Prelog Chow rings and degenerations
Prelog Chow rings and degenerations
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Prelog Chow 环和退化
DOI:
10.1007/s12215-022-00750-x
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发表时间:
2022
期刊:
影响因子:
--
通讯作者:
Böhning C
中科院分区:
文献类型:
--
作者:
Böhning C
For a simple normal crossing varietyX, we introduce the concepts of prelog Chow ring, saturated prelog Chow group, as well as their counterparts for numerical equivalence. Thinking ofXas the central fibre in a (strictly) semistable degeneration, these objects can intuitively be thought of as consisting of cycle classes onXfor which some initial obstruction to arise as specializations of cycle classes on the generic fibre is absent. Cycle classes in the generic fibre specialize to their prelog counterparts in the central fibre, thus extending to Chow rings the method of studying smooth varieties via strictly semistable degenerations. After proving basic properties for prelog Chow rings and groups, we explain how they can be used in an envisaged further development of the degeneration method by Voisin et al. to prove stable irrationality of very general fibres of certain families of varieties; this extension would allow for much more singular degenerations, such as toric degenerations as occur in the Gross–Siebert programme, to be usable. We illustrate that by looking at the example of degenerations of elliptic curves, which, although simple, shows that our notion of prelog decomposition of the diagonal can also be used as an obstruction in cases where all components in a degeneration and their mutual intersections are rational. We also compute the saturated prelog Chow group of degenerations of cubic surfaces.
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影响因子:
3.9
作者:
Stefan Schreieder
通讯作者:
Stefan Schreieder
影响因子:
3.1
作者:
C. Voisin
通讯作者:
C. Voisin
影响因子:
4.9
作者:
M. Gross;Bernd S Siebert
通讯作者:
Bernd S Siebert
DOI:
--
发表时间:
2019
期刊:
Publications mathématiques (Bures-sur-Yvette)
影响因子:
--
作者:
Helge Ruddat;Bernd S Siebert
通讯作者:
Bernd S Siebert
影响因子:
0.9
作者:
Vial C
通讯作者:
Vial C