A5033155545- Diffusion and Search Dynamics
- Random lasers and scattering media
- Theoretical and Computational Physics
- Stochastic processes and statistical mechanics
- Evolutionary Game Theory and Cooperation
- Mathematical and Theoretical Epidemiology and Ecology Models
- Physics of Superconductivity and Magnetism
- Complex Systems and Time Series Analysis
- Orbital Angular Momentum in Optics
- Animal Behavior and Reproduction
- Neural Networks and Reservoir Computing
- Advanced Condensed Matter Physics
- Fractional Differential Equations Solutions
- Quantum and electron transport phenomena
- Plant and animal studies
- stochastic dynamics and bifurcation
- Evolution and Genetic Dynamics
- Photonic Crystals and Applications
- Neural dynamics and brain function
- Magnetic properties of thin films
- Quantum optics and atomic interactions
- Photonic Crystal and Fiber Optics
- Material Dynamics and Properties
- Insect and Arachnid Ecology and Behavior
- Magnetism in coordination complexes
Universidade Federal de Pernambuco
2015-2024
Centre for Research on Ecology and Forestry Applications
2020-2021
Universitat Autònoma de Barcelona
2020-2021
Centre d'Estudis Avançats de Blanes
2020-2021
Universidade Federal do Piauí
2005
Harvard University Press
1998-2001
Harvard University
1997-2000
Abstract Random lasers have been recently exploited as a photonic platform for studies of complex systems. This cross-disciplinary approach opened up new important avenues the understanding random-laser behavior, including Lévy-type distributions strong intensity fluctuations and phase transitions to spin-glass phase. In this work, we employ Nd:YBO random laser system unveil, from single set measurements, physical origin correspondence between Lévy fluctuation regime...
We consider a Lévy flyer of order alpha that starts from point x(0) on an interval [O,L] with absorbing boundaries. find closed-form expression for the average number flights takes and total length it travels before is absorbed. These two quantities are equivalent to mean first passage times walks, respectively. Using fractional differential equations Riesz kernel, we exact analytical expressions both in continuous limit. show numerical solutions discrete processes converge approximations...
Abstract Turbulence is a challenging feature common to wide range of complex phenomena. Random fibre lasers are special class in which the feedback arises from multiple scattering one-dimensional disordered cavity-less medium. Here we report on statistical signatures turbulence distribution intensity fluctuations continuous-wave-pumped erbium-based random laser, with Bragg grating scatterers. The an extensive data set exhibits three qualitatively distinct behaviours: Gaussian regime below...
Abstract Habitat loss and fragmentation are important factors determining animal population dynamics spatial distribution. Such landscape changes can lead to the deleterious impact of a significant drop in number species, caused by critically reduced survival rates for organisms. In order obtain deeper understanding threeway interplay between habitat loss, rates, we propose here spatially explicit multi-scaled movement model individuals that search habitat. By considering basic ecological...
We study through a reaction-diffusion algorithm the influence of landscape diversity on efficiency search dynamics. Remarkably, identical optimal strategy arises in wide variety environments, provided target density is sparse and searcher's information restricted to its close vicinity. Our results strongly impact current debate emergentist vs. evolutionary origins animal foraging. The inherent character solution (i.e., independent for broad scenarios assumed here) suggests an interpretation...
Functional brain networks are often constructed by quantifying correlations between time series of activity regions. Their topological structure includes nodes, edges, triangles, and even higher-dimensional objects. Topological data analysis (TDA) is the emerging framework to process sets under this perspective. In parallel, topology has proven essential for understanding fundamental questions in physics. Here we report discovery phase transitions functional merging concepts from TDA,...
The photonic analog of the paramagnetic to spin-glass phase transition in disordered magnetic systems, signaled by phenomenon replica symmetry breaking, has been reported using random lasers as platform. We report here a demonstration breaking one-dimensional system consisting an erbium-doped fiber laser operating continuous-wave regime. is based on unique grating which plays role scattering, providing feedback mechanism. clear from phase, characterized Parisi overlap parameter, was verified...
We report on measurements of the statistical fluctuations output intensity in a continuous-wave-pumped erbium-doped one-dimensional random fiber laser (RFL), with specially designed Bragg grating scatterers. Transitions from Gaussian to Lévy-like and back regime, similar those observed three-dimensional lasers, are described as input excitation power increases below above RFL threshold. Our results consistent theoretical predictions for sequence regimes systems. also discuss experimental...
We study the role of dynamical constraints in general problem finding best statistical strategy for random searching when targets can be detected only limited vicinity searcher. find that optimal search depends strongly on delay time $\ensuremath{\tau}$ during which a previously visited site becomes unavailable. also is always described large step lengths $\ensuremath{\ell}$ by power-law distribution $P(\ensuremath{\ell})\ensuremath{\sim}{\ensuremath{\ell}}^{\ensuremath{-}\ensuremath{\mu}}$,...
Recent theoretical developments had laid down the proper mathematical means to understand how structural complexity of search patterns may improve foraging efficiency. Under information-deprived scenarios and specific landscape configurations, Lévy walks flights are known lead high efficiencies. Based on a one-dimensional comparative analysis we show mechanism by which, at random, searcher can optimize encounter with close distant targets. The consists combining an optimal diffusivity...
By using specially designed nanoparticles scatterers which prevents photodegradation of the dye, we present clear demonstration replica symmetry break and a photonic paramagnetic to spin-glass phase transition in random laser operating incoherent feedback regime based on ethanol solution Rhodamine 6G amorphous TiO2 nanoparticles.
Abstract Modulation of scattering in random lasers (RLs) by magnetic fields has attracted much attention due to its rich physical insights. We fabricate gain polymer optical fiber generate RLs. From macroscopic experimental phenomena, with the increase field strength, transverse photocurrent exists disordered multiple RLs and emission intensity decreases, which is observation photonic Hall effect (PHE) magnetoresistance (PMR) At microscopic level, based on dependence theory disorder...
Abstract We investigate the critical behavior in quantum regime of Hubbard model $d$-dimensional hypercubic lattices with infinite-range Coulomb interaction. The Haldane-Wu mutual exclusion statistics approach, which comprises three species exclusions, allows us to derive singular part free energy, entropy, and specific heat $g > T$, where $g$ is scaling interaction parameter $T$ temperature. present results from analytic series expansions observables near point: $T = g \mu 0$, $\mu$...
A difficulty in interpreting phenomena related to anomalous diffusion concerns how identify scale invariant superdiffusive from Markovian correlated random walk processes. Here we propose a criterion that can distinguish between these two kinds of walks and describe its usefulness real data. To do so, estimate the correlation time $\ensuremath{\tau}$ orientation persistence general walk. If experimentally observed appears diffusive on scales larger than $\ensuremath{\tau}$, then data cannot...
In this work we discuss some recent contributions to the random search problem. Our analysis includes superdiffusive Lévy processes and correlated walks in several regimes of target site density, mobility revisitability. We present results context mean-field-like closed-form average calculations, as well numerical simulations. then consider searches performed regular lattices with defects, a necessary criterion for distinguishing true superdiffusion from walk processes. invoke energy...