Results 21 to 30 of about 347 (52)

Parallelizations on products of spheres and octonionic geometry

Complex Manifolds, 2019
A classical theoremof Kervaire states that products of spheres are parallelizable if and only if at least one of the factors has odd dimension. Two explicit parallelizations on Sm × S2h−1 seem to be quite natural, and have been previously studied by the ...
Parton Maurizio, Piccinni Paolo
doaj   +1 more source

Collections of parabolic orbits in homogeneous spaces, homogeneous dynamics and hyperkahler geometry

, 2016
Let $M$ be a hyperk\"ahler manifold with $b_2(M)\geq 5$. We improve our earlier results on the Morrison-Kawamata cone conjecture by showing that the Beauville-Bogomolov square of the primitive MBM classes (i.e.
Amerik, Ekaterina, Verbitsky, Misha
core   +1 more source

On quaternionic functions [PDF]

, 2013
Several sets of quaternionic functions are described and studied.
Dolbeault, Pierre
core   +2 more sources

The odd-dimensional Goldberg Conjecture

, 2003
An odd-dimensional version of the Goldberg conjecture was formulated and proved by Boyer and Galicki, using an orbifold analogue of Sekigawa's formulas, and an approximation argument of K-contact structures with quasi-regular ones.
Apostolov, Blair, Blair, Blair, Boyer, Gallot, Olszak, Sekigawa, Thomas   +8 more
core   +7 more sources

On the cohomology of some exceptional symmetric spaces

, 2016
This is a survey on the construction of a canonical or "octonionic K\"ahler" 8-form, representing one of the generators of the cohomology of the four Cayley-Rosenfeld projective planes.
A. Borel, A. Borel, A. Moroianu, C.R. LeBrun, F.L. Zak, H. Toda, K. Galicki, K. Ishitoya, K. Ishitoya, K. Ishitoya, L. Ornea, M. Berger, M. Castrillón López, M. Castrillón López, M. Nakagawa, M. Parton, M. Parton, S. Araki, S.M. Salamon, T. Friedrich, T. Watanabe   +20 more
core   +1 more source

Almost h-semi-slant Riemannian maps [PDF]

, 2012
As a generalization of slant Riemannian maps (Sahin), semi-slant Riemannian maps (Park), almost h-slant submersions (Park 2012), and almost h-semi-slant submersions (Park 2011), we introduce the notion of almost h-semi-slant Riemannian maps from almost ...
Park, Kwang-Soon
core  

A connection with parallel totally skew-symmetric torsion on a class of almost hypercomplex manifolds with Hermitian and anti-Hermitian metrics

, 2010
The subject of investigations are the almost hypercomplex manifolds with Hermitian and anti-Hermitian (Norden) metrics. A linear connection D is introduced such that the structure of these manifolds is parallel with respect to D and its torsion is ...
Alekseevsky D. V., Boyer C. P., Ganchev G., Ganchev G., Gaudochon P., Gray A., Gray A., Kirichenko V. F., KOSTADIN GRIBACHEV, MANCHO MANEV, Manev M., Mekerov D., Mekerov D., Mekerov D., Michelson J.   +14 more
core   +1 more source

3-quasi-Sasakian manifolds

, 2007
In the present paper we carry on a systematic study of 3-quasi-Sasakian manifolds. In particular we prove that the three Reeb vector fields generate an involutive distribution determining a canonical totally geodesic and Riemannian foliation.
A.R. Rustanov, Antonio De Nicola, B. Cappelletti Montano, Beniamino Cappelletti Montano, C. Călin, C. Udriste, C.P. Boyer, D.E. Blair, D.E. Blair, D.E. Blair, D.E. Blair, Giulia Dileo, J.C. Gonzales, K. Yano, N.J. Hitchin, P.M. Chacón, P.M. Chacón, S. Kanemaki, S. Sasaki, S. Tanno, T. Friedrich, T. Kashiwada, V.F. Kirichenko, Y.Y. Kuo, Y.Y. Kuo, Z. Olszak   +25 more
core   +6 more sources

The geometry of recursion operators

, 2007
We study the fields of endomorphisms intertwining pairs of symplectic structures. Using these endomorphisms we prove an analogue of Moser's theorem for simultaneous isotopies of two families of symplectic forms.
A. Andrada, A. Fino, A.S. Dancer, C. Benson, C.M. Hull, C.T.C. Wall, D. Guan, D. Kotschick, D. Kotschick, F.A. Bogomolov, F.J. Turiel, G. Bande, G. Bande, G. Bande, H. Geiges, I.G. Dotti, J. Barrett, J. Moser, M.F. Atiyah, N.J. Hitchin, S.K. Donaldson, W. Barth   +21 more
core   +3 more sources

Special almost Hermitian geometry

, 2005
We study the classification of special almost hermitian manifolds in Gray and Hervella's type classes. We prove that the exterior derivatives of the symplectic form and the complex volume form contain all the information about the intrinsic torsion of ...
Berger, Bröcker, Chiossi, Cleyton, Falcitelli, Francisco Martín Cabrera, Gray, Gray, Gray, Hitchin, Martín Cabrera, Martín Cabrera, Salamon, Swann   +13 more
core   +1 more source