Ultrafilters on omega --- their ideals and their cardinal\n characteristics

1997/10/14 by Jörg Brendle, Saharon Shelah, Brendle, Jörg +1
Computer Science · Mathematics · #Advanced Algebra and Logic #Advanced Topology and Set Theory #Computability, Logic, AI Algorithms #FOS: Mathematics #Logic (math.LO)

paper · pdf · doi:10.48550/arxiv.math/9710217

openalex publication_date 1997/10/14 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28

Abstract

For a free ultrafilter U on omega we study several cardinal characteristics\nwhich describe part of the combinatorial structure of U. We provide various\nconsistency results; e.g. we show how to force simultaneously many characters\nand many pi --characters. We also investigate two ideals on the Baire space\nomega^omega naturally related to U and calculate cardinal coefficients of these\nideals in terms of cardinal characteristics of the underlying ultrafilter.\n

Related

• The spectrum of characters of ultrafilters on omega
• The combinatorics of reasonable ultrafilters
• The character spectrum of beta(N)
• Ultrafilters on omega
• On Ultrapowers and Cohesive Ultrafilters