English

Rigidity of 2-step Carnot groups

Representation Theory 2017-05-23 v2 Differential Geometry

Abstract

In the present paper we study the rigidity of 2-step Carnot groups, or equivalently, of graded 2-step nilpotent Lie algebras. We prove the alternative that depending on bi-dimensions of the algebra, the Lie algebra structure makes it either always of infinite type or generically rigid, and we specify the bi-dimensions for each of the choices. Explicit criteria for rigidity of pseudo HH- and JJ-type algebras are given. In particular, we establish the relation of the so-called J2J^2-condition to rigidity, and we explore these conditions in relation to pseudo HH-type algebras.

Keywords

Cite

@article{arxiv.1603.00373,
  title  = {Rigidity of 2-step Carnot groups},
  author = {Mauricio Godoy Molina and Boris Kruglikov and Irina Markina and Alexander Vasil'ev},
  journal= {arXiv preprint arXiv:1603.00373},
  year   = {2017}
}

Comments

Except for minor polishing this version is enriched with two appendices concerning pseudo H-type algebras with J^2-condition. In Appendix A we relate these algebras to division algebras and their split versions. In Appendix B we relate these algebras to real graded simple Lie algebras

R2 v1 2026-06-22T13:01:13.248Z