On the Bauer-Furuta and Seiberg-Witten invariants of families of 4‐manifolds
On the Bauer-Furuta and Seiberg-Witten invariants of families of 4‐manifolds
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关于 4 流形族的 Bauer-Furuta 和 Seiberg-Witten 不变量
DOI:
10.1112/topo.12229
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发表时间:
2022
影响因子:
1.1
通讯作者:
Konno Hokuto
中科院分区:
文献类型:
--
作者:
Baraglia David;Konno Hokuto
We show how the families Seiberg–Witten invariants of a family of smooth 4‐manifolds can be recovered from the families Bauer–Furuta invariant via a cohomological formula. We use this formula to deduce several properties of the families Seiberg–Witten invariants. We give a formula for the Steenrod squares of the families Seiberg–Witten invariants leading to a series of mod 2 relations between these invariants and the Chern classes of the spinc$^c$ index bundle of the family. As a result, we discover a new aspect of the ordinary Seiberg–Witten invariants of a 4‐manifold X$X$: they obstruct the existence of certain families of 4‐manifolds with fibres diffeomorphic to X$X$. As a concrete geometric application, we shall detect a non‐smoothable family of K3$K3$ surfaces. Our formalism also leads to a simple new proof of the families wall crossing formula. Lastly, we introduce K$K$‐theoretic Seiberg–Witten invariants and give a formula expressing the Chern character of the K$K$‐theoretic Seiberg–Witten invariants in terms of the cohomological Seiberg–Witten invariants. This leads to new divisibility properties of the families Seiberg–Witten invariants.