I.B. Samsonov

Quantum = 3, d = 3 Chern-Simons matter theories in harmonic superspace

We develop the background field method for studying classical and quantum aspects of = 3, d = 3 Chern-Simons and matter theories in = 3 harmonic superspace. As one of the immediate consequences, we prove a nonrenormalization theorem implying the ultra-violet finiteness of the corresponding supergraph perturbation theory. We also derive the general hypermultiplet and gauge superfield propagators in a Chern-Simons background. The leading supergraphs with two and four external lines are evaluated. In contrast to the non-supersymmetric theory, the leading quantum correction to the massive charged hypermultiplet proves to be the super Yang-Mills action rather than the Chern-Simons one. The hypermultiplet mass is induced by a constant triplet of central charges in the = 3, d = 3 Poincare superalgebra.

Scale invariant low-energy effective action in N=3 SYM theory

Abstract Using the harmonic superspace approach we study the problem of low-energy effective action in N =3 SYM theory. The candidate effective action is a scale and γ5-invariant functional in full N =3 superspace built out of N =3 off-shell superfield strengths. This action is constructed as N =3 superfield generalization of F4/φ4 component term which is leading in the low-energy effective action and is simultaneously the first nontrivial term in scale invariant Born–Infeld action. All higher-order terms in the scale invariant Born–Infeld action are also shown to admit an off-shell superfield completion in N =3 harmonic superspace.

Renormalizability of nonanticommutative N=(1,1) theories with singlet deformation

Abstract We study the quantum properties of two theories with a nonanticommutative (or nilpotent) chiral singlet deformation of N = ( 1 , 1 ) supersymmetry: the Abelian model of a vector gauge multiplet and the model of a gauge multiplet interacting with a neutral hypermultiplet. In spite of the presence of a negative-mass-dimension coupling constant (deformation parameter), both theories are shown to be finite in the sense that the full effective action is one-loop exact and contains finitely many divergent terms, which vanish on-shell. The β-function for the coupling constant is equal to zero. The divergencies can all be removed off shell by a redefinition of one of the two scalar fields of the gauge multiplet. These notable quantum properties are tightly related to the existence of a Seiberg–Witten-type transformation in both models.

Two-loop effective potentials in general N=2, d=3 chiral superfield model

Abstract We study local superspace contributions to the low-energy effective action in general chiral three-dimensional superfield model. The effective Kahler and chiral potentials are computed in an explicit form up to the two-loop order. In accordance with the non-renormalization theorem, the ultraviolet divergences appear only in the full superspace while the effective chiral potential receives only finite quantum contributions in the massless case. As an application, the two-loop effective scalar potential is found for the three-dimensional N = 2 supersymmetric Wess–Zumino model.

Two-loop low-energy effective actions in \mathcal{N}=2 and \mathcal{N}=4 three-dimensional SQED

A bstractWe study two-loop Euler-Heisenberg effective actions in three-dimensional

Superconformal \mathcal{N} = {3} SYM low-energy effective action

\mathcal{N}=2

Two-loop low-energy effective action in Abelian supersymmetric Chern–Simons matter models

and

Vector-multiplet effective action in the non-anticommutative charged hypermultiplet model

\mathcal{N}=4

Two-loop effective potentials in general N=2N=2, d=3d=3 chiral superfield model

supersymmetric quantum electrodynamics (SQED) without Chern-Simons term. We find exact expressions for propagators of chiral superfields interacting with slowly-varying

On low-energy effective action in three-dimensional = 2 and = 4 supersymmetric electrodynamics

\mathcal{N}=2