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Z. Khviengia

Publications and source records attributed to Z. Khviengia.

9 recordsLinked to original sources
arXiv1997

D=9 supergravity and p-brane solitons

We construct the N=2, D=9 supergravity theory up to the quartic fermionic terms and derive the supersymmetry transformation rules for the fields modulo cubic fermions. We consider a class of p-brane solutions of this theory, the stainless p-branes, which cannot be isotropically oxidized into higher dimensions. The new stainless elementary membrane and elementary particle solutions are found. It is explicitly verified that these solutions preserve half of the supersymmetry.

hep-th↗
arXiv1997

Towards a Field Theory of F-theory

We make a proposal for a bosonic field theory in twelve dimensions that admits the bosonic sector of eleven-dimensional supergravity as a consistent truncation. It can also be consistently truncated to a ten-dimensional Lagrangian that contains all the BPS p-brane solitons of the type IIB theory. The mechanism allowing the consistent truncation in the latter case is unusual, in that additional fields with an off-diagonal kinetic term are non-vanishing and yet do not contribute to the dynamics of the ten-dimensional theory. They do, however, influence the oxidation of solutions back to twelve dimensions. We present a discussion of the oxidations of all the basic BPS solitons of M-theory and the type IIB string to D=12. In particular, the NS-NS and R-R strings of the type IIB theory arise as the wrappings of membranes in D=12 around one or other circle of the compactifying 2-torus.

hep-th↗
arXiv1996

Intersecting M-branes and bound states

In this paper, we construct multi-scalar, multi-center $p$-brane solutions in toroidally compactified M-theory. We use these solutions to show that all supersymmetric $p$-branes can be viewed as bound states of certain basic building blocks, namely $p$-branes that preserve $1/2$ of the supersymmetry. We also explore the M-theory interpretation of $p$-branes in lower dimensions. We show that all the supersymmetric $p$-branes can be viewed as intersections of M-branes or boosted M-branes in $D=11$.

hep-th↗
arXiv1995

Physical states for non-linear $SO(N)$ strings

We study some low-lying physical states in a superstring theory based on the quadratically non-linear $SO(N)$--extended superconformal algebra. In the realisation of the algebra that we use, all the physical states are discrete, analogous to the situation in a one-scalar bosonic string. The BRST operator for the $N=3$ case needs to be treated separately, and its construction is given here.

hep-th↗
arXiv1995

$N=1$ Superstring in $2+2$ Dimensions

In this paper we construct a $(2,2)$ dimensional string theory with manifest $N=1$ spacetime supersymmetry. We use Berkovits' approach of augmenting the spacetime supercoordinates by the conjugate momenta for the fermionic variables. The worldsheet symmetry algebra is a twisted and truncated ``small'' $N=4$ superconformal algebra. The realisation of the symmetry algebra is reducible with an infinite order of reducibility. We study the physical states of the theory by two different methods. In one of them, we identify a subset of irreducible constraints, which is by itself critical. We construct the BRST operator for the irreducible constraints, and study the cohomology and interactions. This method breaks the $SO(2,2)$ spacetime symmetry of the original reducible theory. In another approach, we study the theory in a fully covariant manner, which involves the introduction of infinitely many ghosts for ghosts.

hep-th↗
arXiv1994

A Superstring Theory in 2+2 Dimensions

In this paper we construct a $(2,2)$ dimensional string theory with manifest $N=1$ spacetime supersymmetry. We use Berkovits' approach of augmenting the spacetime supercoordinates by the conjugate momenta for the fermionic variables. The worldsheet symmetry algebra is a twisted and truncated ``small'' $N=4$ superconformal algebra. The physical spectrum of the open string contains an infinite number of massless states, including a supermultiplet of a self-dual Yang-Mills field and a right-handed spinor and a supermultiplet of an anti-self-dual Yang-Mills field and a left-handed spinor. The higher-spin multiplets are natural generalisations of these self-dual and anti-self-dual multiplets.

hep-th↗
arXiv1993

BRST Operator for Superconformal Algebras with Quadratic Nonlinearity

We construct the quantum BRST operators for a large class of superconformal and quasi--superconformal algebras with quadratic nonlinearity. The only free parameter in these algebras is the level of the (super) Kac-Moody sector. The nilpotency of the quantum BRST operator imposes a condition on the level. We find this condition for (quasi) superconformal algebras with a Kac-Moody sector based on a simple Lie algebra and for the $Z_2\times Z_2$--graded superconformal algebras with a Kac-Mody sector based on the superalgebra $osp(N\vert 2M)$ or $s\ell(N+2\vert N)$.

hep-th↗
arXiv1992

Self-Duality in 3+3 Dimensions and the KP Equation

We consider two types of generalized self-duality conditions for Yang-Mills fields on paracomplex manifolds of arbitrary dimension. We then specialize to $3+3$ dimensions and show how one can obtain the KP equation from these self-duality conditions on $SL(2,R)$ valued gauge fields.

hep-th↗