ar X iv : 0 81 0 . 01 29 v 2 [ m at h . A G ] 2 7 M ay 2 00 9 Varieties swept out by grassmannians of lines
نویسندگان
چکیده
We classify complex projective varieties of dimension 2r ≥ 8 swept out by a family of codimension two grassmannians of lines G(1, r). They are either fibrations onto normal surfaces such that the general fibers are isomorphic to G(1, r) or the grassmannian G(1, r +1). The cases r = 2 and r = 3 are also considered in the more general context of varieties swept out by codimension two linear spaces or quadrics.
منابع مشابه
ar X iv : 0 81 1 . 47 25 v 2 [ m at h . R A ] 1 2 M ay 2 00 9 On the deformation theory of structure constants for associative algebras
Algebraic scheme for constructing deformations of structure constants for associative algebras generated by a deformation driving algebras (DDAs) is discussed. An ideal of left divisors of zero plays a central role in this construction. Deformations of associative three-dimensional algebras with the DDA being a three-dimensional Lie algebra and their connection with integrable systems are studied.
متن کاملar X iv : 0 80 5 . 32 59 v 1 [ m at h . A G ] 2 1 M ay 2 00 8 SELF - DUAL PROJECTIVE TORIC VARIETIES
Let T be a torus over an algebraically closed field k of characteristic 0, and consider a projective T -module P(V ). We determine when a projective toric subvariety X ⊂ P(V ) is self-dual, in terms of the configuration of weights of V .
متن کاملar X iv : 0 70 5 . 39 48 v 1 [ m at h . R T ] 2 7 M ay 2 00 7 DEGENERATION OF A - INFINITY MODULES
In this paper we use A∞-modules to study the derived category of a finite dimensional algebra over an algebraically closed field. We study varieties parameterising A∞-modules. These varieties carry an action of an algebraic group such that orbits correspond to quasiisomorphism classes of complexes in the derived category. We describe orbit closures in these varieties, generalising a result of Z...
متن کاملar X iv : 0 90 2 . 17 97 v 2 [ m at h . A G ] 1 9 N ov 2 00 9 DERIVED EQUIVALENCES FOR COTANGENT BUNDLES OF GRASSMANNIANS VIA CATEGORICAL sl 2 ACTIONS
We construct an equivalence of categories from a strong categorical sl(2) action, following the work of Chuang-Rouquier. As an application, we give an explicit, natural equivalence between the derived categories of coherent sheaves on cotangent bundles to complementary Grassmannians.
متن کامل