Some dynamical properties of a classical dissipative bouncing ball model with two nonlinearities

Some dynamical properties for a bouncing ball model are studied. We show that when dissipation is introduced the structure of the phase space is changed and attractors appear. Increasing the amount of dissipation, the edges of the basins of attraction of an attracting fixed point touch the chaotic attractor. Consequently the chaotic attractor and its basin of attraction are destroyed given place to a transient described by a power law with exponent -2. The parameter-space is also studied and we show that it presents a rich structure with infinite self-similar structures of shrimp-shape. © 2013 Elsevier B.V. All rights reserved.

Sending classical information through relativistic quantum channels

We investigate how special relativity influences the transmission of classical information through quantum channels by evaluating the Holevo bound when the sender and the receiver are in (relativistic) relative motion. By using the spin degrees of freedom of spin-1/2 fermions to encode the classical information, we show that, for some configurations, the accessible information in the receiver can be increased when the spin detector moves fast enough. This is possible by allowing the momentum wave packet of one of the particles to be sufficiently wide while the momentum wave packets of other particles are kept relatively narrow. In this way, one can take advantage of the fact that boosts entangle the spin and momentum degrees of freedom of spin-1/2 fermions to increase the accessible information in the former. We close the paper with a discussion of how this relativistic quantum channel cannot in general be described by completely positive quantum maps. © 2013 American Physical Society.

Chaotic thermalization in classical gauge theories

We explore the idea that chaos concepts might be useful for understanding the thermalization in gauge theories. The SU(2) Higgs model is discussed as a prototype of system with gauge fields coupled to matter fields. Through the numerical solution of the equations of motion, we are able to characterize chaotic behavior via the corresponding Lyapunov exponent. Then it is demonstrated that the system's approach to equilibrium can be understood through direct application of the principles of Statistical Mechanics. © 2013 AIP Publishing LLC.

Dynamical properties for an ensemble of classical particles moving in a driven potential well with different time perturbation

We consider dynamical properties for an ensemble of classical particles confined to an infinite box of potential and containing a time-dependent potential well described by different nonlinear functions. For smooth functions, the phase space contains chaotic trajectories, periodic islands and invariant spanning curves preventing the unlimited particle diffusion along the energy axis. Average properties of the chaotic sea are characterised as a function of the control parameters and exponents describing their behaviour show no dependence on the perturbation functions. Given invariant spanning curves are present in the phase space, a sticky region was observed and show to modify locally the diffusion of the particles. © 2013 Elsevier B.V.

Mito e realidade em Hesíodo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Epigramas de Marcial traduzidos por José Feliciano de Castilho: edição, notas e comentários

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tipologia e uso da voz média em Apolodoro: estudo semântico baseado em corpus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phoenissae de Sêneca: estudo introdutório, tradução e notas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Type-II defects in integrable classical field theories

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A paideia machadiana nas Memórias póstumas: de Aquiles a Brás Cubas

No presente estudo, são analisadas as alusões ao herói mitológico Aquiles, da Ilíada, de Homero, enfocando o diálogo intertextual construído por Machado com a epopéia clássica, em Memórias póstumas de Brás Cubas, a fim de realizar uma desautomatização do processo de leitura, como um processo de educação, chamado pelos gregos de Paidéia.

Iracema, de José de Alencar, e as Heroides, de Ovídio

Manuais de literatura ensinam que o Romantismo, centrado no eu romântico em seus conflitos e anseios libertários, rompe com os códigos clássicos da poética do Arcadismo. Em Iracema: a lenda do Ceará, Alencar narra a união da índia Iracema com Martim, o colonizador português que a fascina, e dessa união nasce Moacir, fruto da primeira miscigenação de povos em terras brasileiras. A matéria-prima que Alencar ficcionalizou tem, por um lado, o componente histórico, pois personagens como o guerreiro Martim e o índio Camarão estão registradas nos anais da história; por outro lado, a construção da heroína assenta-se em figuras femininas da mitologia grega. Essa dívida com a tradição clássica, intermediada pelo poeta latino Ovídio, o próprio José de Alencar a reconhece em carta-posfácio, onde confessa ter composto “uma heroida que tem por assunto as tradições dos indígenas brasileiros e seus costumes. (ALENCAR, 1978, p.88).

Zeros of classical orthogonal polynomials of a discrete variable

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Stieltjes functions and discrete classical orthogonal polynomials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantum versus classical instability of scalar fields in curved backgrounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cardiac autonomic regulation during exposure to auditory stimulation with classical baroque or heavy metal music of different intensities

Objectives: The effects of chronic music auditory stimulation on the cardiovascular system have been investigated in the literature. However, data regarding the acute effects of different styles of music on cardiac autonomic regulation are lacking. The literature has indicated that auditory stimulation with white noise above 50 dB induces cardiac responses. We aimed to evaluate the acute effects of classical baroque and heavy metal music of different intensities on cardiac autonomic regulation. Study design: The study was performed in 16 healthy men aged 18-25 years. All procedures were performed in the same soundproof room. We analyzed heart rate variability (HRV) in time (standard deviation of normal-to-normal R-R intervals [SDNN], root-mean square of differences [RMSSD] and percentage of adjacent NN intervals with a difference of duration greater than 50 ms [pNN50]) and frequency (low frequency [LF], high frequency [HF] and LF/HF ratio) domains. HRV was recorded at rest for 10 minutes. Subsequently, the volunteers were exposed to one of the two musical styles (classical baroque or heavy metal music) for five minutes through an earphone, followed by a five-minute period of rest, and then they were exposed to the other style for another five minutes. The subjects were exposed to three equivalent sound levels (60- 70dB, 70-80dB and 80-90dB). The sequence of songs was randomized for each individual. Results: Auditory stimulation with heavy metal music did not influence HRV indices in the time and frequency domains in the three equivalent sound level ranges. The same was observed with classical baroque musical auditory stimulation with the three equivalent sound level ranges. Conclusion: Musical auditory stimulation of different intensities did not influence cardiac autonomic regulation in men.