Subject: Stasheff - Steenrod question
From: "Claude Schochet"
Date: Tue, 24 Jul 2007 14:05:28 -0400
Jim - I have some mimeo notes (60 pages) with the same title as the
article
below, and Section 10 "Obstructions" of the mimeo notes does what you're
talking about. The notes I have say "Colloquium Lectures, August 1957". So
try looking there. If needed I can have the mimeo notes scanned.
MR0298655 (45 #7705) Steenrod, Norman E. Cohomology operations, and
obstructions to extending continuous functions. Advances in Math. 8,
371--416. (1972). (Reviewer: John R. Harper) 55G35
Claude
Subject: query
From: jim stasheff
Date: Mon, 23 Jul 2007 22:02:07 -0400
In a course on algebraic topolgoy I took from Steenrod, I seem to recall
his
treatment of the SECONDARY obstruction to
extension:
Le K^n denote the n-skeleton.
Assume f:K^n --> X extends to K^{n+1}
but that extension does NOT extend to K^{n+2}.
Consider the set of obstructions to extending to K^{n+2} using all
possible
extensions to K^{n+1}.
If that doesn't work,
Then retreat to f|K^{n-1} and try again. Consider the set of obstructions
to extending to K^{n+2} using all possible extensions to K^n.
Anyone know where this appears in print?
jim
Subject: Steenrod on obstruction theory
From: Robert Bruner
Date: Wed, 25 Jul 2007 02:00:10 -0400 (EDT)
Jim,
I saw this in a document that is in the library at U of Chicago. It
contains a very clean account of obstruction theory. I don't have it
at hand, so this is purely from memory.
A few years ago I looked it up while visiting UofC and discovered it
was some sort of report on an AFOSR grant, or something like that. It
is one of these documents characteristic of the time, typed and then
reproduced in about 100 copies with a distribution list at the front.
Most major research universities (in the late 50's) were on the list,
so may have a copy, if they keep and catalog such items as Eckhart
does.
If someone at UofC were williing to look through Eckhart for Steenrod's
pub's, it is (roughly) 8.5 x 11, typed, one-sided. Hard to miss.
Bob Bruner