RT Journal Article
T1 Unitary quantization of a scalar charged field and Schwinger effect
A1 Garay Elizondo, Luis Javier
A1 Martín Caro, Alberto García
A1 Martín Benito, Mercedes
AB Quantum field theory in curved spacetimes suffers in general from an infinite ambiguity in the choice of Fock representation and associated vacuum. In cosmological backgrounds, the requirement of a unitary implementation of the field dynamics in the physical Hilbert space of the theory is a good criterion to ameliorate such ambiguity. In- deed, this criterion, together with a unitary implementation of the symmetries of the equations of motion, leads to an equivalence class of unitarily equivalent quantizations that, even though it is still formed by an infinite number of Fock representations, is unique. In this work, we apply the procedure developed for fields in cosmological settings to analyze the quantization of a scalar field in the presence of an external electromagnetic classical field in a flat background. We find a natural Fock representation that admits a unitary implementation of the quantum field dynamics. It automatically allows to define a particle number density at all times in the evolution with the correct asymptotic behavior, when the electric field vanishes. Moreover we show the unitary equivalence of all the quantizations that fulfill our criteria, so that they form a unique equivalence class. Although we perform the field quantization in a specific gauge, we also show the equivalence between the procedures taken in different gauges.
PB Springer
SN 1029-8479
YR 2020
FD 2020-04-20
LK https://hdl.handle.net/20.500.14352/7257
UL https://hdl.handle.net/20.500.14352/7257
LA eng
NO Ministerio de Ciencia e Innovación (MICINN)/FEDER
NO Ministerio de Educación, Cultura y Deporte (MECD)
NO Ministerio de Ciencia e Innovación (MICINN)
NO Unidad de Excelencia María de Maeztu
NO Xunta de Galicia
DS Docta Complutense
RD 5 abr 2025