Skip to main content
8 events
when toggle format what by license comment
Dec 22, 2016 at 8:22 answer added Matthias Wendt timeline score: 4
Dec 21, 2016 at 19:58 comment added Matthias Wendt My comment on continuity of Cech cohomology was a bit hasty. The classical sources only do this for compact spaces. However, there is a weak continuity for paracompact spaces by results of Lee and Raymond. I'll search a bit more through the literature and then come back to give more details.
Dec 21, 2016 at 14:11 comment added Mehmet Onat @MatthiasWendt Is it true that Cech cohomology on paracompact spaces has the continuity property?
Dec 21, 2016 at 14:09 comment added Mehmet Onat @MatthiasWendt Actually i want to know that if $G$ is a compact totally disconnected group acting on a paracompact space X, then the orbit map $X\rightarrow X/G$ induces isomorphism (or monomorphism) on Alexander-spanier cohomology with closed supports?
Dec 21, 2016 at 14:04 comment added Mehmet Onat @MatthiasWendt I know only that the continuity holds for Alexander-Spanier cohomology with compact supports on locally compact spaces. You can look at Bredon's Sheaf Theory book (14.6. Corollary page 103). I dont know that it holds on Alexander-Spanier cohomology with closed support on paracompact spaces.
Dec 20, 2016 at 13:13 comment added Matthias Wendt Do you mean closed support or compact support? (Every function on a topological space has closed support by definition.) You probably are aware of the fact that continuity holds for Alexander-Spanier cohomology (no support condition) on paracompact spaces, by identification with Cech cohomology (via sheaf cohomology). This is discussed in Spanier's "Algebraic topology".
Dec 19, 2016 at 16:58 history edited Mehmet Onat CC BY-SA 3.0
deleted 5 characters in body; edited tags
Dec 19, 2016 at 14:51 history asked Mehmet Onat CC BY-SA 3.0