Abstract
Let \(\ell \) and p be two distinct primes. We study the p-adic valuation of the number of spanning trees in an abelian \(\ell \)-tower of connected multigraphs. This is analogous to the classical theorem of Washington–Sinnott on the growth of the p-part of the class group in a cyclotomic \({\mathbb {Z}}_\ell \)-extension of abelian extensions of \({\mathbb {Q}}\). Furthermore, we show that under certain hypotheses, the number of primes dividing the number of spanning trees is unbounded in such a tower.
Similar content being viewed by others
Data availability
Data sharing not applicable to this article as no datasets were generated or analysed during the current study.
References
Baker, M., Norine, S.: Harmonic morphisms and hyperelliptic graphs. Int. Math. Res. Not. IMRN 15, 2914–2955 (2009)
Dion, C., Ray, A.: Topological Iwasawa invariants and arithmetic statistics. Doc. Math. 27, 89–149 (2022)
Gilmer, R.: Commutative Semigroup Rings. Chicago Lectures in Mathematics. University of Chicago Press, Chicago (1984)
Gonet, S.R.: Jacobians of finite and infinite voltage covers of graphs. Ph.D. Thesis, The University of Vermont and State Agricultural College. ProQuest LLC, Ann Arbor (2021)
Gonet, S.R.: Iwasawa theory of Jacobians of graphs. Algebr. Combin. 5(5), 827–848 (2022)
Hammer, K., Mattman, T.W., Sands, J.W., Vallières, D.: The special value \(u=1\) of Artin–Ihara \(L\)-functions. arXiv:1907.04910
Hillman, J., Matei, D., Morishita, M.: Pro-\(p\) link groups and \(p\)-homology groups. In: Primes and Knots. Contemporary Mathematics, vol. 416, pp. 121–136. American Mathematical Society, Providence (2006)
Iwasawa, K.: On \(\Gamma \)-extensions of algebraic number fields. Bull. Am. Math. Soc. 65, 183–226 (1959)
Iwasawa, K.: On \({\mathbb{Z} }_{l}\)-extensions of algebraic number fields. Ann. Math. 2(98), 246–326 (1973)
Kadokami, T., Mizusawa, Y.: On the Iwasawa invariants of a link in the 3-sphere. Kyushu J. Math. 67(1), 215–226 (2013)
McGown, K.J., Vallières, D.: On abelian \(\ell \)-towers of multigraphs II. Ann. Math. Québec (2021). https://doi.org/10.1007/s40316-021-00183-5
McGown, K.J., Vallières, D.: On abelian \(\ell \)-towers of multigraphs III. Ann. Math. Québec (2022). https://doi.org/10.1007/s40316-022-00194-w
Schinzel, A.: Primitive divisors of the expression \(A^{n}-B^{n}\) in algebraic number fields. J. Reine Angew. Math. 268(269), 27–33 (1974)
Sinnott, W.: On a theorem of L. Washington. Astérisque 147–148, 209–224, 344 (1987). Journées arithmétiques de Besançon (Besançon, 1985)
Sunada, T.: Topological Crystallography. Surveys and Tutorials in the Applied Mathematical Sciences, vol. 6. Springer, Tokyo (2013). With a view towards discrete geometric analysis
Terras, A.: Zeta Functions of Graphs. Cambridge Studies in Advanced Mathematics, vol. 128. Cambridge University Press, Cambridge (2011). A stroll through the garden
Vallières, D.: On abelian \(\ell \)-towers of multigraphs. Ann. Math. Québec 45(2), 433–452 (2021)
William S.: Sage: Open Source Mathematical Software (Version 8.5). The Sage Group (2018). http://www.sagemath.org
Washington, L.C.: Class numbers and \( {Z}_{p}\)-extensions. Math. Ann. 214, 177–193 (1975)
Washington, L.C.: The non-\(p\)-part of the class number in a cyclotomic \( {Z}_{p}\)-extension. Invent. Math. 49(1), 87–97 (1978)
Acknowledgements
The authors would like to thank Cédric Dion and Anwesh Ray for interesting discussions on topics related to the present article. DV would like to thank the pure mathematics group at the California State University - Chico including John Lind, Thomas Mattman, and Kevin McGown for several stimulating discussions during our seminar. DV would also like to thank AL for inviting him to give a talk at the Université Laval on related topics from which the current paper is a result of discussions that followed. AL’s research is supported by the NSERC Discovery Grants Program RGPIN-2020-04259 and RGPAS-2020-00096. AL would like to thank DV for introducing this beautiful subject to him.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Lei, A., Vallières, D. The non-\(\ell \)-part of the number of spanning trees in abelian \(\ell \)-towers of multigraphs. Res. number theory 9, 18 (2023). https://doi.org/10.1007/s40993-023-00425-1
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s40993-023-00425-1