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Plenary and Semi-Plenary Talks

Plenary Talk: Will Brian

Forbes 1022

Times: 2025 Mar 06 from 08:30AM to 09:25AM (Eastern Time (US & Canada))

Order-reversing maps on $\mathbb N^\ast$ and $\mathbb H^\ast$

Will Brian ⟨wbrian.math@gmail.com⟩

Abstract:

I will discuss two related questions concerning the two spaces in the title: the Čech-Stone remainder of the natural numbers $\mathbb N$, and the Čech-Stone remainder of the half-line $\mathbb H = [0,\infty)$. Both $\mathbb N$ and $\mathbb H$ are naturally ordered from left to right. These orders on $\mathbb N$ and $\mathbb H$ are reflected in their Čech-Stone remainders, in certain dynamical systems on $\mathbb N^\ast$ and in certain subcontinua of $\mathbb H^\ast$. Are these left-to-right aspects of $\mathbb N^\ast$ and $\mathbb H^\ast$ truly topological, or can either of the spaces be “reversed” via some self-homeomorphism?

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