Equidiscontinuity of Borsuk-Ulam functions

Lester Eli Dubins and Gideon Schwarz

Vol. 95 (1981), No. 1, 51–59

DOI: 10.2140/pjm.1981.95.51

Abstract

No idempotent function on the unit disc onto its boundary is continuous. The stronger fact that no such function has a modulus of discontinuity smaller than is a prototype of the contents of this paper.

Mathematical Subject Classification 2000

Primary: 54F60, 54F60

Secondary: 54C05, 55M20, 55P05

Milestones

Received: 22 February 1980

Published: 1 July 1981