Zobrazeno 1 - 10
of 43
pro vyhledávání: '"Christophersen, Jan Arthur"'
Publikováno v:
Comm. Algebra 45 (2017) no. 9 pp. 3929-3947
We use representation theory and Bott's theorem to show vanishing of higher cotangent cohomology modules for the homogeneous coordinate ring of Grassmannians in the Pl\"ucker embedding. As a biproduct we answer a question of Wahl about the cohomology
Externí odkaz:
http://arxiv.org/abs/1409.3432
Publikováno v:
Collectanea Mathematica online (2018)
We compare deformations of algebras to deformations of schemes in the setting of invariant theory. Our results generalize comparison theorems of Schlessinger and the second author for projective schemes. We consider deformations (abstract and embedde
Externí odkaz:
http://arxiv.org/abs/1209.3444
Publikováno v:
J. reine angew. Math. 717 (2016) pp. 77-100
For fixed degree $d\leq 12$, we study the Hilbert scheme of degree $d$ smooth Fano threefolds in their anticanonical embeddings. We use this to classify all possible degenerations of these varieties to toric Fano varieties with at most canonical Gore
Externí odkaz:
http://arxiv.org/abs/1202.0510
Publikováno v:
Math. Z. 278 (2014) 1-2 pp. 131-148
We construct degenerations of Mukai varieties and linear sections thereof to special unobstructed Fano Stanley-Reisner schemes corresponding to convex deltahedra. This can be used to find toric degenerations of rank one index one Fano threefolds. In
Externí odkaz:
http://arxiv.org/abs/1102.4521
Autor:
Christophersen, Jan Arthur
The versal deformation of Stanley-Reisner schemes associated to equivelar triangulations of the torus is studied. The deformation space is defined by binomials and there is a toric smoothing component which I describe in terms of cones and lattices.
Externí odkaz:
http://arxiv.org/abs/1003.4004
We study the deformation theory of projective Stanley-Reisner schemes associated to combinatorial manifolds. We achieve detailed descriptions of first order deformations and obstruction spaces. Versal base spaces are given for certain Stanley-Reisner
Externí odkaz:
http://arxiv.org/abs/0901.2502
Publikováno v:
manuscripta math. 115, 361-378 (2004)
Simplicial complexes X provide commutative rings A(X) via the Stanley-Reisner construction. We calculated the cotangent cohomology, i.e., T1 and T2 of A(X) in terms of X. These modules provide information about the deformation theory of the algebro g
Externí odkaz:
http://arxiv.org/abs/math/0006139
The purpose of this paper is to prove dimension formulas for $T^1$ and $T^2$ for rational surface singularities. These modules play an important role in the deformation theory of isolated singularities in analytic and algebraic geometry. The first ma
Externí odkaz:
http://arxiv.org/abs/math/9903058
