Smooth contact lifts to central extensions of Carnot groups

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Hakavuori, Eero, Heikkilä, Susanna, Ikonen, Toni
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912545647886336
author Hakavuori, Eero
Heikkilä, Susanna
Ikonen, Toni
author_facet Hakavuori, Eero
Heikkilä, Susanna
Ikonen, Toni
contents We consider the existence problem of lifting a smooth contact map between Carnot groups to a smooth contact map between central extensions of the original groups. Our main result is a necessary and sufficient criterion formulated using the pullback of any de Rham potential of the codomain central extension 2-cocycle: the Rumin differential of the pullback is in a linear image of the domain central extension 2-cocycle. We also show a necessary criterion using the Pansu pullback: the Pansu pullback of the codomain central extension 2-cocycle and a linear image of the domain central extension 2-cocycle are in the same Lie algebra cohomology class. We prove that the latter criterion is sufficient if the domain group is Lipschitz 1-connected, or if the pullback has maximal weight among Lie algebra 2-cohomology classes.
format Preprint
id arxiv_https___arxiv_org_abs_2508_14647
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Smooth contact lifts to central extensions of Carnot groups
Hakavuori, Eero
Heikkilä, Susanna
Ikonen, Toni
Differential Geometry
Metric Geometry
Primary: 35R03. Secondary: 20F65, 22E30, 53C17, 53C24, 57T10
We consider the existence problem of lifting a smooth contact map between Carnot groups to a smooth contact map between central extensions of the original groups. Our main result is a necessary and sufficient criterion formulated using the pullback of any de Rham potential of the codomain central extension 2-cocycle: the Rumin differential of the pullback is in a linear image of the domain central extension 2-cocycle. We also show a necessary criterion using the Pansu pullback: the Pansu pullback of the codomain central extension 2-cocycle and a linear image of the domain central extension 2-cocycle are in the same Lie algebra cohomology class. We prove that the latter criterion is sufficient if the domain group is Lipschitz 1-connected, or if the pullback has maximal weight among Lie algebra 2-cohomology classes.
title Smooth contact lifts to central extensions of Carnot groups
topic Differential Geometry
Metric Geometry
Primary: 35R03. Secondary: 20F65, 22E30, 53C17, 53C24, 57T10
url https://arxiv.org/abs/2508.14647