Title Information
Title
Non-Markovian Interacting Particle Systems on Large Sparse Graphs: Hydrodynamic Limits and Marginal Characterizations
Type of Resource (primo)
dissertations
Name: Personal
Name Part
Ganguly, Ankan
Role
Role Term: Text
creator
Name: Personal
Name Part
Ramanan, Kavita
Role
Role Term: Text
Advisor
Name: Personal
Name Part
Geman, Stuart
Role
Role Term: Text
Reader
Name: Personal
Name Part
Durrett, Rick
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Department of Applied Mathematics
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2022
Physical Description
Extent
xi, 208 p.
digitalOrigin
born digital
Note: thesis
Thesis (Ph. D.)--Brown University, 2022
Genre (aat)
theses
Abstract
Consider a (possibly non-Markovian) interacting particle system (IPS) indexed by the nodes of a (possibly random) locally finite graph whose vertices and edges are equipped with marks representing parameters of the model such as the environment and initial conditions. Each particle takes values in a countable state space and evolves according to a pure jump process whose jump intensities depend only on its own history and marks as well as the histories and marks of particles and edges in its neighborhood. Under mild conditions, we establish the well-posedness of IPS on a large class of locally finite graphs, and we provide an explicit example in which well-posedness fails. We additionally prove that under suitably mild conditions, the trajectories of the IPS are continuous with respect to their initial conditions in three different respects, one of which is novel and another of which directly implies the convergence of multiple hydrodynamic limits. It is well-known that the majority of sparse graph sequences of interest in the literature converge to trees, so we next address the problem of characterizing the marginal distribution of an IPS on a regular tree (an infinite tree of homogeneous degree). We derive an autonomous, non-Markovian, non-linear SDE called the local equation, and we prove that, for sufficiently symmetric initial conditions, the local equation is well-posed and the law of its solutions is equal to the marginal law of the IPS. This extends recent work that proved similar results for interacting diffusions with i.i.d. initial conditions. Our extension allows us to investigate flow and stationary properties of solutions to the local equation. We finish by deriving a Markovian approximation to the local equation, proving that it exactly captures stationary solutions to certain reversible IPS and present numerical examples demonstrating the efficacy of this approximation to different IPS.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01133519")
Topic
Stochastic processes
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01010351")
Topic
Markov random fields
Subject
Topic
Hydrodynamic limit
Subject
Topic
local weak convergence
Subject
Topic
interacting particle systems
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20221018