Results 31 to 40 of about 190,240 (109)
Paracomplex Paracontact Pseudo‐Riemannian Submersions
Geometry, Volume 2014, Issue 1, 2014., 2014 We introduce the notion of paracomplex paracontact pseudo‐Riemannian submersions from almost para‐Hermitian manifolds onto almost paracontact metric manifolds. We discuss the transference of structures on total manifolds and base manifolds and provide some examples.
S. S. Shukla +2 more
wiley +1 more source
Ricci collineations in Friedmann-Robertson-Walker spacetimes
, 2002 Ricci collineations and Ricci inheritance collineations of Friedmann-Robertson-Walker spacetimes are considered. When the Ricci tensor is nondegenerate, it is shown that the spacetime always admits a 15-parameter group of Ricci inheritance collineations;
Camci, U, Barnes, A
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Comment on Ricci Collineations for spherically symmetric space-times
, 2002 It is shown that the results of the paper Contreras, G., Nunez, L. A., Percoco, U. Ricci Collineations for Non-degenerate, Diagonal and Spherically Symmetric Ricci Tensors (2000). Gen. Rel. Grav.
Apostolopoulos, P.S., Tsamparlis, M.
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, 2021 By extending the notion of Lie derivative to distribution-valued tensor fields of order $m$, Lie derivatives with respect to $C^k$ vector fields, $k\geqslant m+1$, can be shown to be well defined. Geometric symmetries, definable in terms of these Lie derivatives, can then be considered.
Calles, Juan, Pantoja, Nelson
openaire +2 more sources
Matter collineations of BKS-type spacetimes
, 2014 In the present work, we classified the BKS-type (we refer to Bianchi-Kantowski- Sachs type spacetimes collectively as the BKS-type spacetimes) spacetimes (Bianchi type-V, Bianchi type-VI (m), Bianchi type-VII(m), Kantowski-Sachs) according to their ...
Korunur, Murat +4 more
core +3 more sources
Conformal Ricci collineations of static spherically symmetric spacetimes [PDF]
, 2008 Conformal Ricci collineations of static spherically symmetric spacetimes are studied. The general form of the vector fields generating conformal Ricci collineations is found when the Ricci tensor is non-degenerate, in which case the number of independent
Qadir, Asghar +2 more
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Collineations of polar spaces with restricted displacements
, 2011 Let J be a set of types of subspaces of a polar space. A collineation (which is a type-preserving automorphism) of a polar space is called J-domestic if it maps no flag of type J to an opposite one.
Van Maldeghem, Hendrik +5 more
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Mean Curvature Flow with a Neumann Boundary Condition in Flat Spaces [PDF]
, 2012 In this thesis I study mean curvature flow in both Euclidean and Minkowski space with a Neumann boundary condition. In Minkowski space I show that for a convex timelike cone boundary condition, with compatible spacelike initial data, mean curvature flow
LAMBERT, BENJAMIN,STEPHEN
core
The spinor representation of constant mean curvature one surfaces in the Hyperbolic space [PDF]
, 1970 We review and comment on some aspects of the spinor representation for constant mean curvature one surfaces in hyperbolic space developed by Bobenko-Pavlyukevich-Springborn in [1].
Nicolodi, Lorenzo +4 more
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Ricci collineations in perfect fluid Bianchi V spacetime [PDF]
, 2004 The Bianchi V spacetimes with perfect-fluid matter are classified according to their Ricci collineations. We have found that in the degenerate case there are infinitely many Ricci collineations whereas a subcase gives a finite number of Ricci ...
Türkyilmaz, I, Camci, U
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