Results 1 to 10 of about 445 (111)

Hypersurfaces in a conformally flat space with curvature collineation [PDF]

International Journal of Mathematics and Mathematical Sciences, 1991
We classify the shape operators of Einstein and pseudo Einstein hypersurfaces in a conformally flat space with a symmetry called curvature collineation. We solve the fundamental problem of finding all possible forms of non-diagonalizable shape operators.
K. L. Duggal, R. Sharma
doaj   +3 more sources

WEYL COLLINEATIONS THAT ARE NOT CURVATURE COLLINEATIONS [PDF]

International Journal of Modern Physics D, 2005
Though the Weyl tensor is a linear combination of the curvature tensor, Ricci tensor and Ricci scalar, it does not have all and only the Lie symmetries of these tensors since it is possible, in principle, that "asymmetries cancel." Here we investigate if, when and how the symmetries can be different.
Hussain, Ibrar, Qadir, Asghar, Saifullah, K.   +2 more
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CURVATURE AND WEYL COLLINEATIONS OF SPACETIMES [PDF]

The Twelfth Marcel Grossmann Meeting, 2012
Lie symmetries of various geometrical and physical quantities in general relativity play an important role in understanding the curvature structure of manifolds. The Riemann curvature and Weyl tensors are two fourth-rank tensors in the theory. Interrelations between the symmetries of these two tensors (known as collineations) are studied.
Kashif, A. R., Saifullah, K.
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Conformal vector fields on doubly warped product manifolds and applications [PDF]

, 2016
In this article, we present a complete study of two disjoint classes of conformal vector fields on doubly warped product manifolds as well as on doubly warped space-times.
El-Sayied, H. K., Shenawy, Sameh, Syied, Noha   +2 more
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Ricci Collineations for Non-Degenerate, Diagonal and Spherically Symmetric Ricci Tensors [PDF]

, 1999
The expression of the vector field generator of a Ricci Collineation for diagonal, spherically symmetric and non-degenerate Ricci tensors is obtained.
A. H. Bokhari, A. H. Bokhari, D. Kramer, G. Contreras, G. H. Katzin, J. Carot, L. A. Nùñez, L. A. Núñez, M. J. Amir, R. Bertolotti, R. Chan, U. Percoco   +11 more
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Matter collineations of Spacetime Homogeneous G\"odel-type Metrics [PDF]

, 2003
The spacetime homogeneous G\"odel-type spacetimes which have four classes of metrics are studied according to their matter collineations. The obtained results are compared with Killing vectors and Ricci collineations.
Ahsan Z, Ahsan Z, Banerjee A, Bokhari A H, Calvão M O, Camci U, Camci U, Carot J, Carot J, Coley A A, Collinson C D, Davis W R, Gödel K, Hall G S, Hall G S, Katzin G H, M Sharif, Melfo A, Núbar nez L, Raychaudhuri A K, Rebouças M J, Rebouças M J, Rebouças M J, Rebouças M J, Sharif M, Sharif M, Sharif M, Som M M, Teixeira A F F, Tsamparlis M, U Camci, Yavuz dot I   +31 more
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Symmetries of Bianchi I space-times [PDF]

, 2000
All diagonal proper Bianchi I space-times are determined which admit certain important symmetries. It is shown that for Homotheties, Conformal motions and Kinematic Self-Similarities the resulting space-times are defined explicitly in terms of a set of ...
Belinski V. A., Bilyalov R. F., Carter B., Coley A. A., Coley A. A., Datta B. K., Geroh R. P., Hall G. S., Hall G. S., Hall G. S., Hall G. S., Kolassis C. A., Maartens R., Maartens R., Melfo A., Michael Tsamparlis, Pantelis S. Apostolopoulos, Rendall A. D., Sintes A. M., van den Hoogen R. J.   +19 more
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PROPER CURVATURE COLLINEATIONS IN NONSTATIC SPHERICALLY SYMMETRIC SPACE–TIMES [PDF]

International Journal of Modern Physics A, 2008
A study of nonstatic spherically symmetric space–times according to their proper curvature collineations is given by using the rank of the 6×6 Riemann matrix and direct integration techniques. Studying proper curvature collineations in each case of the above space–times it is shown that when the above space–times admit proper curvature collineations ...
Shabbir, Ghulam, Ramzan, M.
openaire   +1 more source

Ricci Collineations for type B warped space-times [PDF]

, 1997
We present the general structure of proper Ricci Collineations (RC) for type B warped space-times. Within this framework, we give a detailed description of the most general proper RC for spherically symmetric metrics.
A. A. Coley, A. H. Bokhari, A. Melfo, A. Melfo, B. Haddow, D. Kramer, D. R. Oliver, G. H. Katzin, G. S. Hall, G. S. Hall, J. Carot, J. Carot, J. Carot, K. L. Duggal, L. A. Núñez, L. Aulestia, L. H. Green, L. Núñez, M. Jamil Amir, M. L. Bedran, M. Tsamparlis, P. Aichelburg, R. Bertolotti, S. Hojman, S. Weinberg, T. B. Farid, U. Percoco   +26 more
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Classification of Spherically Symmetric Static Spacetimes according to their Matter Collineations [PDF]

, 2003
The spherically symmetric static spacetimes are classified according to their matter collineations. These are studied when the energy-momentum tensor is degenerate and also when it is non-degenerate.
A. A. Coley, A. Z. Petrov, C. W. Misner, G. H. Katzin, G. S. Hall, I. Yavuz, J. Carot, J. Carot, L. H. Green, L. Hojman, M. J. Amir, M. Sharif, M. Sharif, M. Sharif, M. Tsamparlis, Sehar Aziz, U. Camci, U. Camci, U. Camci, U. Camci   +19 more
core   +2 more sources