arXiv subjects

Pentti Haukkanen

Publications and source records attributed to Pentti Haukkanen.

23 records · Page 2Linked to original sources

arXiv2011

Some properties of row-adjusted meet and join matrices

Let $(P,\preceq)$ be a lattice, $S$ a finite subset of $P$ and $f_1,f_2,...,f_n$ complex-valued functions on $P$. We define row-adjusted meet and join matrices on $S$ by $(S)_{f_1,...,f_n}=(f_i(x_i\wedge x_j))$ and $[S]_{f_1,...,f_n}=(f_i(x_i\vee x_j))$. In this paper we determine the structure of the matrix $(S)_{f_1,...,f_n}$ in general case and in the case when the set $S$ is meet closed we give bounds for $\text{rank} (S)_{f_1,...,f_n}$ and present expressions for $\det (S)_{f_1,...,f_n}$ and $(S)_{f_1,...,f_n}^{-1}$. The same is carried out dually for row-adjusted join matrix of a join closed set $S$.

math.NT↗

arXiv2011

Some formulas for numbers of line segments and lines in a rectangular grid

We present a formula for the number of line segments connecting q+1 points of an n_1 x...x n_k rectangular grid. As corollaries, we obtain formulas for the number of lines through at least q points and, respectively, through exactly q points of the grid. The well-known case k=2 is so generalized. We also present recursive formulas for these numbers assuming k=2, n_1=n_2. The well-known case q=2 is so generalized.

math.CO↗

arXiv2010

The discrete Fourier transform of $r$-even functions

We give a detailed study of the discrete Fourier transform (DFT) of $r$-even arithmetic functions, which form a subspace of the space of $r$-periodic arithmetic functions. We consider the DFT of sequences of $r$-even functions, their mean values and Dirichlet series. Our results generalize properties of the Ramanujan sum. We show that some known properties of $r$-even functions and of the Ramanujan sum can be obtained in a simple manner via the DFT.

math.NT↗

arXiv2010

An analogue of Ramanujan's sum with respect to regular integers (mod $r$)

An integer $a$ is said to be regular (mod $r$) if there exists an integer $x$ such that $a^2x\equiv a\pmod{r}$. In this paper we introduce an analogue of Ramanujan's sum with respect to regular integers (mod $r$) and show that this analogue possesses properties similar to those of the usual Ramanujan's sum.

math.NT↗

arXiv2010

On the binomial convolution of arithmetical functions

Let $n=\prod_p p^{ν_p(n)}$ denote the canonical factorization of $n\in \N$. The binomial convolution of arithmetical functions $f$ and $g$ is defined as $(f\circ g)(n)=\sum_{d\mid n} (\prod_p \binom{ν_p(n)}{ν_p(d)}) f(d)g(n/d),$ where $\binom{a}{b}$ is the binomial coefficient. We provide properties of the binomial convolution. We study the $\C$-algebra $({\cal A},+,\circ,\C)$, characterizations of completely multiplicative functions, Selberg multiplicative functions, exponential Dirichlet series, exponential generating functions and a generalized binomial convolution leading to various Möbius-type inversion formulas. Throughout the paper we compare our results with those of the Dirichlet convolution *. Our main result is that $({\cal A},+,\circ,\C)$ is isomorphic to $({\cal A},+,*,\C)$. We also obtain a "multiplicative" version of the multinomial theorem.

math.NT↗