Even Values of Ramanujan’s Tau-Function
Even Values of Ramanujan’s Tau-Function
复制标题
拉马努金 Tau 函数的偶数值
DOI:
10.1007/s44007-021-00005-8
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发表时间:
2022
期刊:
影响因子:
--
通讯作者:
Tsai, Wei-Lun
中科院分区:
文献类型:
--
作者:
Balakrishnan, Jennifer S.;Ono, Ken;Tsai, Wei-Lun
In the spirit of Lehmer’s speculation that Ramanujan’s tau-function never vanishes, it is natural to ask whether any given integeris a value of. For odd, Murty, Murty, and Shorey proved thatfor sufficiently largen. Several recent papers have identified explicit examples of oddwhich are not tau-values. Here we apply these results (most notably the recent work of Bennett, Gherga, Patel, and Siksek) to offer the first examples of even integers that are not tau-values. Namely, for primeswe find that $$\begin{aligned} \tau (n)\not \in \{ \pm 2\ell \ : \ 3\le \ell< 100\}&\cup&\{\pm 2\ell ^2 \ : \ 3\le \ell<100\}\\&\cup&\{\pm 2\ell ^3 \ : \ 3\le \ell <100\ {\text {with }\ell \ne 59}\}. \end{aligned}$$Moreover, we obtain such results for infinitely many powers of each prime. As an example, forwe prove that $$\begin{aligned} \tau (n)\not \in \{ 2\cdot 97^j \ : \ 1\le j\not \equiv 0\pmod {44}\}\cup \{-2\cdot 97^j \ : \ j\ge 1\}. \end{aligned}$$The method of proof appliesmutatis mutandisto newforms with residually reducible mod 2 Galois representation and is easily adapted to generic newforms with integer coefficients.
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DOI:
10.1007/s11139-021-00388-w
发表时间:
2022
期刊:
The Ramanujan Journal
影响因子:
--
作者:
Amir, Malik;Hong, Letong
通讯作者:
Hong, Letong
影响因子:
0.7
作者:
Balakrishnan, Jennifer S.;Craig, William;Ono, Ken
通讯作者:
Ono, Ken
影响因子:
1.7
作者:
Balakrishnan, Jennifer S.;Craig, William;Ono, Ken;Tsai, Wei-Lun
通讯作者:
Tsai, Wei-Lun
影响因子:
0.7
作者:
Dembner, Spencer;Jain, Vanshika
通讯作者:
Jain, Vanshika
影响因子:
0.7
作者:
Hanada, Mitsuki;Madhukara, Rachana
通讯作者:
Madhukara, Rachana