Talk detail

Participant	Vardanyan, Tereza
Institution	University of Bologna, Department of Physics and Astronomy - via Irnerio, 46 - Bologna - - Italy

Session	DE1	Accepted		Order	Time
Talk	Oral abstract	Title	Pauli–Zeldovich cancellation of the vacuum energy divergences, auxiliary fields and supersymmetry
Coauthors
Abstract	We have considered the Pauli–Zeldovich mechanism for the cancellation of the ultraviolet divergences in vacuum energy. This mechanism arises because bosons and fermions give contributions of the opposite signs. In contrast with the preceding papers devoted to this topic wherein mainly free fields were studied, here we have taken their interactions into account to the lowest order of perturbation theory. We have constructed some simple toy models having particles with spin 0 and spin 1 / 2, where masses of the particles are equal while the interactions can be quite non-trivial.
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Session	EU2B	Accepted		Order	Time
Talk	Oral abstract	Title	The Quantum Fokker-Planck Equation of Stochastic Inflation
Coauthors
Abstract	We derive the stochastic description of a massless, interacting scalar field in de Sitter space directly from the quantum theory. This is done by showing that the density matrix for the effective theory of the long wavelength fluctuations of the field obeys a quantum version of the Fokker-Planck equation. This equation has a simple connection with the standard Fokker-Planck equation of the classical stochastic theory, which can be generalised to any order in perturbation theory. We illustrate this formalism in detail for the theory of a massless scalar field with a quartic interaction.
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