Kurt Gödel Research Center

2016 seminar talk: Linear orders: when embedding and epimorphism coincide

Talk held by Raphaël Carroy (KGRC) at the KGRC seminar on 2016-11-03.

Abstract

When a linear order has an order preserving surjection onto each of its suborders, we say that it is strongly surjective. I will mainly talk about countable strongly surjective linear orders, outlining the proof that they form a complete set for the class of unions of an analytic and a coanalytic set. I will then discuss the case of uncountable strongly surjective orders.

This is a joint work with Riccardo Camerlo and Alberto Marcone.