んちゃ!
今回はゼータ関数の加速級数を発見したので紹介いたします。
使用するのはコネクターだけです。
参考記事:記号や詳細についてはこちらの記事を参照(👈クリック)
\begin{equation} C(n,m)=\frac{1}{\begin{pmatrix}n+m\\m\end{pmatrix}^{k}} \end{equation}
\begin{equation} f_{N}(n)=\sum_{n\lt m}\frac{C(n,m)}{m^{N}} \end{equation}
\begin{equation} f_{N}(n-1)=2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{(m+p)^{k}}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}-\sum_{n-1\lt m}\sum_{m\lt p}\frac{1}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}} \end{equation}
[1]
\begin{eqnarray}
f_{N}(n-1)-f_{N}(n)&=&\sum_{n-1\lt m}\frac{C(n-1,m)}{m^{N}}-\sum_{n\lt m}\frac{C(n,m)}{m^{N}}\\
&=&\frac{C(n-1,n)}{n^{N}}+\sum_{n\lt m}\frac{C(n-1,m)-C(n,m)}{m^{N}}\\
&=&\frac{(n!)^{k}\{(n-1)!\}^{k}}{n^{N}\{(2n-1)!\}^{k}}+\sum_{n\lt m}\frac{\sum_{l=1}^{k}\begin{pmatrix}k\\l\end{pmatrix}n^{k-l}m^{l}C(n,m)}{n^{k}m^{N}}\\
&=&\frac{2^{k}}{n^{N}\begin{pmatrix}2n\\n\end{pmatrix}^{k}}+\frac{1}{n^{k}}\sum_{l=1}^{k}\begin{pmatrix}k\\l\end{pmatrix}n^{k-l}\sum_{n\lt m}\frac{C(n,m)}{m^{N-l}}\\
&=&\frac{2^{k}}{n^{N}\begin{pmatrix}2n\\n\end{pmatrix}^{k}}+\frac{1}{n^{k}}\sum_{l=1}^{k}\begin{pmatrix}k\\l\end{pmatrix}n^{k-l}f_{N-l}(n)\\
\end{eqnarray}
[3]
\begin{eqnarray}
f_{N}(n-1)&=&f_{N}(n)+\frac{2^{k}}{n^{N}\begin{pmatrix}2n\\n\end{pmatrix}^{k}}+\sum_{l=0}^{k}\begin{pmatrix}k\\k-l\end{pmatrix}n^{k-l-k}f_{N+k-l-k}(n)-f_{N}(n)\\
&=&f_{N}(n)+\frac{2^{k}}{n^{N}\begin{pmatrix}2n\\n\end{pmatrix}^{k}}+\sum_{l=0}^{k}\begin{pmatrix}k\\l\end{pmatrix}n^{l-k}f_{N+l-k}(n)-f_{N}(n)\\
&=&f_{N}(n)+\frac{2^{k}}{n^{N}\begin{pmatrix}2n\\n\end{pmatrix}^{k}}+\sum_{l=0}^{k-1}\begin{pmatrix}k\\l\end{pmatrix}n^{l-k}f_{N+l-k}(n)\\
&=&2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\sum_{l=0}^{k-1}\begin{pmatrix}k\\l\end{pmatrix}\frac{1}{m^{k-l}}f_{N+l-k}(m)\\
&=&2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\sum_{l=0}^{k-1}\begin{pmatrix}k\\l\end{pmatrix}\frac{1}{m^{k-l}}\sum_{m\lt p}\frac{1}{p^{N+l-k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}\\
&=&2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\sum_{m\lt p}\sum_{l=0}^{k-1}\begin{pmatrix}k\\l\end{pmatrix}\frac{1}{m^{k-l}p^{l}}\frac{1}{p^{N-k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}\\
&=&2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\sum_{m\lt p}\{\sum_{l=0}^{k}\begin{pmatrix}k\\l\end{pmatrix}\frac{1}{m^{k-l}p^{l}}-\frac{1}{p^{k}}\}\frac{1}{p^{N-k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}\\
&=&2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\sum_{m\lt p}(\frac{1}{m}+\frac{1}{p})^{k}\frac{1}{p^{N-k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}-\sum_{n-1\lt m}\sum_{m\lt p}\frac{1}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}\\
&=&2^{k}\sum_{n-1\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{n-1\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{(m+p)^{k}}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}-\sum_{n-1\lt m}\sum_{m\lt p}\frac{1}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}
\end{eqnarray}
\begin{equation} \zeta(N)=2^{k}\sum_{0\lt m}\frac{1}{m^{N}\begin{pmatrix}2m\\m\end{pmatrix}^{k}}+\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{(m+p)^{k}}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}-\sum_{0\lt m}\sum_{m\lt p}\frac{1}{p^{N}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}} \end{equation}
\begin{equation} \sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{(m+p)^{k}-m^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}=\sum_{0\lt m}\frac{1}{m^{k}\begin{pmatrix}2m\\m\end{pmatrix}}+\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{p^{k}-m^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}} \end{equation}
\begin{eqnarray} \sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{(m+p)^{k}-m^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}&=&\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{(m+p)^{k}-p^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}+\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{p^{k}-m^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}\\ &=&\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\{\frac{1}{\begin{pmatrix}m+p-1\\p-1\end{pmatrix}}-\frac{1}{\begin{pmatrix}m+p\\p\end{pmatrix}}\}+\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{p^{k}-m^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}^{k}}\\ &=&\sum_{0\lt m}\frac{1}{m^{k}\begin{pmatrix}2m\\m\end{pmatrix}}+\sum_{0\lt m}\frac{1}{m^{k}}\sum_{m\lt p}\frac{p^{k}-m^{k}}{p^{k}\begin{pmatrix}m+p\\p\end{pmatrix}} \end{eqnarray}
任意の複素数$s\in\mathbb{C}(1\lt\Re(s))$に対して以下の式が成り立つ。
\begin{equation}
\zeta(s)=(2^{s}+1)\sum_{0\lt m}\frac{1}{m^{s}\begin{pmatrix}2m\\m\end{pmatrix}^{s}}+\sum_{0\lt m}\frac{1}{m^{s}}\sum_{m\lt p}\frac{p^{s}-m^{s}}{p^{s}\begin{pmatrix}m+p\\p\end{pmatrix}^{s}}
\end{equation}
import sympy as sp
def binomial(n, k):
return sp.binomial(n, k)
def compute_rhs(k, max_m=100, max_p=100):
term1 = sum(1 / (sp.Pow(m, k) * sp.Pow(binomial(2 * m, m), k)) for m in range(1, max_m + 1)) * (sp.Pow(2, k) + 1)
term2 = sum((sp.Pow(p, k) - sp.Pow(m, k)) / (sp.Pow(m, k) * sp.Pow(p, k) * sp.Pow(binomial(m + p, p), k))
for m in range(1, max_m + 1) for p in range(m + 1, max_p + 1))
return term1 + term2
def matching_digits(x, y):
if x.is_real and y.is_real:
x_val = float(x.evalf(50))
y_val = float(y.evalf(50))
x_str = f"{x_val:.50f}"
y_str = f"{y_val:.50f}"
else:
x_real, x_imag = float(x.as_real_imag()[0].evalf(50)), float(x.as_real_imag()[1].evalf(50))
y_real, y_imag = float(y.as_real_imag()[0].evalf(50)), float(y.as_real_imag()[1].evalf(50))
x_str = f"{x_real:.50f}{x_imag:+.50f}j"
y_str = f"{y_real:.50f}{y_imag:+.50f}j"
count = 0
for a, b in zip(x_str, y_str):
if a == b:
count += 1
else:
break
return count
def main(k, max_m=10, max_p=10):
lhs = sp.N(sp.zeta(k), 20) # ζ(k) の高精度計算
rhs = compute_rhs(k, max_m, max_p)
matched_digits = matching_digits(lhs, rhs)
print(f"LHS (Zeta Function): {lhs}")
print(f"RHS (Computed Sum) : {rhs.evalf(20)}")
print(f"Matching Digits : {matched_digits}")
if name == "main":
k = 2 + 0.5j # 複素数の例
main(k)