The Experts below are selected from a list of 6768 Experts worldwide ranked by ideXlab platform
Giovanni Felder - One of the best experts on this subject based on the ideXlab platform.
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poncelet property and Quasi Periodicity of the integrable boltzmann system
Letters in Mathematical Physics, 2021Co-Authors: Giovanni FelderAbstract:We study the motion of a particle in a plane subject to an attractive central force with inverse-square law on one side of a wall at which it is reflected elastically. This model is a special case of a class of systems considered by Boltzmann which was recently shown by Gallavotti and Jauslin to admit a second integral of motion additionally to the energy. By recording the subsequent positions and momenta of the particle as it hits the wall, we obtain a three-dimensional discrete-time dynamical system. We show that this system has the Poncelet property: If for given generic values of the integrals one orbit is periodic, then all orbits for these values are periodic and have the same period. The reason for this is the same as in the case of the Poncelet theorem: The generic level set of the integrals of motion is an elliptic curve, and the Poincare map is the composition of two involutions with fixed points and is thus the translation by a fixed element. Another consequence of our result is the proof of a conjecture of Gallavotti and Jauslin on the Quasi-Periodicity of the integrable Boltzmann system, implying the applicability of KAM perturbation theory to the Boltzmann system with weak centrifugal force.
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Poncelet property and Quasi-Periodicity of the integrable Boltzmann system
Letters in Mathematical Physics, 2021Co-Authors: Giovanni FelderAbstract:We study the motion of a particle in a plane subject to an attractive central force with inverse-square law on one side of a wall at which it is reflected elastically. This model is a special case of a class of systems considered by Boltzmann which was recently shown by Gallavotti and Jauslin to admit a second integral of motion additionally to the energy. By recording the subsequent positions and momenta of the particle as it hits the wall, we obtain a three-dimensional discrete-time dynamical system. We show that this system has the Poncelet property: If for given generic values of the integrals one orbit is periodic, then all orbits for these values are periodic and have the same period. The reason for this is the same as in the case of the Poncelet theorem: The generic level set of the integrals of motion is an elliptic curve, and the Poincaré map is the composition of two involutions with fixed points and is thus the translation by a fixed element. Another consequence of our result is the proof of a conjecture of Gallavotti and Jauslin on the Quasi-Periodicity of the integrable Boltzmann system, implying the applicability of KAM perturbation theory to the Boltzmann system with weak centrifugal force.
Yi Guang Zhao - One of the best experts on this subject based on the ideXlab platform.
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simulation studies of frequency locking Quasi Periodicity subharmonic bifurcation and chaos in modulated semiconductor lasers
IEEE Journal of Quantum Electronics, 1992Co-Authors: Yi Guang ZhaoAbstract:A method of finding self-consistent solutions for the field equation and rate equations has been used to study frequency locking, Quasi-Periodicity, subharmonic bifurcations, and chaos in gain-guided stripe-geometry semiconductor lasers under high-frequency modulation current. The results show that chaotic behavior arises in unstable semiconductor lasers. The route to chaos is not through period doubling, but rather through Quasi-Periodicity. The frequency-locked regions have been studied. For lasers whose dynamic response exhibits quickly damped relaxation oscillations, only period-two oscillations have been obtained. The calculated results agree with experiment. >
D Y Shen - One of the best experts on this subject based on the ideXlab platform.
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Quasi Periodicity of vector solitons in a graphene mode locked fiber laser
Laser Physics Letters, 2013Co-Authors: Yufeng Song, Dingyuan Tang, D Y ShenAbstract:We report on the experimental observation of Quasi-periodic dynamics of vector solitons in an erbium-doped fiber laser passively mode-locked with atomic layer graphene. Apart from the stable polarization-locked vector soliton emission, it was found that under certain conditions the fiber laser could also emit vector solitons with Quasi-periodic pulse energy variation and polarization rotation during the cavity roundtrips. We show that the physical mechanism for the Quasi-periodic vector soliton evolution is cavity-induced soliton modulation instability. Quasi-periodic evolution of multiple vector solitons was also observed in the same laser.
H S Ahluwalia - One of the best experts on this subject based on the ideXlab platform.
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three cycle Quasi Periodicity in solar geophysical cosmic ray data and global climate change
IJRSP Vol.41(5) [October 2012], 2012Co-Authors: H S AhluwaliaAbstract:The discovery of a three-cycle Quasi-Periodicity (TCQP) in the planetary indices (Ap/aa), interplanetary magnetic field (IMF) intensity (B) and galactic cosmic rays (GCRs) has been described [Ahluwalia H S, Three activity cycle Periodicity in galactic cosmic rays? Proc 25th Int Cosmic Ray Conf (Durban, South Africa), 2, 1997b, pp 109-112; Ahluwalia H S, The predicted size of cycle 23 based on the inferred three cycle Quasi-Periodicity of the planetary index Ap, J Geophys Res (USA), 103 (1998) pp 12103–12109; Ahluwalia H S, The development of solar cycle 23: Reply to Wilson & Hathaway’s comment, J Geophys Res (USA), 104 (1999) pp 2559–2561]. It led to the development of a heuristic methodology for predicting the peak smooth sunspot numbers (SSNs) and the rise time for a new solar activity cycle. The scheme was used to predict key parameters for the SSN cycle 23. The predictions were right on the mark, one of the very few predictions to have achieved this status. The smoothed SSNs for cycle 24 have been increasing slowly since its onset in December 2008. Ahluwalia & Jackewicz [Ahluwalia H S & Jackiewicz J, Sunspot cycle 23 descent to an unusual minimum and forecasts for cycle 24 activity, Adv Space Res (UK), 50 (2012) pp 662-668] have predicted that cycle 24 will be only half as active as cycle 23 and reach its peak in May 2013 ± 6 months. In the present paper, the present status of the ascending phase of cycle 24 has been reported and its timeline has been compared with those of the previous ten cycles (10-23) of the twentieth century. Drawing from the past history, Ahluwalia & Jackewicz noted that we may be on the eve of a Dalton-like minimum. The ascending phase of cycle 24 is compared with those of cycles 5 and 14 that led to the start of two recent Grand Minima, namely the Dalton and the Gleissberg Minima, respectively. The physical significance of the findings is discussed and speculated about their implications for the global climate change and probable socioeconomic and political future happenings.
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the predicted size of cycle 23 based on the inferred three cycle Quasi Periodicity of the planetary index ap
Journal of Geophysical Research, 1998Co-Authors: H S AhluwaliaAbstract:A review of the solar and the geophysical data for the last 6 decades indicates the existence of a three-solar-activity-cycle Quasi-Periodicity in them. It is also present in other data sets extending over several centuries. A new cycle may have started after 1996. If true, cycle 23 will be more modest (a la cycle 17) with an annual mean sunspot number count of 119.3 ± 30 at the maximum. This inference is in contrast to the predictions of some of the solar astronomers who are predicting a very active cycle 23 (a la cycle 19).
D S Chemla - One of the best experts on this subject based on the ideXlab platform.
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period doubling and Quasi Periodicity in additive pulse mode locked lasers
Optics Letters, 1995Co-Authors: G Sucha, S R Bolton, Shimon Weiss, D S ChemlaAbstract:We have observed period doubling and Quasi-Periodicity in an additive-pulse mode-locked F-center laser. Experiments show that period doubling is often present even though standard diagnostics such as pulse autocorrelations and spectra give no indication of it. Numerical simulations show that the period doubling is associated with strong pulse reshaping.