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Journal of Lie Theory 18 (2008), No. 1, 067--082 Copyright Heldermann Verlag 2008 Klein Geometries, Parabolic Geometries and Differential Equations of Finite Type Ender Abadoglu Yeditepe Universitesi, Matematik Bölümü, 26 Agustos Yerlesimi, 81120 Kayisdagi -- Istanbul, Turkey eabadoglu@yeditepe.edu.tr Ercüment Ortacgil Bogazici Universitesi, Matematik Bölümü, 34342 Bebek -- Istanbul, Turkey ortacgil@boun.edu.tr Ferit Öztürk Bogazici Universitesi, Matematik Bölümü, 34342 Bebek -- Istanbul, Turkey ferit.ozturk@boun.edu.tr [Abstract-pdf] We define the infinitesimal and geometric orders of an effective Klein geometry $G/H$. Using these concepts, we prove (i) For any integer $m\geq 2$, there exists an effective Klein geometry $G/H$ of infinitesimal order $m$ such that $G/H$ is a projective variety. (ii) An effective Klein geometry $G/H$ of geometric order $M$ defines a differential equation of order $M+1$ on $G/H$ whose global solution space is $G$. Keywords: Homogeneous space, jet. MSC: 53C30 [ Fulltext-pdf (225 KB)] for subscribers only. |