Hyper-Kähler geometry and dualization

2005

We construct N=4 supersymmetric mechanics using the N=4 nonlinear chiral supermultiplet. The two bosonic degrees of freedom of this supermultiplet parameterize the sphere S(2) and go into the bosonic components of the standard chiral multiplet when the radius of the sphere goes to infinity. We construct the most general action and demonstrate that the nonlinearity of the supermultiplet results in the deformation of the connection, which couples the fermionic degrees of freedom with the background, and of the bosonic potential. Also a non-zero magnetic field could appear in the system.

It is presented a method of construction of sigma-models with target space geometries different from conformally flat ones. The method is based on a treating of a constancy of a coupling constant as a dynamical constraint following as an equation of motion. In this way we build N=4 and N=8 supersymmetric four-dimensional sigma-models in d=1 with hyper-Kahler target space possessing one isometry, which commutes with supersymmetry.

Communications in Mathematical Physics, 2006

We solve the long standing problem of finding an off-shell supersymmetric formulation for a general N = (2, 2) nonlinear two dimensional sigma model. Geometrically the problem is equivalent to proving the existence of special coordinates; these correspond to particular superfields that allow for a superspace description. We construct and explain the geometric significance of the generalized Kähler potential for any generalized Kähler manifold; this potential is the superspace Lagrangian.

2005

We show that the nonlinear chiral supermultiplet allows one to construct, over given two-dimensional bosonic mechanics, the family of two-dimensional N = 4 supersymmetric mechanics parameterized with the holomorphic function λ(z). We show, that this family includes, as a particular case, the N = 4 superextensions of twodimensional mechanics with magnetic fields, which have factorizable Schroedinger equations.

Physical Review D, 2001

The geometric models of N = 4 supersymmetric mechanics with (2d.2d) I C-dimensional phase space are proposed, which can be viewed as one-dimensional counterparts of two-dimensional N = 2 supersymmetric sigma-models by Alvarez-Gaumé and Freedman. The related construction of supersymmetric mechanics whose phase space is a Kähler supermanifold is considered. Also, its relation with antisymplectic geometry is discussed.

Czechoslovak Journal of Physics, 2006

We present a method of construction of sigma-models with target space geometries different from conformally flat ones. The method is based on treating the constancy of a coupling constant as a dynamical constraint following as an equation of motion. In this way we build N = 8 supersymmetric four-dimensional sigma-models in d = 1 with hyper-K/ihler target space possessing one isometry, which commutes with supersymmetry.

Letters in Mathematical Physics, 2011

We discuss the conditions for extra supersymmetry in N = (2, 2) supersymmetric nonlinear sigma models described by one left and one right semi-chiral superfield and carrying a pair of non-commuting complex structures. Focus is on linear non-manifest transformations of these fields that have an algebra that closes off-shell. We solve the conditions for invariance of the action and show that a class of these solutions correspond to a bihermitian metric of signature (2, 2) and a pseudo-hyperkähler geometry of the target space. This is in contrast to the usual sector of bi-hermitian geometry with commuting complex structures where extra supersymmetries lead to bi-hypercomplex target space geometry.

Physics Letters B, 2007

We analyse the geometry of four-dimensional bosonic manifolds arising within the context of N = 4, D = 1 supersymmetry. We demonstrate that both cases of general hyper-Kähler manifolds, i.e. those with translation or rotational isometries, may be supersymmetrized in the same way. We start from a generic N=4 supersymmetric three-dimensional action and perform dualization of the coupling constant, initially present in the action. As a result, we end up with explicit component actions for N = 4, D = 1 nonlinear sigma-models with hyper-Kähler geometry (with both types of isometries) in the target space. In the case of hyper-Kähler geometry with translational isometry we find that the action possesses an additional hidden N = 4 supersymmetry, and therefore it is N = 8 supersymmetric one.

Classical and Quantum Gravity, 2007

We perform an su(2) Hamiltonian reduction in the bosonic sector of the su(2)-invariant action for two free (4, 4, 0) supermultiplets. As a result, we get the five dimensional N = 4 supersymmetric mechanics describing the motion of an isospin carrying particle interacting with a Yang monopole. We provide the Lagrangian and Hamiltonian descriptions of this system. Some possible generalizations of the action to the cases of systems with a more general bosonic action, a four-dimensional system which still includes eight fermionic components, and a variant of five-dimensional N = 4 mechanics constructed with the help of the ordinary and twisted N = 4 hypermultiplets were also considered.

Communications in Mathematical Physics, 1987

We present a new construction of hyperkahler metrics that derives from the 3-dimensional N = 4 nonlinear supermultiplet. Further, we give a detailed description of the nonlinear multiplet in N = 2 and 4 superspace.