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K. V. Stepanyantz

Publications and source records attributed to K. V. Stepanyantz.

62 records · Page 4Linked to original sources

Four-loop verification of algorithm for Feynman diagrams summation in N=1 supersymmetric electrodynamics

A method of Feynman diagrams summation, based on using Schwinger-Dyson equations and Ward identities, is verified by calculating some four-loop diagrams in N=1 supersymmetric electrodynamics, regularized by higher derivatives. In particular, for the considered diagrams correctness of an additional identity for Green functions, which is not reduced to the gauge Ward identity, is proved.

hep-th↗

Investigation of the anomaly puzzle in N=1 supersymmetric electrodynamics

Using Schwinger-Dyson equations and Ward identities in N=1 supersymmetric electrodynamics, regularized by higher derivatives, we find, that it is possible to calculate some contributions to the two-point Green function of the gauge field and to the beta-function exactly to all orders of the perturbation theory. The results are applied for the investigation of the anomaly puzzle in the considered theory.

hep-th↗

Anomaly puzzle in N=1 supersymmetric electrodynamics as artifact of dimensional reduction

Calculations of the two-loop $β$-function for N=1 supersymmetric electrodynamics are compared for regularizations by higher derivatives and by the dimensional reduction. The renormalized effective action are found to be the same for both regularizations. However, unlike the dimensional reduction, the higher derivative regularization does not lead to anomaly puzzle, because it allows to perform correct calculation of diagrams with insertions of counterterms. In particular, using this method a contribution of diagrams with insertions of counterterms is calculated exactly to all orders. This contribution appears to be 0 if the theory is regularized by the dimensional reduction. We argue, that this result follows from mathematical inconsistency of the dimensional reduction and is responsible for the anomaly puzzle.

hep-th↗

Detailed analysis of the dependence of the one-loop counterterms on the gauge and parametrization in the Einstein gravity with the cosmological constant

In this paper, the dependence of the Einstein gravity with the cosmological constant as well as of this theory in the first-order formalism on the gauge and parametrization is been analyzed. The one-loop counterterms off the mass shell have been plainly calculated in arbitrary gauge and parametrization. The tensor package of analytic calculations, written in REDUCE, allowed all the calculations to be carried out. A method of renormalization group functions calculations off shell is discussed.

hep-th↗