Results 41 to 50 of about 651,446 (197)
Characterizations of projective spaces and hyperquadrics [PDF]
Asian Journal of Mathematics, 2013 In this paper we prove that if the r-th tensor power of the tangent bundle of a smooth projective variety X contains the determinant of an ample vector bundle of rank at least r, then X is isomorphic either to a projective space or to a smooth quadric hypersurface.
Druel, Stéphane, Paris, Matthieu
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Colouring lines in projective space
Journal of Combinatorial Theory, Series A, 2006 19 pages; to appear in J.
Chowdhury, Ameera +2 more
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Global deformations of certain rational almost homogeneous projective bundles [PDF]
arXiv, 2016 We study global deformations of certain projective bundles over projective spaces. We show that any projective global deformation of a projective bundle over $\bP^1$ carries the structure of a projective bundle over some projective space. Furthermore, we construct examples in arbitrary dimension $\ge 3$ of almost homogeneous Fano projective bundles ...
arxiv
Projective Rigidity of Circle Packings [PDF]
arXiv, 2023 We prove that the space of circle packings consistent with a given triangulation on a surface of genus at least two is projectively rigid, so that a packing on a complex projective surface is not deformable within that complex projective structure. More broadly, we show that the space of circle packings is a submanifold within the space of complex ...
arxiv
Flat deformations of ${\mathbb P}^n$ [PDF]
arXiv, 2012 In this paper we study projective flat deformations of projective spaces. We prove that the singular fibers of projective flat deformations of projective spaces appear either in codimension 1 or over singular points of the base. We also describe projective flat deformations of projective spaces with smooth total space, and discuss flatness criteria.
arxiv
Homological Projective Duality [PDF]
arXiv, 2005 We introduce a notion of Homological Projective Duality for smooth algebraic varieties in dual projective spaces, a homological extension of the classical projective duality. If algebraic varieties $X$ and $Y$ in dual projective spaces are Homologically Projectively Dual, then we prove that the orthogonal linear sections of $X$ and $Y$ admit ...
arxiv
Proper projective collineation in non-static spherically symmetric space-times [PDF]
, 2008 We investigate the proper projective collineation in non-static spherically symmetric space-times using direct integration and algebraic techniques. Studying projective collineation in the above space-times, it is shown that the space-times which admit proper projective collineations turn out to be very special classes of static spherically symmetric ...
arxiv +1 more source
Linear Algebra and its Applications, 2009 AbstractLet (H,J) be a Krein space with selfadjoint involution J. Starting with a canonical representation of a J-selfadjoint projection, J-projection in short, as the sum of a J-positive projection and a J-negative one we study in detail the structure of a regular subspace, that is, the range of a J-projection. We treat the problem when the sum of two
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Multiplications on projective spaces. [PDF]
Michigan Mathematical Journal, 1969 Elmer Rees
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Fake weighted projective spaces [PDF]
arXiv, 2008 We define fake weighted projective spaces as a generalisation of weighted projective spaces. We introduce the notions of fundamental group in codimension 1 and of universal covering in codimension 1. We prove that for every fake weighted projective space its universal cover in codimension 1 is a weighted projective space.
arxiv