Mathematics Problem Archive
Showing 1-22 of 22 problems
Baker's Dozen — Commuting billiard maps
v1.3 research notesConsider two nested convex plane domains, and let $T_1,T_2$ be their billiard ball maps on the oriented lines intersecting both domains. If $T_1\circ ...
Baker's Dozen — A converse Desargues theorem
v1.3 research notesLet $f(x,y)$ be a polynomial for which $0$ is a nonsingular value, let $\gamma$ be an oval component of $f(x,y)=0$, and assume that $\gamma_\varepsilo...
Baker's Dozen — Origami hyperbolic paraboloids
v1.3 research notesAssume the origami hyperbolic-paraboloid pattern has invisible straight folds along a chosen diagonal of each elementary trapezoid. What is the shape ...
Baker's Dozen — Configuration theorems
v1.3 research notesFind conceptual proofs and possible generalizations of the new projective-geometry configuration theorems described in the source. In particular, prov...
Baker's Dozen — Relations among triangle areas
v1.3 research notesFor a fixed combinatorial dissection of a square into $n$ triangles, the ordered triangle areas satisfy a polynomial relation depending only on the co...
Acute triangulation of the cube
v1.3 research notesDoes the three-dimensional cube admit a triangulation into tetrahedra all of whose dihedral angles are acute?...
Straight skeleton of a simple polygon
v1.3 research notesIs there a near-linear-time algorithm to construct the straight skeleton of a simple polygon? Determine the optimal complexity, including for polygons...
Crashing motorcycles efficiently
v1.3 research notesGiven motorcycles moving simultaneously along fixed rays and crashing upon reaching another track, determine the motorcycle graph in near-linear time....
Mirrored-room illumination
v1.3 research notesGiven a polygonal room with perfectly reflecting sides and a point light source, characterize when every point of the room is illuminated. In particul...
Surface Reconstruction
v1.3 research notesGiven a sufficiently dense sample of points on a surface (technically, an $\epsilon$-sample), reconstruct a surface homeomorphic to the original....
Freeze-Tag: Optimal Strategies for Awakening a Swarm of Robots
v1.3 research notesAn optimization problem that naturally arises in the study of ``swarm robotics'' is to wake up a set of ``asleep'' robots, starting with only one ``aw...
Moduli of Minimal Sphere Immersions
v1.3 research notesConsider minimal immersions $S^n\to S^N(1)$ with total area at most a fixed constant $A$, identifying immersions which differ by a motion of the ambie...
Wu's Higher-Dimensional Picard Conjecture
v1.3 research notesLet $B$ be a set of $n+2$ hyperplanes in general position in complex projective space $\mathbb{P}^n(\mathbb{C})$. Prove that there is no nondegenerate...
Extension into a Complete Hermitian Ball
v1.3 research notesLet $\Delta$ be a ball in $\mathbb{C}^n$, $n\geq2$, and let $F$ be a complete Hermitian manifold. Does every holomorphic map from $\Delta\setminus\{0\...
Boundaries of Groups and Kleinian Groups — Problem 69
v1.3 research notesThere almost surely exists a horofunction h such that lim n→∞ − 1 n h(xn) = A, where A = lim n→∞ 1 n d(x0, xn). A theorem of Karlsson states that ∀ϵ >...
D. Damanik: Quantum Mechanics and Quasicrystals — Problem
v1.3 research notesDetermine all single sided (resp. double sided) sequences that are pattern Sturmian....
Triple Bubble in $\mathbb{R}^3$
v1.3 research notesProve that the pictured standard triple soap bubble is the least-perimeter way to enclose and separate three given volumes in $\mathbb{R}^3$....
Spherical submetries
v1.3 research notesIs every Laplacian algebra of polynomials maximal?...
Geometry of Curves and Surfaces — Problem 1.6
v1.3 research notesDoes every curve bounding a surface of positive curvature in 3-space have (at least) four points where the torsion vanishes?...
Geometry of Curves and Surfaces — Problem 2.2
v1.3 research notesDoes connectedness of the shadows imply that f(M) is convex?...
Geometry of Curves and Surfaces — Problem 7.1
v1.3 research notesAre there any complete surfaces of negative curvature in Euclidean 3-space whose principal curvatures are bounded away from zero?...
Does every convex polyhedron have Rupert's property
v1.3 research notesDoes every convex polyhedron have Rupert's property?...