On Odd Parameters in Geometry

Dimitry Leites¹

¹Department of Mathematics, University of Stockholm, Sweden

Journal of Lie Theory, Tome 33 (2023) no. 4, pp. 965-1004

Résumé

(1) In 1976, looking at the list of simple finite-dimensional complex Lie superalgebras, J. Bernstein and I, and independently M. Duflo, observed that some divergence-free vectorial Lie superalgebras have deformations with odd parameters and conjectured that no other simple Lie superalgebras have such deformations. Here, I prove this conjecture and overview the known classification of simple finite-dimensional complex Lie superalgebras, their presentations, realizations, and relations with simple Lie (super)algebras over fields of positive characteristic.
(2) Any ringed space of the form (a manifold M, the sheaf of sections of the exterior algebra of a vector bundle over M) is called split supermanifold. K. Gawedzki (1977) and M. Batchelor (1979) proved that every smooth supermanifold is split. In 1982, P. Green and V. P. Palamodov showed that a complex-analytic supermanifold can be non-split. So far, researchers considered only even obstructions to splitness. This lead them to the conclusion that any supermanifold of superdimension m|1 is split. I'll show there are non-split supermanifolds of superdimension m|1; e.g., certain superstrings, the obstructions to their splitness depend on odd parameters.

Détail

Classification : 58A50, 17B60
Mots-clés : Simple Lie superalgebra, deformation, non-split supermanifold