Mathematics Problem Archive

Showing 1-50 of 179 problems (Page 1 of 4)

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AMR-010-0110
Partially Solved

Questions in Geometric Group Theory — Q 1.10

v1.3 research notes

(Canary) Let $G$ be word-hyperbolic and $H$ a finitely presented subgroup of $G$. Suppose that for every $g\in G$ there is $n>0$ such that $g^n\in H$....

L4
Group Theory
AMR-010-0808
Partially Solved

Questions in Geometric Group Theory — Q 8.8

v1.3 research notes

Compute the asymptotic dimension of CAT(0) groups, Out(Fn), mapping class groups, nonuniform lattices, Thompson’s group. Is there a group of finite ty...

L4
Group Theory
AMR-010-1105
Partially Solved

Questions in Geometric Group Theory — Q 11.5

v1.3 research notes

(Bridson) Classify the mapping tori of automorphisms $\mathbb{Z}^n\to\mathbb{Z}^n$ up to quasi-isometry....

L4
Group Theory
AMR-011-0041
Partially Solved

Some Questions — Question 41

v1.3 research notes

Does every countable group have fixed price; that is, do all its free probability-measure-preserving actions have the same cost?...

L4
Group Theory
AMR-014-0015
Partially Solved

Algebraic Stories — Hilbert functions of fat points.

v1.3 research notes

Given a scheme of generic fat points $X \subset \mathbb{P}^{n_1-1}\times\ldots\times \mathbb{P}^{n_t-1}$, what is the multi-graded Hilbert function $\...

L4
Algebra
AMR-015-0011
Partially Solved

Green's conjecture

v1.3 research notes

For a non-hyperelliptic algebraic curve, is its Clifford index determined by the extent to which its canonical embedding has linear syzygies?...

L4
Algebra
AMR-019-0004
Partially Solved

Some Open Problems in Elasticity — Lavrentiev phenomena

v1.3 research notes

Can the Lavrentiev phenomenon occur for elastostatics under growth conditions ensuring that all finite-energy deformations are continuous?...

L4
Partial Differential Equations
AMR-019-0012
Partially Solved

Some Open Problems in Elasticity — Global dynamics

v1.3 research notes

Prove global existence and uniqueness for suitable initial-boundary-value problems in dynamic nonlinear elasticity....

L4
Partial Differential Equations
AMR-022-2078
Partially Solved

Research Problems in Function Theory — Problem 2.78

v1.3 research notes

(Fatou's conjecture) Show that the subset $U$ of functions $g$ in $R_d$, such that all the critical points of $g$ are in the basins of attraction of p...

L4
Analysis
AMR-022-2088
Partially Solved

Research Problems in Function Theory — Problem 2.88

v1.3 research notes

Let $B$ denote the boundary of the Mandelbrot set (or, equivalently, the topological bifurcation set of the family $z\mapsto z^2+c$, $c\in\mathbb{C}$....

L4
Analysis
AMR-023-0002
Partially Solved

Fuglede's conjecture in dimensions one and two

v1.3 research notes

For nonconvex subsets of $\mathbb{R}$ and $\mathbb{R}^2$, is a set spectral if and only if it tiles by translations?...

L4
Analysis
AMR-023-0008
Partially Solved

Pompeiu problem

v1.3 research notes

Characterize the domains for which there exists a nonzero function whose integral vanishes over every congruent copy of the domain....

L4
Analysis
AMR-023-0014
Partially Solved

Vlasov–Maxwell regularity

v1.3 research notes

Establish global regularity, or exhibit breakdown, for solutions of the Vlasov–Maxwell equations from appropriate smooth initial data....

L4
Partial Differential Equations
AMR-026-0001
Partially Solved

Five Open Problems — Global Cauchy theory for one-dimensional Euler–Fourier flow

v1.3 research notes

Develop a global-in-time theory of the Cauchy problem for the one-dimensional Euler–Fourier system for initial data constrained only by finite energy ...

L4
Partial Differential Equations
AMR-026-0002
Partially Solved

Five Open Problems — Compensated compactness for symmetric matrices

v1.3 research notes

Develop a compensated-compactness calculus for symmetric matrices when compensated compactness yields only inequalities. As a first application, prove...

L4
Partial Differential Equations
AMR-026-0003
Partially Solved

Five Open Problems — Compressible Navier–Stokes near vacuum

v1.3 research notes

For compressible Navier–Stokes equations with constant viscosities near vacuum, does the unphysical one-dimensional consequence identified by Hoff and...

L4
Partial Differential Equations
AMR-026-0004
Partially Solved

Five Open Problems — Eternal finite-energy compressible Euler flow

v1.3 research notes

Does the compressible Euler system in odd spatial dimension admit a nontrivial smooth eternal solution having finite nonzero mass and energy?...

L4
Partial Differential Equations
AMR-026-0005
Partially Solved

Five Open Problems — Regular reflection without irrotationality

v1.3 research notes

Prove existence of a regular reflection for compressible flow against a wedge without assuming that the flow is irrotational....

L4
Partial Differential Equations
AMR-027-0303
Partially Solved

10 Lectures and 42 Open Problems — Open Problem 3.3

v1.3 research notes

Let ${G=(V,E,W)}$ be a graph and ${k}$ a positive integer, is the following true? $\rho_G(k) \leq \mathrm{polylog}(k) \sqrt{\lambda_k}. \ \ \ \ \ (2)$...

L4
Computer Science
AMR-027-0501
Partially Solved

10 Lectures and 42 Open Problems — Deterministic Restricted Isometry Property matrices

v1.3 research notes

Construct deterministic matrices $A\in\mathbb{C}^{M\times N}$ (or $A\in\mathbb{R}^{M\times N}$ ) satisfying the $(s,\frac13)$ -RIP for $s\approx\frac{...

L4
Computer Science
AMR-027-0605
Partially Solved

10 Lectures and 42 Open Problems — Constructive Kadison-Singer

v1.3 research notes

Give a (polynomial time) construction of the tight frame partition satisfying the properties required in the Kadison-Singer problem (or the related We...

L4
Computer Science
AMR-029-0039
Partially Solved

Goddyn's conjecture on thin spanning trees

v1.3 research notes

A spanning tree of a graph G is called $\epsilon$-thin if it contains at most an $\epsilon$ fraction of the edges of each cut. Is there a function $f:...

L4
Combinatorics
AMR-029-0072
Partially Solved

Rota's conjecture on disjoint bases

v1.3 research notes

Let $M$ be a matroid of rank n whose ground set S can be partitioned into n disjoint bases $B_1,\dots,B_n$. Is it true that $B_1,\dots,B_n$ always hav...

L4
Combinatorics
AMR-030-0048
Partially Solved

Suppose I have a sequence of positive integers whose reciprocals sum to infinity

v1.3 research notes

Erdős: Suppose I have a sequence of positive integers whose reciprocals sum to infinity. Must that sequence contain arbitrarily long arithmetic progre...

L4
Number Theory
AMR-030-0067
Partially Solved

How quickly do the gaps between successive primes grow

v1.3 research notes

How quickly do the gaps between successive primes grow? Is it slower than n^(ľ) for every ľ > 0? See this....

L4
Number Theory
AMR-030-0068
Partially Solved

Is there a prime between n^(2)and (n+1)^(2 )for every n > 0

v1.3 research notes

Erdős: Is there a prime between n^(2)and (n+1)^(2 )for every n > 0?...

L4
Number Theory
AMR-030-0069
Partially Solved

Is the least quadratic residue modulo p at most p^(ľ)^( )for any ľ > 0

v1.3 research notes

Is the least quadratic residue modulo p at most p^(ľ)^( )for any ľ > 0?...

L4
Number Theory
AMR-031-0008
Partially Solved

Rudin's conjecture on squares in progressions

v1.3 research notes

For positive integers $N,q,a$, let $Q(N;q,a)$ be the number of perfect squares among $a,a+q,\ldots,a+(N-1)q$, and let $Q(N)=\max_{q,a\geq1}Q(N;q,a)$. ...

L4
Combinatorics
AMR-036-0029
Partially Solved

Littlewood constants $lpha$ and $eta$

v1.3 research notes

For $\phi(n)=\sup_{\deg p=n}\int_{|z|<1}|p'|/(1+|p|^2)\,dm$, let $\alpha=\limsup\log\phi(n)/\log n$. For a regular compact set $E$, define $\beta_E$ f...

L4
Analysis
AMR-037-0001
Partially Solved

Unfolding convex polytopes

v1.3 research notes

Does every three-dimensional convex polytope have a non-self-intersecting edge unfolding? Does a minimum spanning tree of the dual edge graph, with a ...

L4
Geometry
AMR-038-0001
Partially Solved

Antipodes of symmetric convex bodies

v1.3 research notes

On a centrally symmetric convex body, must every pair of points at maximum intrinsic surface distance be antipodal? Resolve this even for rectangular ...

L4
Geometry
AMR-038-0005
Partially Solved

Triangulating a hypercube

v1.3 research notes

Determine the minimum number of $d$-simplices needed to triangulate the $d$-dimensional cube, and its asymptotic growth with $d$....

L4
Geometry
AMR-038-0006
Partially Solved

Embedding the hyperbolic plane

v1.3 research notes

Does the hyperbolic plane admit a smooth isometric immersion into $\mathbb R^4$? More generally, determine the least Euclidean dimension for such an i...

L4
Geometry
AMR-038-0007
Partially Solved

Rationality of Hermite constants

v1.3 research notes

Are the Hermite constants associated with densest lattice sphere packings always rational? Determine their arithmetic nature in dimensions where the e...

L4
Geometry
AMR-038-0011
Partially Solved

Prince Rupert ratio for tetrahedra

v1.3 research notes

What is the largest possible ratio between the sum of edge lengths of a tetrahedron that can pass through or fit inside another tetrahedron and the su...

L4
Geometry
AMR-038-0012
Partially Solved

Perfect rational triangles

v1.3 research notes

Does there exist a nondegenerate triangle whose side lengths, three medians, three altitudes, and area are all rational?...

L4
Geometry
AMR-041-0006
Partially Solved

Conjugacy

v1.3 research notes

If two Birkhoff billiard maps $T_1$ and $T_2$ satisfy $T_1=ST_2S^{-1}$ for a homeomorphism $S$, must their tables be similar? Relatedly, can one hear ...

L4
Dynamical Systems
AMR-041-0007
Partially Solved

Periodic orbits

v1.3 research notes

(a) Is the set of $n$-periodic orbits of a smooth strictly convex Birkhoff billiard nowhere dense for every $n$? (b) Does every polygonal Birkhoff bil...

L4
Dynamical Systems
AMR-041-0011
Partially Solved

Mañé's last theorem

v1.3 research notes

In the space of area-preserving $C^1$ diffeomorphisms of a compact manifold, is it generic that the dynamics is either hyperbolic or has zero Lyapunov...

L4
Dynamical Systems
AMR-041-0013
Partially Solved

Calogero–Moser–Vlasov

v1.3 research notes

For the infinite-dimensional Calogero–Moser system, in which particles on the real line interact through the inverse-square potential, does the dynami...

L4
Dynamical Systems
AMR-042-0001
Partially Solved

Order of mixing

v1.3 research notes

Let $p$ be a prime for which $$f(u_1,u_2)=1+u_1u_2+u_1^2u_2+u_1^3u_2+u_1^4+u_2^2+u_1^4u_2^2$$ is irreducible, and consider the algebraic $\mathbb{Z}^2...

L4
Dynamical Systems
AMR-042-0004
Partially Solved

Typical group automorphisms

v1.3 research notes

Choose a random subset $Q$ of the primes by independently retaining each prime with probability $1/2$. Is it almost surely true that $$\limsup_{n\to\i...

L4
Number Theory
AMR-042-0005
Partially Solved

Entropy values and Lehmer's problem

v1.3 research notes

Given $\varepsilon>0$, does there exist a polynomial $f(x)=\prod_{i=1}^d(x-\alpha_i)\in\mathbb{Z}[x]$ whose logarithmic Mahler measure $$m(f)=\sum_{i:...

L4
Number Theory
AMR-042-0006
Partially Solved

Entropy and Deligne periods

v1.3 research notes

Let $\log_p:\mathbb{C}_p^*\to\mathbb{C}_p$ be the branch of the $p$-adic logarithm with $\log_p(p)=0$, and let $T_\lambda:x\mapsto\lambda x$ on $\math...

L4
Dynamical Systems
AMR-043-0005
Partially Solved

Pingree open problems — Ledrappier problem 1

v1.3 research notes

Let $M$ be a compact Riemannian manifold of constant negative curvature and $(g_t)_{t\in\mathbb{R}}$ its geodesic flow. Does there exist a probability...

L4
Dynamical Systems
AMR-045-0008
Partially Solved

Factor maps between sofic shifts

v1.3 research notes

For sofic shifts $S,T$ with $h(S)\ge h(T)$, give necessary and sufficient conditions for a factor map from $S$ onto $T$. The most fundamental unequal-...

L4
Dynamical Systems
AMR-045-0011
Partially Solved

Beta functions

v1.3 research notes

Characterize the functions that occur as beta functions of mixing Markov shifts....

L4
Dynamical Systems
AMR-045-0012
Partially Solved

Expansive directions of two-dimensional SFTs

v1.3 research notes

For a $\mathbb Z^2$ shift of finite type $\alpha$, characterize the possible sets $E_1(\alpha)$ of expansive directions, especially under the assumpti...

L4
Dynamical Systems
AMR-045-0017
Partially Solved

Furstenberg times-p-times-q problem

v1.3 research notes

For multiplicatively independent integers $p,q>1$, can there exist a nonatomic Borel probability measure on the circle, other than Haar measure, that ...

L4
Dynamical Systems
AMR-045-0018
Partially Solved

Full-support invariant measures

v1.3 research notes

For the symbolic system $X$ constructed in Section 14 of the source from a commuting pair of full-shift endomorphisms, is Haar measure its only invari...

L4
Dynamical Systems
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