publications

2026

1. arXiv Preprint

   Finite-Index Extensions of Essentially Free Countable Borel Equivalence Relations

   Jason Zesheng Chen

   #borel-equivalence-relations

   Bib HTML PDF

   @misc{chenFiniteIndexExtensions2026,
     title = {Finite-Index Extensions of Essentially Free Countable Borel Equivalence Relations},
     author = {Chen, Jason Zesheng},
     year = {2026},
     publisher = {arXiv},
     doi = {10.48550/arXiv.2609.02997},
     keywords = {FOS: Mathematics,Logic (math.LO)},
   }

2. arXiv Preprint

   Ideals, Well-Orderable Families, and Baire Category in Truss’s Feferman-Type Model

   Jason Zesheng Chen

   #set-theory#choice#descriptive-set-theory#measure-and-category

   Bib HTML PDF

   @misc{chenIdealsWellOrderable2026,
     title = {Ideals, Well-Orderable Families, and Baire Category in Truss's Feferman-Type Model},
     author = {Chen, Jason Zesheng},
     year = {2026},
     publisher = {arXiv},
     doi = {10.48550/arXiv.2608.21649},
     keywords = {FOS: Mathematics,Logic (math.LO)},
   }

3. arXiv Preprint

   Equivalence of Random Generics Is Not Essentially Free

   Jason Zesheng Chen

   #descriptive-set-theory#borel-equivalence-relations#forcing

   Bib HTML PDF

   @misc{chenEquivalenceRandomGenerics2026,
     title = {Equivalence of Random Generics Is Not Essentially Free},
     author = {Chen, Jason Zesheng},
     year = {2026},
     publisher = {arXiv},
     doi = {10.48550/arXiv.2608.21706},
     keywords = {FOS: Mathematics,Logic (math.LO)},
   }

4. Synthese

   Varieties of Confluence Arguments, Part 1: Practical Applications

   Jason Zesheng Chen

   #philosophy-of-mathematics#mathematical-practice#confluence

   Abs Bib Publisher PDF

   Abstract This paper is the self-contained first part of a two-part series that examines the wide varieties of ways that mathematicians and philosophers have appealed to confluence phenomena in their work. In this part, we focus on the practical roles such phenomena can play, paying special attention to how they facilitate the communication of mathematical ideas (proofs, definitions, and conjectures) in actual practice. Through surveying the wide array of such arguments, I shall eventually hone in on two subtly distinct facets concerning the uses of confluence arguments (and another that is revealed to be rather trivial upon analysis), which are sometimes conflated in philosophical discussions: one (dubbed Rigor Assurance) guarantees the formal rigor of a proof, while the other (Coding Invariance) ensures the results obtained are not a mere artifact of the coding that is used. I will then attempt to tease these two facets apart with actual examples in print, citing crucial evidence witnessing the distinction. With this setup in place, we will see how certain recent philosophical debates about the practical use of the Church-Turing Thesis may naturally dissolve, as the combatants do not share the same assumptions of the roles confluence arguments play in each case, and thus end up merely talking past each other.

   @article{chenVarietiesConfluenceArguments2026,
     title = {Varieties of Confluence Arguments, Part 1: Practical Applications},
     shorttitle = {Varieties of Confluence Arguments, Part 1},
     author = {Chen, Jason Zesheng},
     year = {2026},
     date = {2026-02-23},
     journaltitle = {Synthese},
     shortjournal = {Synthese},
     volume = {207},
     number = {3},
     pages = {99},
     issn = {1573-0964},
     doi = {10.1007/s11229-026-05482-4},
     url = {https://link.springer.com/10.1007/s11229-026-05482-4},
     urldate = {2026-02-23},
   }

2025

1. arXiv Preprint

   Teasing Apart Definitional Equivalence

   Jason Chen, and Toby Meadows

   #foundations-of-mathematics#definitional-equivalence

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   In a recent paper, Enayat and Łełyk [2024] show that second order arithmetic and countable set theory are not definitionally equivalent. It is well known that these theories are biinterpretable. Thus, we have a pair of natural theories that illustrate a meaningful difference between definitional equivalence and bi-interpretability. This is particularly interesting given that Visser and Friedman [2014] have shown that a wide class of natural foundational theories in mathematics are such that if they are bi-interpretable, then they are also definitionally equivalent. The proof offered by Enayat and Łełyk makes use of an inaccessible cardinal. In this short note, we show that the failure of bi-interpretability can be established in Peano Arithmetic merely supposing that one of our target theories are consistent.

   @misc{chenTeasingApartDefinitional2025,
     title = {Teasing Apart Definitional Equivalence},
     author = {Chen, Jason and Meadows, Toby},
     year = {2025},
     publisher = {arXiv},
     doi = {10.48550/ARXIV.2508.03956},
     urldate = {2025-08-07},
     copyright = {Creative Commons Attribution 4.0 International},
     keywords = {FOS: Mathematics,Logic (math.LO)},
   }

2024

1. PhD Dissertation

   Confluence and Classification: Towards a Philosophy of Descriptive-Set-Theoretic Practice

   Jason Zesheng Chen

   University of California, Irvine

   #philosophy-of-mathematics#mathematical-practice#descriptive-set-theory#confluence

   Bib HTML

   @phdthesis{chen2024confluence,
     title = {Confluence and Classification: Towards a Philosophy of Descriptive-Set-Theoretic Practice},
     author = {Chen, Jason Zesheng},
     year = {2024},
     school = {University of California, Irvine},
   }