The subelliptic heat kernels of the quaternionic Hopf fibration

F Baudoin, J Wang - Potential analysis, 2014 - Springer
The main goal of this work is to study the sub-Laplacian of the unit sphere which is obtained
by lifting with respect to the Hopf fibration the Laplacian of the quaternionic projective space …

The Lichnerowicz and Obata first eigenvalue theorems and the Obata uniqueness result in the Yamabe problem on CR and quaternionic contact manifolds

S Ivanov, D Vassilev - Nonlinear Analysis, 2015 - Elsevier
We report on some aspects and recent progress in certain problems in the sub-Riemannian
CR and quaternionic contact (QC) geometries. The focus are the corresponding Yamabe …

The lichnerowicz–obata theorem on sub-riemannian manifolds with transverse symmetries

F Baudoin, B Kim - The Journal of Geometric Analysis, 2016 - Springer
We prove a lower bound for the first eigenvalue of the sub-Laplacian on sub-Riemannian
manifolds with transverse symmetries. When the manifold is of H H-type, we obtain a …

The Obata sphere theorems on a quaternionic contact manifold of dimension bigger than seven

S Ivanov, A Petkov, D Vassilev - Journal of Spectral Theory, 2017 - ems.press
On a compact quaternionic contact (qc) manifold of dimension bigger than seven and
satisfying a Lichnerowicz type lower bound estimate we show that if the rst positive …

A Lichnerowicz-type result on a seven-dimensional quaternionic contact manifold

A Petkov - arxiv preprint arxiv:1404.4377, 2014 - arxiv.org
In this paper we establish an analogue of the classical Lichnerowicz'theorem giving a sharp
lower bound of the first non-zero eigenvalue of the sub-Laplacian on a compact seven …