Timeline for Is the "addition" of flat morphisms flat?

7 events

when toggle format	what		by	license	comment
Oct 14, 2017 at 21:02	history	bumped	CommunityBot		This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Sep 14, 2017 at 20:20	history	bumped	CommunityBot		This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Aug 15, 2017 at 20:12	history	bumped	CommunityBot		This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Jul 16, 2017 at 19:32	history	bumped	CommunityBot		This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Feb 7, 2017 at 0:55	comment	added	Jason Starr		That is not true. For $X=Y=\text{Proj}\ k[u,v,w]$, for $F=\mathcal{O}_X^{\oplus 3}$, for $G=\mathcal{O}_X(1)$, for $\phi_1=(u,v,w)$, and for $\phi_2 = (-u,u-v,v-w)$, both $\phi_1$ and $\phi_2$ are surjective, but $\phi_1+\phi_2$ has image $\mathcal{I}\cdot G$, where $\mathcal{I}$ is the ideal sheaf of the closed point of the homogeneous prime ideal $\langle u,v\rangle$.
Feb 7, 2017 at 0:51	answer	added	user104547		timeline score: 1
Feb 7, 2017 at 0:28	history	asked	user43198	CC BY-SA 3.0