Timeline for $K_0$ of a non-separated scheme
Current License: CC BY-SA 2.5
4 events
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Mar 8, 2010 at 21:43 | comment | added | Clark Barwick | Yes, I'm using $n\geq 2$, but only in (B) at the line you quote. When $n=1$, everything is the same, except the naive K-theory happens to agree with the "true" K-theory. You are, of course, correct that $K_0$ is older notation. Nowadays $K_0$ usually refers to the thing I describe in (A), and $G_0$ refers to the object you were interested in. (Of course you can use any notation you like, as long as you're clear about what you mean, just as you were here! The only risk is that it's sometimes tricky to keep track of which theorems apply to which objects...) | |
Mar 7, 2010 at 18:34 | vote | accept | Ariyan Javanpeykar | ||
Mar 7, 2010 at 8:05 | comment | added | Ariyan Javanpeykar | Great! Just a couple of questions. You said, "the inclusion $\mathbf{A}^n \rightarrow X$ induces an equivalence between...". Are you supposing $n\geq 2$ here? What happens when $n=1$? I'm not good with vector bundles so details are much appreciated here. My question was originally just for $K_0(X)$. (I'm guessing this is old notation only used in the 60's.) Thanks for the enlightment on $K^0(X)$, i.e., the Grothendieck group of vector bundles on $X$. This clearly shows that the Cartan morphism need not be an isomorphism when $X$ is not separated. | |
Mar 6, 2010 at 20:56 | history | answered | Clark Barwick | CC BY-SA 2.5 |