Related papers: Ward Identities in Non-equilibrium QED

We study the discrete and gauge symmetries of Quantum Electrodynamics at finite temperature within the real-time formalism. The gauge invariance of the complete generating functional leads to the finite temperature Ward identities. These…

We derive the spectral representations of QED 3-point functions and then explicitly calculate the 3-point spectral densities in hard thermal loop approximation within the real time formalism. The Ward identities obeyed by the retarded and…

We derive spectral representations for the different components of the 4-point function at finite temperature in the real time formalism in terms of five real spectral densities. We explicitly calculate all these functions in QED in the…

In this paper we calculated the n-point hard-thermal-loop (HTL) vertex functions in QCD/QED for n= 2, 3 and 4 in the physical representation in the real time formalism (RTF). The result showed that the n-point HTL vertex functions can be…

We discuss, using the imaginary time method, some aspects of the connection between the Ward identity, the non-analyticity of amplitudes and the causality relation in QED at finite temperature.

We present an extension of the HTL resummation technique to non-equilibrium situations, starting from the real time formalism in the Keldysh representation. As an example we calculate the HTL photon self energy, from which we derive the…

We study the Ward identity for the effective photon-electron vertex summing the ladder diagrams contributing to the electrical conductivity in hot QED at leading logarithmic order. It is shown that the Ward identity requires the inclusion…

We derive quantum field theory Ward identities based on linear area preserving and conformal transformations in 2+1 dimensions. The identities relate Hall viscosities, Hall conductivities and the angular momentum. They apply both for…

We study the issue of symmetries and associated Ward-like identities in the context of two-particle-irreducible (2PI) functional techniques for abelian gauge theories. In the 2PI framework, the $n$-point proper vertices of the theory can be…

We study conformal Ward-Takahashi identities for two-point functions in $d(\geq3)$-dimensional finite-temperature conformal field theory. We first show that the conformal Ward-Takahashi identities can be translated into the intertwining…

We study the parity-breaking terms generated by the box diagram in 2+1 dimensional thermal QED. These lead, in the long wave limit, to a gauge invariant extensive action which behaves as 1/T at high temperature. In contrast, the effective…

We have written a {\it Mathematica} program that calculates the integrand corresponding to any amplitude in the closed-time-path formulation of real time statistical field theory. The program is designed so that it can be used by someone…

The Keldysh three- and four-point functions are related to analytical continuations of the Imaginary Time amplitudes,in momentum space. The relation provides an interesting interpretation of the amplitudes that are specific to the Keldysh…

We examine the parity violating terms generated by the box diagram in QED_3 at finite temperature. These lead to both extensive as well as non-extensive effective actions, which have very distinct behavior in the long wavelength and static…

It is shown that, by means of canonical operator approach, the Ward-Takahashi identity (WTI) at finite temperature $T$ and finite chemical potential $\mu$ for complete vectorial vertex and complete fermion propagator can be simply proven,…

We derive the complete set of supersymmetric Ward identities involving only two- and three- point proper vertices in supersymmetric QED. We also present the most general form of the proper vertices consistent with both the supersymmetric…

We investigate the use of the hard thermal loop (HTL) resummation technique in non-equilibrium field theory. We use the Keldysh representation of the real time formalism (RTF). We derive the HTL photon self energy and the resummed photon…

We present a general study of 3-point functions of conformal field theory (CFT) in momentum space, following a reconstruction method for tensor correlators, based on the solution of the conformal Ward identities (CWIs), introduced in recent…

Although noncommutative QED presents a nonabelian structure, it does not present structure constants. In view of this we investigate how Ward identity is satisfied in pair annihilation process and $\gamma \gamma \to \gamma \gamma$…

The Ward identities for the charge and heat currents are derived for particle-particle and particle-hole pairs. They are the exact constraints on the current-vertex functions imposed by conservation laws and should be satisfied by…