Mathematics Problem Archive
Showing 1-33 of 33 problems
10 Lectures and 42 Open Problems — Hardness at the Cheeger square-root gap
v1.3 research notesDoes there exist $c>0$ such that it is NP-hard, given a graph $G$ and $\phi>0$, to distinguish $h_G\le\phi$ from $h_G\ge c\sqrt{\phi}$?...
10 Lectures and 42 Open Problems — Certifying that matrices are PSD
v1.3 research notesGiven a symmetric matrix ${M}$ with small condition number, is there a quasi-linear time (on ${n}$ and the number of non-zero entries of ${M}$ ) proce...
10 Lectures and 42 Open Problems — Open Problem 3.3
v1.3 research notesLet ${G=(V,E,W)}$ be a graph and ${k}$ a positive integer, is the following true? $\rho_G(k) \leq \mathrm{polylog}(k) \sqrt{\lambda_k}. \ \ \ \ \ (2)$...
10 Lectures and 42 Open Problems — Deterministic Restricted Isometry Property matrices
v1.3 research notesConstruct 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{...
10 Lectures and 42 Open Problems — Certifying the Restricted Isometry Property
v1.3 research notesLet $N = 2M$ . For which $s$ is there a polynomial time algorithm that is guaranteed to, with high probability, certify that a gaussian matrix $A$ is ...
10 Lectures and 42 Open Problems — Random Partial Discrete Fourier Transform
v1.3 research notesConsider a $A\in\mathbb{C}^{M\times N}$ obtained by sampling random rows of a Discrete Fourier Tranform. How large does $M$ need to be in order for, w...
10 Lectures and 42 Open Problems — Mutually Unbiased Bases
v1.3 research notesHow many mutually unbiased bases are there in 6 dimensions?...
10 Lectures and 42 Open Problems — The Paley ETF Conjecture
v1.3 research notesDoes the Paley Equiangular tight frame satisfy the Restricted Isometry Property pass the square root bottleneck? (even by logarithmic factors?)....
10 Lectures and 42 Open Problems — Constructive Kadison-Singer
v1.3 research notesGive a (polynomial time) construction of the tight frame partition satisfying the properties required in the Kadison-Singer problem (or the related We...
10 Lectures and 42 Open Problems — Gilbert-Varshamov bound
v1.3 research notesExplicit deterministic constructions of codes achieving the GV bound Is the GV bound tight?...
10 Lectures and 42 Open Problems — Boolean classification and annulus conjecture
v1.3 research notesProve or disprove: $R_A(\alpha n,\beta n,n)=\alpha+(1-\alpha)R_A(1,\beta n,(1-\alpha)n)+o(1)$....
10 Lectures and 42 Open Problems — The Deletion Channel
v1.3 research notesWhat are the asymptotics of $\mathcal{D}\left(n;\frac12\right)$ ? \item An interesting aspect of the Deletion Channel is that different messages may h...
10 Lectures and 42 Open Problems — Sum of Squares approximation ratio for Max-Cut
v1.3 research notesWhat is the approximation ratio (or integrality gap) for the Sum-of-Squares (SOS) relaxation of degree 4 for the Max-Cut problem? What about other con...
10 Lectures and 42 Open Problems — The Grothendieck Constant
v1.3 research notesWhat is the value of the (real) Grothendieck constant?...
10 Lectures and 42 Open Problems — The Paley Clique Problem
v1.3 research notesWhat is the clique number of the Paley graph? Can the the SOS degree 4 analogue of the theta number help upper bound it?...
10 Lectures and 42 Open Problems — Maximum and minimum bisections on random regular graphs
v1.3 research notesGiven a $d$ -regular graph on $n$ nodes $G$ . Let $MaxBis(G)$ and $MinBis(G)$ denote, respectively, the size of its largest and smallest bisection. Is...
10 Lectures and 42 Open Problems — Angular Synchronization via Projected Power Method
v1.3 research notesDoes the projected power method converge (with high probability) to the optimal solution of the angular synchronization problem with (small enough) ga...
10 Lectures and 42 Open Problems — Sharp tightness of the Angular Synchronization SDP
v1.3 research notesIs the SDP for angular synchronization tight (with high probability) for noise levels $\sigma$ essentially until the solution of angular synchronizati...
10 Lectures and 42 Open Problems — Tightness of the Multireference Alignment SDP
v1.3 research notesFor which levels of noise is the SDP for Multireference Alignment tight?...
10 Lectures and 42 Open Problems — Consistency and sample complexity of Multireference Alignment
v1.3 research notesIs the Maximum likelihood for Multireference Alignment consistent? (after fixing the power spectrum) What is the sample complexity of the Multireferen...
Simple Linear-Time Polygon Triangulation
v1.3 research notesIs there a deterministic, linear-time polygon triangulation algorithm significantly simpler than that of Chazelle?...
Point Location in 3D Subdivision
v1.3 research notesIs there an $O(n)$-space data structure that supports $O(\log n)$-time point-location queries in a three-dimensional subdivision of $n$ faces?...
Flip Graph Connectivity in 3D
v1.3 research notesIs 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 ...
Hamiltonian Tetrahedralizations
v1.3 research notesCan every convex polytope in $\mathbb{R}^3$ be partitioned into tetrahedra such that the dual graph has a Hamiltonian path?...
Compatible Triangulations
v1.3 research notesIs 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...
The Number of Pointed Pseudotriangulations
v1.3 research notesFor a planar point set $S$, is the number of pointed pseudotriangulations always at least the number of triangulations? A pseudotriangle is a planar p...
Sorting $X+Y$ (Pairwise Sums)
v1.3 research notesGiven 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 ...
Dynamic Planar Nearest Neighbors
v1.3 research notesIs there a data structure maintaining a set of $n$ points in the plane subject to insertions, deletions, and nearest-neighbor queries in $O(\log n)$ t...
Computational Diffie–Hellman problem
v1.3 research notesGiven a prime modulus $p$, a group generator $g$, and the public values $g^a$ and $g^b$ modulo $p$, can the shared value $g^{ab}\bmod p$ be computed e...
Hartmanis–Stearns conjecture
v1.3 research notesIf the base-$b$ expansion of a real number can be emitted in real time by a multitape Turing machine (bounded time between successive digits), must th...
3.10 (Futer, Schleimer) — A practical 3-manifold homeomorphism algorithm
v1.3 research notesIs there a practical algorithm to test whether a pair of $3$-manifolds are homeomorphic?...
5.8 (Schleimer) — Why SnapPy works in practice
v1.3 research notesGive a rigorous explanation for why SnapPy works so well in practice....
8.4 (Schleimer) — Detecting reducible Heegaard splittings
v1.3 research notesIs there an algorithm to detect whether a Heegaard splitting is reducible and, if so, find a reducing curve?...