J 2020

Sizes and filtrations in accessible categories

LIEBERMAN, Michael; Jiří ROSICKÝ and Sébastien Bernard VASEY

Basic information

Original name

Sizes and filtrations in accessible categories

Authors

LIEBERMAN, Michael (840 United States of America, belonging to the institution); Jiří ROSICKÝ (203 Czech Republic, guarantor, belonging to the institution) and Sébastien Bernard VASEY (756 Switzerland)

Edition

Israel Journal of Mathematics, Hebrew University Magnes Press, 2020, 0021-2172

Other information

Language

English

Type of outcome

Article in a journal

Field of Study

10101 Pure mathematics

Country of publisher

Israel

Confidentiality degree

is not subject to a state or trade secret

References:

Impact factor

Impact factor: 0.907

RIV identification code

RIV/00216224:14310/20:00114333

Organization unit

Faculty of Science

UT WoS

000534408400007

EID Scopus

2-s2.0-85085392830

Keywords in English

internal size; presentability rank; existence spectrum; accessibility spectrum; filtrations; singular cardinal hypothesis

Tags

International impact, Reviewed
Changed: 5/3/2021 19:26, prof. RNDr. Jiří Rosický, DrSc.

Abstract

In the original language

Accessible categories admit a purely category-theoretic replacement for cardinality: the internal size. We examine set-theoretic problems related to internal sizes and prove several Löwenheim–Skolem theorems for accessible categories. For example, assuming the singular cardinal hypothesis, we show that a large accessible category has an object in all internal sizes of high enough co-finality. We also prove that accessible categories with directed colimits have filtrations: any object of sufficiently high internal size is (the retract of) a colimit of a chain of strictly smaller objects.

Links

GA19-00902S, research and development project
Name: Injektivita a monády v algebře a topologii
Investor: Czech Science Foundation