24 янв. 2014 г. · You need a topology not weaker than the Nisnevich one in order to prove the homotopy purity theorem of Morel-Voevodsky. On the other hand, it's ...

3 февр. 2022 г. · He used the topology to give a cohomological interpretation of the class group/set c(G) of an affine algebraic group (which is defined in ...

18 окт. 2011 г. · It boils down to being a etale covering family admitting local sections over a different, finite, cover of a particular sort.

20 окт. 2011 г. · The cohomology of a constant sheaf agrees with the cohomology of the generic point, and this vanishies as fields have no higher Nisnevich cohomology.

27 июл. 2012 г. · A representative example is where you take some arbitrary etale cover Y of X which splits over a closed subvariety Z of X, then form the Nisnevich cover of X.

27 июл. 2012 г. · A Nisnevich cover which is not Zariski ... The Nisnevich topology on Sch is a Grothendieck topology strictly finer than the Zariski topology, and ...

14 сент. 2011 г. · If F is a sheaf on the big Nisnevich site, then is the morphism F(X)→⨿F(x) injective where the sum is over ALL the points of X (not just the closed ones).

A Nisnevich cover which is not Zariski. The Nisnevich topology on Sch is a Grothendieck topology strictly finer than the Zariski topology, and the etale ...

7 июн. 2013 г. · A Nisnevich cover in this context is a surjective, etale morphism f:U→X such that for all x∈X, there exists a u∈U with f(u)=x such that the ...