Mario Tonin

Covariant Action for the Super-Five-Brane of M Theory

We propose a complete, d=6 covariant and kappa-symmetric, action for the M theory five-brane propagating in D=11 supergravity background. This opens a direct way of relating a wide class of super-p -brane solutions of string theory with the five-brane of M theory, which should be useful for studying corresponding dualities and nonperturbative aspects of these theories. {copyright} {ital 1997} {ital The American Physical Society}

Covariant action for a D = 11 five-brane with the chiral field

Abstract We propose a complete Born-Infeld-like action for a bosonic 5-brane with a worldvolume chiral field in a background of gravitational and antisymmetric gauge fields of D = 11 supergravity. When the five-brane couples to a three-rank antisymmetric gauge field, local symmetries of the five-brane require the addition to the action of an appropriate Wess-Zumino term. To preseve general coordinate and Lorentz invariance of the model we introduce a single auxiliary scalar field. The auxiliary field can be eliminated by gauge fixing a corresponding local symmetry at the price of the loss of manifest d = 6 worldvolume covariance. The double dimensional reduction of the five-brane model results in the Born-Infeld action with the Wess-Zumino term for a D = 10 four-D-brane.

Lorentz-invariant actions for chiral p-forms

We demonstrate how a Lorentz-covariant formulation of the chiral p-form model in D=2(p+1) containing infinitely many auxiliary fields is related to a Lorentz-covariant formulation with only one auxiliary scalar field entering a chiral p-form action in a nonpolynomial way. The latter can be regarded as a consistent Lorentz-covariant truncation of the former. We make the Hamiltonian analysis of the model based on the nonpolynomial action and show that the Dirac constraints have a simple form and are all first class. In contrast with the Siegel model the constraints are not the square of second-class constraints. The canonical Hamiltonian is quadratic and determines the energy of a single chiral p-form. In the case of D=2 chiral scalars the constraint can be improved by use of a {open_quotes}twisting{close_quotes} procedure (without the loss of the property to be first class) in such a way that the central charge of the quantum constraint algebra is zero. This points to the possible absence of an anomaly in an appropriate quantum version of the model. {copyright} {ital 1997} {ital The American Physical Society}

Superfield Formulation of Extended BRS Symmetry

Abstract In the light of a recently discovered new BRS-like symmetry in gauge theories, we reformulate a superfield treatment of lagrangian gauge theories supplemented by gauge-fixing and Faddeev-Popov terms.

Superstrings and supermembranes in the doubly supersymmetric geometrical approach

Abstract We perform a generalization of the geometrical approach to describing extended objects for studying the doubly supersymmetric twistor-like formulation of super p -branes. Some basic features of the embedding world supersurface into target superspace specified by a geometrodynamical condition are considered. It is shown that the main attributes of the geometrical approach, such as the second fundamental form and extrinsic torsion of the embedded surface, and the Codazzi, Gauss and Ricci equations, have their doubly supersymmetric counterparts. At the same time the embedding of the supersurface into target superspace has its particular features. For instance, the embedding may cause more rigid restrictions on the geometrical properties of the supersurface. This is demonstrated with the examples of an N = 1 twistor-like supermembrane in D = 11 and type II superstrings in D = 10, where the geometrodynamical condition causes the embedded supersurface to be minimal and puts the theories on the mass shell.

The superembedding origin of the Berkovits pure spinor covariant quantization of superstrings

Abstract We show that the pure spinor formalism proposed by Berkovits to covariantly quantize superstrings is a gauge fixed, twisted version of the complexified n=2 superembedding formulation of the superstring. This provides the Berkovits approach with a geometrical superdiffeomorphism invariant ground. As a consequence, the absence of the worldsheet (super)diffeomorphism ghosts in the pure spinor quantization prescription and the nature of the Berkovits BRST charge and antighost are clarified. Since superembedding is classically equivalent to the Green–Schwarz formulation, we thus also relate the latter to the pure spinor construction.

On the Equivalence of Different Formulations of the M Theory Five-Brane

Abstract We show that the field equations for the supercoordinates and the self-dual antisymmetric tensor field derived from the recently constructed κ-invariant action for the M theory five-brane are equivalent to the equations of motion obtained in the doubly supersymmetric geometrical approach at the worldvolume component level.

D = 10, N = IIB supergravity

We present a manifestly Lorentz invariant and supersymmetric component field action for

Note on manifest Lorentz and general coordinate invariance in duality symmetric models

D = 10

Duality symmetric actions with manifest space-time symmetries

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