Mathematics Problem Archive
Showing 1-14 of 14 problems
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=...
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...
Stationary distributions in higher dimensions
v1.3 research notesOn $\mathbb{Z}^2$, take nearest-neighbor jump probabilities $p_1,q_1,p_2,q_2$ in directions $\pm e_1,\pm e_2$, with $p_1>q_1$ and $p_2>q_2$. If the an...
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...
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...
Aldous-Lyons soficity conjecture
v1.3 research notesDoes every unimodular random countable locally finite rooted graph arise as a local weak limit of finite graphs?...
Exact coupling of singular non-discrete random walks
v1.3 research notesLet $S$ and $S'$ be random walks on $\mathbb{R}$ with the same i.i.d. step-length distribution, starting at $0$ and $x$. Suppose the step lengths are ...
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 ...
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 $h(G)>0$....
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 $...