Let $q$, $h$, $a$, $b$ be integers with $q>0$. The classical and the homogeneous Dedekind sums are defined by $$s(h,q)=\sum _{j=1}^q\left(\left(\frac{j}{q}\right)\right)\left(\left(\frac{hj}{q}\right)\right),s(a,b,q)=\sum _{j=1}^q\left(\left(\frac{aj}{q}\right)\right)\left(\left(\frac{bj}{q}\right)\right),$$ respectively, where $$\left(\left(x\right)\right)=\left\{\begin{array}{cc}x-\left[x\right]-\frac{1}{2},\hfill & \text{if}x\text{is}\text{not}\text{an}\text{integer};\hfill \\ 0,\hfill & \text{if}x\text{is}\text{an}\text{integer}.\hfill \end{array}\right.$$ The Knopp identities for the classical and the homogeneous Dedekind sum were the following: $$\begin{array}{c}\sum _{d\mid n}\sum _{r=1}^{d}s\left(\frac{n}{d}a+rq,dq\right)=\sigma \left(n\right)s(a,q),\\ \sum _{d\mid n}\sum _{r_1=1}^d\sum _{r_2=1}^{d}s\left(\frac{n}{d}a+r_{1}q,\frac{n}{d}b+r_{2}q,dq\right)=n\sigma \left(n\right)s(a,b,q),\end{array}$$ where $\sigma \left(n\right)={\sum }_{d\mid n}d$. In this paper generalized homogeneous Hardy sums and Cochrane-Hardy sums are defined, and their arithmetic properties are studied. Generalized Knopp identities for homogeneous Hardy sums and Cochrane-Hardy sums are given.

In this article we study the problem of finding such finite groups that the modular forms associated with all elements of these groups by means of a certain faithful representation belong to a special class of modular forms (so-called multiplicative $\eta -$products). This problem is open.We find metacyclic groups with such property and describe the Sylow $p$-subgroups, $p\ne 2,$ for such groups. We also give a review of the results about the connection between multiplicative $\eta$-products and elements of finite orders...

Let $p$ be an odd prime and $c$ a fixed integer with $(c,p)=1$. For each integer $a$ with $1\le a\le p-1$, it is clear that there exists one and only one $b$ with $0\le b\le p-1$ such that $ab\equiv c$ (mod $p$). Let $N(c,p)$ denote the number of all solutions of the congruence equation $ab\equiv c$ (mod $p$) for $1\le a$, $b\le p-1$ in which $a$ and $\overline{b}$ are of opposite parity, where $\overline{b}$ is defined by the congruence equation $b\overline{b}\equiv 1(modp)$. The main purpose of this paper is to use the properties of Dedekind sums and the mean value theorem for Dirichlet $L$-functions to study the hybrid mean value problem involving...

Various properties of classical Dedekind sums $S(h,q)$ have been investigated by many authors. For example, Wenpeng Zhang, On the mean values of Dedekind sums, J. Théor. Nombres Bordx, 8 (1996), 429–442, studied the asymptotic behavior of the mean value of Dedekind sums, and H. Rademacher and E. Grosswald, Dedekind Sums, The Carus Mathematical Monographs No. 16, The Mathematical Association of America, Washington, D.C., 1972, studied the related properties. In this paper, we use the algebraic method to...

In this paper we study the asymptotic behavior of the mean value of Dedekind sums, and give a sharper asymptotic formula.

In this article we consider one special class of modular forms which are products of Dedekind $\eta$-functions and the relationships between these functions and representations of finite groups.