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0 votes
0 answers
116 views

Multivariate polynomial representations of the infinite dihedral group

The presentation given in Wikipedia for the infinite dihedral group is $$\langle r,s\mid s^2 =1, srs = r^{-1}\rangle.$$ Let $[R]$ denote the infinite set of reciprocal partition polynomials $R_n(u_1,...
4 votes
1 answer
370 views

Determining when quotient of a polynomial ring is a Gorenstein ring

I would like to be able to look at the ring $R=\mathbb{Z}[x_1,x_2,\ldots,x_n]/\mathcal{I},$ where $\mathcal{I}$ is generated by a finite number of monomials and say whether $R$ is a Gorenstein ring. ...
3 votes
0 answers
116 views

A theory of refined h- and f-polynomials for the permutahedra, associahedra, noncrossing partitions, and tropical Grassmannians (references)

Looking for references (insights) on a theory encompassing a notion of refined face polynomials and their associated refined h-polynomials that are generalizations of the relation between ordinary f-...
1 vote
0 answers
329 views

Outlier absences of monomials in a group of inversion partition polynomials

Revamped and updated on Sep 12, 2022: Given the complex coefficients $a_n$ of some generic formal power, Taylor, Laurent or other series, say the ordinary generating functions (o.g.f.) $f(z) = z +a_1 ...
11 votes
1 answer
329 views

Are there three non-commutative polynomials in three variables with finite dimensional quotient?

$\newcommand\la{\langle}\newcommand\ra{\rangle}$Let $K$ be a field and $K\la x,y,z\ra$ the non-commutative polynomial ring in 3 variables. Question 1: Are there three (fewer is probably not possible?!...
2 votes
0 answers
63 views

Finding non-commutative finite-dimensional "hypersurface" algebras

Fix a field $K$. Call a non-commutative polynomial $f(x_i)$ whose monomial terms are all of degree at least 2 in the variables $x_i$ magic if the finite dimensional $K$-algebra $A_{f,n}:=K<x_i>/(...
11 votes
0 answers
450 views

A congruence involving roots of unity

Let $f(x) \in \mathbb{Z}[x]$ and suppose $f(\omega^j) \in \mathbb{Z}$ for all $j= 1, \dots, n$ where $\omega = e^{2 \pi i/n}$ is a primitive $n^{\text{th}}$ root of unity. Computational evidence ...
18 votes
2 answers
2k views

Can Schwartz-Zippel be formulated for commutative rings instead of fields?

The polynomials which occur in the Schwartz-Zippel lemma could be defined for any commutative ring, yet the lemma is restricted to fields. This makes it inapplicable for $(1+x^n)=1+x^n(\operatorname{...
5 votes
2 answers
306 views

Dickson/determinant type polynomial (updated)

For $2\leq \ell \leq k$, consider the polynomial \begin{equation} P_{k,\ell} = \prod_{1\leq a_1+\ldots+a_k\leq \ell} (a_1x_1+\ldots + a_kx_k)\in \mathbb{F}_2[x_1,\ldots, x_k] \end{equation} ...
5 votes
0 answers
220 views

Operator connected with Hermite polynomials

For $n \geq 1$, define the following operator $M_n$ on the ring of all polynomials with real coefficients. $$M_n P(x) = nP(x)^2 - x \int_0^x (P'(t))^2 \, \mathrm{d}t$$ Monomials $x^k$ are mapped to $n ...
13 votes
4 answers
1k views

Showing that a family of polynomials has positive and real roots.

Hi everybody, for my research I am dealing with the following function: $$\alpha_n(x):=\left.\frac{\partial^{2n+1}}{\partial z^{2n+1}}\frac{\sinh(z)}{\cosh(z)-1+x}\right|_{z=0},\quad n\in \mathbb{N},...