Results 51 to 60 of about 507 (127)

Special Recurrent Transformation in an NPR-Finsler Space

Cubo, 2012
In this paper, an infinitesimal transformation , where the vector vi is recurrent has been considered in an NPR- Finsler space. Such transformation is being called special recurrent transformation if the recurrence vector of the NPR- Finsler space is Lie
Anjali Goswami
doaj  

About Bianchi I with VSL

, 2008
In this paper we study how to attack, through different techniques, a perfect fluid Bianchi I model with variable G,c and Lambda, but taking into account the effects of a $c$-variable into the curvature tensor. We study the model under the assumption,div(
A. Albrecht, A. Beesham, A. Beesham, A. Einstein, A. Harvey, A. Pradhan, A. Pradhan, A. Pradhan, A. Pradhan, A.-M.M. Abdel-Rahman, A.-M.M. Abdel-Rahman, A.A. Coley, A.I. Arbab, A.K. Raychaudhuri, A.M. Sintes, A.Z. Petrov, B. Carter, B. Carter, B. Saha, B. Saha, B.A. Bassett, B.J. Cantwell, B.J. Carr, C.B. Collins, C.P. Singh, D. Kalligas, D.M. Eardley, E. Kasner, E.R. Harrison, G.F.R. Ellis, G.I. Barenblatt, G.S. Hall, G.S. Hall, G.W. Bluman, H. Maeda, H. Stephani, I. Waga, İ. Yavuz, J. Caminati, J. Carot, J. Carot, J. Magueijo, J. Wainwright, J. Wainwright, J.A. Belinchón, J.A. Belinchón, J.A. Belinchón, J.A.S. Lima, J.A.S. Lima, J.C. Carvalho, J.D. Barrow, J.D. Barrow, J.W. Moffat, José Antonio Belinchón, K. Rosquits, K. Rosquits, K.L. Duggal, L. Hsu, M. Sharif, M. Sharif, M. Sharif, M. Szydlowski, M. Tsamparlis, M. Tsamparlis, M.A.H. MacCallum, M.E. Cahill, M.P. Ryan, M.S. Berman, N.H. Ibragimov, P.A.M. Dirac, P.J.E. Peebles, P.M. Benoit, P.P. Avelino, P.T. Olver, R.F. Sistero, T. Harko, T. Padmanabhan, T. Padmanabhan, T. Singh, U. Camcı, U. Camcı, V. Sahni, W. Chen, Y.K. Lau, Y.K. Lau   +84 more
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Geometric equations of state in Friedmann-Lema\^{i}tre universes admitting matter and Ricci Collineations

, 2003
As a rule in General Relativity the spacetime metric fixes the Einstein tensor and through the Field Equations (FE) the energy-momentum tensor. However one cannot write the FE explicitly until a class of observers has been considered.
Apostolopoulos, Pantelis S., Tsamparlis, Michael   +1 more
core   +1 more source

Proper Matter Collineations of Plane Symmetric Spacetimes [PDF]

, 2006
We investigate matter collineations of plane symmetric spacetimes when the energy-momentum tensor is degenerate. There exists three interesting cases where the group of matter collineations is finite-dimensional.
Guo Z. K., Ratra B., Sen A., Sen A., Sen A., WEI WANG, YING SHAO, YUAN-XING GUI   +7 more
core   +4 more sources

Lie and Noether symmetries of geodesic equations and collineations

, 2011
The Lie symmetries of the geodesic equations in a Riemannian space are computed in terms of the special projective group and its degenerates (affine vectors, homothetic vector and Killing vectors) of the metric.
A. Barnes, A.H. Bokhari, A.H. Bokhari, A.V. Aminova, A.V. Aminova, A.V. Aminova, Andronikos Paliathanasis, G.E. Prince, G.H. Katzin, G.H. Katzin, G.H. Katzin, G.H. Katzin, H. Stephani, K. Yano, K.J.A. Scouten, M. Tsamparlis, M.S. Knebelman, Michael Tsamparlis, R. Maartens, R. Maartens, T. Feroze   +20 more
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On the definition of matter collineations

, 2010
It is shown that when the stress-energy tensor of a spacetime is diagonal and is written in the mixed form, its collineations admit infinite dimensional Lie algebras except possibly in the case when the tensor depends on all the spacetime coordinates ...
ASGHAR QADIR, K. SAIFULLAH, Misner C. W., Penrose R., Saifullah K.   +4 more
core   +1 more source

Symmetries of distributional domain wall geometries

, 2003
Generalizing the Lie derivative of smooth tensor fields to distribution-valued tensors, we examine the Killing symmetries and the collineations of the curvature tensors of some distributional domain wall geometries.
Alberto Sanoja, Choquet-Bruhat Y., Choquet-Bruhat Y., Lichnerowicz A., Nelson Pantoja   +4 more
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Autonomous three dimensional Newtonian systems which admit Lie and Noether point symmetries

, 2012
We determine the autonomous three dimensional Newtonian systems which admit Lie point symmetries and the three dimensional autonomous Newtonian Hamiltonian systems, which admit Noether point symmetries.
Andronikos Paliathanasis, Barnes A, Eisenhart L P, Kalotas T M, Leonidas Karpathopoulos, Michael Tsamparlis, Prince G E, Sarlet W, Stephani H, Tsamparlis M, Yano K   +10 more
core   +1 more source

Note on Matter Collineations in Kantowski-Sachs, Bianchi Types I and III Spacetimes

, 2003
We show that the classification of Kantowski-Sachs, Bianchi Types I and III spacetimes admitting Matter Collineations (MCs) presented in a recent paper by Camci et al. [Camci, U., and Sharif, M.
G. S. Hall, J. Carot, Michael Tsamparlis, Pantelis S. Apostolopoulos, U. Camci   +4 more
core   +1 more source

Semiconformal symmetry- A new symmetry of the spacetime manifold of the general relativity

, 2019
In this paper we have introduced a new symmetry property of spacetime which is named as semiconformal curvature collineation, and its relationship with other known symmetry properties has been established.
Ahsan, Zafar, Ali, Musavvir, Pundeer, Naeem Ahmad   +2 more
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