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arXiv · 2206.08200

Adiabatic regularization and preferred vacuum state for the $λϕ^4$ field theory in cosmological spacetimes

Antonio Ferreiro·Silvia Pla
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Abstract

We extend the method of adiabatic regularization by introducing an arbitrary parameter $μ$ for a scalar field with quartic self-coupling in a Friedmann-Lemaître-Robertson-Walker (FLRW) spacetime at one-loop order. The subtraction terms constructed from this extended version allow us to define a preferred vacuum state at a fixed time $η= η_0$ for this theory. We compute this vacuum state for two commonly used background fields in cosmology. We also give a possible prescription for an adequate value for $μ$.

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Antonio Ferreiro, Silvia Pla. 2023-04-20. Adiabatic regularization and preferred vacuum state for the $λϕ^4$ field theory in cosmological spacetimes. https://doi.org/10.1103/physrevd.106.065015

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