Large gauge Ward identity

Large Gauge Ward Identity

We study the question of the Ward identity for “large” gauge invariance in 0+1 dimensional theories. We derive the relevant Ward identities for a single flavor fermion and a single flavor complex scalar field interacting with an Abelian gauge field. These identities are nonlinear. The Ward identity for any other complicated theory can be derived from these basic sets of identities. However, the...

The Master Ward Identity andGeneralized

Generalized Ward identity and gauge invariance of the color-superconducting gap

Due to asymptotic freedom of quantum chromodynamics (QCD) the strong coupling constant g becomes small at large momentum [1]. In cold, dense quark matter, the typical momentum scale is of the order of the quark chemical potential μ. Consequently, at asymptotically large densities, where μ ≫ ΛQCD, quark matter is a weakly coupled system. In this case, the dominant interaction between two quarks ...

Ward identity and electrical conductivity in hot QED

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 of a new diagram in the integral equation for the vertex that has not been considered before. The real part of this diagram is subleading and therefore the fi...

Structure of Fluctuation Terms in the Trace Dynamics Ward Identity

We give a detailed analysis of the anti-self-adjoint operator contribution to the fluctuation terms in the trace dynamics Ward identity. This clarifies the origin of the apparent inconsistency between two forms of this identity discussed in Chapter 6 of our recent book on emergent quantum theory.