3 citations · 8 across the 5 of their papers we have counts for
5 papers
Non-umbilical quaternionic contact hypersurfaces in hyper-Kähler manifolds
Stefan Ivanov, Ivan Minchev, Dimiter Vassilev
We show that any compact quaternionic contact (qc) hypersurfaces in a hyper-Kähler manifold which is not totally umbilical has an induced qc structure, locally qc homothetic to the…
The quaternionic Heisenberg group and Heterotic String Solutions with non-constant dilaton in dimensions 7 and 5
Marisa Fernandez, Stefan Ivanov, Luis Ugarte +1
New smooth solutions of the Strominger system with non vanishing flux, non-trivial instanton and non-constant dilaton based on the quaternionic Heisenberg group are constructed. We…
Quaternionic contact hypersurfaces in hyper-Kähler manifolds
Stefan Ivanov, Ivan Minchev, Dimiter Vassilev
We describe explicitly all quaternionic contact hypersurfaces (qc-hypersurfaces) in the flat quaternion space $\Hnn$ and the quaternion projective space. We show that up to a quate…
An Obata type result for the first eigenvalue of the sub-Laplacian on a CR manifold with a divergence free torsion
Stefan Ivanov, Dimiter Vassilev
We prove a CR Obata type result that if the first positive eigenvalue of the sub-Laplacian on a compact strictly pseudoconvex pseudohermitian manifold with a divergence free pseudo…
Quaternionic Kaehler and Spin(7) metrics arising from quaternionic contact Einstein structures
Luis C. de Andrés, Marisa Fernández, Stefan Ivanov +3
We construct left invariant quaternionic contact (qc) structures on Lie groups with zero and non-zero torsion and with non-vanishing quaternionic contact conformal curvature tensor…