Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 11 of 11 for “"Directed Percolation"”.
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Speciation dynamics of an agent-based evolution model in phenotype space
… exponents, this case is shown to belong to the directed percolation universality class. Finally, lineage behavior is explored for both organisms and clusters. The lineage lifetimes of the initial population of organisms are found to have a power-law probability density which scales with the …
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Self-organization in Models of Cyclically Sheared Suspensions
… and could be consistent with either the directed percolation universality class or conserved directed percolation. In Chapter 4, we summarize this body of work and present an outlook for future directions.</p>
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Phase transitions in fluids and biological systems
… a coarse-grained, phenomenological model in the directed percolation universality class. To relate this critical phenomena approach closer to the fluid dynamics, I consider the transition to turbulence in the Burgers equation, a simplified model for Navier-Stokes equations. Via a transformation …
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Evolutionary dynamics of speciation and extinction
… to the reaction-diffusion rules of the 2D directed percolation universality class. Offspring are generated according to one of three reproduction schemes. Mate choice dictates offspring placement, and it defines a species based on reproductive isolation (known as the biological species …
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Study of Critical Phenomena with Monte Carlo and Machine Learning Techniques
… of systems belonging to the Voter or the Directed Percolation (DP) universality class. To be more precise, we focus on the aging properties of two-state and three-state Potts models with absorbing states and we determine temporal scaling of autocorrelation and autoresponse functions. We …
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DISORDER EFFECTS IN FRUSTRATED MAGNETS AND ABSORBING STATE TRANSITIONS
… the stripe phase. Combining symmetry arguments, percolation theory and Monte Carlo simulations, we show that a weak spatial interaction anisotropy restores the stripe phase. Moreover, we determine the phase diagram and explain it using percolation theory. We also analyze the critical behavior of …
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Applications of Field Theory to Reaction Diffusion Models and Driven Diffusive Systems
… of the well-known field theory for directed percolation (DP). The DP theory is known to describe an evolving population, near extinction. We have coupled this evolving population to an environment with its own nontrivial spatio-temporal dynamics. Here, we consider the special case …
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Population dynamics of stochastic lattice Lotka-Volterra models
… are in accord with the established values of the directed percolation universality class. Following a sudden predation rate change to its critical value, one finds critical aging for the predator density autocorrelation function that is also governed by universal scaling exponents. This aging …
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Interacting Stochastic Processes: from Viciousness to Caging to Force Chains
… new universality from what is known as conserved directed percolation. The latter transition may have implications for the onset of glassiness in dense, particulate systems. In addition, this thesis also includes analysis of the heterogeneous force network present in amorphous solids near the …
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Spatial-temporal patterns in evolutionary ecology and fluid turbulence
… We address these questions in the context of directed evolution experiments on bacterial chemotactic phenotypes. Our stochastic modeling and experiments on the evolution of chemotactic fronts suggest that the strength of selection can determine whether or not phenotypic fluctuations grow or …
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Some Aspects of Fluctuation Driven Phenomena
… (PCPD), which naturally generalizes the Directed Percolation (DP) reactions. We revisit the single-species PCPD model in the Doi-Peliti formalism and propose a possible perturbative solution for the model. In addition, we investigate the two-species effective model of PCPD and demonstrate …