Timeline for Homotopy pullbacks and pushouts of spectra

7 events

when toggle format	what		by	license	comment
Jun 18, 2020 at 0:22	history	edited	David White	CC BY-SA 4.0	Fixed minor typos since it was on the front page anyway, and gave it a more descriptive title
Jun 18, 2020 at 0:21	answer	added	David White		timeline score: 3
Apr 19, 2018 at 0:23	review	Close votes
Apr 21, 2018 at 17:41
May 30, 2013 at 20:32	comment	added	Tom Goodwillie		Dylan, in some sense it's more elementary than Blakers-Massey. To get the idea, here's why $X\to \Omega\Sigma X$ is a weak equivalence when $X$ is a spectrum: $X$ consists of spaces $X_n$; the map is given by Freudenthal maps $X_n\to \Omega\Sigma X_n$; an inverse on spectrum homotopy groups is given by the obvious maps $\Omega\Sigma X_n\to \Omega X_{n+1}$.
May 30, 2013 at 16:21	comment	added	Jacob Bell		if you accept the fact that the category of spectra is stable, then it follows from the axioms of being stable (how tautological was this comment?)
May 30, 2013 at 16:19	comment	added	Dylan Wilson		Yes. This is a consequence of the Blakers-Massey theorem.
May 30, 2013 at 16:18	history	asked	Kun Wang	CC BY-SA 3.0