A5063244231- Fluid Dynamics and Turbulent Flows
- Nonlinear Dynamics and Pattern Formation
- Quantum chaos and dynamical systems
- Hydrology and Sediment Transport Processes
- Semiconductor Quantum Structures and Devices
- Soil erosion and sediment transport
- Stability and Controllability of Differential Equations
- Plant Water Relations and Carbon Dynamics
- Nonlinear Waves and Solitons
- Stochastic processes and financial applications
- Mathematical and Theoretical Epidemiology and Ecology Models
- Nonlinear Photonic Systems
- Complex Systems and Time Series Analysis
- Quantum and electron transport phenomena
- Mathematical Biology Tumor Growth
- Fish Ecology and Management Studies
- Wind and Air Flow Studies
- Marine and fisheries research
- Spectroscopy and Quantum Chemical Studies
- Advanced Mathematical Modeling in Engineering
- Computational Fluid Dynamics and Aerodynamics
- Hydrology and Watershed Management Studies
- Advanced Mathematical Physics Problems
- earthquake and tectonic studies
- Particle Dynamics in Fluid Flows
University of California, Santa Barbara
2014-2024
University of Iceland
2003-2022
Delft University of Technology
2022
Western Norway University of Applied Sciences
2022
Marine and Freshwater Research Institute
2022
Norwegian Institute of Marine Research
2022
Max Planck Society
2013
University of California System
2007
The dynamical Franz-Keldysh effect is exposed by exploring near-band-gap absorption in the presence of intense THz electric fields. It bridges gap between dc and multiphoton competes with ac Stark shifting energy excitonic resonance. A theoretical model which includes strong field nonperturbatively via a nonequilibrium Green functions technique able to describe absorption.
Abstract. Conditions under which a single oscillator model coupled with Dieterich-Ruina's rate and state dependent friction exhibits chaotic dynamics is studied. Properties of spring-block models are discussed. The parameter values the system explored corresponding numerical solutions presented. Bifurcation analysis performed to determine bifurcations stability stationary we find that undergoes Hopf bifurcation periodic orbit. This orbit then period doubling cascade into strange attractor,...
We investigate the emergent dynamics when slip law formulation of non-linear rate-and-state friction is attached to a Burridge–Knopoff spring-block model. derive both discrete equations and continuum governing system in this framework. The (ODEs) exhibits periodic chaotic motion, where system′s transition chaos size-dependent, that is, how many blocks are considered. From model we elastic wave equation by taking limit. This results partial differential (PDE) find ensues same parameter...
Abstract Barbaro, A., Einarsson, B., Birnir, Sigurðsson, S., Valdimarsson, H., Pálsson, Ó. K., Sveinbjörnsson, and Þ. 2009. Modelling simulations of the migration pelagic fish. – ICES Journal Marine Science, 66: 826–838. We applied an interacting particle model to Icelandic capelin stock reproduce spawning route for three different years, successfully predicting 2008. Using available temperature data approximated currents, without using artificial forcing terms or a homing instinct, our was...
Static solutions of large-$N$ quantum dilaton gravity in $1+1$ dimensions are analyzed and found to exhibit some unusual behavior. As expected from previous work, infinite-mass describing a black hole equilibrium with bath Hawking radiation. Surprisingly, the finite mass approach zero coupling both at horizon spatial infinity, ``bounce'' off strong between. Several new -- candidate vacua also described.
The motion of a single bubble in periodically driven pressure field is examined from geometric point view using Poincaré maps. It shown that the equations can be transformed to perturbation Hamiltonian system. conditions determining nonlinear resonance are found; these correspond subharmonic bifurcations. Further it illustrated how resonant response interacts with nonresonant one produce jump Results also presented indicating periodic undergoes complex bifurcation sequence and strange...
The KdV equation with smooth complex initial data that blows up in a finite amount of time is studied. First, examples are given using the elliptic solutions Airault, McKean and Moser. Second, flow spectral coordinates described showing blow-up occurs when eigenvalues run to infinity time, but eigenvalue collisions harmless do not cause singularity. Eigenvalue studied numerically. Finally, continued through singularity by continuing coordinate flows on appropriate Riemann surface.
A stream of fluid flowing down a partially wetting inclined plane usually meanders, unless the volume flow rate is maintained at highly constant value. Here we investigate whether meandering this an inherent instability. In our experiment, eliminate on several substrates by reducing perturbations entering flow. By re-introducing controlled fluctuations, show that they are responsible for onset meandering. We derive theoretical model shape, %from first principles which includes dynamics and...
Abstract Angiogenesis is a multiscale process by which blood vessels grow from existing ones and carry oxygen to distant organs. essential for normal organ growth wounded tissue repair but it may also be induced tumours amplify their own growth. Mathematical computational models contribute understanding angiogenesis developing anti-angiogenic drugs, most work only involves numerical simulations analysis has lagged. A recent stochastic model of tumour-induced including vessel branching,...
We study the effect of many-body interactions on collective response confined electrons in doped quantum-well (QW) heterostructures to intense far-infrared radiation. Absorption line shapes are computed both by numerically integrating equations motion and using appropriately time-averaged equations. For a two-subband double-QW system, optical bistability period-doubling bifurcations observed their parameter range activity is given. three-subband asymmetric triple-QW system driven at...