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Computing r -removed P -orderings and P -orderings of order h

Keith Johnson (2010)

Actes des rencontres du CIRM

We develop a recursive method for computing the r -removed P -orderings and P -orderings of order h , the characteristic sequences associated to these and limits associated to these sequences for subsets S of a Dedekind domain D . This method is applied to compute these objects for S = and S = p .

Conservative polynomials and yet another action of Gal ( ¯ / ) on plane trees

Fedor Pakovich (2008)

Journal de Théorie des Nombres de Bordeaux

In this paper we study an action D of the absolute Galois group Γ = Gal ( ¯ / ) on bicolored plane trees. In distinction with the similar action provided by the Grothendieck theory of “Dessins d’enfants” the action D is induced by the action of Γ on equivalence classes of conservative polynomials which are the simplest examples of postcritically finite rational functions. We establish some basic properties of the action D and compare it with the Grothendieck action.

Coppersmith-Rivlin type inequalities and the order of vanishing of polynomials at 1

(2016)

Acta Arithmetica

For n ∈ ℕ, L > 0, and p ≥ 1 let κ p ( n , L ) be the largest possible value of k for which there is a polynomial P ≢ 0 of the form P ( x ) = j = 0 n a j x j , | a 0 | L ( j = 1 n | a j | p ) 1 / p , a j , such that ( x - 1 ) k divides P(x). For n ∈ ℕ, L > 0, and q ≥ 1 let μ q ( n , L ) be the smallest value of k for which there is a polynomial Q of degree k with complex coefficients such that | Q ( 0 ) | > 1 / L ( j = 1 n | Q ( j ) | q ) 1 / q . We find the size of κ p ( n , L ) and μ q ( n , L ) for all n ∈ ℕ, L > 0, and 1 ≤ p,q ≤ ∞. The result about μ ( n , L ) is due to Coppersmith and Rivlin, but our proof is completely different and much shorter even in that special...

Counting invertible matrices and uniform distribution

Christian Roettger (2005)

Journal de Théorie des Nombres de Bordeaux

Consider the group SL 2 ( O K ) over the ring of algebraic integers of a number field K . Define the height of a matrix to be the maximum over all the conjugates of its entries in absolute value. Let SL 2 ( O K , t ) be the number of matrices in SL 2 ( O K ) with height bounded by t . We determine the asymptotic behaviour of SL 2 ( O K , t ) as t goes to infinity including an error term, SL 2 ( O K , t ) = C t 2 n + O ( t 2 n - η ) with n being the degree of K . The constant C involves the discriminant of K , an integral depending only on the signature of K , and the value of the Dedekind zeta function...

Determinant Representations of Sequences: A Survey

A. R. Moghaddamfar, S. Navid Salehy, S. Nima Salehy (2014)

Special Matrices

This is a survey of recent results concerning (integer) matrices whose leading principal minors are well-known sequences such as Fibonacci, Lucas, Jacobsthal and Pell (sub)sequences. There are different ways for constructing such matrices. Some of these matrices are constructed by homogeneous or nonhomogeneous recurrence relations, and others are constructed by convolution of two sequences. In this article, we will illustrate the idea of these methods by constructing some integer matrices of this...

Determinants of matrices associated with incidence functions on posets

Shaofang Hong, Qi Sun (2004)

Czechoslovak Mathematical Journal

Let S = { x 1 , , x n } be a finite subset of a partially ordered set P . Let f be an incidence function of P . Let [ f ( x i x j ) ] denote the n × n matrix having f evaluated at the meet x i x j of x i and x j as its i , j -entry and [ f ( x i x j ) ] denote the n × n matrix having f evaluated at the join x i x j of x i and x j as its i , j -entry. The set S is said to be meet-closed if x i x j S for all 1 i , j n . In this paper we get explicit combinatorial formulas for the determinants of matrices [ f ( x i x j ) ] and [ f ( x i x j ) ] on any meet-closed set S . We also obtain necessary and sufficient conditions for the matrices...

Currently displaying 61 – 80 of 350