Stark units for real quadratic fields and reciprocity laws

A mix of human-written and AI-generated textHuman understanding: all partsmath.NT — Number Theorymath.QA — Quantum Algebra

Contributed by Danylo Radchenko ↗, Campbell Wheeler

Version 1 / Oct 10, 2026 / CC BY 4.0

Abstract

We prove that every value of the arithmetic finite quantum dilogarithms constructed by Radchenko and Wheeler (arXiv:2609.21892) is an algebraic unit, and determine the Artin action for arbitrary quadratic pseudolattices. In particular, the associated Stark units belong to the predicted ray class fields and have the predicted Galois action. We use finite Fourier transforms and distribution relations to obtain Frobenius congruences. We also give conductor bounds for individual values and obtain the unitary conjugates needed for Zauner's conjecture.

Provenance statement

Large language models were used to develop the arguments and draft much of the text. The human contributors checked the arguments and edited the exposition. A detailed account of the work's provenance is given in the paper's Disclaimer.

References

  1. Marcus Appleby, Steven T Flammia, and Gene S Kopp. A constructive approach to Z auner's conjecture via the S tark conjectures, 2025. Preprint, https://arxiv.org/abs/2501.03970 arXiv:2501.03970 .arXiv
  2. Marcus Appleby, Steven T Flammia, and Gene S Kopp. The twisted convolution identity and ghost r-SICs from finite quantum dilogarithms, 2026. Preprint, https://arxiv.org/abs/2609.39192 arXiv:2609.39192 .arXiv
  3. Matthias K ü nzer and Harald Weber. On the cyclotomic D edekind embedding and the cyclic W edderburn embedding. Algebr. Represent. Theory , 7(3):211--259, 2004. https://arxiv.org/abs/math/0103125 arXiv:math/0103125 .arXiv
  4. Yuri I. Manin. Real multiplication and noncommutative geometry (ein A lterstraum). In The Legacy of Niels Henrik Abel , pages 685--727. Springer, Berlin, 2004. https://arxiv.org/abs/math/0202109 arXiv:math/0202109 .arXiv
  5. James S. Milne. Class field theory, 2020. Version 4.03. https://www.jmilne.org/math/CourseNotes/CFT.pdf Course notes .link
  6. J ü rgen Neukirch. Algebraic Number Theory , volume 322 of Grundlehren der mathematischen Wissenschaften . Springer, Berlin, 1999. Translated from the German by N. Schappacher.
  7. Danylo Radchenko and Campbell Wheeler. Real quadratic fields and finite quantum dilogarithms I , 2026. https://arxiv.org/abs/2609.21892 arXiv:2609.21892 .arXiv
  8. Harold M. Stark. LL -functions at s=1s=1. III . T otally real fields and H ilbert's twelfth problem. Advances in Math. , 22(1):64--84, 1976.
  9. Harold M. Stark. LL -functions at s=1s=1. IV . F irst derivatives at s=0s=0. Advances in Math. , 35(3):197--235, 1980.
  10. John Tate. Les C onjectures de S tark sur les F onctions LL d' A rtin en s=0s=0 , volume 47 of Progr. Math. Birkh ä user, Boston, MA, 1984. Notes d'un cours à O rsay r é dig é es par D. Bernardi et N. Schappacher.

Version history

  1. v1Submitted by Danylo RadchenkoInitial depositCurrentOct 10, 2026