dorsal/arxiv
View SchemaStrong Projective Witnesses
| Authors | Vera Fischer, Julia Millhouse |
|---|---|
| Categories | |
| ArXiv ID | 2601.08718vv1 |
| URL | https://arxiv.org/abs/2601.08718 |
| License | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
Abstract
We show Shelah's original creature forcing from 1984 strongly preserves tight mad families. In particular, answering questions of Fischer and Friedman and Friedman and Zdomskyy, we show the constellation $\aleph_1 = \mathfrak{a} < \mathfrak{s} = \aleph_2$ is consistent with the existence of a $\Delta_3^1$ wellorder of the reals and tight mad families of sizes $\aleph_1, \aleph_2$ which are $\Pi_1^1, \Pi_2^1$-definable, respectively. Each of these projective definitions is of minimal possible complexity.
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"abstract": "We show Shelah\u0027s original creature forcing from 1984 strongly preserves tight mad families. In particular, answering questions of Fischer and Friedman and Friedman and Zdomskyy, we show the constellation $\\aleph_1 = \\mathfrak{a} \u003c \\mathfrak{s} = \\aleph_2$ is consistent with the existence of a $\\Delta_3^1$ wellorder of the reals and tight mad families of sizes $\\aleph_1, \\aleph_2$ which are $\\Pi_1^1, \\Pi_2^1$-definable, respectively. Each of these projective definitions is of minimal possible complexity.",
"arxiv_id": "2601.08718",
"authors": [
"Vera Fischer",
"Julia Millhouse"
],
"categories": [
"math.LO"
],
"license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
"title": "Strong Projective Witnesses",
"url": "https://arxiv.org/abs/2601.08718",
"version": "v1"
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