Currently displaying 1 – 2 of 2

Showing per page

Order by Relevance | Title | Year of publication

Lelek fan from a projective Fraïssé limit

Dana Bartošová;  Aleksandra Kwiatkowska — 2015

Fundamenta Mathematicae

We show that a natural quotient of the projective Fraïssé limit of a family that consists of finite rooted trees is the Lelek fan. Using this construction, we study properties of the Lelek fan and of its homeomorphism group. We show that the Lelek fan is projectively universal and projectively ultrahomogeneous in the class of smooth fans. We further show that the homeomorphism group of the Lelek fan is totally disconnected, generated by every neighbourhood of the identity, has a dense conjugacy...

Fraïssé structures and a conjecture of Furstenberg

Dana Bartošová;  Andy Zucker — 2019

Commentationes Mathematicae Universitatis Carolinae

We study problems concerning the Samuel compactification of the automorphism group of a countable first-order structure. A key motivating question is a problem of Furstenberg and a counter-conjecture by Pestov regarding the difference between S ( G ) , the Samuel compactification, and E ( M ( G ) ) , the enveloping semigroup of the universal minimal flow. We resolve Furstenberg’s problem for several automorphism groups and give a detailed study in the case of G = S ∞ , leading us to define and investigate several new types...

Page 1

Download Results (CSV)