Revision as of 18:31, 23 January 2015 edit 206.214.242.230 (talk) →Is convexity required? ← Previous edit		Revision as of 08:51, 15 September 2015 edit undo Tsirel (talk \| contribs) Extended confirmed users 8,857 edits →A proof using the oriented area: new section Next edit →
Line 181: * For a ''compact'' convex set, all of which are homeomorphic to a ball. So e.g. an annulus is compact non-convex, and a rotation maps it to itself without fixpoint. --[[Special:Contributions/206.214.242.230\|206.214.242.230]] ([[User talk:206.214.242.230\|talk]]) 18:30, 23 January 2015 (UTC) == A proof using the oriented area == "Differentiating under the sign of integral it is not difficult to check that ''φ′(t)=0'' for all ''t''" — really? How to check it? Maybe the Milnor-Rogers-Gröger approach is meant? There, ''φ'' is polynomial (not just smooth) and appears to be constant near 0, therefore everywhere. [[User:Tsirel\|Boris Tsirelson]] ([[User talk:Tsirel\|talk]]) 08:51, 15 September 2015 (UTC)

Talk:Brouwer fixed-point theorem: Difference between revisions