3,769 research outputs found
Unrestricted Stone Duality for Markov Processes
Stone duality relates logic, in the form of Boolean algebra, to spaces. Stone-type dualities abound in computer science and have been of great use in understanding the relationship between computational models and the languages used to reason about them. Recent work on probabilistic processes has established a Stone-type duality for a restricted class of Markov processes. The dual category was a new notion--Aumann algebras--which are Boolean algebras equipped with countable family of modalities indexed by rational probabilities. In this article we consider an alternative definition of Aumann algebra that leads to dual adjunction for Markov processes that is a duality for many measurable spaces occurring in practice. This extends a duality for measurable spaces due to Sikorski. In particular, we do not require that the probabilistic modalities preserve a distinguished base of clopen sets, nor that morphisms of Markov processes do so. The extra generality allows us to give a perspicuous definition of event bisimulation on Aumann algebras
Minimization via duality
We show how to use duality theory to construct minimized versions of a wide class of automata. We work out three cases in detail: (a variant of) ordinary automata, weighted automata and probabilistic automata. The basic idea is that instead of constructing a maximal quotient we go to the dual and look for a minimal subalgebra and then return to the original category. Duality ensures that the minimal subobject becomes the maximally quotiented object
Continuous-state branching processes with competition: duality and reflection at Infinity
The boundary behavior of continuous-state branching processes with quadratic
competition is studied in whole generality. We first observe that despite
competition, explosion can occur for certain branching mechanisms. We obtain a
necessary and sufficient condition for to be accessible in terms of
the branching mechanism and the competition parameter . We show that when
is inaccessible, it is always an entrance boundary. In the case where
is accessible, explosion can occur either by a single jump to
(the process at jumps to at rate for some )
or by accumulation of large jumps over finite intervals. We construct a natural
extension of the minimal process and show that when is accessible and
, the extended process is reflected at . In
the case , is an exit of the extended
process. When the branching mechanism is not the Laplace exponent of a
subordinator, we show that the process with reflection at get extinct
almost-surely. Moreover absorption at is almost-sure if and only if Grey's
condition is satisfied. When the branching mechanism is the Laplace exponent of
a subordinator, necessary and sufficient conditions are given for a stationary
distribution to exist. The Laplace transform of the latter is provided. The
study is based on classical time-change arguments and on a new duality method
relating logistic CSBPs with certain generalized Feller diffusions.Comment: minor modifications and new lemma 4.
Balls-in-boxes duality for coalescing random walks and coalescing Brownian motions
We present a duality relation between two systems of coalescing random walks
and an analogous duality relation between two systems of coalescing Brownian
motions. Our results extends previous work in the literature and we apply it to
the study of a system of coalescing Brownian motions with Poisson immigration.Comment: 13 page
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