相关论文: Low-energy dynamics in N = 2 super QED: Two-loop a…
The two-loop Euler-Heisenberg-type effective action for N = 1 supersymmetric QED is computed within the background field approach. The background vector multiplet is chosen to obey the constraints D_\a W_\b = D_{(\a} W_{\b)} = const, but is…
We study two-loop Euler-Heisenberg effective actions in three-dimensional N=2 and N=4 supersymmetric quantum electrodynamics (SQED) without Chern-Simons term. We find exact expressions for propagators of chiral superfields interacting with…
We study two-loop quantum corrections to the low-energy effective actions in N=(2,2) and N=(4,4) SQED in the Coulomb branch. In the latter model, the low-energy effective action is described by a generalized Kahler potential which depends…
A closed-form expression is obtained for a holomorphic sector of the two-loop low-energy effective action for the N = 4 super Yang-Mills theory on its Coulomb branch where the gauge group SU(N) is spontaneously broken to SU(N-1) x U(1) and…
We compute two-loop low-energy effective actions in Abelian Chern-Simons matter models with N=2 and N=3 supersymmetry up to four-derivative order. Calculations are performed with a slowly-varying gauge superfield background. Though the…
A closed-form expression is obtained for a holomorphic sector of the two-loop Euler-Heisenberg type effective action for N = 2 supersymmetric QED derived in hep-th/0308136. In the framework of the background-field method, this sector is…
More evidence is provided for the conjectured correspondence between the D3-brane action in AdS_5 x S^5 and the low-energy effective action for N = 4 SU(N) SYM on its Coulomb branch, where the gauge group SU(N) is spontaneously broken to…
Using the N = 2 off-shell formulation in harmonic superspace for N = 4 super Yang-Mills theory, we present a representation of the one-loop effective action which is free of so-called coinciding harmonic singularities and admits a…
We show that in arbitrary even dimension, the two-loop scalar QED Heisenberg-Euler effective action can be reduced to simple one-loop quantities, using just algebraic manipulations, when the constant background field satisfies F^2 = -f^2 I,…
We develop the derivative expansion of the one-loop ${\cal N}=4$ SYM effective action depending both on ${\cal N}=2$ vector multiplet and on hypermultiplet background fields. We get a new derivation of the complete ${\cal N}=4$…
We review the approach to calculation of one-loop effective action in ${\cal N}=2,4$ SYM theories. We compute the non-holomorphic corrections to low-energy effective action (higher derivative terms) in ${\cal N}=2$, SU(2) SYM theory coupled…
We review the basic results concerning the structure of effective action in N=4 supersymmetric Yang-Mills theory in Coulomb phase. Various classical formulations of this theory are considered. We show that the low-energy effective action…
We compute the two-loop effective K\"ahler potential in three-dimensional N=2 supersymmetric electrodynamics with Chern-Simons kinetic term for the gauge superfield. The effective action is constructed on the base of background field method…
We present, in the N=2, D=4 harmonic superspace formalism, a general method for constructing the off-shell effective action of an N=2 abelian gauge superfield coupled to matter hypermultiplets. Using manifestly N=2 supersymmetric harmonic…
The Euler-Heisenberg effective action in a self-dual background is remarkably simple at two-loop. This simplicity is due to the inter-relationship between self-duality, helicity and supersymmetry. Applications include two-loop helicity…
The effective low-energy hyper-K"ahler potential for a massive N=2 matter in the N=2 super-QCD is investigated. The N=2 extended supersymmetry severely restricts that N=2 matter self-couplings so that their exact form can be fixed by a few…
Using the covariant N=2 harmonic supergraph techniques we calculate the one-loop low-energy effective action of N=4 super-Yang-Mills theory in Coulomb branch with gauge group SU(2) spontaneously broken down to U(1). The full dependence of…
We briefly review a recent progress in constructing the low-energy effective action in ${\cal N}=2,4$ super Yang-Mills theories. Using superfield methods we study the one- and two-loop contributions to the effective action in the Coulomb…
We review the recent progress in studying the quantum structure of $6D$, ${\cal N}=(1,0)$ and ${\cal N}=(1,1)$ supersymmetric gauge theories formulated through unconstrained harmonic superfields. The harmonic superfield approach allows one…
We study one-loop effective action of hypermultiplet theory coupled to external N=2 vector multiplet. We formulate this theory in N=1 superspace and develop a general approach to constructing derivative expansion of the effective action…