Cosmological phase transitions: field theoretical and numerical improvements

• Applicants: Professor Dr. Haye Hinrichsen; Professor Dr. Werner R. Porod
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 387095756

• Final Report Year: 2023

Final Report Abstract

In this project we investigated the use of the so-called 2PI formalism for the study of cosmological phase transitions. This formalism has the advantage of encoding nonequilibrium aspects. We have developed a software-package named KBS solving the equations of motion which are a coupled system partial integro-differential equations. The current version is designed for use in 1+1 space-time dimensions and can easily be extended for use in higher space-time dimensions. We have investigated basic toy models containing the main features of cosmological phase transitions. Moreover, we have developed an on-shell scheme for the renormalized equations of motions which allows for a quantitative comparison with other schemes. Finally we have investigated the generation of the observed baryon asymmetry of the Universe via leptogenesis in so-called scotogenic models.

Publications

• Temperature effects on the Z2 symmetry breaking in the scotogenic model. Physical Review D, 105(3).
  Alvarez, Alexandre; Cepedello, Ricardo; Hirsch, Martin & Porod, Werner
  
• Accommodating muon (g − 2) and leptogenesis in a scotogenic model. Journal of High Energy Physics, 2023(6).
  Alvarez, A.; Banik, A.; Cepedello, R.; Herrmann, B.; Porod, W.; Sarazin, M. & Schnelke, M.
  
• Renormalized equations of motion for scalars and fermions in the 2PI formalism. International Journal of Modern Physics A, 39(21).
  Banik, A.; Hinrichsen, H. & Porod, W.