Ramanujan graphs and exponential sums over function fields
Ramanujan graphs and exponential sums over function fields
复制标题
拉马努金图和函数域上的指数和
DOI:
10.1016/j.jnt.2020.05.010
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发表时间:
2020
影响因子:
0.7
通讯作者:
Zargar, Masoud
中科院分区:
文献类型:
--
作者:
Sardari, Naser T.;Zargar, Masoud
We prove that q+ 1-regular Morgenstern Ramanujan graphs X q, g (depending on g∈ F q [t]) have diameter at most (4 3+ ε) log q| X q, g|+ O ε (1)(at least for odd q and irreducible g) provided that a twisted Linnik–Selberg conjecture over F q (t) is true. This would break the 30 year-old upper bound of 2 log q| X q, g|+ O (1), a consequence of a well-known upper bound on the diameter of regular Ramanujan graphs proved by Lubotzky, Phillips, and Sarnak using the Ramanujan bound on Fourier coefficients of modular forms. We also unconditionally construct infinite families of Ramanujan graphs that prove that 4 3 cannot be improved.
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影响因子:
0.8
作者:
P. Sarnak
通讯作者:
P. Sarnak
影响因子:
1.1
作者:
Naser T. Sardari
通讯作者:
Naser T. Sardari
影响因子:
2.5
作者:
Naser T. Sardari
通讯作者:
Naser T. Sardari
影响因子:
0.8
作者:
Steiner, Raphael S.
通讯作者:
Steiner, Raphael S.
DOI:
10.1093/imrn/rnx116
发表时间:
2016
期刊:
arXiv: Number Theory
影响因子:
--
作者:
T D Browning;V Vinay Kumaraswamy;R S Steiner
通讯作者:
R S Steiner