For a continuous map on the unit interval or circle, we define the bifurcation set to be the collection of those interval holes whose surviving set is sensitive to arbitrarily small changes of (some of) their endpoints. ...

We show the existence of computable complex numbers lambda for which the bifurcation locus of the one-parameter complex family f(b)(z) = lambda z + bz(2) + z(3) is not Turing computable. (C) 2018 Elsevier Inc. All rights reserved.

Seja S uma superf´ıcie regular em R3 sem pontos parab´olicos. O conjunto focal de S ´e o lugar geom´etrico dos centros das esferas que possuem contato degenerado com S em cada ponto. Tal contato ´e medido pelas singularidades ...