scholarly journals Composite and Background Fields in Non-Abelian Gauge Models

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1985
Author(s):  
Pavel Yu. Moshin ◽  
Alexander A. Reshetnyak

A joint introduction of composite and background fields into non-Abelian quantum gauge theories is suggested based on the symmetries of the generating functional of Green’s functions, with the systematic analysis focused on quantum Yang–Mills theories, including the properties of the generating functional of vertex Green’s functions (effective action). For the effective action in such theories, gauge dependence is found in terms of a nilpotent operator with composite and background fields, and on-shell independence from gauge fixing is established. The basic concept of a joint introduction of composite and background fields into non-Abelian gauge theories is extended to the Volovich–Katanaev model of two-dimensional gravity with dynamical torsion, as well as to the Gribov–Zwanziger theory.

2012 ◽  
Vol 27 (22) ◽  
pp. 1250132 ◽  
Author(s):  
PETER M. LAVROV

We study a dependence of Green's functions for the Curci–Ferrari model on the parameter resembling the gauge parameter in massless Yang–Mills theories. It is shown that the on-shell generating functional of vertex functions (effective action) depends on this parameter.


1997 ◽  
Vol 12 (27) ◽  
pp. 4881-4893
Author(s):  
Taeyeon Lee

Renormalization of composite operators (at zero momentum transfer) is discussed in non-Abelian gauge theories. Composite operators are inserted into Green's functions by differentiating Z, the generating functional for Green's functions, with respect to the parameters coupled to the composite operators. In the case of the field strength tensor with no coupling parameter, it is possible to have the form of [Formula: see text] by rescaling gauge fields as Aμa → Aμa/g. Then the renormalization of [Formula: see text] can be carried out by the differentiation [Formula: see text]. By doing this, the renormalization procedure is different from the previous work of Kluberg–Stern and Zuber. The procedure of this paper naturally leads to the proper basis of operators which makes the triangular renormalization matrix. Explicit forms for the relation between bare and renormalized composite operators are presented, with the dimensional regularization and minimal subtraction scheme.


1991 ◽  
Vol 06 (22) ◽  
pp. 2051-2057 ◽  
Author(s):  
P. M. LAVROV

The gauge dependence of the Green's functions generating functionals in the framework of extended Lagrangian BRST quantization is investigated.


1998 ◽  
Vol 13 (23) ◽  
pp. 4077-4089 ◽  
Author(s):  
S. FALKENBERG ◽  
B. GEYER ◽  
P. LAVROV ◽  
P. MOSHIN

We consider generating functionals of Green's functions with external fields in the framework of BV and BLT quantization schemes for general gauge theories. The corresponding Ward identities are obtained, and the gauge dependence is studied.


2012 ◽  
Vol 27 (13) ◽  
pp. 1250067 ◽  
Author(s):  
P. M. LAVROV ◽  
O. V. RADCHENKO ◽  
A. A. RESHETNYAK

We continue investigation of soft breaking of BRST symmetry in the Batalin–Vilkovisky (BV) formalism beyond regularizations like dimensional ones used in our previous paper [JHEP 1110, 043 (2011)]. We generalize a definition of soft breaking of BRST symmetry valid for general gauge theories and arbitrary gauge fixing. The gauge dependence of generating functionals of Green's functions is investigated. It is proved that such introduction of a soft breaking of BRST symmetry into gauge theories leads to inconsistency of the conventional BV formalism.


1987 ◽  
Vol 02 (03) ◽  
pp. 785-796 ◽  
Author(s):  
D. G. C. McKEON ◽  
T. N. SHERRY

Operator regularization is introduced as a procedure to compute Green's functions perturbatively. At the one-loop level the effective action is regularized by means of the ζ-function. A perturbative expansion due to Schwinger allows one to compute from the ζ-function one-loop one-particle irreducible Green's functions. By regulating in this way, we do not have to compute Feynman diagrams, we avoid having to introduce a regulating parameter into the initial Lagrangian and we do not encounter any divergent integrals. This procedure is illustrated for N = 1 super Yang-Mills theory in which the one-loop one-particle irreducible Green's function associated with the decay of the supercurrent into a vector and a spinor particle is treated. Gauge invariance is automatically maintained and the usual anomaly in the divergence of the super-current is recovered.


1985 ◽  
Vol 63 (10) ◽  
pp. 1334-1336
Author(s):  
Stephen Phillips

The mathematical problem of inverting the operator [Formula: see text] as it arises in the path-integral quantization of an Abelian gauge theory, such as quantum electrodynamics, when no gauge-fixing Lagrangian field density is included, is studied in this article.Making use of the fact that the Schwinger source functions, which are introduced for the purpose of generating Green's functions, are free of divergence, a result that follows from the conversion of the exponentiated action into a Gaussian form, the apparently noninvertible partial differential equation, [Formula: see text], can, by the addition and subsequent subtraction of terms containing the divergence of the source function, be cast into a form that does possess a Green's function solution. The gauge-field propagator is the same as that obtained by the conventional technique, which involves gauge fixing when the gauge parameter, α, is set equal to one.Such an analysis suggests also that, provided the effect of fictitious particles that propagate only in closed loops are included for the study of Green's functions in non-Abelian gauge theories in Landau-type gauges, then, in quantizing either Abelian gauge theories or non-Abelian gauge theories in this generic kind of gauge, it is not necessary to add an explicit gauge-fixing term to the bilinear part of the gauge-field action.


1989 ◽  
Vol 04 (19) ◽  
pp. 5205-5212 ◽  
Author(s):  
P. M. LAVROV ◽  
S. D. ODINTSOV

The gauge dependence of the effective action of composite fields is investigated. The Ward identities for general gauge theories with arbitrary composite fields are found. It is proved that the extremum of the action of composite fields does not depend on the gauge condition. An example of the calculation of the effective action of composite fields in Yang-Mills theory is discussed.


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