Browsing Mathematics Research Institute (MRI) by Title
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Encoding via conjugate symmetries of slow oscillations for globally coupled oscillators
(American Physical Society, 2004)We study properties of the dynamics underlying slow cluster oscillations in two systems of five globally coupled oscillators. These slow oscillations are due to the appearance of structurally stable heteroclinic connections ... 
Energycrossing number relations for braided magnetic fields
(American Physical Society, 1993)This Letter derives lower bounds on the energy of braided magnetic fields, based on crossing number techniques pioneered by Freedman and He. Mean crossing numbers are defined for magnetic fields inside a cylinder; for ... 
Explicit representation of subgrid heterogeneity in a GCM land surface scheme
(American Meteorological Society, 2003)A land surface scheme that may be run with or without a tiled representation of subgrid heterogeneity and includes an implicit atmospheric coupling scheme is described. Simulated average surface air temperatures and diurnal ... 
Extreme Sensitivity to Detuning for Globally Coupled Phase Oscillators
(American Physical Society, 2006)We discuss the sensitivity of a population of coupled oscillators to differences in their natural frequencies, i.e., to detuning. We argue that for three or more oscillators, one can get great sensitivity even if the ... 
Fast simulation of phasechange processes in chalcogenide alloys using a Gillespietype cellular automata approach
(American Institute of Physics, 2008)A stochastic cellular automata simulator capable of spatiotemporal modeling of the crystallization and amorphization behavior of phasechange materials during the complex annealing cycles used in optical and electrical ... 
Front propagation in a phase field model with phasedependent heat absorption
(Elsevier, 2006)We present a model for the spatiotemporal behaviour of films exposed to radiative heating, where the film can change reversibly between amorphous (glassy) and crystalline states. Such phase change materials are used ... 
GLACE: the global land–atmosphere coupling experiment. Part I: overview
(American Meteorological Society, 2006)The Global Land–Atmosphere Coupling Experiment (GLACE) is a model intercomparison study focusing on a typically neglected yet critical element of numerical weather and climate modeling: land–atmosphere coupling strength, ... 
GLACE: the global land–atmosphere coupling experiment. Part II: analysis
(American Meteorological Society, 2006)The 12 weather and climate models participating in the Global Land–Atmosphere Coupling Experiment (GLACE) show both a wide variation in the strength of land–atmosphere coupling and some intriguing commonalities. In this ... 
Group theoretic conditions for existence of robust relative homoclinic trajectories
(Cambridge University Press, 2002)We consider robust relative homoclinic trajectories (RHTs) for Gequivariant vector fields. We give some conditions on the group and representation that imply existence of equivariant vector fields with such trajectories. ... 
Hopf bifurcation with cubic symmetry and instability of ABC
(Royal Society, 2003)We examine the dynamics of generic Hopf bifurcation in a system that is symmetric under the action of the rotational symmetries of the cube. We classify the generic branches of periodic solutions at bifurcation; there are ... 
Hypermeander of spirals: local bifurcations and statistical properties
(Elsevier, 2001)In both experimental studies and numerical simulations of waves in excitable media, rigidly rotating spiral waves are observed to undergo transitions to complicated spatial dynamics with longterm Brownianlike motion of ... 
Impact of climatecarbon cycle feedbacks on emissions scenarios to achieve stabilisation
(Cambridge University Press, 200602)As atmospheric concentrations of CO2 increase due to burning of fossil fuels, stabilisation scenarios are receiving increasing amounts of interest both politically and scientifically, leading to the question, ‘what emissions ... 
Infinities of stable periodic orbits in systems of coupled oscillators
(American Physical Society, 2002)We consider the dynamical behavior of coupled oscillators with robust heteroclinic cycles between saddles that may be periodic or chaotic. We differentiate attracting cycles into types that we call phase resetting and free ... 
The influence of periodic islands in the flow on a scalar tracer in the presence of a steady source
(American Institute of Physics, 2009)In this paper we examine the influence of periodic islands within a time periodic chaotic flow on the evolution of a scalar tracer. The passive scalar tracer is injected into the flow field by means of a steady source term. ... 
In–out intermittency in partial differential equation and ordinary differential equation models
(American Institute of Physics, 2001)We find concrete evidence for a recently discovered form of intermittency, referred to as in–out intermittency, in both partial differential equation (PDE) and ordinary differential equation (ODE) models of mean field ... 
Kinematic dynamo action in large magnetic Reynolds number flows driven by shear and convection
(Cambridge University Press, 2001)A numerical investigation is presented of kinematic dynamo action in a dynamically driven fluid flow. The model isolates basic dynamo processes relevant to field generation in the Solar tachocline. The horizontal plane ... 
Learning of spatio–temporal codes in a coupled oscillator system
(IEEE, 2009)In this paper, we consider a learning strategy that allows one to transmit information between two coupled phase oscillator systems (called teaching and learning systems) via frequency adaptation. The dynamics of these ... 
Linear and nonlinear decay of cat's eyes in twodimensional vortices, and the link to Landau poles
(Cambridge University Press, 2007)This paper considers the evolution of smooth, twodimensional vortices subject to a rotating external strain field, which generates regions of recirculating, cat's eye stream line topology within a vortex. When the external ... 
Masterequation approach to the study of phasechange processes in data storage media
(American Physical Society, 2005)We study the dynamics of crystallization in phasechange materials using a masterequation approach in which the state of the crystallizing material is described by a cluster size distribution function. A model is developed ... 
Masterequation approach to understanding multistate phasechange memories and processors
(American Institute of Physics, 2007)A masterequation approach is used to perform dynamic modeling of phasetransformation processes that define the operating regimes and performance attributes of electronic (and optical) processors and multistate memory ...