelenghts magnetic field; we prove that the amplitude of the magnetic field is strongly suppressed and that its correlation lenght is of order of the correlation lenght of the scalars.
• [M2] Large scale magnetogenesis from a non-equilibrium phase transition in the radiation dominated era, D. Boyanovsky, M. Simionato, H.J. de Vega, hep-ph/0211022, 25pp. Submitted to Phys. Rev. D. In this second paper we apply the framework developed in [M1] to the analysis of the magnetic spectrum generated by non-equilibrium effects during a second order phase transition at the beginning of the the radiation dominated era. The new effect is a very strong production during the scaling regime epoch of the phase transition which maybe enough to produce the seeds needed to explain the cosmic magnetic fields observed today on the Megaparsec scale, if the scaling regime endures until the electroweak phase transition.