181 citations · 551 across the 67 of their papers we have counts for
7 papers · 1 filter
Confluence Theory for Graphs
Adam S. Sikora, Bruce W. Westbury
We develop a theory of confluence of graphs. We describe an algorithm for proving that a given system of reduction rules for abstract graphs and graphs in surfaces is locally confl…
Comparison of the classical BMO with the BMO spaces associated with operators and applications
Donggao Deng, Xuan Thinh Duong, Adam Sikora +1
Let L be a generator of a semigroup satisfying the Gaussian upper bounds. In this paper, we study further a new BMO_L space associated with L which was introduced recently by Duong…
Gaussian heat kernel upper bounds via Phragmén-Lindelöf theorem
Thierry Coulhon, Adam Sikora
We prove that in presence of Gaussian estimates, so-called Davies-Gaffney estimates, on-diagonal upper bounds imply precise off-diagonal Gaussian upper bounds for the kernels…
Analysis of degenerate elliptic operators of Grushin type
Derek W. Robinson, Adam Sikora
We analyze degenerate, second-order, elliptic operators in divergence form on . We assume the coefficients are real symmetric and $a_1H_δ\geq…
Degenerate elliptic operators: capacity, flux and separation
Derek W. Robinson, Adam Sikora
Let be the semigroup generated on $L_2(\Ri^d)$ by a self-adjoint, second-order, divergence-form, elliptic operator with Lipschitz continuous coefficients.…
Small time asymptotics of diffusion processes
A. F. M. ter Elst, Derek W. Robinson, Adam Sikora
We establish the short-time asymptotic behaviour of the Markovian semigroups associated with strongly local Dirichlet forms under very general hypotheses. Our results apply to a wi…