Related papers: The low-energy N=4 SYM effective action in diverse…
We discuss the general issues and ambiguities involved in matching the exact results for the low energy effective action of scale invariant N=2 supersymmetric QCD to those obtained by instanton methods. We resolve the reported disagreements…
The Coulomb branch of $N=2$ supersymmetric gauge theories in four dimensions is described in general by an integrable Hamiltonian system in the holomorphic sense. A natural construction of such systems comes from two-dimensional gauge…
We study one-loop low-energy effective action in the hypermultiplet sector for ${\cal N}=2$ superconformal models. Any such a model contains ${\cal N}=2$ vector multiplet and some number of hypermultiplets. Gauge group $G$ is assumed to be…
We analyse the relationship between the N=2 harmonic and projective superspaces which are the only approaches developed to describe general N=2 super Yang-Mills theories in terms of off-shell supermultiplets with conventional supersymmetry.…
We consider noncommutative {\cal N}=4 supersymmetric U(N) Yang-Mills theory. Using the {\cal N}=1 superfield formalism and the background field method we compute one-loop four point contributions to the effective action and compare the…
We show that the four derivative terms in the effective action of three-dimensional N=8 Yang-Mills theory are determined by supersymmetry. These terms receive both perturbative and non-perturbative corrections. Using our technique for…
We present the explicit superfield realizations of the hidden $SU(4)$ and $O(5)$ $R$-symmetries in $4D, {\cal N}=4$ and $5D, {\cal N}=2$ supersymmetric Yang-Mills theories in the harmonic superspace approach. The $R$-symmetry…
We analyze the superfield equations of the 4-dimensional N=2 and N=4 SYM-theories using light-cone gauge conditions and the harmonic-superspace approach. The harmonic superfield equations of motion are drastically simplified in this gauge,…
We present $\mathcal{N}=2$ superconformal $\mathsf{U}(1)$ duality-invariant models for an Abelian vector multiplet coupled to conformal supergravity. In a Minkowski background, such a nonlinear theory is expected to describe (the planar…
We study the gauge transformation of the recently computed one-loop four-point function of {\cal N}=4 supersymmetric Yang-Mills theory with gauge group U(N). The contributions from nonplanar diagrams are not gauge invariant. We compute…
For all types of N=4 anti-de Sitter (AdS) supersymmetry in three dimensions, we construct manifestly supersymmetric actions for Abelian vector multiplets and explain how to extend the construction to the non-Abelian case. Manifestly N=4…
This dissertation reviews various aspects of the N=4 supersymmetric Yang--Mills theory in particular in relation with the AdS/CFT correspondence. The first two chapters are introductory. The first one contains a description of the general…
We discuss a formulation of harmonic superspace approach for noncommuative N=2 supersymmetric field theories paying main attention on new features arising because of noncommutativity. We begin with the known notions of the harmonic…
We study a problem of systematical evaluation of the quantum corrections for general 4D supersymmetric K\"ahler sigma models with chiral and antichiral superpotentials. Using manifestly reparametrization covariant techniques (the…
We integrate out fast varying quantum fluctuations around static A_4 and A_i fields for the SU(N) gauge group. By assuming that the gluon fields are slowly varying but allowing for an arbitrary amplitude of A_4 we obtain two variants of the…
When the $SU(N)$ ${\cal N} = 4$ super-Yang-Mills (SYM) theory with complexified gauge coupling $\tau$ is placed on a round four-sphere and deformed by an ${\cal N} = 2$-preserving mass parameter $m$, its free energy $F(m, \tau, \bar \tau)$…
The low energy effective theory on the moduli space of vacua of 4d superYang-Mills (sYM) theory defines a special K\"ahler geometry. For simple sYM gauge algebras, $\mathfrak{g}$, we classify all compatible special K\"ahler structures by…
We initiate a systematic study of amplitudes with massive external particles on the Coulomb-branch of N=4 super Yang Mills theory: 1) We propose that (multi-)soft-scalar limits of massless amplitudes at the origin of moduli space can be…
We consider the harmonic-superspace formalism in the $N=4$ supersymmetry using the $SU(4)/SU(2)\times SU(2)\times U(1)$ harmonics which was earlier applied to the abelian gauge theory. The N=4 non-abelian constraints in a standard…
We describe an infinite-dimensional algebra of hidden symmetries of N=4 supersymmetric Yang-Mills (SYM) theory. Our derivation is based on a generalization of the supertwistor correspondence. Using the latter, we construct an infinite…