arXiv subjects

Lucas Vicente García-Consuegra

Publications and source records attributed to Lucas Vicente García-Consuegra.

3 recordsLinked to original sources

arXiv2026

Stochastic Schwinger Effect: de Sitter and beyond

We develop a stochastic formulation of the Schwinger effect in de Sitter spacetime using the Schwinger--Keldysh (in-in) formalism, tailored to particle production by non-stationary gauge backgrounds in the early Universe. Treating the gauge field as a prescribed classical stochastic ensemble, we integrate out massless charged matter and derive the corresponding influence functional and particle-production kernel to leading non-trivial order in the gauge coupling. Conformal invariance allows the result to be extended directly from de Sitter to generic spatially flat FLRW spacetimes, without relying on asymptotic out states. We establish the infrared safety and classicality conditions of the stochastic description and clarify its relation to the conventional static Schwinger effect. We further extend the framework to massless conformally coupled scalars and to weakly coupled non-Abelian gauge sectors, including Standard Model and hidden-sector examples, in regimes where thermal corrections are negligible. Our results provide a general framework for matter creation by stochastic gauge fields in inflation, preheating, and non-thermal BSM sectors, connecting quantum field theory in curved spacetime with early-Universe and high-energy phenomenology.

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arXiv2026

Scalar field effective potentials in de Sitter spacetime

We investigate two different definitions of a scalar field effective potential in quantum field theory in de Sitter spacetime: the standard textbook definition, and the constraint effective potential proposed by O'Raifeartaigh et al. in 1986. While these definitions are equivalent in Minkowski spacetime, they differ significantly in de Sitter. We demonstrate this by computing them both explicitly at one-loop order in perturbation theory. It is well known that the perturbative expansion of the standard effective potential fails converge for light fields. In contrast, the constraint effective potential does not suffer from this infrared problem, and it can therefore be computed using perturbation theory. We discuss the physical interpretation of the two effective potentials. In particular, we provide evidence supporting an earlier conjecture that the constraint effective potential is the correct one to use in the stochastic Starobinsky-Yokoyama theory.

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arXiv2026

The Stochastic Schwinger Effect

We formulate a stochastic generalisation of the Schwinger effect, extending pair production to statistically fluctuating gauge-field backgrounds. Our approach captures realistic field configurations that are transient, inhomogeneous, and stochastic, as commonly encountered in cosmological and high-energy astrophysical settings. Using the effective action formalism, we compute the vacuum decay rate and number density of charged particles, obtaining closed-form analytical expressions for both scalar and fermionic cases. To isolate the essential physics, the analysis is performed in flat spacetime and at zero temperature, providing a controlled setting in which curvature and thermal effects can be neglected. As a proof of concept, we present representative phenomenological examples relevant to astrophysical plasmas and early-Universe-motivated scenarios.

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