Direct factors of polynomial rings over finite fields

Let G_q denote the multiplicative semigroup of all monic polynomials in one indeterminate over a finite field F_q with q elements. By a direct factor of G_q is understood a subset B₁ of G_q such that, for some subset B₂ of G_q, every polynomial w G_q has a unique factorization in the form w = b₁b₂ for b_i B_i. An asymptotic formula B₁^#(n) c₁qⁿ as n → ∞ is derived for the total number B₁^#(n) of polynomials of degree n in an arbitrary direct factor B₁ of G_q, c₁ a constant depending on B₁.     

The least common multiple of random sets in polynomial rings over finite fields

The Ramanujan Journal - In this paper we investigate the distribution of degrees of the least common multiples of random subsets of monic polynomials of degree n in $${\mathbb {F}}_q[t]$$ . We...     

Quadratic forms over polynomial rings over global fields

It is proved that a quadratic space over the polynomial extension of a global field K is extended from K if it is extended from K_v for every completion K_v of K.     

Cycles of polynomial mappings in two variables over rings of integers in quadratic fields

We find all possible cycle-lengths for polynomial mappings in two variables over rings of integers in quadratic extensions of rationals.     

Unimodular polynomial matrices over finite fields

Journal of Algebraic Combinatorics - We consider some combinatorial problems on matrix polynomials over finite fields. Using results from control theory, we give a proof of a result of Lieb, Jordan...     

Multiplicative arithmetic of finite quadratic forms over Dedekind rings

Letq(X) be a quadratic form in an even numberm of variables with coefficients in a Dedekind ringK. Let us assume that the setsR(q,a) = {N∈K ^m ;q(N) = a} of representations of elementsa ofK by the formq are finite. Then certain multiplicative relations are obtained by elementary means between the setsR(q,a) andR(q,ab), whereb is a product of prime elementsρ ofK with finite coefficientsK/ρK. The relations imply similar multiplicative relations between the numbers of elements of the setsR(q,a), which formerly could be obtained only in some special cases like the case whenK = ℤ is the ring of rational integers and only by means of the theory of Hecke operators on the spaces of theta-series. As an application, an almost elementary proof of the Siegel theorem on the mean number of representations of integers by integral positive quadratic forms of determinant 1 is given. Dedicated to the memory of Professor K G Ramanathan     

On the polynomial Ramanujan sums over finite fields

The polynomial Ramanujan sum was first introduced by Carlitz (Duke Math J 14:1105–1120, 1947), and a generalized version by Cohen (Duke Math J 16:85–90, 1949). In this paper, we study the arithmetical and analytic properties of these sums, deriving various fundamental identities, such as Hölder formula, reciprocity formula, orthogonality relation, and Davenport–Hasse type formula. In particular, we show that the special Dirichlet series involving the polynomial Ramanujan sums are, indeed, the entire functions on the whole complex plane, and we also give a square mean values estimation. The main results of this paper are new appearance to us, which indicate the particularity of the polynomial Ramanujan sums.     

Indecomposable rank 4 quadratic spaces of non-trivial discriminant over polynomial rings

Mathematische Zeitschrift -     

Finite polynomial orbits in quadratic rings

All finite orbits of polynomial mappings in one variable in rings of integers of quadratic number fields are determined. The largest such orbit has seven elements and lies in the third cyclotomic field. 2000 Mathematics Subject Classification Primary—11R09, 11R11, 37F10     

A remark on polynomial function over finite commutative rings with identity

In the present paper, the degree of polynomial functions on a finite commutative ringR with identity is investigated. An upper bound for the degree is given (Theorem 3) with the help of a reduction formula for powers (Theorem 1).     

Hensel lifting and bivariate polynomial factorisation over finite fields

This paper presents an average time analysis of a Hensel lifting based factorisation algorithm for bivariate polynomials over finite fields. It is shown that the average running time is almost linear in the input size. This explains why the Hensel lifting technique is fast in practice for most polynomials.