5,372 research outputs found
Free differential algebras and generic 2D dilatonic (super)gravities
The field equations for both generic bosonic and generic locally
supersymmetric 2D dilatonic gravity theories in the absence of matter are
written as free differential algebras. This constitutes a generalization of the
gauge theoretic formulation. Moreover, it is shown that the condition of free
differential algebra can be used to obtain the equations in the locally
supersymmetric case. Using this formulation, the general solution of the field
equations is found in the language of differential forms. The relation with the
ordinary formulation and the coupling to supersymmetric conformal matter are
also studied.Comment: 19 pages, Late
Minimal D=4 supergravity from the superMaxwell algebra
We show that the first-order D=4, N=1 pure supergravity lagrangian four-form
can be obtained geometrically as a quadratic expression in the curvatures of
the Maxwell superalgebra. This is achieved by noticing that the relative
coefficient between the two terms of the Lagrangian that makes the action
locally supersymmetric also determines trivial field equations for the gauge
fields associated with the extra generators of the Maxwell superalgebra. Along
the way, a convenient geometric procedure to check the local supersymmetry of a
class of lagrangians is developed.Comment: Plain latex, 14 pages. Two misprints corrected, one reference adde
Superalgebra cohomology, the geometry of extended superspaces and superbranes
We present here a cohomological analysis of the new spacetime superalgebras
that arise in the context of superbrane theory. They lead to enlarged
superspaces that allow us to write D-brane actions in terms of fields
associated with the additional superspace variables. This suggests that there
is an extended superspace/worldvolume fields democracy for superbranes.Comment: 12 pages, LATEX. Invited lecture delivered at the XXXVII Karpacz
Winter School on "New Developments in Fundamental Interaction Theories" (6-15
February, 2001, Karpacz, Poland). To be published in the Proceeding
Contractions from to the M-theory superalgebra extended by additional fermionic generators
We study here the generalized Weimar-Woods contractions of the superalgebra
in order to obtain a suitable algebra that could
describe the gauge group of supergravity. The contracted superalgebras
are assumed to be given in terms of fermionic extensions of the M-theory
superalgebra. We show that the only superalgebra of this type obtained by
contraction is the only one for which the three-form of supergravity
cannot be trivialized. Therefore, supergravity cannot be connected in
this way with a contraction of
Generalizations of Maxwell (super)algebras by the expansion method
The Lie algebras expansion method is used to show that the Maxwell
(super)algebras and some of their generalizations can be derived in a simple
way as particular expansions of o(3,2) and osp(N|4).Comment: Discussion slightly expanded; published versio
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