Page 1

Displaying 1 – 15 of 15

Showing per page

On a generalized Calabi-Yau equation

Hongyu Wang, Peng Zhu (2010)

Annales de l’institut Fourier

Dealing with the generalized Calabi-Yau equation proposed by Gromov on closed almost-Kähler manifolds, we extend to arbitrary dimension a non-existence result proved in complex dimension 2 .

On Deligne-Malgrange lattices, resolution of turning points and harmonic bundles

Takuro Mochizuki (2009)

Annales de l’institut Fourier

In this short survey, we would like to overview the recent development of the study on Deligne-Malgrange lattices and resolution of turning points for algebraic meromorphic flat bundles. We also explain their relation with wild harmonic bundles. The author hopes that it would be helpful for access to his work on wild harmonic bundles.

On g -natural conformal vector fields on unit tangent bundles

Mohamed Tahar Kadaoui Abbassi, Noura Amri (2021)

Czechoslovak Mathematical Journal

We study conformal and Killing vector fields on the unit tangent bundle, over a Riemannian manifold, equipped with an arbitrary pseudo-Riemannian g -natural metric. We characterize the conformal and Killing conditions for classical lifts of vector fields and we give a full classification of conformal fiber-preserving vector fields on the unit tangent bundle endowed with an arbitrary pseudo-Riemannian Kaluza-Klein type metric.

On left invariant CR structures on SU ( 2 )

Andreas Čap (2006)

Archivum Mathematicum

There is a well known one–parameter family of left invariant CR structures on S U ( 2 ) S 3 . We show how purely algebraic methods can be used to explicitly compute the canonical Cartan connections associated to these structures and their curvatures. We also obtain explicit descriptions of tractor bundles and tractor connections.

On natural metrics on tangent bundles of Riemannian manifolds

Mohamed Tahar Kadaoui Abbassi, Maâti Sarih (2005)

Archivum Mathematicum

There is a class of metrics on the tangent bundle T M of a Riemannian manifold ( M , g ) (oriented , or non-oriented, respectively), which are ’naturally constructed’ from the base metric g [Kow-Sek1]. We call them “ g -natural metrics" on T M . To our knowledge, the geometric properties of these general metrics have not been studied yet. In this paper, generalizing a process of Musso-Tricerri (cf. [Mus-Tri]) of finding Riemannian metrics on T M from some quadratic forms on O M × m to find metrics (not necessary Riemannian)...

On projectable objects on fibred manifolds

Vasile Cruceanu, Marcela Popescu, Paul Popescu (2001)

Archivum Mathematicum

The aim of this paper is to study the projectable and N -projectable objects (tensors, derivations and linear connections) on the total space E of a fibred manifold ξ , where N is a normalization of ξ .

On the completeness of total spaces of horizontally conformal submersions

Mohamed Tahar Kadaoui Abbassi, Ibrahim Lakrini (2021)

Communications in Mathematics

In this paper, we address the completeness problem of certain classes of Riemannian metrics on vector bundles. We first establish a general result on the completeness of the total space of a vector bundle when the projection is a horizontally conformal submersion with a bound condition on the dilation function, and in particular when it is a Riemannian submersion. This allows us to give completeness results for spherically symmetric metrics on vector bundle manifolds and eventually for the class...

Currently displaying 1 – 15 of 15

Page 1