Dmitrij P. Sorokin

On the generalized action principle for superstrings and supermembranes

Abstract We revise the twistor-like superfield approach to describing super- p -branes by use of the basic principles of the group-manifold approach [Y. Neeman and T. Regge, Phys. Lett. B 74 (1978) 54; Rivista del Nuovo Cim. 1 (1978) 1; R. DAuria, P. Fre and T. Regge, Rivista del Nuovo Cim. 3 1980 1; L. Castellani, R. DAuria and P. Fre, Supergravity and superstrings, a geometric perspective, World Scientific, Singapore, 1991 (and references therein)]. A super- p -brane action is constructed solely by geometrical objects as the integral over a ( p + 1)-surface. The Lagrangian is the external product of supervielbein differential forms in world supersurface and target superspace without any use of Lagrange multipliers. This allows one to escape the problem of infinite reducible symmetries and redundant propagating fields. All the constraints on the geometry of world supersurface and the conditions of its embedding into target superspace arise from the action as differential form equations.

N=4 Superconformal Mechanics and the Potential Structure of AdS Spaces

Abstract The dynamics of an N =4 spinning particle in a curved background is described using the N =4 superfield formalism. The SU (2) local × SU (2) global N =4 superconformal symmetry of the particle action requires the background to be a real “Kahler-like” manifold whose metric is generated by a sigma-model superpotential. The anti-de-Sitter spaces are shown to belong to this class of manifolds.

Doubly supersymmetric null strings and string tension generation

Abstract We propose a twistor-like formulation of N = 1, D = 3, 4, 6 and 10 null superstrings. The model possesses N = 1 target space supersymmetry and n = D − 2 local worldsheet supersymmetry, the latter replaces the κ-symmetry of the conventional approach to the strings. Adding a Wess-Zumino term to a null superstring action we observe a string tension generation mechanism [J.A. De Azcarraga, J.M. Izquierdo and P.K. Townsend, Phys. Rev. D 45 (1992) 3321; P.K. Townsend, Phys. Lett. B 277 (1992) 285; E. Bergshoeff, L.A.J. London and P.K. Townsend, Class. Quantum Grav. 9 (1992) 2545; and F. Delduc, A. Galperin, P. Howe and E. Sokatchev, Phys. Rev. D 47 (1992) 578]: the induced worldsheet metric becomes nondegenerate and the resulting model turns out to be classically equivalent to the heterotic string.

New supersymmetric generalization of the Liouville equation

Abstract We present n = (1,1) and n = (1,0) supersymmetric generalization of the Liouville equation which originate from a geometrical approach to describing the classical dynamics of Green-Schwarz superstrings in N = 2, D = 3 and N = 1, D = 3 target superspace. Considered are a zero curvature representation and Backlund transformations associated with the supersymmetric non-linear equations.

Comment on {open_quotes}Covariant duality symmetric actions{close_quotes}

We demonstrate that an action proposed by A. Khoudeir and N. R. Pantoja in Phys. Rev. D53, 5974 (1996) for endowing Maxwell theory with manifest electric–magnetic duality symmetry contains, besides the Maxwell field, additional propagating vector degrees of freedom. Hence it cannot be considered as a duality symmetric action for a single abelian gauge field. PACS numbers: 11.15-q, 11.17+y The action proposed in [1] to describe abelian vector fields in four–dimensional Minkowski space has the following form: I = − 1 2 ∫ dx (un F αmnΦαmpu p + ΛαmpΦαmp), (1) where α = 1, 2, Lαβ is the antisymmetric unit tensor, Φαmp ≡ F α mp + L αβ F β mp, (2) is a self–dual tensor Φαmn ≡ 1 2 εmnpqLαβΦ βpq constructed out of the field strengths of two abelian gauge fields Aαm F α mn = ∂mA α n − ∂nA α m, F αmn = 1 2 εF α pq; (3) um(x) is an auxiliary vector field satisfying the condition umu m = −1, (4) and Λαmn ≡ − 1 2 εmnpqLαβΛ βpq (5) e–mail: pasti@pd.infn.it on leave from Kharkov Institute of Physics and Technology, Kharkov, 310108, Ukraine. e–mail: sorokin@pd.infn.it e–mail: tonin@pd.infn.it for details of notation and convention see [1]

D = (0|2) DIRAC–MAXWELL–EINSTEIN THEORY AS A WAY FOR DESCRIBING SUPERSYMMETRIC QUARTIONS

Drawing an analogy with the Dirac theory of fermions interacting with electromagnetic and gravitational field we write down supersymmetric equations of motion and construct a superfield action for particles with spin 1/4 and 3/4 (quartions), where the role of quartion momentum in effective (2+1)--dimensional space-time is played by an abelian gauge superfield propagating in a basic two-dimensional Grassmann-odd space with a cosmological constant showing itself as the quartion mass. So, the (0|2) (0 even and 2 odd) dimensional model of quartions interacting with the gauge and gravitational field manifests itself as an effective (2+1)-dimensional supersymmetric theory of free quartions.

An \({n = \left( {1,1} \right)}\) Super-Toda Model Based on OSp \(1|{\kern 1pt} 4\)

AbstractWe show that a Hamiltonian reduction of affine Lie superalgebras having bosonic simple roots (such as OSpn

An Super-Toda Model Based on OSp

1|{kern 1pt} 4