Schwinger Mechanism Research Articles

Catastrophic emission of charges from near-extremal Nariai black holes

Using both the in-out formalism and the monodromy method, we study the emission of charges from near-extremal charged Nariai black holes with the black hole event and cosmological horizons close to each other, whose near-horizon geometry is dS2×S2. The emission becomes catastrophic for a charge with energy greater than its chemical potential, whose leading exponential factor increases inversely proportional to the separation of two horizons. This effect may prevent near-extremal Nariai black holes with large charges that evaporate dominantly through the charge emission from evolving to black holes with a naked singularity, in analog to near-extremal RN-dS black holes that have the Breitenlohner-Friedman bound, below which they become stable against Hawking radiation and Schwinger effect of charge emission. The near-extremal Nariai black holes with small charges, which are close to near-extremal Schwarzschild-de Sitter black holes, emit dominantly charge-neutral particles and evolve to black holes with increasing charge to mass ratio. We illuminate the origin of the catastrophic emission in the phase-integral formulation and monodromy method by comparing near-extremal charged Nariai black holes with near-extremal Reissner-Nordtröm-dS black holes. Published by the American Physical Society 2024

Schwinger vs Unruh (Mini-review)

It is shown that the temperatures which characterise the Unruh effect, the Gibbons-Hawking radiation from the de Sitter cosmological horizon and the Hawking radiation from the black hole horizon acquire the extra factor 2 compared with their traditional values. The reason for that is the coherence of different processes. The combination of the coherent processes also allows us to make the connection between the Schwinger pair production and the Unruh effect.

Roles of electric field/time-dependent Wilson line in toroidal compactification with or without magnetic fluxes

We discuss the effects of electric fields along compact directions within (supersymmetric) gauge theory in ℝ1,3×T2×T2×T2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {\\mathbb{R}}^{1,3}\ imes {\\mathbbm{T}}^2\\left(\ imes {\\mathbbm{T}}^2\ imes {\\mathbbm{T}}^2\\right) $$\\end{document}. The electric field along compact directions is equivalent to time-dependent homogeneous configuration of Wilson line moduli, which would be relevant to physics in the early universe. In particular, we consider models with and without background magnetic fluxes, which lead to completely different effects of the electric field due to the difference in the Kaluza-Klein (KK) level structure. We show that, in the case without magnetic fluxes, the deceleration of KK momenta may cause non-perturbative KK particle production dubbed as the KK Schwinger effect, whereas in the case with magnetic flux such KK particle production does not take place but flavor structure of low energy effective theory may be affected.

Schwinger dark matter production

Building on recently constructed inflationary vector dark matter production mechanisms as well as studies of magnetogenesis, we show that an inflationary dark Schwinger mechanism can generate the observed dark matter relic abundance for `dark electron' masses as light as ∼ 0.1 eV and as heavy as 1012 GeV. The dark matter can interact very weakly via the exchange of light dark photons with a power spectrum which is peaked at very small scales, thus evading isocurvature constraints. This mechanism is viable even when (purely) gravitational particle production is negligible. Thus dark matter can be produced solely via the Schwinger effect during inflation including for light masses.

The Schwinger pair production method in the framework of non-commutative phase space coordinates and its applications

In noncommutative phase space (NCPS), we investigate the pair creation rate for the problem of scalar and spinorial particles emerging from a vacuum under the influence of uniform external electromagnetic fields using the Schwinger formal technique. It is demonstrated that under specific conditions, where the speed of light c approaches the Fermi velocity [Formula: see text] and [Formula: see text] (with [Formula: see text] representing the cyclotron frequency), the behavior of the Dirac oscillator problem in a uniform electromagnetic field within NCPS is akin to the monolayer graphene problem in NCPS. In addition, the production probability per unit volume per unit time is discussed, along with the limits of parameter deformations.

Quantum metrology of Schwinger effect

We propose a scheme for the quantum metrology of the Schwinger effect and the dynamics of Gaussian interference power (GIP). The ongoing reliability of the estimation strategy for the probe state prepared in particle–particle modes is demonstrated. Although the GIP sensitively depends on the strength of the external electric field and the transverse momentum, the advantage of quantum parameter estimation is still maintained even in the limit of an infinite electric field and zero transverse momentum. It is shown that the entanglement between the particle–particle modes provides a guarantee for obtaining higher precision for the black-box estimation. In contrast, for the probe state prepared in particle–antiparticle modes, the advantage of quantum parameter estimation can also be ensured even though there is no entanglement in the probe state. Put differently, some non-entanglement quantum correlations play the role of quantum resources in the estimation for particle–antiparticle modes.

Band structure for relativistic charged particles immersed in a structurally chiral electromagnetic field

In this paper, we determine the band structure of an electromagnetic space-time crystal. We construct a coordinate transformation in which the matrix elements of the Dirac equation are constant. Consequently, their corresponding band structure is recovered analytically. The band structure is fragmented into three different energy regions. In the center, there is a region prohibited for all particles (universal band gap), which is symmetrically enveloped by two energy regions of the same width. These regions allow the passage of particles with a specific spin (discriminatory band gaps). Furthermore, we demonstrate that, through the appropriate combination of the refractive index, the length of the electromagnetic wave, and the amplitude of the electric field, it is possible to shorten the bandwidth of the universal gap and replace it with a discriminatory band gap. In that sense, the proposed system constitutes an alternative procedure to observe the Schwinger mechanism experimentally.

Nonlinear Schwinger mechanism in QCD, and Fredholm alternatives theorem

We present a novel implementation of the Schwinger mechanism in QCD, which fixes uniquely the scale of the effective gluon mass scale and streamlines considerably the procedure of multiplicative renormalization. The key advantage of this method stems from the nonlinear nature of the dynamical equation that generates massless poles in the longitudinal sector of the three-gluon vertex. An exceptional feature of this approach is an extensive cancellation involving the components of the integral expression that determines the gluon mass scale; it is triggered once the Schwinger–Dyson equation of the pole-free part of the three-gluon vertex has been appropriately exploited. It turns out that this cancellation is driven by the so-called Fredholm alternatives theorem, which operates among the set of integral equations describing this system. Quite remarkably, in the linearized approximation this theorem enforces the exact masslessness of the gluon. Instead, the nonlinearity induced by the full treatment of the relevant kernel evades this theorem, allowing for the emergence of a nonvanishing mass scale. The numerical results obtained from the resulting equations are compatible with the lattice findings, and may be further refined through the inclusion of the remaining fundamental vertices of the theory.

MoEDAL Search in the CMS Beam Pipe for Magnetic Monopoles Produced via the Schwinger Effect.

We report on a search for magnetic monopoles (MMs) produced in ultraperipheral Pb-Pb collisions during Run 1 of the LHC. The beam pipe surrounding the interaction region of the CMS experiment was exposed to 184.07 μb^{-1} of Pb-Pb collisions at 2.76TeV center-of-mass energy per collision in December 2011, before being removed in 2013. It was scanned by the MoEDAL experiment using a SQUID magnetometer to search for trapped MMs. No MM signal was observed. The two distinctive features of this search are the use of a trapping volume very close to the collision point and ultrahigh magnetic fields generated during the heavy-ion run that could produce MMs via the Schwinger effect. These two advantages allowed setting the first reliable, world-leading mass limits on MMs with high magnetic charge. In particular, the established limits are the strongest available in the range between 2 and 45 Dirac units, excluding MMs with masses of up to 80GeV at a 95% confidence level.

Kaluza–Klein Schwinger Effect

Abstract We show that electric fields in compactified spaces may produce Kaluza–Klein (KK) particles even when the energy of the electric fields is smaller than the KK scale. As an illustrative example, we consider a charged massless complex scalar coupled to U(1) gauge theory in $\mathbb {R}^{1,3}\times {\mathbb {S}}^1$ and discuss the effect of background gauge potential along a compact direction. The electric field produces the charged KK particle nonperturbatively, which we call the KK Schwinger effect. We quantitatively show that KK modes can be produced even when the electric field energy is far below the KK scale. The mechanism is rather general and similar phenomena would occur in any compactification models when a gauge potential along a compact direction evolves in time and experiences a large enough field excursion. We also discuss the subtlety of 4D effective theory truncated by KK modes at an initial time, when the electric field is turned on.

Evaporation of Primordial Charged Black Holes: Timescale and Evolution of Thermodynamic Parameters

The evolution of primordial black holes formed during the reheating phase is revisited. For reheating temperatures in the range of 1012–1013 GeV, the initial masses are respectively of the order of 1010–108MP, where MP is the Planck mass. These newborn black holes have a small charge-to-mass ratio of the order of 10−3, a consequence of statistical fluctuations present in the plasma constituting the collapsing matter. Charged black holes can be rapidly discharged by the Schwinger mechanism, but one expects that, for very light black holes satisfying the condition M/MP<<MP/mW (mW is the mass of the heaviest standard model charged W-boson), the pair production process is probably strongly quenched. Under these conditions, these black holes evaporate until attaining extremality with final masses of about 107–105MP. Timescales to reach extremality as a function of the initial charge excess were computed, as well as the evolution of the horizon temperature and the charge-to-mass ratio. The behavior of the horizon temperature can be understood in terms of the well-known discontinuity present in the heat capacity for a critical charge-to-mass ratio Q/GM=3/2.

Complete analysis of the Landau-gauge three-gluon vertex from lattice QCD

Several continuum and lattice investigations of the QCD three-gluon vertex have recently exposed its key properties, some intimately connected with the low-momentum behavior of the two-point gluon Green’s function and especially relevant for the emergence of a mass scale in this latter, via the Schwinger mechanism. In the present study, we report on a lattice determination of the Landau-gauge, transversely projected three-gluon vertex, particularly scrutinizing an outstanding one of these properties, termed , exploring its implications and capitalizing on it to gain further insight on the low-momentum running of both the three-gluon vertex and its associated strong coupling. Published by the American Physical Society 2024

Schwinger mechanism of magnon-antimagnon pair production on magnetic field inhomogeneities and the bosonic Klein effect

Schwinger mechanism of magnon-antimagnon pair production on magnetic field inhomogeneities and the bosonic Klein effect

Hidden conformal symmetry and Schwinger effect in extremal magnetized Kerr black holes

This paper explores the near-extremal and extremal magnetized Kerr black hole, revealing the Schwinger effect in the absorption cross section at the spacetime's extremal limit. The agreement with CFT2 hints at hidden conformal symmetry. The analysis uncovers SL(2,R)L×SL(2,R)R symmetry for the massless scalar near the black hole, suggesting the Kerr/CFT correspondence for the magnetized Kerr black holes. Cardy formula of the conformal field theory is used to reproduce the black hole entropy in both extremal and near-extremal cases.

Holographic Schwinger effect with higher derivative corrections in presence of string cloud

Holographic Schwinger effect with higher derivative corrections in presence of string cloud

Gluon mass generation from renormalons and resurgence

We establish a link between the concepts of infrared renormalons, infrared fixed point, and dynamical nonperturbative mass generation of gluons in pure Yang-Mills theories. By utilizing recent results in the resurgent analysis of renormalons through non-linear ordinary differential equations, we develop a new description for the gluon propagator, thereby realizing the Schwinger mechanism. Specifically, this approach leads to a nonperturbative, dynamic mass generation for Yang-Mills gauge bosons in the deep infrared region, a phenomenon closely associated with color confinement. Furthermore, we present arguments about the limit of applicability of the Borel-Ecalle resummation of the renormalons by comparing it with the Kallen-Lehman representation of the gluon propagator.

Resummed heat kernel and effective action for Yukawa and QED

In this letter, we prove the existence of resummed expressions for the diagonal of the heat kernel and the effective action of a quantum field which interacts with a scalar or an electromagnetic background. Working in an arbitrary number of spacetime dimensions, we propose an Ansatz beyond the Schwinger–DeWitt proposal, effectively resumming an infinite number of invariants which can be constructed from powers of the background, as well as its first and second derivatives in the Yukawa case. This provides a proof of the recent conjecture that all terms containing the invariants FμνFμν and F˜μνFμν in the proper-time series expansion of the SQED effective action can be resummed. Possible generalizations and several applications are also discussed—in particular, the existence of an analogue of the Schwinger effect for Yukawa couplings.

Pair of dyon production near magnetized dyonic Reissner-Nordstrom black holes* *Supported by LPPM UNPAR

We investigate the phenomenon of pair production of massive scalar particles with magnetic charge near the horizon of a magnetized dyonic Reissner-Nordstrom black hole. The intrinsic symmetry between the electric and magnetic quantities in the Einstein-Maxwell equations suggests that the pair can be generated through Hawking radiation and the Schwinger effect, provided that the Dirac quantization condition is satisfied.

Pair production of scalar fields near the accelerating Reissner–Nordstrom black hole

Accelerating space–time is commonly utilized to depict the formation of pairs of black holes. This paper studies the pair production of charged scalar particles in the vicinity of an accelerating Reissner–Nordstrom black hole’s event horizon. Essentially, we aim to investigate the production of particles that accompanies the creation of black hole pairs. In a near extremal state, this pair production manifests as a combination of Hawking radiation and the Schwinger effect. Under extremal conditions, only the latter effect remains. Furthermore, this research explores the influence of the acceleration parameter on the absorption cross section of scalar particles in proximity to the black hole.

Holographic Schwinger effect in anisotropic media

According to gauge/gravity correspondence, we study the holographic Schwinger effect within an anisotropic background. Firstly, the separate length of the particle–antiparticle pairs is computed within the context of an anisotropic background which is parameterized by dynamical exponent ν\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ u $$\\end{document}. It is found that the maximum separate length x increases with the increase of dynamical exponent ν\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ u $$\\end{document}. By analyzing the potential energy, we find that the potential barrier increases with the dynamical exponent ν\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ u $$\\end{document} at a small separate distance. This observation implies that the Schwinger effect within an anisotropic background is comparatively weaker when contrasted with its manifestation in an isotropic background. Finally, we also find that the Schwinger effect in the transverse direction is weakened compared to the parallel direction in the anisotropic background, which is consistent with the top-down model.