English

The transcendence degree of the reals over certain set-theoretical subfields

Logic 2026-01-13 v2 Commutative Algebra

Abstract

It is a well-known result that, after adding one Cohen real, the transcendence degree of the reals over the ground-model reals is continuum. We extend this result for a set XX of finitely many Cohen reals, by showing that, in the forcing extension, the transcendence degree of the reals over a combination of the reals in the extension given by each proper subset of XX is also maximal. This answers a question of Kanovei and Schindler.

Keywords

Cite

@article{arxiv.2412.00616,
  title  = {The transcendence degree of the reals over certain set-theoretical subfields},
  author = {Azul Fatalini and Ralf Schindler},
  journal= {arXiv preprint arXiv:2412.00616},
  year   = {2026}
}

Comments

We thank the reviewer that spotted a mistake in the argument of the proof Lemma 3.1. The proof has been replaced. Def 1.13 and Lemma 1.15 added, and other minor changes to improve the text. This is the last version, published in JSL