23 research outputs found
Exact Renormalization Group in Algebraic Noncovariant Gauges
I study a class of Wilsonian formulations of non-Abelian gauge theories in
algebraic noncovariant gauges where the Wilsonian infrared cutoff is
inserted as a mass term for the propagating fields. In this way the
Ward-Takahashi identities are preserved to all scales. Nevertheless the
BRS-invariance in broken and the theory is gauge-dependent and unphysical at
. Then I discuss the infrared limit . I show that
the singularities of the axial gauge choice are avoided in planar gauge and in
light-cone gauge. Finally the rectangular Wilson loop of size is
evaluated at lowest order in perturbation theory and a noncommutativity between
the limits and is pointed out.Comment: 6 pages, latex2e, Proceeding of the Second Conference on the Exact R
Gauge-Invariant Renormalization Group at Finite Temperature
We propose a gauge-invariant version of Wilson Renormalization Group for
thermal field theories in real time. The application to the computation of the
thermal masses of the gauge bosons in an SU(N) Yang-Mills theory is discussed.Comment: 23 pages, latex2e, 1 EPS figure. The discussions of BRS identities
and of the RG kernel have been modified. Final version, to appear on Nucl.
Phys.
Axial anomalies in gauge theory by exact renormalization group method
The global chiral symmetry of a gauge theory is studied in the
framework of renormalization group (RG). The theory is defined by the RG flow
equations in the infrared cutoff \L and the boundary conditions for the
relevant couplings. The physical theory is obtained at \L=0. In our approach
the symmetry is implemented by choosing the boundary conditions for the
relevant couplings not at the ultraviolet point \L=\L_0\to\infty but at the
physical value \L=0. As an illustration, we compute the triangle axial
anomalies.Comment: 11 pages + 1 appended EPS figure, LaTeX, UPRF 94-39
Background field method in the Wilson formulation
A cutoff regularization for a pure Yang-Mills theory is implemented within
the background field method keeping explicit the gauge invariance of the
effective action. The method has been applied to compute the beta function at
one loop order.Comment: LaTex 13 pages, 1 figure; to appear in Nucl.Phys.
Spontaneous symmetry breaking with Wilson renormalization group
We study the conditions under which a symmetry is spontaneously broken in the
Wilson renormalization group formulation. Both for a global and local symmetry,
the result is that in perturbation theory one has to perform a fine tuning of
the boundary conditions for the flow of the relevant couplings. We consider in
detail the discrete case and the Abelian Higgs model.Comment: 19 pages, latex, no figure
Gauge invariance and background field formalism in the exact renormalisation group
We discuss gauge symmetry and Ward-Takahashi identities for Wilsonian flows
in pure Yang-Mills theories. The background field formalism is used for the
construction of a gauge invariant effective action. The symmetries of the
effective action under gauge transformations for both the gauge field and the
auxiliary background field are separately evaluated. We examine how the
symmetry properties of the full theory are restored in the limit where the
cut-off is removed.Comment: version to be published in PL