All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 45 Next

Displaying 881 – 900 of 1303

Showing per page

Riemannian manifolds not quasi-isometric to leaves in codimension one foliations

Paul A. Schweitzer (2011)

Annales de l’institut Fourier

Every open manifold L of dimension greater than one has complete Riemannian metrics g with bounded geometry such that ( L , g ) is not quasi-isometric to a leaf of a codimension one foliation of a closed manifold. Hence no conditions on the local geometry of ( L , g ) suffice to make it quasi-isometric to a leaf of such a foliation. We introduce the ‘bounded homology property’, a semi-local property of ( L , g ) that is necessary for it to be a leaf in a compact manifold in codimension one, up to quasi-isometry. An essential...

Ruled W-surfaces in Minkowski 3-space ℜ 1 3

Rashad A. Abdel-Baky, H. N. Abd-Ellah (2008)

Archivum Mathematicum

In this paper, we study a spacelike (timelike) ruled W-surface in Minkowski 3-space which satisfies nontrivial relation between elements of the set { K , K I I , H , H I I } , where ( K , H ) and ( K I I , H I I ) are the Gaussian and mean curvatures of the first and second fundamental forms, respectively. Finally, some examples are constructed and plotted.

Seiberg-Witten Theory

Jürgen Eichhorn, Thomas Friedrich (1997)

Banach Center Publications

We give an introduction into and exposition of Seiberg-Witten theory.

Selfdual Einstein hermitian four-manifolds

Vestislav Apostolov, Paul Gauduchon (2002)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

We provide a local classification of selfdual Einstein riemannian four-manifolds admitting a positively oriented hermitian structure and characterize those which carry a hyperhermitian, non-hyperkähler structure compatible with the negative orientation. We show that selfdual Einstein 4-manifolds obtained as quaternionic quotients of ℍ P 2 and ℍ H 2 are hermitian.

Selfdual spaces with complex structures, Einstein-Weyl geometry and geodesics

David M J. Calderbank, Henrik Pedersen (2000)

Annales de l'institut Fourier

We study the Jones and Tod correspondence between selfdual conformal 4 -manifolds with a conformal vector field and abelian monopoles on Einstein-Weyl 3 -manifolds, and prove that invariant complex structures correspond to shear-free geodesic congruences. Such congruences exist in abundance and so provide a tool for constructing interesting selfdual geometries with symmetry, unifying the theories of scalar-flat Kähler metrics and hypercomplex structures with symmetry. We also show that in the presence...

Self-duality and pointwise Osserman manifolds

Dimitri V. Alekseevsky, Novica Blažić, Neda Bokan, Zoran Rakić (1999)

Archivum Mathematicum

This paper is a contribution to the mathematical modelling of the hump effect. We present a mathematical study (existence, homogenization) of a Hamilton-Jacobi problem which represents the propagation of a front f lame in a striated media.

Currently displaying 881 – 900 of 1303