Related papers: Analytic results for the effective action
At the simple example of a massless scalar field propagating in the static background we study the resummed expressions for the effective action at zero and finite temperature that are free from a usual sickness of the effective action…
Some free--field spectral problems on a generalised cylinder are revisited. In two dimensions, conformal scalar effective actions for various boundary conditions are written in elliptic function terms and some special values given. Fermions…
We compute the effective action of QED at one loop order for an electric field which points in the $\hat{z}$ direction and depends arbitrarily upon the light cone time coordinate, $x^+ = (x^0 + x^3)/\sqrt{2}$. This calculation generalizes…
We study two-loop Euler-Heisenberg effective actions in three-dimensional N=2 and N=4 supersymmetric quantum electrodynamics (SQED) without Chern-Simons term. We find exact expressions for propagators of chiral superfields interacting with…
It is shown how operator regularization can be used to obtain an expansion of the effective action in powers of derivatives of the background field. This is applied to massless scalar electrodynamics to find the one-loop corrections to the…
The "exact" or "functional" renormalization group equation describes the renormalization group flow of the effective average action $\Gamma_k$. The ordinary effective action $\Gamma_0$ can be obtained by integrating the flow equation from…
In the $\mathcal{N}=1$, $d=3$ superspace, we propose a massive superfield theory formulated in terms of a spinor gauge superfield, whose component content includes a two-form field, and a real scalar matter superfield. For this model, we…
The main goal of this paper is a direct diagrammatic evaluation of the effective four-photon Lagrangian of the Euler-Heisenberg type for the quantum electrodynamics of massive charged vector bosons. This QED model is naturally embedded in…
We consider quantum electrodynamics with additional coupling of spinor fields to the space-time independent axial vector violating both Lorentz and CPT symmetries. The Fock-Schwinger proper time method is used to calculate the one-loop…
Extending work by Gies and Karbstein on the Euler-Heisenberg Lagrangian, it has recently been shown that the one-loop propagator of a charged scalar particle in a constant electromagnetic field has a one-particle reducible contribution in…
We review the one-loop effective action in scalar QED and the Schwinger effect in a uniform electric field in a two-dimensional (anti-) de Sitter space. The Schwinger effect has a thermal interpretation in terms of the effective temperature…
A method is described for the development of the one-loop effective action expansion as an asymptotic series in inverse powers of the fermion mass. The method is based on the Schwinger-DeWitt proper-time technique, which allows for loop…
We derive a systematic treatment of one-loop effective potentials for interacting scalar fields in curved spacetimes, providing a general formula valid in arbitrary geometries and explicit results for de Sitter and anti-de Sitter…
We derive the quantum effective action up to second order in gradients and up to two-loop order for an interacting scalar field theory. This expansion of the effective action is useful to study problems in cosmological settings where…
We revisit the effective field theory of long relativistic strings such as confining flux tubes in QCD. We derive the Polchinski-Strominger interaction by a calculation in static gauge. This interaction implies that a non-critical string…
We consider the one-loop effective action due to a spinor loop coupled to an abelian vector and axial vector field background. After rewriting this effective action in terms of an auxiliary non-abelian gauge connection, we use the De Witt…
We derive a new kind of recursion relation to obtain the one-particle-irreducible (1PI) Feynman diagrams for the effective action. By using this method, we have obtained the graphical representation of the four-loop effective action in case…
We compute the three-loop beta functions of long-range multi-scalar models with general quartic interactions. The long-range nature of the models is encoded in a kinetic term with a Laplacian to the power $0<\zeta<1$, rendering the…
In this work we make use of proper-time method to evaluate Schwinger effect in the presence of Lorentz-violating background fields. Specifically, we evaluate the one-loop effective Lagrangian in the presence of Lorentz-violating time-like…
We present explicit closed-form expressions for the two-loop Euler-Heisenberg Lagrangians in a constant self-dual field, for both spinor and scalar QED. The simplicity of these representations allows us to examine in detail the asymptotic…