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Sato-Tate distribution of \(p\)-adic hypergeometric functions. (English) Zbl 1518.11051

Let \(p\) be an odd prime, and let \(\mathbb{F}_q\) be the finite field with \(q=p^r\) elements. For positive integer \(n, k (1\leq k\leq n)\) let \(a_k, b_k\in\mathbb{Q}\cap\mathbb{Z}_p\), D. McCarthy [Pac. J. Math. 261, No. 1, 219–236 (2013; Zbl 1296.11079); Int. J. Number Theory 8, No. 7, 1581–1612 (2012; Zbl 1253.33024)] defined, using \(p\)-adic Gamma function, \(p\)-adic hypergeometric functions \(_{n}G_{n}\left[\begin{matrix} a_1& a_2\cdots &a_n \\ b_1& b_2& \cdots& b_n\end{matrix} |\, t \right]_p\).
The main results of this article are about \(_nG_n\) for \(n=2, 6\) and are formulated in the following theorem.
Theorem: Let \(m\) be a fixed positive integer and \(p\equiv 1\pmod 3\) for \(n=2\) (resp. \(p\equiv 2\pmod 3\) for \(n=6\)) be a prime. Then as \(p\to\infty\), \(\sum_{\lambda\in\mathbb{F}_p}nG_{n}(\lambda)_p^m\) is equal to \(a_m(p^{\frac{m}{2}+1})\) if \(m\) is odd, and to \(\frac{(2n)!}{n!(n+1)!}p^{n+1}+a_m(p^{n+1})\) if \(m=2n\) is even.
Corollary: Let \(-2\leq 2<b\leq 2\) and \(p\equiv 1\pmod 3\) for \(n=2\) (resp. \(p\equiv 2\pmod 3\) for \(n=6\)). Then \[ \lim_{p\to\infty}\frac{|\{\lambda\in\mathbb{F}_p\,|\, p^{-\frac{1}{2}}_{n}G_{n}(\lambda)_p\in[a,b]\,\}|}{p} =\displaystyle\frac{1}{2\pi} \int_a^b\sqrt{4-t^2}dt. \] As applications, the trace formulas for the \(p\)th Hecke operators acting on the space of cusp forms of weight \(4\) (resp. \(8\)) in terms of \(_2G_2\) (resp. \(_6G_6\)) are derived.

MSC:

11G20 Curves over finite and local fields
11T24 Other character sums and Gauss sums
33E50 Special functions in characteristic \(p\) (gamma functions, etc.)

References:

[1] Ahlgren, S., The points of a certain fivefold over finite fields and the twelfth power of the eta function, Finite Fields Appl., 8, 1, 18-33 (2002) · Zbl 1026.11053 · doi:10.1006/ffta.2001.0315
[2] Ahlgren, S.; Ono, K., Modularity of a certain Calabi-Yau threefold, Montash. Math., 129, 3, 177-190 (2000) · Zbl 0999.11031 · doi:10.1007/s006050050069
[3] Berndt, B.; Evans, R.; Williams, K., Gauss and Jacobi Sums, Canadian Mathematical Society Series of Monographs and Advanced Texts (1998), New York: A Wiley-Interscience Publication. Wiley, New York · Zbl 0906.11001
[4] Birch, BJ, How the number of points of an elliptic curve over a fixed prime field varies, J. Lond. Math. Soc., 43, 57-60 (1968) · Zbl 0183.25503 · doi:10.1112/jlms/s1-43.1.57
[5] Bringmann, K., Kane, B., Pujahari, S.: Odd moments for the trace of Frobenius and the Sato-Tate conjecture in arithmetic progressions. arXiv:2112.08205
[6] Frechette, S.; Ono, K.; Papanikolas, M., Gaussian hypergeometric functions and traces of Hecke operators, Int. Math. Res. Not., 2004, 60, 3233-3262 (2004) · Zbl 1088.11029 · doi:10.1155/S1073792804132522
[7] Frechette, S.; Ono, K.; Papanikolas, M., The combinatorics of traces of Hecke operators, Proc. Natl. Acad. Sci. U.S.A., 101, 17016-17020 (2004) · Zbl 1064.11038 · doi:10.1073/pnas.0407223101
[8] Fuselier, J., Traces of Hecke operators in level 1 and Gaussian hypergeometric functions, Proc. Am. Math. Soc., 141, 6, 1871-1881 (2013) · Zbl 1297.11026 · doi:10.1090/S0002-9939-2012-11540-0
[9] Fuselier, J., Hypergeometric functions over \(\mathbb{F}_p\) and relations to elliptic curves and modular forms, Proc. Am. Math. Soc., 138, 1, 109-123 (2010) · Zbl 1222.11058 · doi:10.1090/S0002-9939-09-10068-0
[10] Fuselier, J.; McCarthy, D., Hypergeometric type identities in the \(p\)-adic setting and modular forms, Proc. Am. Math. Soc., 144, 1493-1508 (2016) · Zbl 1397.11078 · doi:10.1090/proc/12837
[11] Greene, J., Hypergeometric functions over finite fields, Trans. Am. Math. Soc., 301, 1, 77-101 (1987) · Zbl 0629.12017 · doi:10.1090/S0002-9947-1987-0879564-8
[12] Gross, BH; Koblitz, N., Gauss sum and the \(p\)-adic \(\Gamma \)-function, Ann. Math., 109, 569-581 (1979) · Zbl 0406.12010 · doi:10.2307/1971226
[13] Ireland, K.; Rosen, M., A Classical Introduction to Modern Number Theory (2005), New York: Springer, New York
[14] Kane, B., Pujahari, S: Distribution of moments of Hurwitz class numbers in arithmatic progressions and holomorphic projection. arXiv:2010.15325
[15] Katz, NM, Exponential Sums and Differential Equations (1990), Princeton: Princeton University Press, Princeton · Zbl 0731.14008 · doi:10.1515/9781400882434
[16] Koblitz, N.: \(p\)-adic Analysis: A short course on recent work. London Math. Soc. Lecture Note Series, 46. Cambridge University Press, Cambridge (1980) · Zbl 0439.12011
[17] McCarthy, D., The trace of Frobenius of elliptic curves and the \(p\)-adic gamma function, Pac. J. Math., 261, 1, 219-236 (2013) · Zbl 1296.11079 · doi:10.2140/pjm.2013.261.219
[18] McCarthy, D., Extending Gaussian hypergeometric series to the \(p\)-adic setting, Int. J. Number Theory, 8, 7, 1581-1612 (2012) · Zbl 1253.33024 · doi:10.1142/S1793042112500844
[19] McCarthy, D., Transformations of well-poised hypergeometric functions over finite fields, Finite Fields Appl., 18, 6, 1133-1147 (2012) · Zbl 1276.11198 · doi:10.1016/j.ffa.2012.08.007
[20] Ono, K., Values of Gaussian hypergeometric series, Trans. Am. Math. Soc., 350, 3, 1205-1223 (1998) · Zbl 0910.11054 · doi:10.1090/S0002-9947-98-01887-X
[21] Ono, K., Saad, H., Saikia, N.: Distribution of values of Gaussian hypergeometric functions. arXiv:2108.09560
[22] Pujahari, S.; Saikia, N., Traces of Hecke operators in level 1 and \(p\)-adic hypergeometric functions, Ramanujan J., 52, 519-539 (2020) · Zbl 1465.11108 · doi:10.1007/s11139-019-00170-z
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