Zobrazeno 1 - 10
of 11
pro vyhledávání: '"Jan Arthur Christophersen"'
The proceedings from the Abel Symposium on Geometry of Moduli, held at Svinøya Rorbuer, Svolvær in Lofoten, in August 2017, present both survey and research articles on the recent surge of developments in understanding moduli problems in algebraic
Publikováno v:
Collectanea Mathematica
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:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bef8311d823a4aaba6739b36351a7778
http://hdl.handle.net/10852/70796
http://hdl.handle.net/10852/70796
Publikováno v:
Mathematische Annalen. 348:513-537
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–Rei
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5c830b27c3554ae2af146a3bace73702
https://doi.org/10.1007/s00208-010-0490-x
https://doi.org/10.1007/s00208-010-0490-x
Publikováno v:
manuscripta mathematica. 115:361-378
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:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::faabd52ee688efca28bee8d375ec37fe
https://doi.org/10.1007/s00229-004-0496-3
https://doi.org/10.1007/s00229-004-0496-3
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:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::42d75da2a29eb181c7c8ed726598fc98
http://arxiv.org/abs/1409.3432
http://arxiv.org/abs/1409.3432
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:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ad5385307f7d3c362f5d263ce04f0554
http://arxiv.org/abs/1202.0510
http://arxiv.org/abs/1202.0510
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:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::263dfa47822ed7e533576cba88301a24
Autor:
Jan Arthur Christophersen, Kurt Behnke
Publikováno v:
Transactions of the American Mathematical Society. 335:175-193
We study the obstruction space T 2 {T^2} for minimally elliptic surface singularities. We apply the main lemma of our previous paper [3] which relates T 2 {T^2} to deformations of hypersurface sections. To use this we classify general hypersurface se
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1470475209ec6a0c78999cb01be148b7
https://doi.org/10.1090/s0002-9947-1993-1069742-2
https://doi.org/10.1090/s0002-9947-1993-1069742-2
Publikováno v:
Manuscripta Mathematica; Nov2004, Vol. 115 Issue 3, p361-378, 55p
Autor:
Kurt Behnke, Jan Arthur Christophersen
Publikováno v:
American Journal of Mathematics. 116:881
INTRODUCTION Due to the work in [Brieskorn], [Tjurina], [Artin], [Wahl 2] and [Lipman] one understands very well the notion of simultaneous resolution for rational surface singularities. Given a rational surface singularity X, there exists a smooth p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::854c9ba4e04935f5977502325edb4824
https://doi.org/10.2307/2375004
https://doi.org/10.2307/2375004