projective cycle
1Projective unitary group — In mathematics, the projective unitary group PU( n ) is the quotient of the unitary group U( n ) by the right multiplication of its center, U(1), embedded as scalars.Abstractly, it is the isometry group of complex projective space, just as the… …
2Cycle double cover — Unsolved problems in mathematics Does every bridgeless graph have a multiset of cycles covering every edge exactly twice? …
3Cycle index — In mathematics, and in particular in the field of combinatorics, cycle indices are used in combinatorial enumeration when symmetries are to be taken into account. This is particularly important in species theory. Each permutation π of a finite… …
4Vanishing cycle — In mathematics, vanishing cycles are studied in singularity theory and other part of algebraic geometry. They are those homology cycles of a smooth fiber in a family which vanish in the singular fiber.A classical result is the Picard Lefschetz… …
5GÉOMÉTRIE ALGÉBRIQUE — Sous sa forme actuelle, la géométrie algébrique est une branche de l’algèbre relativement récente (cf. ALGÈBRE, DEDEKIND). Pour «comprendre» les phénomènes d’intersection des courbes et des surfaces, il s’est révélé nécessaire d’élaborer des… …
6Automorphisms of the symmetric and alternating groups — In group theory, a branch of mathematics, the automorphisms and outer automorphisms of the symmetric groups and alternating groups are both standard examples of these automorphisms, and objects of study in their own right, particularly the… …
7Hodge conjecture — The Hodge conjecture is a major unsolved problem in algebraic geometry which relates the algebraic topology of a non singular complex algebraic variety and the subvarieties of that variety. More specifically, the conjecture says that certain de… …
8COURBES ALGÉBRIQUES — En fondant la géométrie analytique, Descartes avait substitué au plan de la géométrie d’Euclide l’ensemble R2 des couples de nombres réels et, de ce fait, à la notion de courbe, celle d’équation. La construction d’un point, puis la détermination… …
9Diviseur (géométrie algébrique) — En mathématiques, plus précisément en géométrie algébrique, les diviseurs sont une généralisation des sous variétés de codimension 1 de variétés algébriques ; deux généralisations différentes sont d un usage commun : les diviseurs de… …
10Lie sphere geometry — is a geometrical theory of planar or spatial geometry in which the fundamental concept is the circle or sphere. It was introduced by Sophus Lie in the nineteenth century. [The definitive modern textbook on Lie sphere geometry is Harvnb|Cecil|1992 …
