On a problem of Malyshev A. V. of integer points on multidimensional hyperboloids
R. A. Dokhov Kabardino-Balkar State University, Nal'chik
Abstract:
Some development early conducted investigations on the problem of Malyshev A. V.
about the number of integer points lying in some areas on multidimensional
hyperboloids is given in this work. The task of obtaining of asymptotic formulae
for quantity of integer points in areas of the kind of De Luri on multidimensional
hyperboloids is put by Malyshev A. V. [1]. De Luri [3]
in case of four-dimensional hyperbolic surface
\begin{equation*}
p\left(x_1, \ldots, x_4\right) =
\sum\limits_{k=1}^{4}
a_k x_k^2 -m =0,
\quad
m \ne 0
\end{equation*}
in the area
$\Omega_p (L)$ on it by defined inequality
\begin{equation*}
\sum\limits_{k=1}^{4}
\left| a_k \right| x_k^2 \leqslant L
\end{equation*}
obtained asymptotic formula (in
$L\to\infty$ and fixed
$a_1, a_2, a_3, a_4$, and
$m$)
for value of
$R \left( \Omega_p (L) \right)$, equaled to the number of integer points
in the area
$\Omega_p (L)$ on the mentioned hyperboloid, but in so doing De Luri
does not value the remainder formula.
Later on in [1] generalization of this value is given on
multidimensional hyperboloid given by the equation
\begin{equation*}
p = p\left(x_1, \ldots, x_s\right) =
\sum\limits_{k=1}^{s}
a_k x_k^2 +
\sum\limits_{k=1}^{s}
b_k x_k + c = 0,
\end{equation*}
where
$a_k$,
$b_k$,
$(k = 1, \ldots, s)$,
$c \ne 0$ — integers, in addition to
coefficients
$a_k$ not all is one sign, but area of
$\Omega_p (L)$ on this hyperboloid
is given by the inequality
\begin{equation*}
\sum\limits_{k=1}^{s}
\left| a_k \right| x_k^2 \leqslant L.
\end{equation*}
In development of indicated task of Malyshev A. V. we examine arbitrary quadratic form
equivalent to the diagonal in the equation of hyperboloid, and the area of
\begin{equation*}
\Omega_p (L) :
\sum\limits_{k=1}^{s}
\left| a_k \right| x_k^2 \leqslant L
\end{equation*}
is substituted for the area
\begin{equation*}
\sum\limits_{i=1}^{s}
\left\{
Q_i^{(1)} \left(x_i, y_i\right) +
Q_i^{(2)} \left(z_i, t_i\right)
\right\} \leqslant L,
\end{equation*}
where
$Q_i^{(1)}$ è
$Q_i^{(2)}$ — binary quadratic forms, equivalent to diagonal
forms. In conclusion of our asymptotic result about quantity of
$R \left( \Omega_p, L \right)$ the theorem about weighted number of integer points
$I_h (n, s)$ from [2] is used in
$n\to\infty$ and the complex variant
of tauberian’s theorem with remainder term for the power series
(see [5, 6]).
Also wee will note that our obtained result is analogous to one result of
Davenport [7] by generalized problem of Varing in power
$k=2$, but in such meaning of
$k$ our question of hyperbolic surface has
several more common kind.
Bibliography: 16 titles.
Keywords:
A. V. Malyshev problem, integer number, multidimensional hyperboloid, quadratic forms, tauberian theorem, asymptotic formula.
UDC:
511.3
Received: 29.07.2015