Weak Fraisse categories

Abstract

We develop the theory of weak Fraisse categories, where the crucial concept is the weak amalgamation property, discovered relatively recently in model theory. We show that, in a suitable framework, every weak Fraisse category has its unique limit, a special object in a bigger category, characterized by certain variant of injectivity. This significantly extends the present theory of Fraisse limits.

Several examples and comments added; new subsection 6.2 (38 pages)

References in corpus (2)

• Metric-enriched categories and approximate Fraïssé limits
• Games with finitely generated structures

Cited by in corpus (1)

• Strongly self-absorbing $C^{\ast }$-algebras and Fraïssé limits