PreprintCC BY 4.0arXiv
Closed maximal eventually different families for Σ03 and weakly Farah ideals
Abstract
Motivated by the existence of closed maximal ℐ-eventually different (ℐ-MED) families, we study uniform combinatorial properties of ideals. For a fixed ideal, a property is uniform if its witnesses can be chosen by a single Borel map. We prove that every Σ03 ideal is uniformly weakly P+. We also prove that the classes of Farah and weakly Farah ideals coincide, answering a question of Hrušák and Meza-Alcántara. We then show that every weakly Farah ideal is uniformly weakly Ramsey. As an application, we obtain closed ℐ-MED families for Σ03 ideals and weakly Farah ideals.
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BibTeX
@misc{he2026closed,
title = {{Closed maximal eventually different families for $\boldsymbolΣ^0_3$ and weakly Farah ideals}},
author = {Jialiang He and Jiaheng Zhuang and Yi Zhou},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.28275},
eprint = {2610.28275},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.28275},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Closed maximal eventually different families for Σ^0_3 and weakly Farah ideals
AU - Jialiang He
AU - Jiaheng Zhuang
AU - Yi Zhou
PY - 2026
DA - 2026/10/20
PB - arXiv
DO - 10.48550/arxiv.2610.28275
UR - https://arxiv.org/abs/2610.28275
AB - Motivated by the existence of closed maximal ℐ-eventually different (ℐ-MED) families, we study uniform combinatorial properties of ideals. For a fixed ideal, a property is uniform if its witnesses can be chosen by a single Borel map. We prove that every Σ^0_3 ideal is uniformly weakly P^+. We also prove that the classes of Farah and weakly Farah ideals coincide, answering a question of Hrušák and Meza-Alcántara. We then show that every weakly Farah ideal is uniformly weakly Ramsey. As an application, we obtain closed ℐ-MED families for Σ^0_3 ideals and weakly Farah ideals.
ER -