Zeros of the Davenport–Heilbronn function in short intervals of the critical line
Z. Kh. Rakhmonova,
Sh. A. Khayrulloevb,
A. S. Aminova a Dzhuraev Institute of Mathematics, Academy of Sciences of Republic of Tajikistan, Dushanbe
b Tajik National University, Dushanbe
Abstract:
Davenport and Heilbronn introduced the function
$f(s)$ and showed that
$f(s)$ satisfies the Riemannian type functional equation, however, the Riemann hypothesis fails for
$f(s)$, and moreover, the number of zeros of
$f(s)$ in the region
$Re s>1$,
$0<Im s\ le T$ exceeds
$cT$, where
$c>0$ is an absolute constant. S.M. Voronin proved that, nevertheless, the critical line
$Re s=\frac12 $ is an exceptional set for the zeros of
$f(s)$, i.e. for
$N_0(T)$, where
$N_0(T)$ is the number of zeros of
$f(s)$ on the interval
$Re s=\frac12$,
$0<Im s\le T$, we have the estimate $N_0(T)>cT\exp\left(0.05\sqrt{\ln\ln\ln\ln T}\right)$, where
$c>0$ is an absolute constant,
$T\ge T_0>0$. While studying the number of zeros of the function
$f(s)$ in short intervals of the critical line, A.A. Karatsuba, proved: if
$\varepsilon$ and
$\varepsilon_1$ are arbitrarily small fixed positive numbers not exceeding
$0.001 $;
$T\geq T_0(\varepsilon,\varepsilon_1)>0$ and
$H=T^{\frac{27}{82}+\varepsilon_1}$, then we have
$$ N_0(T+H)-N_0(T)\ge H(\ln T)^{\frac{1}{2}-\varepsilon}. $$
This paper demonstrates that for the number of zeros of the Davenport-Heilbronn function
$f(s)$ in short intervals of the form
$[T,T+H]$ of the critical line the last relationship holds for
$H\ge T^{\frac{131}{416}+\varepsilon_1}$. In particular, this result is an application of a new, in terms of exponential pairs, estimates of special exponential sums
$W_j(T)$,
$j=0,1,2$ which are uniform across parameters, where the problem of the non-triviality of estimates for these sums with respect to the parameter
$H$ is reduced to the problem of finding the exponential pairs..
Keywords:
Davenport-Heilbronn function, exponential pair, Riemann hypothesis, Selberg soothing factors.
UDC:
511.32
Received: 15.11.2019
Accepted: 20.12.2019
DOI:
10.22405/2226-8383-2018-20-4-306-329