Gauge Covariance and the Chiral Condenate in QED3
نویسندگان
چکیده
The ambiguities associated with the lack of gauge invariance in the non-perturbative truncations of Schwinger-Dyson equations (SDEs) are a challenging problem which has not yet been resolved in a decisive fashion. Pursuing this aim, we study dynamical chiral symmetry breaking in quantum electrodynamics in three space-time dimensions (QED3). We investigate the gauge dependence of the chiral condensate both in the quenched and the unquenched versions of the theory and emphasize the importance of taking into account the gauge covariance properties of the fermion propagator as dictated by its Landau-Khalatnikov-Fradkin transformation (LKFT). We present numerical solutions of the SDE of the fermion propagator which respect Ward-Green-Takahashi identities (WGTI) and LKFT simultaneously. As a striking consequence, we obtain a practically gauge independent chiral condensate.
منابع مشابه
Truncated Schwinger-Dyson equations and gauge covariance in QED3
We study the Landau-Khalatnikov-Fradkin transformations (LKFT) in momentum space for the dynamically generated mass function in QED3. Starting from the Landau gauge results in the rainbow approximation, we construct solutions in other covariant gauges. We confirm that the chiral condensate is gauge invariant as the structure of the LKFT predicts. We also check that the gauge dependence of the c...
متن کاملChiral symmetry breaking in three-dimensional quantum electrodynamics in the presence of irrelevant interactions: A renormalization group study
Motivated by recent theoretical approaches to high temperature superconductivity, we study dynamical mass generation in three-dimensional quantum electrodynamics !QED3" in the presence of irrelevant four-fermion quartic terms. The problem is reformulated in terms of the renormalization group flows of certain four-fermion couplings and charge, and then studied in the limit of a large number of f...
متن کاملChiral Symmetry Breaking in Three Dimensional QED
Over the past few years three dimensional Quantum Electrodynamics (QED3) has attracted a lot of attention, because it may be an effective theory for the underdoped and nonsuperconducting region of the phase diagram of high Tc cuprate compounds. We present results from lattice simulations of the non-compact version of the theory in order to address the issue of whether chiral symmetry is spontan...
متن کاملON THE INTERPLAY OF FERMIONS AND MONOPOLES IN COMPACT QED3 SIMON HANDS, JOHN B. KOGUT and BIAGIO LUCINI
The infra-red properties of three-dimensional abelian lattice gauge theory are known to be governed by a neutral plasma of magnetic monopole excitations. We address the fate of these monopoles in the presence of light dynamical fermions, using a lattice formulation of compact QED3 with Nf = 4 fermion flavors supplemented by a four-fermi contact term permitting numerical Monte Carlo simulations ...
متن کاملChiral Symmetry Restoration in Anisotropic QED3
We present results from a Monte Carlo simulation of non-compact lattice QED in 3 dimensions in which an explicit anisotropy κ between x and y hopping terms has been introduced into the action. Using a parameter set corresponding to broken chiral symmetry in the isotropic limit κ = 1, we study the chiral condensate on 16, 20, and 24 lattices as κ is varied, and fit the data to an equation of sta...
متن کامل