Mathematics Problem Archive

Showing 951-1000 of 2196 problems (Page 20 of 44)

AMR-052-0057
Open

Boundary theorems for geometric coding trees

v1.3 research notes

Which theorems about boundary behavior of Riemann maps have analogues for geometric coding trees?...

L3
Dynamical Systems
AMR-052-0059
Open

Representative transcendental entire dynamics

v1.3 research notes

Find a collection of representative examples of transcendental entire maps whose dynamics may serve as models for general phenomena....

L3
Dynamical Systems
AMR-052-0066
Open

Newton dynamics for entire functions

v1.3 research notes

Describe the dynamics of Newton's method when applied to broad natural classes of transcendental entire functions....

L3
Dynamical Systems
AMR-052-0069
Open

An orbit converging to an irrationally indifferent fixed point

v1.3 research notes

Under the hypotheses of Eremenko–Lyubich Question 2, can even a single orbit converge to $z_0$?...

L3
Dynamical Systems
AMR-052-0070
Open

Degenerate-flow limits of bad Newton polynomials

v1.3 research notes

Call a polynomial bad if its Newton map has an attracting cycle that is not a root. Prove that every bad degree-$d$ polynomial $f_1$ belongs to a one-...

L3
Dynamical Systems
AMR-052-0072
Open

Local connectivity of quadratic Julia sets

v1.3 research notes

For $P_c(z)=z^2+c$ with connected Julia set, characterize the parameters $c$ for which $J(P_c)$ is locally connected....

L4
Dynamical Systems
AMR-052-0077
Open

Lift-family criterion for finite kneading data

v1.3 research notes

Find a general property of a lifting family that guarantees convergence of the real Thurston algorithm for every periodic or preperiodic kneading sequ...

L3
Dynamical Systems
AMR-052-0078
Open

Lift-family criterion for arbitrary kneading data

v1.3 research notes

Find a general property of a lifting family that guarantees convergence of the real Thurston algorithm for arbitrary kneading sequences....

L3
Dynamical Systems
AMR-052-0080
Open

Boundary fixed points in rank-zero Hénon components

v1.3 research notes

In the rank-zero case, if the limiting map on an invariant stable component is constant with value $x_0\in\partial U$, prove that one eigenvalue at $x...

L3
Dynamical Systems
AMR-052-0081
Open

Herman-ring retracts for Hénon maps

v1.3 research notes

Can the subsequential limit map on an invariant stable component of a polynomial diffeomorphism of $\mathbb C^2$ be a retraction onto a Herman ring or...

L3
Dynamical Systems
AMR-052-0082
Open

Products involving Herman rings as stable components

v1.3 research notes

In the rank-two case for a polynomial diffeomorphism of $\mathbb C^2$, can an invariant stable component be a product of two Herman rings, or a produc...

L3
Dynamical Systems
AMR-052-0083
Open

Density of hyperbolic rational maps

v1.3 research notes

For every degree $d$, prove that expanding (hyperbolic, Axiom A) maps are dense in the spaces $\operatorname{Rat}_d$ of rational maps and $\operatorna...

L4
Dynamical Systems
AMR-052-0086
Open

Haken-type decomposition for rational maps

v1.3 research notes

Develop an analogue of the Haken decomposition for geometrically finite rational maps. In particular, if the Julia set is disconnected, can the map be...

L3
Dynamical Systems
AMR-054-0003
Open

Voronoi Diagram of Lines in 3D

v1.3 research notes

What is the combinatorial complexity of the Voronoi diagram of a set of lines (or line segments) in three dimensions?...

L3
Geometry
AMR-054-0004
Open

Union of Fat Objects in 3D

v1.3 research notes

What is the complexity of the union of ``fat'' objects in $\mathbb{R}^3$?...

L3
Combinatorics
AMR-054-0007
Open

$k$-sets

v1.3 research notes

What is the maximum number of $k$-sets? (Equivalently, what is the maximum complexity of a $k$-level in an arrangement of hyperplanes?)...

L3
Combinatorics
AMR-054-0010
Open

Simple Linear-Time Polygon Triangulation

v1.3 research notes

Is there a deterministic, linear-time polygon triangulation algorithm significantly simpler than that of Chazelle?...

L4
Computer Science
AMR-054-0013
Open

Point Location in 3D Subdivision

v1.3 research notes

Is there an $O(n)$-space data structure that supports $O(\log n)$-time point-location queries in a three-dimensional subdivision of $n$ faces?...

L3
Computer Science
AMR-054-0016
Open

Simple Polygonalizations

v1.3 research notes

Can the number of simple polygonalizations of a set of $n$ points in the plane be computed in polynomial time? A simple polygonalization is a simple p...

L4
Geometry
AMR-054-0017
Open

Visibility Graph Recognition

v1.3 research notes

Given a visibility graph $G$ and a Hamiltonian circuit $C$, determine in polynomial time whether there is a simple polygon whose vertex visibility gra...

L4
Graph Theory
AMR-054-0019
Open

Vertical Decompositions in $\mathbb{R}^d$

v1.3 research notes

What is the complexity of the vertical decomposition of $n$ surfaces in $\mathbb{R}^d$, $d \ge 5$?...

L3
Combinatorics
AMR-054-0022
Open

Minimum-Link Path in 2D

v1.3 research notes

Can a minimum-link path among polygonal obstacles be found in subquadratic time?...

L3
Geometry
AMR-054-0024
Open

Polygonal Curve Simplification

v1.3 research notes

Can an $n$-vertex polygonal curve be simplified in time nearly linear in $n$?...

L3
Geometry
AMR-054-0025
Open

Polyhedral Surface Approximation

v1.3 research notes

How efficiently can one compute a polyhedral surface that is an $\epsilon$-approximation of a given triangulated surface in $\mathbb{R}^3$?...

L3
Geometry
AMR-054-0028
Open

Flip Graph Connectivity in 3D

v1.3 research notes

Is the flip graph connected for general-position points in $\mathbb{R}^3$? Given a set of $n$ points in $\mathbb{R}^3$, the flip graph has a node for ...

L3
Computer Science
AMR-054-0029
Open

Hamiltonian Tetrahedralizations

v1.3 research notes

Can every convex polytope in $\mathbb{R}^3$ be partitioned into tetrahedra such that the dual graph has a Hamiltonian path?...

L3
Computer Science
AMR-054-0031
Open

Trapping Light Rays with Segment Mirrors

v1.3 research notes

Is it possible to trap all the light from one point source by a finite collection of two-sided disjoint segment mirrors? A light ray is trapped if it ...

L3
Geometry
AMR-054-0034
Open

Extending Pseudosegment Arrangements by Subdivision

v1.3 research notes

How many intersections among an arrangement of pseudosegments in the plane must be added as vertices to allow the pseudosegment arrangment to be exten...

L3
Combinatorics
AMR-054-0037
Open

Counting Polyominoes

v1.3 research notes

How many polyominoes on $n$ squares are there? A polyomino is a connected interior-disjoint union of axis-aligned unit squares joined edge-to-edge, in...

L3
Combinatorics
AMR-054-0038
Open

Compatible Triangulations

v1.3 research notes

Is it true that every two sets of $n$ planar points in general position with the same number points on their convex hulls have compatible triangulatio...

L3
Computer Science
AMR-054-0040
Open

The Number of Pointed Pseudotriangulations

v1.3 research notes

For a planar point set $S$, is the number of pointed pseudotriangulations always at least the number of triangulations? A pseudotriangle is a planar p...

L3
Computer Science
AMR-054-0041
Open

Sorting $X+Y$ (Pairwise Sums)

v1.3 research notes

Given two sets of numbers, each of size $n$, how quickly can the set of all pairwise sums be sorted? In symbols, given two sets $X$ and $Y$, our goal ...

L4
Computer Science
AMR-054-0042
Open

Vertex-Unfolding Polyhedra

v1.3 research notes

Consider a polyhedron with simply connected facets (no holes on a facet) and without boundary (every edge is incident to exactly two facets). Can the ...

L3
Geometry
AMR-054-0043
Open

General Unfoldings of Nonconvex Polyhedra

v1.3 research notes

Can every closed polyhedron be cut along its surface and unfolded into one piece in the plane without overlap? Such an unfolding is called a general u...

L3
Geometry
AMR-054-0046
Open

3D Minimum-Bend Orthogonal Graph Drawings

v1.3 research notes

Does every simple graph with maximum vertex degree $\Delta \leq 6$ have a 3D orthogonal point-drawing with no more than two bends per edge? A 3D ortho...

L3
Graph Theory
AMR-054-0049
Open

Planar Euclidean Maximum TSP

v1.3 research notes

What is the complexity of finding a tour of maximum Euclidean length for a planar point set?...

L3
Geometry
AMR-054-0054
Open

Traveling Salesman Problem in Solid Grid Graphs

v1.3 research notes

What is the complexity of finding a shortest tour in a solid planar grid graph? A planar grid graph is a graph whose vertices are any set of points on...

L3
Geometry
AMR-054-0055
Open

Pallet Loading

v1.3 research notes

What is the complexity of the pallet loading problem? Given two pairs of numbers, $(A,B)$ and $(a,b)$, and a number $n$, decide whether $n$ small rect...

L3
Geometry
AMR-054-0059
Open

Most Circular Partition of a Square

v1.3 research notes

What is the optimal partition of a square into convex pieces such that the circularity of the pieces is optimized? The circularity of a polygon is the...

L3
Geometry
AMR-054-0060
Open

Transforming Polygons via Vertex-Centroid Moves

v1.3 research notes

Given an arbitrary polygon, transform it by a finite sequence of ``vertex-centroid'' moves to a regular polygon. A vertex-centroid move is a translati...

L3
Geometry
AMR-054-0061
Open

Lines Tangent to Four Unit Balls

v1.3 research notes

Given a set of $n$ unit-radius balls in $\mathbb{R}^3$, what is the number of lines that are tangent to four of the balls in the set, and miss all the...

L3
Combinatorics
AMR-054-0062
Open

Volume Maximizing Convex Shape

v1.3 research notes

Let $C$ be a convex piece of paper; its boundary may be a smooth curve, or a polygon. A perimeter halving folding is a folding of $C$ obtained by iden...

L3
Geometry
AMR-054-0064
Open

Edge-Unfolding Polycubes

v1.3 research notes

Is there any genus-zero orthogonal polyhedron $P$ built by gluing together cubes face-to-face that cannot be edge-unfolded, where all cube edges on th...

L3
Geometry
AMR-054-0068
Open

Rolling a Die over a Labeled Board

v1.3 research notes

Label the faces of a unit cube with numbers $1$--$6$ as in a die. Place the cube to sit on an integer lattice grid, with one corner at the origin and ...

L3
Combinatorics
AMR-054-0072
Open

Polyhedron with Regular Pentagon Faces

v1.3 research notes

Let $M$ be a closed polyhedral surface homeomorphic to $S^2$ which is entirely composed of equal regular pentagons. If $M$ is immersed in 3-space, is ...

L3
Geometry
AMR-054-0073
Open

Congruent Partitions of Polygons

v1.3 research notes

Partition a given polygon $P$ into $n$ mutually congruent pieces so that the area of $P$ not covered by the union of the pieces is as small as possibl...

L3
Geometry
AMR-054-0074
Open

Slicing Axes-Parallel Rectangles

v1.3 research notes

Let us say that two rectangles in the place are independent if both their $x$- and $y$-axis projections are disjoint. A set of rectangles is then inde...

L3
Combinatorics
AMR-054-0077
Open

Zipper Unfoldings of Convex Polyhedra

v1.3 research notes

Does every convex polyhedron $P$ have a zipper unfolding? A zipper unfolding cuts open $P$ via a single path, necessarily a Hamiltonian path (to span ...

L3
Geometry
AMR-055-0008
Open

Rigidity of Smooth Isometric Families of Compact Surfaces

v1.3 research notes

Let $M$ be a compact surface, $I=(-1,1)$, and $f:M\times I\to\mathbb{R}^3$ a differentiable map such that each $f_t$ is an immersion and its induced m...

L4
Geometry
AMR-058-0003
Open

Stability of Spherical Plateau Clusters

v1.3 research notes

Is every bubble cluster in $\mathbb{R}^3$ made of spherical pieces meeting according to Plateau's rules necessarily stable, in the sense of having non...

L3
Geometry