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arXiv · hep-ph/9812413

Real-Time Dynamics with Fermions on a Lattice

Gert Aarts·Jan Smit
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Abstract

The 1+1 dimensional abelian Higgs model with fermions is a toy model for the theory of electroweak baryogenesis. We study the dynamics of the model with axially coupled fermions in real-time. The model is defined on a spacetime lattice to preserve gauge invariance and to obtain numerical stability in a simple way. We take into account the phenomenon of lattice fermion doubling. The dynamics is approximated by treating the inhomogeneous Bose fields classically, which is justified in a large N_f approximation. The back reaction on the Bose fields due to fermion field fluctuations is calculated using a mode function expansion. We discuss and present numerical results for the response of fermions to sphaleron transitions, the renormalizability of the effective equations of motion and non-perturbative dynamics in the framework of non-equilibrium quantum field theory. The long-time behaviour of the system is discussed and we speculate about applications to finite density calculations.

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Gert Aarts, Jan Smit. 1999-06-01. Real-Time Dynamics with Fermions on a Lattice. https://doi.org/10.1016/s0550-3213(99)00320-x

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