Nikolay Kozyrev

We study the gauge structure of interacting antisymmetric tensor field models obtained by the dimensional reduction on a group manifold. In such models a dimensionful parameter related to the size of the compact manifold plays the role of a coupling constant. We focus on open issues of reducibility of the gauge transformations in these theories and show that stages of reducibility of the interacting models coincide with ones of corresponding free counterparts.

We construct superconformal mechanics with N = 3 and N = 4 supersymmetries that were inspired by analogy with the supersymmetric Schwarzian mechanics. The Schwarzian, being another system with superconformal symmetry, provides insight into the field content of supersymmetric mechanics, most notably, on the number and properties of the fermionic fields involved. Adding more fermionic fields (four in the N = 3 case and eight in the N = 4 case) made it possible to construct systems possessing maximal superconformal symmetries in N = 3 and N = 4, namely osp(3|2) and D(1, 2; α). In the case of N = 4 supersymmetry, we explicitly construct a new variant of N = 4 superconformal mechanics in which all bosonic subalgebras of the D(1, 2; α) superalgebra have a bosonic realization. In addition, the constructed systems involve the so(3) currents whose parameterization is not fixed, which allows one to consider different underlying geometries.

Construction of the superfield action of the N = (1, 0), d = 6 non-Abelian tensor multiplet based on the non-Abelian tensor hierarchies is considered. It is shown that while straightforward non-Abelian generalization of the Pasti-Sorokin-Tonin action is not a workable solution, a suitable truncation of the PST action still can be modified to include non-Abelian tensor field. In the modified action, the self-dual equation of motion of the tensor field is induced by a composite Lagrange multiplier, which is not a component of a standard dynamical tensor multiplet. As a result, the constraint that enforces the gauge group to be non-compact, as in the usual tensor hierarchies, can be avoided.

In this paper the harmonic superspace action of the tensor multiplet of N = (1, 0), d = 6 supersymmetry is constructed which in the bosonic limit reduces to the known Pasti-Sorokin-Tonin action for the self-dual tensor field. The action involves, besides the potential containing the dynamical fields, also an auxiliary tensor multiplet and a set of analytic superfields with gauge PST scalar among them. For each of gauge symmetries of the PST action, a superfield analog is found. The equations of motion are calculated and it is shown that no extra degrees of freedom appear.

In this paper we demonstrate that the different generalizations of the Schwarzians, supersymmetric or purely bosonic, can be easily constructed by using the nonlinear realizations technique.