Fernando Oliveira | UNIVERSIDADE DE BRASÍLIA (original) (raw)
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Papers by Fernando Oliveira
arXiv (Cornell University), May 2, 2008
Physica A: Statistical Mechanics and its Applications, 2016
Frontiers in Physics, 2022
arXiv: Pattern Formation and Solitons, 2016
In this work, we investigate the pattern solutions of doubly non-local Fisher population equation... more In this work, we investigate the pattern solutions of doubly non-local Fisher population equation that include spatial kernels in both growth and competition terms. We show the existence of two types of stationary nonlinear solutions: one cosine, which we refer to as a wavelike solution and another in the form of Gaussians. We obtain analytical expressions that describe the nonlinear pattern behavior in the system and establish the stability criterion. Based on this, the pattern-no-pattern and pattern-pattern transitions are properly analyzed. We show that these pattern solutions may be related to the recently observed peak-adding phenomenon in non-linear optics.
arXiv (Cornell University), Nov 19, 2021
Physica D: Nonlinear Phenomena, Oct 1, 2016
Physica D: Nonlinear Phenomena, Feb 1, 2020
arXiv: Statistical Mechanics, 2020
The Kardar-Parisi-Zhang (KPZ) equation in the d+1d + 1d+1 dimensional space has been connected to a l... more The Kardar-Parisi-Zhang (KPZ) equation in the d+1d + 1d+1 dimensional space has been connected to a large number of important stochastic processes in physics, chemistry and growth phenomena. A central quest in this field is the search for ever more precise universal growth exponents. In this work, we present physical and geometric analytical methods that directly associate these exponents to the fractal dimension of the rough interface. Based on this, we determine exactly the growth exponents for the d+1d + 1d+1 dimensions. In addition, we show that the KPZ model has no upper critical dimension.
The Kardar-Parisi-Zhang (KPZ) equation in the d+1 dimensional space has been connected with a lar... more The Kardar-Parisi-Zhang (KPZ) equation in the d+1 dimensional space has been connected with a large number of stochastic process in physics and chemistry. Therefore, the quest for its universal exponents has been a very intensive field of research. In this work using geometric analytical methods, we associate these exponents with the fractal dimension of the rough surface. Consequently, we obtain the exponents exactly for 2 + 1 dimensions and, for higher dimensions, we set theoretical limits for them. We prove as well that the KPZ model has no upper critical dimension.
Frontiers in Physics, 2021
Growth in crystals can be usually described by field equations such as the Kardar-Parisi-Zhang (K... more Growth in crystals can be usually described by field equations such as the Kardar-Parisi-Zhang (KPZ) equation. While the crystalline structure can be characterized by Euclidean geometry with its peculiar symmetries, the growth dynamics creates a fractal structure at the interface of a crystal and its growth medium, which in turn determines the growth. Recent work by Gomes-Filho et al. (Results in Physics, 104,435 (2021)) associated the fractal dimension of the interface with the growth exponents for KPZ and provides explicit values for them. In this work, we discuss how the fluctuations and the responses to it are associated with this fractal geometry and the new hidden symmetry associated with the universality of the exponents.
Physics Subject Headings (PhySH)
Cornell University - arXiv, Aug 29, 2006
Europhysics Letters (EPL), 2007
arXiv: Pattern Formation and Solitons, 2016
In this work, we study the pattern solutions of doubly nonlocal logistic map that include spatial... more In this work, we study the pattern solutions of doubly nonlocal logistic map that include spatial kernels in both growth and competition terms. We show that this map includes as a particular case the nonlocal Fisher-Kolmogorov equation, and we demonstrate the existence of three kinds of stationary nonlinear solutions: one uniform, one cosine type that we refer to as wavelike solution, and another in the form of Gaussian. We also obtain analytical expressions that describe the nonlinear pattern behavior in the system, and we establish the stability criterion. We define thermodynamics grandeurs such as entropy and the order parameter. Based on this, the pattern-no-pattern and pattern-pattern transitions are properly analyzed. We show that these pattern solutions may be related to the recently observed peak adding phenomenon in nonlinear optics.
Heritage of Humanity, the Brasilia's Pilot Plan has a distinctive sound ambience, atypical to... more Heritage of Humanity, the Brasilia's Pilot Plan has a distinctive sound ambience, atypical to a big city. When the urban plan was designed by Lucio Costa, noise was not an evident principle, but the adopted solutions incorporated premises that contribute with the urban acoustic comfort-like the existence of local commercial buildings and green belt, which protects the residential buildings. Scientific research carried out for UNESCO identified low percentage of people by traffic noise. However, the nocturnal noise is actually a relevant nuisance factor to the population, causing conflicts between community, bar owners and cultural producers. These annoyances emerged mainly due to the growth of nocturnal activity in Local Commercial Sectors in recent years, and due to their proximity with residential buildings of the Superblocks. By evaluating the soundscape of North Superblock 410 (SQN 410), a place of intense nocturnal activity, we sought to identify and analyze the different s...
arXiv (Cornell University), May 2, 2008
Physica A: Statistical Mechanics and its Applications, 2016
Frontiers in Physics, 2022
arXiv: Pattern Formation and Solitons, 2016
In this work, we investigate the pattern solutions of doubly non-local Fisher population equation... more In this work, we investigate the pattern solutions of doubly non-local Fisher population equation that include spatial kernels in both growth and competition terms. We show the existence of two types of stationary nonlinear solutions: one cosine, which we refer to as a wavelike solution and another in the form of Gaussians. We obtain analytical expressions that describe the nonlinear pattern behavior in the system and establish the stability criterion. Based on this, the pattern-no-pattern and pattern-pattern transitions are properly analyzed. We show that these pattern solutions may be related to the recently observed peak-adding phenomenon in non-linear optics.
arXiv (Cornell University), Nov 19, 2021
Physica D: Nonlinear Phenomena, Oct 1, 2016
Physica D: Nonlinear Phenomena, Feb 1, 2020
arXiv: Statistical Mechanics, 2020
The Kardar-Parisi-Zhang (KPZ) equation in the d+1d + 1d+1 dimensional space has been connected to a l... more The Kardar-Parisi-Zhang (KPZ) equation in the d+1d + 1d+1 dimensional space has been connected to a large number of important stochastic processes in physics, chemistry and growth phenomena. A central quest in this field is the search for ever more precise universal growth exponents. In this work, we present physical and geometric analytical methods that directly associate these exponents to the fractal dimension of the rough interface. Based on this, we determine exactly the growth exponents for the d+1d + 1d+1 dimensions. In addition, we show that the KPZ model has no upper critical dimension.
The Kardar-Parisi-Zhang (KPZ) equation in the d+1 dimensional space has been connected with a lar... more The Kardar-Parisi-Zhang (KPZ) equation in the d+1 dimensional space has been connected with a large number of stochastic process in physics and chemistry. Therefore, the quest for its universal exponents has been a very intensive field of research. In this work using geometric analytical methods, we associate these exponents with the fractal dimension of the rough surface. Consequently, we obtain the exponents exactly for 2 + 1 dimensions and, for higher dimensions, we set theoretical limits for them. We prove as well that the KPZ model has no upper critical dimension.
Frontiers in Physics, 2021
Growth in crystals can be usually described by field equations such as the Kardar-Parisi-Zhang (K... more Growth in crystals can be usually described by field equations such as the Kardar-Parisi-Zhang (KPZ) equation. While the crystalline structure can be characterized by Euclidean geometry with its peculiar symmetries, the growth dynamics creates a fractal structure at the interface of a crystal and its growth medium, which in turn determines the growth. Recent work by Gomes-Filho et al. (Results in Physics, 104,435 (2021)) associated the fractal dimension of the interface with the growth exponents for KPZ and provides explicit values for them. In this work, we discuss how the fluctuations and the responses to it are associated with this fractal geometry and the new hidden symmetry associated with the universality of the exponents.
Physics Subject Headings (PhySH)
Cornell University - arXiv, Aug 29, 2006
Europhysics Letters (EPL), 2007
arXiv: Pattern Formation and Solitons, 2016
In this work, we study the pattern solutions of doubly nonlocal logistic map that include spatial... more In this work, we study the pattern solutions of doubly nonlocal logistic map that include spatial kernels in both growth and competition terms. We show that this map includes as a particular case the nonlocal Fisher-Kolmogorov equation, and we demonstrate the existence of three kinds of stationary nonlinear solutions: one uniform, one cosine type that we refer to as wavelike solution, and another in the form of Gaussian. We also obtain analytical expressions that describe the nonlinear pattern behavior in the system, and we establish the stability criterion. We define thermodynamics grandeurs such as entropy and the order parameter. Based on this, the pattern-no-pattern and pattern-pattern transitions are properly analyzed. We show that these pattern solutions may be related to the recently observed peak adding phenomenon in nonlinear optics.
Heritage of Humanity, the Brasilia's Pilot Plan has a distinctive sound ambience, atypical to... more Heritage of Humanity, the Brasilia's Pilot Plan has a distinctive sound ambience, atypical to a big city. When the urban plan was designed by Lucio Costa, noise was not an evident principle, but the adopted solutions incorporated premises that contribute with the urban acoustic comfort-like the existence of local commercial buildings and green belt, which protects the residential buildings. Scientific research carried out for UNESCO identified low percentage of people by traffic noise. However, the nocturnal noise is actually a relevant nuisance factor to the population, causing conflicts between community, bar owners and cultural producers. These annoyances emerged mainly due to the growth of nocturnal activity in Local Commercial Sectors in recent years, and due to their proximity with residential buildings of the Superblocks. By evaluating the soundscape of North Superblock 410 (SQN 410), a place of intense nocturnal activity, we sought to identify and analyze the different s...