We study the growth of the values of integer binary quadratic forms Q on a binary planar tree as it was described by Conway. We show that the corresponding Lyapunov exponents _Q(x) as a function of the path determined by x 2 RP1 are twice the values of the
corresponding exponents for the growth of Markov numbers [10], except for the paths corresponding to the Conway river, when _Q(x) = 0: The relation with the Galois result about pure periodic continued fractions is explained and interpreted geometrically.
Funding
The work of K.S. was supported by the EPSRC as part of PhD study at Loughborough
History
School
Science
Department
Mathematical Sciences
Published in
Bulletin of the London Mathematical Society
Citation
SPALDING, K. and VESELOV, A.P., 2018. Growth of values of binary quadratic forms and Conway rivers. Bulletin of the London Mathematical Society, 50 (3), pp.513-528.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Acceptance date
2018-03-06
Publication date
2018-04-16
Notes
This is the peer reviewed version of the following article: SPALDING, K. and VESELOV, A.P., 2018. Growth of values of binary quadratic forms and Conway rivers. Bulletin of the London Mathematical Society, 50 (3), pp.513-528, which has been published in final form at https://doi.org/10.1112/blms.12156. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.