Mathematics Problem Archive
Are there infinitely many palindromic primes to every base
v1.3 research notesAre there infinitely many palindromic primes to every base?...
Global Gan–Gross–Prasad conjecture
v1.3 research notesIn the global Gan–Gross–Prasad setting, is nonvanishing of the relevant $H$-period on an irreducible cuspidal automorphic representation equivalent to...
Iwasawa mu-invariant conjecture for number fields
v1.3 research notesFor every number field $K$ and every prime $\ell$, does the Iwasawa invariant $\mu_\ell(K)$ vanish?...
Greenberg's p-rationality conjecture
v1.3 research notesFor every odd prime $p$ and every positive integer $t$, does there exist a $p$-rational number field $K$ with $\operatorname{Gal}(K/\mathbb Q)\cong(\m...
Brumer–Stark conjecture
v1.3 research notesFor a finite abelian extension of number fields, does the Brumer–Stark element have the predicted ideal-class annihilation and principalization proper...
Probabilistic McMillan theorem in higher dimensions
v1.3 research notesLet $X_t$ be $d$-dimensional Brownian motion starting at the origin, let $D$ be an open subset of $\mathbb{R}^d$ containing the origin, and let $\tau=...
Non-extinction of a Fleming–Viot particle model
v1.3 research notesLet $N$ particles move as independent Brownian motions in a bounded connected open set $D\subset\mathbb{R}^d$. Whenever a particle hits the complement...
Are shy couplings necessarily rigid?
v1.3 research notesLet $D\subset\mathbb{R}^d$, $d\ge2$, be bounded, connected, and open. Suppose there are coupled reflected Brownian motions $X_t,Y_t$ in $D$ and $\vare...
Stationary distributions in one dimension
v1.3 research notesFor the exclusion process on $\mathbb{Z}$ with $p(x,y)=p(y-x)$, assume $\sum_x|x|p(x)<\infty$, $\sum_xxp(x)>0$, and $\sum_{x<0}x^2p(x)=\infty$. Does t...
Exchangeability in the mean-zero exclusion process
v1.3 research notesFor the exclusion process on $\mathbb{Z}^d$ with translation-invariant kernel $p(x,y)=p(y-x)$ and zero mean $\sum_xxp(x)=0$, prove that every stationa...
Negative association for asymmetric exclusion
v1.3 research notesFor nearest-neighbor asymmetric exclusion on $\mathbb{Z}$ with $p(1)=p>q=p(-1)$, start from the deterministic configuration $\cdots11110000\cdots$. Is...
Unbalanced regimes of the spatial city-growth model
v1.3 research notesFor the city-growth model, prove: (a) if $\alpha>1$, the eventual number of cities $M(\infty)$ is finite almost surely; (b) if $\beta<2\alpha$, the la...
A mathematically natural SIRSN
v1.3 research notesConstruct a scale-invariant random spatial network whose law is mathematically natural, for example with an explicit formula for the distribution of $...
A visually realistic SIRSN
v1.3 research notesConstruct a scale-invariant random spatial network that is visually realistic, in the sense of not looking very different from a real-world road netwo...
Converse implications among SIRSN properties
v1.3 research notesProve or disprove each of the proposed implications between the SIRSN properties numbered (16), (20), (49), (50), and (51): (16)$\Rightarrow$(20), uni...
Topology and geometry of a self-similar random planar partition
v1.3 research notesFor Aldous's self-similar random partition of the plane, determine its topological properties: in particular, do region boundaries have fractal dimens...
Topological realization of compact Markov-chain limits
v1.3 research notesFor the measure-theoretic limit transition densities $p_\infty(x,y,t)$ arising from sequences of finite reversible Markov chains, construct a natural ...
Scaling total life in a null-recurrent renewal process
v1.3 research notesFor the null-recurrent renewal process of Problem 1.1, is there a non-decreasing function $\phi$ such that $D_t/\phi(t)$ converges in distribution to ...
Joint limit of total life and relative age
v1.3 research notesFor the null-recurrent renewal process of Problems 1.1–1.2, assuming their answers are positive, does $(D_t/\phi(t),U_t)$ converge in distribution to ...
Mass-stationarity of diffuse random measures via allocations
v1.3 research notesLet $(X,\xi)$ consist of a random element and a diffuse random measure on a locally compact second countable Abelian group. Is mass-stationarity of $(...
Markovian-kernel characterization of mass-stationarity
v1.3 research notesDoes the invariant-transport characterization of mass-stationarity remain valid if the bounded jointly invariant preserving kernels are restricted to ...
Equilibrium point configurations on the line
v1.3 research notesLet $(a_n)_{n\in\mathbb{Z}}$ be a locally finite configuration of points on $\mathbb{R}$. For the force law $F(x,y)=|x-y|^{-2}$, call the configuratio...
Percolation thresholds along expander limits
v1.3 research notesLet $(G_n)$ be a bounded-degree expander family converging locally to an infinite graph $G$. Prove that the finite-graph percolation thresholds $p_c(G...
Uniqueness of percolation on graphs roughly isometric to lattices
v1.3 research notesProve that Bernoulli percolation has at most one infinite cluster on every bounded-degree graph roughly isometric to $\mathbb{Z}^d$....
Cheeger constant and the percolation nonuniqueness phase
v1.3 research notesFor every infinite vertex-transitive graph $G$, prove that $p_c(G)<p_u(G)$ if and only if $h(G)>0$....
Rough-isometry invariance of percolation nonuniqueness
v1.3 research notesFor bounded-degree graphs, prove that the property $p_c<p_u$ is invariant under rough isometry....
Critical one-dimensional long-range percolation geometry
v1.3 research notesIn one-dimensional long-range percolation with edge probabilities proportional to $\beta|i-j|^{-2}$, study the distance exponent $\theta(\beta)$ defin...
Liouville property under rough isometry to nonamenable Cayley graphs
v1.3 research notesProve that every bounded-degree graph roughly isometric to a nonamenable Cayley graph is non-Liouville....
Time constant in a recursive series-parallel first-passage model
v1.3 research notesLet $D_n$ be the source-to-sink first-passage distance in the recursively substituted hierarchical graph whose distances satisfy $D_n\stackrel d=D_{n-...
Fluctuations in recursive hierarchical first-passage percolation
v1.3 research notesFor the hierarchical first-passage distances $D_n$ satisfying $D_n\stackrel d=D_{n-1}+\min(D'_{n-1},D''_{n-1})$, determine concentration around the me...
Fluctuations and efficient algorithms in first-passage percolation
v1.3 research notesFor i.i.d. first-passage percolation on $\mathbb{Z}^2$, prove or disprove that boundary fluctuations have a Tracy–Widom limit and that the variance of...
Absence of bigeodesics in first-passage percolation
v1.3 research notesProve that natural i.i.d. first-passage-percolation models on $\mathbb{Z}^d$, including exponential edge lengths, almost surely contain no two-sided i...
Resistance growth on the UIPT
v1.3 research notesDetermine the almost-sure asymptotic growth rate of the effective resistance from the root to graph-distance $r$ in the uniform infinite planar triang...
Critical percolation on distributional planar limits
v1.3 research notesLet $G$ be a distributional local limit of finite planar graphs. Prove that $p_c^{\mathrm{site}}(G)\ge1/2$ almost surely and that there is no infinite...
Geodesics in Gaussian-free-field random metrics
v1.3 research notesOn the $n\times n$ grid with a Gaussian free field with no boundary conditions, give every vertex length equal to the exponential of the field. If $\g...
Finite-dimensional distance laws of the Brownian map
v1.3 research notesFor every $p\ge4$, determine the joint law of the matrix of pairwise distances among $p$ independent points sampled from the volume measure of the Bro...
Ends of infinite clusters in the nonuniqueness phase
v1.3 research notesLet $G$ be a connected quasi-transitive graph and let $p\in(0,1)$. If Bernoulli percolation has more than one infinite cluster almost surely, prove th...
When is the uniqueness threshold below one?
v1.3 research notesGive general conditions implying $p_u(G)<1$. In particular, prove or disprove that every one-ended transitive graph has $p_u(G)<1$....
No percolation at the critical point on $\mathbb{Z}^d$
v1.3 research notesFor nearest-neighbor independent bond percolation on $\mathbb{Z}^d$, $d\ge2$, let $p_c(d)$ be the critical edge-retention probability. Prove that at $...
Existence questions — Question 2.1
v1.3 research notesWhich hyperbolic $3$–manifolds admit taut foliations? Give an effective procedure to decide if a hyperbolic $3$–manifold admits a taut foliation. For ...
Rigidity and moduli — Question 3.1
v1.3 research notesLet $M$ be atoroidal. Is there a natural refinement of the polyhedral structure of the unit ball of the Thurston norm to a polyhedron $\mathscr{P}_\ma...
Minimal surfaces — Question 4.1
v1.3 research notesSuppose $\mathscr{F}$ is a taut foliation of $M$. Characterize the space of metrics on $M$ for which $\mathscr{F}$ can be isotoped to consist of minim...
Branched surfaces and triangulations — Question 7.3
v1.3 research notesWhich boundary slopes are realized by essential laminations carried by a fixed taut ideal triangulation? Give an algorithm....
Branched surfaces and triangulations — Question 7.8
v1.3 research notesDo branched surfaces without sink disks carry automatic laminations?...
Leaf spaces and transverse structures — Question 8.1
v1.3 research notesSuppose $M$ is irreducible. Suppose further that $\pi_1(M)$ admits a nontrivial action on $\mathbb{R}$. When does $M$ admit a taut foliation with a tr...
Leaf spaces and transverse structures — Question 8.3
v1.3 research notesSuppose $M$ is atoroidal and admits a taut foliation. Must it admit an $\mathbb{R}$–covered foliation?...
Leaf spaces and transverse structures — Question 8.9
v1.3 research notesWhat possibilities are there for universal circles $S^1_\mathrm{univ}$ for a fixed manifold? For a fixed foliation? For what taut foliations is there ...
Classical 3-manifold theory — Question 9.3
v1.3 research notesWhat is the most general class of knots to which the techniques of Delman–Roberts (in constructing persistent laminations) can be extended?...
Hyperbolic geometry — Question 10.2
v1.3 research notesDo leaves of $\widetilde{\Lambda}$ for $\Lambda$ an essential lamination have the continuous extension property? More generally, what is the relations...
Hyperbolic geometry — Question 10.4
v1.3 research notesSuppose $M$ an atoroidal $3$–manifold admits an essential lamination. Does it admit a (necessarily genuine) lamination with quasi–geodesic leaves?...