Title Information
Title
Wave propagation in spatially extended systems
Name: Personal
Name Part
Dodson, Stephanie
Role
Role Term: Text
creator
Name: Personal
Name Part
Sandstede, Bjorn
Role
Role Term: Text
Advisor
Name: Personal
Name Part
Mallet-Paret, John
Role
Role Term: Text
Reader
Name: Personal
Name Part
Beck, Margaret
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Department of Applied Mathematics
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2019
Physical Description
Extent
xi, 158 p.
digitalOrigin
born digital
Note: thesis
Thesis (Ph. D.)--Brown University, 2019
Genre (aat)
theses
Abstract
Systems of oscillatory and excitable media frequently express regular spiral and traveling wave patterns, but bifurcations to complex structures are also common. Spiral wave patterns observed in models of cardiac arrhythmias and chemical oscillations develop alternans and stationary line defects, both of which can be thought of as period-doubling instabilities. Physically, the period-doubled patterns are observed on bounded domains, leading to the question of if and how the domain geometry contributes to the formation of the instability. We explore this question by first considering impacts of truncating an infinite to bounded domain, and second, how properties of single cells can be extended to spatially extended tissues. The first scenario is relevant for determining on what domains the instabilities will be present, and the second is important for understanding if results from in vitro experiments can be applied to in vivo settings. Bifurcations of bounded spirals may arise from instabilities associated with one of the three distinct regions of the spiral: the core, far-field, and boundary. Here, we introduce a methodology to disentangle the impacts of each region on the instabilities by analyzing spectral properties of spiral waves. We apply our techniques to spirals formed in reaction-diffusion systems and find that the mechanisms driving the period-doubling instabilities are quite different; alternans are driven by the spiral core, whereas line defects appear from boundary effects. Finally, we explore how the spectral properties of reaction-diffusion systems are modified when one species does not diffuse, leading to a rank-deficient diffusion matrix.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00832431")
Topic
Biology--Mathematical models
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01400410")
Topic
Applied mathematics
Subject
Topic
Stability of spiral waves
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20190603
Identifier: DOI
10.26300/4caz-vr35
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations