Mathematics Problem Archive

Showing 151-200 of 2944 problems (Page 4 of 59)

AMR-011-0048
Partially Solved

Some Questions — Question 48

v1.3 research notes

Are two independent random subsets of $\mathbb{Z}$ almost surely quasi-isometric as metric spaces? What is the answer for other Cayley graphs, such as...

L3
Group Theory
AMR-011-0049
Partially Solved

Some Questions — Question 49

v1.3 research notes

Let $P$ be a finite $p$-group of order $n$ and let $w$ be any word. Is the probability that $w$ is satisfied in $P$ at least $1/n$?...

L3
Group Theory
AMR-011-0050
Open

Some Questions — Question 50

v1.3 research notes

Let $M$ be the set of measurable real functions, and define $H_f(x,y)=(x,y+f(x))$ and $V_f(x,y)=(x+f(y),y)$. What group is generated by $\{H_f:f\in M\...

L3
Group Theory
AMR-011-0051
Partially Solved

Some Questions — Question 51

v1.3 research notes

Determine the asymptotic length of the shortest nontrivial word that is a law in every group of order $2^n$....

L3
Group Theory
AMR-014-0001
Open

Algebraic Stories — Generic $k$-rank

v1.3 research notes

Given a triple of positive integers $(k,d,n)$, calculate $\operatorname{rk}_k^\circ(kd,n).$...

L3
Algebra
AMR-014-0002
Open

Algebraic Stories — Generic $k$-rank

v1.3 research notes

The $k$-rank of a general form of degree $kd$ in $n$ variables is given by $$ \operatorname{rk}_k^\circ(kd,n)=\begin{cases} \min \left\{s\ge 1 | s\bin...

L3
Algebra
AMR-014-0003
Open

Algebraic Stories — Maximal $k$-rank

v1.3 research notes

Given a triple of positive integers $(k,d,n)$, calculate $\operatorname{rk}_k^{\max}(kd,n).$...

L3
Algebra
AMR-014-0004
Partially Solved

Algebraic Stories — Maximal $k$-rank

v1.3 research notes

For any positive integers $k,d$, the maximal $k$-rank $\operatorname{rk}^{\max}_k(kd,2)$ of binary forms equals $k$. Additionally, in the above notati...

L3
Algebra
AMR-014-0005
Partially Solved

Algebraic Stories — The $k$-rank of monomials

v1.3 research notes

Given $k \geq 3$ and a monomial $m$ of degree $kd$, determine the monomial $k$-rank $\operatorname{rk}_k(m)$....

L3
Algebra
AMR-014-0006
Partially Solved

Algebraic Stories — The $k$-rank of monomials

v1.3 research notes

Given $k \geq 3$ and a monomial $x^a y^b$ of degree $a+b=kd$, it is known that $\operatorname{rk}_k(x^{a}y^{b}) \leq \max(s,t)+1$, where $s$ and $t$ a...

L3
Algebra
AMR-014-0007
Partially Solved

Algebraic Stories — Degree of the Waring map

v1.3 research notes

Calculate the degree of $\widetilde{W}_{k,d}$ for perfect pairs $(k,d)$....

L3
Algebra
AMR-014-0008
Partially Solved

Algebraic Stories — Ideals of generic forms

v1.3 research notes

[Fr\"oberg's Conjecture, 1985] Let $f_1, \dots, f_r$ be generic forms of degrees $d_1, \dots, d_r$, respectively. Then the Hilbert series of the quoti...

L3
Algebra
AMR-014-0009
Partially Solved

Algebraic Stories — Hilbert series of generic power ideals.

v1.3 research notes

[Fr\"oberg-Iarrobino Conjecture] Given generic linear forms $\ell_1, \ldots, \ell_r$ and a positive integer $d$, let $I$ be the power ideal generated ...

L3
Algebra
AMR-014-0010
Open

Algebraic Stories — Hilbert series of other classes of ideals

v1.3 research notes

For $\mu \neq (d)$, does a generic $\mu$-power ideal have the same Hilbert function as in [source label: eq:RALF]?...

L3
Algebra
AMR-014-0011
Partially Solved

Algebraic Stories — Hilbert series of other classes of ideals

v1.3 research notes

[] For generic forms $g_1,\ldots,g_r$ of degree $d>1$, the ideal $(g_1^k,\ldots,g_r^k)$ has the same Hilbert series as the one generated by $r$ generi...

L3
Algebra
AMR-014-0012
Open

Algebraic Stories — Lefschetz properties of graded algebras

v1.3 research notes

It has been conjectured that each complete intersection $R=S/(f_1,\ldots,f_n)$ satisfies the WLP and also the SLP, see . Does the same hold for $R=S/(...

L3
Algebra
AMR-014-0013
Partially Solved

Algebraic Stories — Lefschetz properties of graded algebras

v1.3 research notes

When are the WLP and the SLP true for $T_{n,d,k}$?...

L3
Algebra
AMR-014-0014
Partially Solved

Algebraic Stories — Lefschetz properties of graded algebras

v1.3 research notes

For $R= S/(f_1,\ldots,f_r)$, where $f_1,\ldots,f_r$ are generic forms, does $R$ satisfy the $\mu$-Lefschetz property for all partitions $\mu$?...

L3
Algebra
AMR-014-0016
Open

Algebraic Stories — Symbolic powers vs. ordinary powers.

v1.3 research notes

For the ideal $I$ of $s$ general points in $\mathbb P^{n-1}$, what is the difference between the Hilbert series of the $m$-th symbolic power and the $...

L3
Algebra
AMR-014-0017
Partially Solved

Algebraic Stories — Hilbert series of numerical semigroup rings

v1.3 research notes

$\mathcal{S}$ is cyclotomic if and only if $k[\mathcal{S}]$ is a complete intersection....

L3
Algebra
AMR-014-0018
Partially Solved

Algebraic Stories — Non-negative forms

v1.3 research notes

Are $B_{n,m}$ and $B'_{n,m}$ finite for any pair $(n,m)$ with even $n$?...

L3
Algebra
AMR-014-0019
Open

Algebraic Stories — Non-negative forms

v1.3 research notes

For any given pair $(n,m)$ with even $n$, $B'_{n,m}=\left(\frac{n}{2}\right)^{m-1}$....

L3
Algebra
AMR-014-0020
Open

Algebraic Stories — Non-negative forms

v1.3 research notes

Determine $\lim_{n\to\infty}\frac{B_{n,3}}{n^2}$....

L3
Algebra
AMR-014-0021
Partially Solved

Algebraic Stories — Polynomial generation

v1.3 research notes

For $n=1$ and given $p$, what are the (lengths of the) possible periods of $\phi$?...

L3
Algebra
AMR-014-0022
Partially Solved

Algebraic Stories — Polynomial generation

v1.3 research notes

For $n = 1$ and given $p$, find the minimal positive integer $i$ such that $\psi^i$ is the identity map on the space of polynomials of degree at most ...

L3
Algebra
AMR-014-0023
Partially Solved

Algebraic Stories — Exterior algebras

v1.3 research notes

Let $f$ be a form of odd degree $d$ in $E$. Is it true that $({\rm Ann}(f))_i = (f)_i$, for $i < (n-d)/2$?...

L3
Algebra
AMR-014-0024
Partially Solved

Algebraic Stories — Exterior algebras

v1.3 research notes

Let $f$ and $g$ be generic quadratic forms in $E$ and let $\ell_1$ and $\ell_2$ be two generic linear forms in $S$. Then the Hilbert series of $E/(f,g...

L3
Algebra
AMR-015-0014
Partially Solved

Williamson matrix existence problem

v1.3 research notes

Determine for which orders Williamson matrices exist; such matrices give a construction of Hadamard matrices....

L3
Algebra
AMR-015-0016
Partially Solved

Hadamard's maximal determinant problem

v1.3 research notes

For each order $n$, determine the largest possible absolute determinant of an $n\times n$ matrix whose entries are all $1$ or $-1$....

L3
Algebra
AMR-017-0002
Partially Solved

Eremenko–Gabrielov secant conjecture

v1.3 research notes

Let $m,p\ge 2$, put $d=m+p-1$, and let $F(x)=(1,x,\ldots,x^d)$ be the rational normal curve. For $j=1,\ldots,mp$, let $X_j$ be the $p$-plane spanned b...

L3
Geometry
AMR-018-0001
Open

Geometry of Continued Fractions — Integer trigonometry and IKEA problem

v1.3 research notes

Find an integer cosine rule for integer triangles in integer trigonometry....

L3
Geometry
AMR-018-0002
Open

Geometry of Continued Fractions — Integer trigonometry and IKEA problem

v1.3 research notes

{\bf(IKEA problem.)} Classify all $n$-tuples of LLS-sequences for the angles that form integer $n$-gons....

L3
Geometry
AMR-018-0003
Open

Geometry of Continued Fractions — Faces of sails

v1.3 research notes

Classify all combinatorial possible types of faces....

L3
Geometry
AMR-018-0004
Partially Solved

Geometry of Continued Fractions — Faces of sails

v1.3 research notes

Classify all empty simplices of dimension $n$ up to lattice congruence....

L3
Geometry
AMR-018-0005
Open

Geometry of Continued Fractions — Faces of sails

v1.3 research notes

Which $n$-gons are realizable as faces of an $m$-dimensional continued fraction? Here are two essentially geometrically different subcases: ; {\bf Fac...

L3
Geometry
AMR-018-0007
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

Describe all finite two-dimensional sails (and the corresponding continued fractions)....

L3
Geometry
AMR-018-0008
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

{\bf (Multidimensional IKEA problem.)} Describe the collections of the sails of the cones for all polytopes of a given combinatorial type....

L3
Geometry
AMR-018-0009
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

{\bf (V. Arnold.)} Does there exist an algorithm to decide whether a given type of fundamental domain is realizable by a periodic continued fraction?...

L3
Geometry
AMR-018-0010
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

{\bf (V. Arnold.)} Torus decompositions of integer noncongruent Klein sails are distinct....

L3
Geometry
AMR-018-0011
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

{\bf (V. Arnold.)} Describe all torus decompositions that are realized by periodic two-dimensional continued fractions....

L3
Geometry
AMR-018-0013
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

{\bf (V. Arnold.)} Classify continued fractions that correspond to the same cubic extension of the field of rational numbers....

L3
Geometry
AMR-018-0014
Open

Geometry of Continued Fractions — Combinatorial structure of sails

v1.3 research notes

Prove the existence of a cone for a single non-periodic combinatorial structure ($n\ge 3$)....

L3
Geometry
AMR-018-0015
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

Find frequencies on $n$-dimensional continued fractions with the highest relative frequencies....

L3
Geometry
AMR-018-0016
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

For every positive integer constant $C$ there exist only finitely many pairwise integer non-congruent faces with frequencies exceeding $C$....

L3
Geometry
AMR-018-0017
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

Is that true that sum of all relative frequencies for all possible faces is finite for higher dimensions $(n\ge 3)$?...

L3
Geometry
AMR-018-0018
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

In case of positive answer to the above question find the generalization of the Gauss map and compare the corresponding frequencies of faces with the ...

L3
Geometry
AMR-018-0019
Partially Solved

Geometry of Continued Fractions — Further open questions

v1.3 research notes

Find a natural generalization of the Farey tessellation to higher-dimensional hyperbolic geometry....

L3
Geometry
AMR-018-0020
Partially Solved

Geometry of Continued Fractions — Further open questions

v1.3 research notes

{\bf (Jacobi's last theorem.)} Let $K$ be a totally real cubic number field. Consider arbitrary elements $y$ and $z$ of $K$ such that $0<y,z<1$ (here ...

L3
Geometry
AMR-018-0022
Partially Solved

Geometry of Continued Fractions — Further open questions

v1.3 research notes

Generalize continued fractions to describe 3-bridge knots....

L3
Geometry
AMR-019-0001
Partially Solved

Some Open Problems in Elasticity — Existence of minimizers

v1.3 research notes

Prove the existence of energy minimizers for elastostatics for quasiconvex stored-energy functions $W$ satisfying $W(A)\to\infty$ as $\det A\to0^+$ ....

L3
Partial Differential Equations