We present an action of ultra-relativistic electrodynamics on a flat Carroll manifold. The model exhibits a couple of physical degrees of freedom per space-point. We observe that the action of the conformal Carroll algebra on the phase space is Hamiltonian in 4 space-time dimensions. Moreover the elements of the algebra give rise to an infinite number of conserved charges and the charge algebra is an exact realization of the kinematical algebra.
We argue that generic field theories defined on null manifolds should have an emergent BMS or conformal Carrollian structure. We then focus on a simple interacting conformal Carrollian theory, viz. Carrollian scalar electrodynamics. We look at weak (on-shell) and strong invariance (off-shell) of its equations of motion under conformal Carrollian symmetries. Helmholtz conditions are necessary and sufficient conditions for a set of equations to arise from a Lagrangian. We investigate whether the equations of motion of Carrollian scalar electrodynamics satisfy these conditions. Then we proposed a…
We construct the free Lagrangian of the magnetic sector of Carrollian electrodynamics. The construction relies on Helmholtz integrability condition for differential equations in a self consistent algorithm, working hand in hand with imposing invariance under infinite dimensional Conformal Carroll algebra. It requires inclusion of new fields in the dynamics and the system is free of gauge redundancies. We next add interaction (quartic) terms to the free Lagrangian, strictly constrained by conformal invariance and Carrollian symmetry. The dynamical realization of the non-semi simple infinite dim…
Self-Dual Electrodynamics via the Characteristic Method: Relativistic and Carrollian Perspectives
Ningbo University（宁波大学）；Peking University（北京大学）；Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（爱因斯坦研究所））；Southeast University（东南大学）；King’s College London（伦敦国王学院）
School of Basic and Applied Sciences, K. R. Mangalam University（K.R.曼加拉姆大学基础与应用科学学院）；Saha Institute of Nuclear Physics（萨哈核物理研究所）；Homi Bhabha National Institute（霍米·巴巴国立学院）
本文构建了Carrollian轴子电动力学理论，通过$c \ o 0$展开得到电型和磁型两类，发现磁型理论中存在Witten效应的Carrollian类比，但线性磁电效应消失。
The problem of dynamical chiral symmetry breaking (DCSB) in multidimensional quantum electrodynamics (QED) is considered. It is shown that for six-dimensional QED the phenomenon of DSCB exists in ladder model for any coupling.
It is well known that the geometrical framework of Riemannian geometry that underlies general relativity and its torsionful extension to Riemann-Cartan geometry can be obtained from a procedure known as gauging the Poincare algebra. Recently it has been shown that gauging the centrally extended Galilei algebra, known as the Bargmann algebra, leads to a geometrical framework that when made dynamical gives rise to Horava-Lifshitz gravity. Here we consider the case where we contract the Poincare algebra by sending the speed of light to zero leading to the Carroll algebra. We show how this algebra…
The dynamical breaking of gauge symmetry in the supersymmetric quantum electrodynamics in three-dimensional spacetime is studied at two-loop approximation. At this level, the effective superpotential is evaluated in a supersymmetric phase. At one-loop order, we observe a generation of the Chern-Simons term due to a parity violating term present in the classical action. At two-loop order, the scalar background superfield acquires a nonvanishing vacuum expectation value, generating a mass term $A^αA_α$ through Coleman-Weinberg mechanism. It is observed that the mass of gauge superfield is predom…
The two-dimensional aether-superspace is constructed and the superfield techniques are applied to the study of dynamical generation of mass in the Lorentz-violating supersymmetric quantum electrodynamics in two dimensions of spacetime. It is shown that such model presents a dynamical generation of mass to the gauge aether-superfield and its dispersion relation has the structure similar of the CPT-even Lorentz-breaking models.
We study the dynamical mass generation in Pseudo Quantum Electrodynamics (PQED) coupled to the Gross-Neveu (GN) interaction, in (2+1) dimensions, at both zero and finite temperatures. We start with a gapless model and show that, under particular conditions, a dynamically generated mass emerges. In order to do so, we use a truncated Schwinger-Dyson equation, at the large-N approximation, in the imaginary-time formalism. In the instantaneous-exchange approximation (the static regime), we obtain two critical parameters, namely, the critical number of fermions $N_c(T)$ and the critical coupling co…
We analytically describe the properties of the s-wave holographic superconductor with the Exponential nonlinear electrodynamics in the Lifshitz black hole background in four-dimensions. Employing an assumption the scalar and gauge fields backreact on the background geometry, we calculate the critical temperature as well as the condensation operator. Based on Sturm-Liouville method, we show that the critical temperature decreases with increasing exponential nonlinear electrodynamics and Lifshitz dynamical exponent, z, indicating that condensation becomes difficult. Also we find that the effects…
We show that the nonlinear Born-Infeld field equations supplemented by the "dynamical condition" (certain boundary condition for the field along the particle's trajectory) define perfectly deterministic theory, i.e. particle's trajectory is determined without any equations of motion. It is a first step towards constructing the consistent theory of point particles interacting with nonlinear electromagnetism.
The influence of a magnetic field on the mass generation in 2+1 dimensional QED is considered.It is shown that the magnetic field is a catalyst of the generation of a fermion dynamical mass. The mass arises in the system with arbitrary number of fermions, not only with $N\leq 4$, as it is in the system without the magnetic field. The polarization tensor is calculated for a constant magnetic field.
In the present contribution we show that the introduction of axial currents in electrodynamics can explain the quantization of electric charge and introduces a dynamical discreteness of space-time, justifying thus the regularization of Feymman's integrals.
We study the dynamical generation of masses for fundamental fermions in quenched quantum electrodynamics in the presence of weak magnetic fields using Schwinger-Dyson equations. Contrary to the case where the magnetic field is strong, in the weak field limit the coupling should exceed certain critical value in order for the generation of masses to take place, just as in the case where no magnetic field is present. The weak field limit is defined as eB << m(0)^2, where m(0) is the value of the dynamically generated mass in the absence of the field. We carry out a numerical analysis to study the…
In the present contribution we show that the introduction of a conserved axial current in electrodynamics can explain the quantization of electric charge, preserving parity conservation, and introduces a dynamical discreteness into space-time.
We study the non-perturbative phenomena of Dynamical Mass Generation and Confinement by truncating at the non-perturbative level the Schwinger-Dyson equations in Maxwell-Chern-Simons planar quantum electrodynamics. We obtain numerical solutions for the fermion propagator in Landau gauge within the so-called rainbow approximation. A comparison with the ordinary theory without the Chern-Simons term is presented.
In this work, we carry out a study of the conserved quantities and dynamical structure of the four-dimensional modified axion electrodynamics theory described by the axion-photon coupling. In the first part of the analysis, we employ the covariant phase space method to construct the conserved currents and to derive the Noether charges associated with the gauge symmetry of the theory. We further derive the improved energy-momentum tensor using the Belinfante-Rosenfeld procedure, which leads us to the expressions for the energy, momentum, and energy flux densities. Thereafter, with the help of F…
We examine three versions of non-relativistic electrodynamics, known as the electric and magnetic limit theories of Maxwell's equations and Galilean electrodynamics (GED) which is the off-shell non-relativistic limit of Maxwell plus a free scalar field. For each of these three cases we study the couplings to non-relativistic dynamical charged matter (point particles and charged complex scalars). The GED theory contains besides the electric and magnetic potentials a so-called mass potential making the mass parameter a local function. The electric and magnetic limit theories can be coupled to tw…
We investigate the existence of action for both the electric and magnetic sectors of Galilean Electrodynamics using Helmholtz conditions. We prove the existence of unique action in magnetic limit with the addition of a scalar field in the system. The check also implies the non existence of action in the electric sector of Galilean electrodynamics. Dirac constraint analysis of the theory reveals that there are no local degrees of freedom in the system. Further, the theory enjoys a reduced but an infinite dimensional subalgebra of Galilean conformal symmetry algebra as global symmetries. The ful…
Carroll fermions from null reduction: A case of good and bad fermions
Center for Space, Time and the Quantum（时空与量子中心）；Aix-Marseille Univ., Centre de Physique Thèorique（艾克斯-马赛大学，理论物理中心）；Facultad de Ingeniería, Universidad San Sebastían（圣塞巴斯蒂安大学工程学院）；Centro de Estudios Científicos (CECs)（科学研究中心）；Department of Physics, Indian Institute of Technology Kharagpur（印度理工学院卡拉格普尔分校物理系）
Using the Dirac Method, we study the Hamiltonian consistency for three field theories. First we study the electrodynamics a la Hořava and we show that this system is consistent for an arbitrary dynamical exponent $z.$ Second, we study a Lifshitz type electrodynamics, which was proposed in [1]. For this last system we found that the canonical momentum and the electrical field are related through a Proca type Green function, however this system is consistent. In addition, we show that the anisotropic Yang-Mills theory with dynamical exponent $z=2$ is consistent. Finally, we study a generalized a…
We study by non perturbative techniques a vector, axial--vector theory characterized by a parameter which interpolates between pure vector and chiral Schwinger models. Main results are two windows in the space of parameters which exhibit acceptable solutions. In the first window we find a free massive and a free massless bosonic excitations and interacting left--right fermions endowed with asymptotic \hbox{states}, which feel however a long range interaction. In the second window the massless bosonic excitation is a negative norm state which can be consistently expunged from the ``physical" Hi…
In a quantum electrodynamics theory that is realized by critical scaling and anomalous dimensions, the action is not chiral invariant and there are no dynamical Goldstone or Higgs boson bound states. In the mean-field approximation to a chiral invariant four-fermion theory the associated mean-field sector action is not chiral invariant either and it also possesses no dynamical bound states, with Goldstone and Higgs bosons instead being generated by an accompanying four-fermion residual interaction. In this paper we show that if a critical scaling electrodynamics in which the dimension $d_θ$ of…
Charged Lifshitz black holes for the Einstein-Proca-Maxwell system with a negative cosmological constant in arbitrary dimension $D$ are known only if the dynamical critical exponent is fixed as $z=2(D-2)$. In the present work, we show that these configurations can be extended to much more general charged black holes which in addition exist for any value of the dynamical exponent $z>1$ by considering a nonlinear electrodynamics instead of the Maxwell theory. More precisely, we introduce a two-parametric nonlinear electrodynamics defined in the more general, but less known, so-called $(\mathcal{…
We consider reduced quantum electrodynamics (RQED$_{d_γ,d_e}$) a model describing fermions in a $d_e$-dimensional space-time and interacting via the exchange of massless bosons in $d_γ$-dimensions ($d_e \leq d_γ$). We compute the two-loop mass anomalous dimension, $γ_m$, in general RQED$_{4,d_e}$ with applications to RQED$_{4,3}$ and QED$_4$. We then proceed on studying dynamical (parity-even) fermion mass generation in RQED$_{4,d_e}$ by constructing a fully gauge-invariant gap equation for RQED$_{4,d_e}$ with $γ_m$ as the only input. This equation allows for a straightforward analytic computa…
Connections and dynamical trajectories in generalised Newton-Cartan gravity II. An ambient perspective
Institut Denis Poisson, Université de Tours, Université d’Orléans, CNRS（德尼·普瓦松研究所，图尔大学，奥尔良大学，法国国家科学研究中心）；Departamento de Ciencias Físicas, Universidad Andres Bello（安第斯贝尔托大学物理科学系）；Departamento de Física, Universidad Técnica Federico Santa María Centro Científico-Tecnológico de Valparaíso（费德里科·圣玛丽亚理工大学物理系，瓦尔帕莱索科技中心）
We study the dynamical behavior of spinor particles, and get the energy-momentum relation of charged particles by solving the Dirac equation. Based on the energy-momentum relation, we investigate the laws of thermodynamics and the weak cosmic censorship conjecture for the (2+1)-dimensional regular black hole with nonlinear electrodynamics sources in the normal phase space and the extended phase space. Our results show that the first law of thermodynamics as well as the weak cosmic censorship conjecture are valid in both the phase spaces. However, the second law of thermodynamics is violated in…
We briefly outline several main results concerning various new physically relevant features found in gravity -- both ordinary Einstein or $f(R)=R+R^2$ gravity in the first-order formalism, coupled to a special kind of nonlinear electrodynamics containing a square-root of the standard Maxwell Lagrangian and known to produce charge confinement in flat spacetime.
We suggest a method to simulate lattice compact Quantum Electrodynamics (cQED) using ultracold atoms in optical lattices, which includes dynamical Dirac fermions in 2+1 dimensions. This allows to test dynamical effects of confinement as well as 2d flux loops deformations and breaking, and to observe Wilson-loop area-law.
Gauge theories are of paramount importance in our understanding of fundamental constituents of matter and their interactions. However, the complete characterization of their phase diagrams and the full understanding of non-perturbative effects are still debated, especially at finite charge density, mostly due to the sign-problem affecting Monte Carlo numerical simulations. Here, we report the Tensor Network simulation of a three dimensional lattice gauge theory in the Hamiltonian formulation including dynamical matter: Using this sign-problem-free method, we simulate the ground states of a com…
