activity
20172023
collaborators

7 papers

math.CT2023

Every theory is eventually of presheaf type

Christian Espíndola, Kristóf Kanalas

We give a detailed and self-contained introduction to the theory of -toposes and prove the following: 1) A -separable -topos has enough -points. 2) The classifying -…

math.LO2019

A short proof of Shelah's eventual categoricity conjecture for AEC's with interpolation, under

Christian Espíndola

We provide a short proof of Shelah's eventual categoricity conjecture, assuming the Generalized Continuum Hypothesis (), for abstract elementary classes (AEC's) with interpola…

math.LO2019

Preservation theorems for strong first-order logics

Christian Espíndola

We prove preservation theorems for , the countable fragment of Vaught's closed game logic. These are direct generalizations of the theorems of Łoś-Tarski (res…

math.LO2019

A proof of Shelah's eventual categoricity conjecture and an extension to accessible categories with directed colimits

Christian Espíndola

We provide a proof, in , of Shelah's eventual categoricity conjecture for abstract elementary classes (AEC's). Moreover, assuming in addition the Singular Cardinal Hypothesis…

math.LO2019

Completeness of infinitary heterogeneous logic

Christian Espíndola

Given a regular cardinal such that (e.g., if the Generalized Continuum Hypothesis holds), we develop a proof system for classical infinitary logic that includes hete…

math.LO2017

Constructive completeness and non-discrete languages

Henrik Forssell, Christian Espíndola

We give an analysis and generalizations of some long-established constructive completeness results in terms of categorical logic and pre-sheaf and sheaf semantics. The purpose is i…

math.LO2017

Infinitary generalizations of Deligne's completeness theorem

Christian Espíndola

Given a regular cardinal such that , we study a class of toposes with enough points, the -separable toposes. These are equivalent to sheaf toposes over a site with…