Results 31 to 40 of about 5,017 (222)
On unitary collineation groups
Journal of Algebra, 1972 If II is a finite projective plane of order q2 over the field K = GF(q2), then 17 admits a polarity 6 which is induced on I7 by a nondegenerate hermitian form on the underlying vector space. The subgroup of the little projective group PSL,(q2) which centralizes 6 is the projective special unitary group PSU,(q). The purpose of this paper is to show that
Alan R. Hoffer
semanticscholar +4 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
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
Collineation group as a subgroup of the symmetric group [PDF]
, 2012 Let ψ be the projectivization (i.e., the set of one-dimensional vector subspaces) of a vector space of dimension ≥ 3 over a field. Let H be a closed (in the pointwise convergence topology) subgroup of the permutation group $\mathfrak{S}_\psi $ of the set
F. Bogomolov, M. Rovinsky
semanticscholar +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
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
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
Gauge-reversing maps on cones, and Hilbert and Thompson isometries [PDF]
, 2013 We show that a cone admits a gauge-reversing map if and only if it is a symmetric cone. We use this to prove that every isometry of a Hilbert geometry is a collineation unless the Hilbert geometry is the projective space of a non-Lorentzian symmetric ...
Cormac Walsh, Thompson Isometries
core +1 more source
, 2011 We introduce a rank 3 geometry for any Ree group over a not necessarily perfect field and show that its full collineation group is the automorphism group of the corresponding Ree group.
Haot, Fabienne +2 more
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On some subvarieties of the Grassmann variety [PDF]
, 2014 Let $\mathcal S$ be a Desarguesian $(t-1)$--spread of $PG(rt-1,q)$, $\Pi$ a $m$-dimensional subspace of $PG(rt-1,q)$ and $\Lambda$ the linear set consisting of the elements of $\mathcal S$ with non-empty intersection with $\Pi$. It is known that the Pl\"{
Giuzzi, Luca, Pepe, Valentina
core +2 more sources