x --- date: 2022-08-30 18:12 modification date: Tuesday 30th August 2022 18:12:24 title: "computations of picard groups" aliases: [computations of picard groups] --- Last modified date: <%+ tp.file.last_modified_date() %> --- - Tags: - #todo/untagged - Refs: - #todo/add-references - Links: - #todo/create-links --- # computations of picard groups ## $\AA^n$ To show $\Pic(\AA^n) = 1$: ![](attachments/Pasted%20image%2020220830181227.png) ## $\PP^n$ Use smoothness and then toric geometry to compute the class group: $\Pic(\PP^n) = \CH^1(\PP^n) \cong \ZZ$. ## Smooth hypersurfaces in $\PP^n$ Identify $\Pic(X) = \CH^1(X)$ and use the Chow exact sequence to get $\Pic(X) \cong C_d$.