3 citations · 3 across the 4 of their papers we have counts for
8 papers
The first eigenvalue of the Dirac operator on locally reducible Riemannian manifolds
Bogdan Alexandrov
We prove a lower estimate for the first eigenvalue of the Dirac operator on a compact locally reducible Riemannian spin manifold with positive scalar curvature. We determine also t…
Hermitian spin surfaces with small eigenvalues of the Dolbeault operator
Bogdan Alexandrov
We study the compact Hermitian spin surfaces with positive conformal scalar curvature on which the first eigenvalue of the Dolbeault operator of the spin structure is the smallest…
On weak holonomy
Bogdan Alexandrov
We prove that SU(n) (n > 2) and Sp(n)U(1) (n > 1) are the only connected Lie groups acting transitively and effectively on some sphere which can be weak holonomy groups of a Rieman…
Sp(n)U(1)-connections with parallel totally skew-symmetric torsion
Bogdan Alexandrov
We consider the unique Hermitian connection with totally skew-symmetric torsion on a Hermitian manifold. We prove that if the torsion is parallel and the holonomy is Sp(n)U(1), con…
Hyper-Hermitian quaternionic Kaehler manifolds
Bogdan Alexandrov
We call a quaternionic Kaehler manifold with non-zero scalar curvature, whose quaternionic structure is trivialized by a hypercomplex structure, a hyper-Hermitian quaternionic Kaeh…
Weyl structures with positive Ricci tensor
Bogdan Alexandrov, Stefan Ivanov
We prove the vanishing of the first Betti number on compact manifolds admitting a Weyl structure whose Ricci tensor satisfies certain positivity conditions, thus obtaining a Bochne…