Results 51 to 60 of about 104 (91)
Homotheties and incidences [PDF]
Discrete Mathematics, 2018 We consider problems involving rich homotheties in a set S of n points in the plane (that is, homotheties that map many points of S to other points of S). By reducing these problems to incidence problems involving points and lines in R^3, we are able to obtain refined and new bounds for the number of rich homotheties, and for the number of distinct ...
Micha Sharir
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Abelian varieties without homotheties [PDF]
Mathematical Research Letters, 2007 A celebrated theorem of Bogomolov asserts that the $\ell$-adic Lie algebra attached to the Galois action on the Tate module of an abelian variety over a number field contains all homotheties. This is not the case in characteristic $p$: a "counterexample" is provided by an ordinary elliptic curve defined over a finite field. In this note we discuss (and
, Zarhin Yuri G
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Finite Minkowski planes of type 20 with respect to homotheties
Finite Fields and Their Applications, 2016 In [J. Geom. 43, No. 1--2, 116--128 (1992; Zbl 0746.51009)], \textit{M. Klein} classified Minkowski planes with respect to \(\{p,p'\}\)-homotheties. If \({\mathcal M}\) is a Minkowski plane and \(p\) and \(p'\) are non-parallel points of \({\mathcal M}\), then a \(\{p,p'\}\)-homothety is an automorphism of \({\mathcal M}\) fixing both \(p\) and \(p ...
Gunter Steinke
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Homotheties of Finsler manifolds∗
SUT Journal of Mathematics, 2010 We give a new and complete proof of the following theorem, discovered by Detlef Laugwitz: (forward) complete and connected finite dimensional Finsler manifolds admitting a proper homothety are Minkowski vector spaces. More precisely, we show that under these hypotheses the Finsler manifold is isometric to the tangent Minkowski vector space of the fixed
Lovas, Rezsö L., Szilasi, József
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Homotheties and topology of tangent sphere bundles [PDF]
Journal of Geometry, 2014 We prove a Theorem on homotheties between two given tangent sphere bundles $S_rM$ of a Riemannian manifold $M,g$ of $\dim\geq 3$, assuming different variable radius functions $r$ and weighted Sasaki metrics induced by the conformal class of $g$. New examples are shown of manifolds with constant positive or with constant negative scalar curvature, which
Rui Albuquerque
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Homotheties and isometries of metric spaces [PDF]
Matematica Contemporanea, 2005 Mauro Patrão
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Some of the next articles are maybe not open access.
On functional classes invariant relative to homotheties
Lecture Notes in Mathematics, 1992Reshetnyak Yu G
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Transformations and Preservation of Self-assembly Dynamics through Homotheties [PDF]
Lecture Notes in Computer Science, 2008 We introduce a new notion in self-assembly, that of transforming the dynamics of assembly. This notion allows us to have transformation of the plane computed within the assembly process. Then we apply this notion to zooming. The possibility of zooming depends on the order condition. This shows that this condition, which arose from engineering concerns (
Florent Becker
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Homothety groups in space-time
General Relativity and Gravitation, 1990The authors investigate Lorentzian space-times which admit an r- dimensional Lie algebra of homothetic vector fields at least one of which is proper homothetic (i.e., it is not a Killing vector field). A complete description of the situation is obtained if \(r\geq 6\) and some results are given for \(r\leq 5\).
Hall, G. S., Steele, J. D.
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On minkowski planes with transitive groups of homotheties
Abhandlungen Aus Dem Mathematischen Seminar Der Universitat Hamburg, 1994In analogy with the well-known Lenz-Barlotti classification of projective planes, there are the Hering classification of Möbius planes [\textit{C. Hering}, Math. Z. 87, 252-262 (1965; Zbl 0126.166)], the Kleinewillinghofer classification of Laguerre planes [\textit{R. Kleinewillinghofer}, Arch. Math.
Klein, M., Kroll, H.-J.
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