48 research outputs found
Hydrodynamic equations for an electron gas in graphene
In this paper we review, and extend to the non-isothermal case, some results
concerning the application of the maximum entropy closure technique to the
derivation of hydrodynamic equations for particles with spin-orbit interaction
and Fermi-Dirac statistics. In the second part of the paper we treat in more
details the case of electrons on a graphene sheet and investigate various
asymptotic regimes.Comment: To appear on the special issue ECMI2014 of Journal of Mathematics in
Industr
Signal-noise interaction in nonlinear optical fibers: a hydrodynamic approach
We present a new perturbative approach to the study of signal-noise
interactions in nonlinear optical fibers. The approach is based on the
hydrodynamic formulation of the nonlinear Schr\"odinger equation that governs
the propagation of light in the fiber. Our method is discussed in general and
is developed in more details for some special cases, namely the
small-dispersion regime, the continuous-wave (CW) signal and the solitonic
pulse. The accuracy of the approach is numerically tested in the CW case.Comment: Revised version, submitted to Optics express, 15 pages, 6 figure
Numerical Methods for the Inverse Nonlinear Fourier Transform
We introduce a new numerical method for the computation of the inverse
nonlinear Fourier transform and compare its computational complexity and
accuracy to those of other methods available in the literature. For a given
accuracy, the proposed method requires the lowest number of operationsComment: To be presented at the Tyrrhenian International Workshop on Digital
Communications (TIWDC) 201
Hamiltonian control of Kuramoto oscillators
Many coordination phenomena are based on a synchronisation process, whose
global behaviour emerges from the interactions among the individual parts.
Often in Nature, such self-organising mechanism allows the system to behave as
a whole and thus grounding its very first existence, or expected functioning,
on such process. There are however cases where synchronisation acts against the
stability of the system; for instance in the case of engineered structures,
resonances among sub parts can destabilise the whole system. In this Letter we
propose an innovative control method to tackle the synchronisation process
based on the use of the Hamiltonian control theory, by adding a small control
term to the system we are able to impede the onset of the synchronisation. We
present our results on the paradigmatic Kuramoto model but the applicability
domain is far more large