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In this paper, we examine the unimodality and strict unimodality of certain formal bivariate Laurent series with non-negative coefficients. We show that the sets of these formal bivariate Laurent series form commutative semirings under the…

Combinatorics · Mathematics 2025-04-28 Nian Hong Zhou

We study a parametric family of piecewise rotations of the torus, in the limit in which the rotation number approaches the rational value 1/4. There is a region of positive measure where the discontinuity set becomes dense in the limit; we…

Dynamical Systems · Mathematics 2015-05-14 John H. Lowenstein , Franco Vivaldi

We produce an infinite family of transcendental numbers which, when raised to their own power, become rational. We extend the method, to investigate positive rational solutions to the equation $x^x = \alpha$, where $\alpha$ is a fixed…

Number Theory · Mathematics 2014-09-15 Sam Chow , Bin Wei

In 2006, Fock and Goncharov constructed a nice basis of the ring of regular functions on the moduli space of framed ${\rm PGL}_2$-local systems on a punctured surface $S$. The moduli space is birational to a cluster $\mathcal{X}$-variety,…

Geometric Topology · Mathematics 2020-12-01 So Young Cho , Hyuna Kim , Hyun Kyu Kim , Doeun Oh

We start from a parametrized system of $d$ generalized polynomial equations (with real exponents) for $d$ positive variables, involving $n$ generalized monomials with $n$ positive parameters. Existence and uniqueness of a solution for all…

Algebraic Geometry · Mathematics 2019-05-08 Stefan Müller , Josef Hofbauer , Georg Regensburger

The range of a trigonometric polynomial with complex coefficients can be interpreted as the image of the unit circle under a Laurent polynomial. We show that this range is contained in a real algebraic subset of the complex plane. Although…

Complex Variables · Mathematics 2020-08-26 Leonid V. Kovalev , Xuerui Yang

We present a Poisson formula for sparse resultants and a formula for the product of the roots of a family of Laurent polynomials, which are valid for arbitrary families of supports. To obtain these formulae, we show that the sparse…

Algebraic Geometry · Mathematics 2015-06-12 Carlos D'Andrea , Martin Sombra

Diophantine quadruples are sets of four distinct positive integers such that the product of any two is one less than a square. All known examples belong to an infinite set which can be constructed recursively. Some observations on these…

Number Theory · Mathematics 2007-05-23 Philip Gibbs

We associate with a matrix over an arbitrary field an infinite family of matrices whose sizes vary from one to infinity; their entries are traces of powers of the original matrix. We explicitly evaluate the determinants of matrices in our…

Combinatorics · Mathematics 2008-10-23 Eugene Gutkin

We obtain a family of polynomials defined by vanishing conditions and associated to tangles. We study more specifically the case where they are related to a O(n) loop model. We conjecture that their specializations at $z_i=1$ are {\it…

Statistical Mechanics · Physics 2009-11-11 M. Kasatani , V. Pasquier

To a univariate monic polynomial is attached a special planar forest that is called the picture of the polynomial. Isotopy classes of pictures are called signatures. All combinatorially possible signatures are realized and spaces of…

Algebraic Geometry · Mathematics 2017-02-21 Norbert A'Campo

The purpose of this paper is twofold. First, we introduce a family of generalized Markov-Hurwitz equations, extending classical Markov-Hurwitz equations with additional degree n-1 interaction terms, Gyoda and Matsushita's generalized Markov…

Number Theory · Mathematics 2026-05-07 Zhichao Chen , Zelin Jia , Wenchao Wu

The dynamical classification of rational maps is a central concern of holomorphic dynamics. Much progress has been made, especially on the classification of polynomials and some approachable one-parameter families of rational maps; the goal…

Dynamical Systems · Mathematics 2022-01-10 Russell Lodge , Yauhen Mikulich , Dierk Schleicher

We define a ring whose elements are rational functions, whose addition is polynomial multiplication, and whose multiplication is a convolution operation. It is then show that this ring's endomorphisms exhibit a strong classification.…

Commutative Algebra · Mathematics 2023-01-31 Milo Moses

In this note it is proved that every rational matrix which lies in the interior of the cone of completely positive matrices also has a rational cp-factorization.

Optimization and Control · Mathematics 2017-02-23 Mathieu Dutour Sikirić , Achill Schürmann , Frank Vallentin

To a $2\times2$ matrix $G$ with complex entries, we relate the sequence of Laurent polynomial $L_n(z,G)=\tr \big(G\big[\begin{smallmatrix}z&0\\ 0&z^{-1}\end{smallmatrix}\big]G^{\ast}\big)^n$. It turns out that for each \(n\), the family…

Classical Analysis and ODEs · Mathematics 2016-05-17 Victor Katsnelson

Let k be a field of characteristic 0. Let G be a reductive group over the ring of Laurent polynomials R=k[x_1^{\pm 1},...,x_n^{\pm 1}]. We prove that G has isotropic rank >=1 over R iff it has isotropic rank >=1 over the field of fractions…

Algebraic Geometry · Mathematics 2020-10-19 Anastasia Stavrova

One introduces a class of projective parameterizations that resemble generalized de Jonqui\`eres maps. Any such parametrization defines a birational map $\mathfrak{F}$ of $\pp^n$ onto a hypersurface $V(F)\subset \pp^{n+1}$ with a strong…

Commutative Algebra · Mathematics 2012-05-08 Seyed Hamid Hassanzadeh , Aron Simis

We give a new demonstration of Loewner's characterization of polynomials, solving in the positive a conjecture proposed by Laird and McCann in 1984.

Classical Analysis and ODEs · Mathematics 2016-05-04 J. M. Almira

In this article, the ring of polynomials is studied in a systematic way through the theory of monoid rings. As a consequence, this study provides natural and canonical approaches in order to find easy and rigorous proofs and methods for…

Commutative Algebra · Mathematics 2018-02-23 Abolfazl Tarizadeh