Results 21 to 30 of about 2,565 (153)
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 +11 more
core +2 more sources
Opposition diagrams for automorphisms of large spherical buildings [PDF]
, 2018 Let $\theta$ be an automorphism of a thick irreducible spherical building $\Delta$ of rank at least $3$ with no Fano plane residues. We prove that if there exist both type $J_1$ and $J_2$ simplices of $\Delta$ mapped onto opposite simplices by $\theta ...
Parkinson, J., Van Maldeghem, H.
core +3 more sources
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 +19 more
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On symplectic semifield spreads of PG(5,q2), q odd [PDF]
, 2017 We prove that there exist exactly three non-equivalent symplectic semifield spreads of PG ( 5 , q2), for q2> 2 .38odd, whose associated semifield has center containing Fq.
Marino, Giuseppe, Pepe, Valentina
core +1 more source
LDPC codes from the Hermitian curve [PDF]
, 2007 In this paper, we study the code C which has as parity check matrix H the incidence matrix of the design of the Hermitian curve and its (q + 1)-secants. This code is known to have good performance with an iterative decoding algorithm, as shown by Johnson
Pepe, Valentina
core +1 more source
On singular projective deformations of two second class totally focal pseudocongruences of planes
International Journal of Mathematics and Mathematical Sciences, 1988 Let C:L→L¯ be a projective deformation of the second order of two totally focal pseudocongruences L and L¯ of (m−1)-planes in projective spaces Pn and P¯n, 2m−1 ...
Ludmila Goldberg
doaj +1 more source
The geometry of GL(2,q) in translation planes of even order q2
International Journal of Mathematics and Mathematical Sciences, 1978 In this article we show the following: Let π be a translation plane of even order q2 that admits GL(2,q) as a collineation group. Then π is either Desarguesian, Hall or Ott-Schaeffer.
N. L. Johnson
doaj +1 more source
Approximate Lie Symmetry Conditions of Autoparallels and Geodesics
Abstract and Applied Analysis, Volume 2020, Issue 1, 2020., 2020 This paper is devoted to the study of approximate Lie point symmetries of general autoparallel systems. The significance of such systems is that they characterize the equations of motion of a Riemannian space under an affine parametrization. In particular, we formulate the first‐order symmetry determining equations based on geometric requirements and ...
Sameerah Jamal, Shi Liang Wu
wiley +1 more source
Hypersurfaces in a conformally flat space with curvature collineation
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 +1 more source
On collineations and dualities of finite generalized polygons [PDF]
, 2009 In this paper we generalize a result of Benson to all finite generalized polygons. In particular, given a collineation theta of a finite generalized polygon S, we obtain a relation between the parameters of S and, for various natural numbers i, the ...
Temmermans, Beukje +2 more
core +2 more sources