Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Schwinger effect in inhomogeneous electric fields   The vacuum of quantum electrodynamics is unstable against the formation of
many-body states in the presence of an external electric field, manifesting
itself as the creation of electron-positron pairs (Schwinger effect). This
effect has been a long-standing but still unobserved prediction as the
generation of the required field strengths has not been feasible so far.
However, due to the advent of a new generation of high-intensity laser systems
such as the European XFEL or the Extreme Light Infrastructure (ELI), this
effect might eventually become observable within the next decades. Based on the
equal-time Wigner formalism, various aspects of the Schwinger effect in
electric fields showing both temporal and spatial variations are investigated.
Regarding the Schwinger effect in time-dependent electric fields, analytic
expressions for the equal-time Wigner function in the presence of a static as
well as a pulsed electric field are derived. Moreover, the pair creation
process in the presence of a pulsed electric field with sub-cycle structure,
which acts as a model for a realistic laser pulse, is examined. Finally, an ab
initio simulation of the Schwinger effect in a simple space- and time-dependent
electric field is performed for the first time, allowing for the calculation of
the time evolution of various observables like the charge density, the particle
number density or the number of created particles.

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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: nlin