10,568 research outputs found
Simulation of Chua's Circuit by Means of Interval Analysis
The Chua's circuit is a paradigm for nonlinear scientific studies. It is
usually simulated by means of numerical methods under IEEE 754-2008 standard.
Although the error propagation problem is well known, little attention has been
given to the relationship between this error and inequalities presented in
Chua's circuit model. Taking the average of round mode towards and
, we showed a qualitative change on the dynamics of Chua's circuit.Comment: 6th International Conference on Nonlinear Science and Complexity -
S\~ao Jos\'e dos Campos, 2016, p. 1-
Higher-Derivative Two-Dimensional Massive Fermion Theories
We consider the canonical quantization of a generalized two-dimensional
massive fermion theory containing higher odd-order derivatives. The
requirements of Lorentz invariance, hermiticity of the Hamiltonian and absence
of tachyon excitations suffice to fix the mass term, which contains a
derivative coupling. We show that the basic quantum excitations of a
higher-derivative theory of order 2N+1 consist of a physical usual massive
fermion, quantized with positive metric, plus 2N unphysical massless fermions,
quantized with opposite metrics. The positive metric Hilbert subspace, which is
isomorphic to the space of states of a massive free fermion theory, is selected
by a subsidiary-like condition. Employing the standard bosonization scheme, the
equivalent boson theory is derived. The results obtained are used as a
guideline to discuss the solution of a theory including a current-current
interaction.Comment: 23 pages, Late
Directed Surfaces in Disordered Media
The critical exponents for a class of one-dimensional models of interface
depinning in disordered media can be calculated through a mapping onto directed
percolation (DP). In higher dimensions these models give rise to directed
surfaces, which do not belong to the directed percolation universality class.
We formulate a scaling theory of directed surfaces, and calculate critical
exponents numerically, using a cellular automaton that locates the directed
surfaces without making reference to the dynamics of the underlying interface
growth models.Comment: 4 pages, REVTEX, 2 Postscript figures avaliable from [email protected]
Comment on: Kinetic Roughening in Slow Combustion of Paper
We comment on a recent Letter by Maunuksela et al. [Phys. Rev. Lett. 79, 1515
(1997)].Comment: 1 page, 1 figure, http://polymer.bu.edu/~hmakse/Home.htm
Driven interfaces in disordered media: determination of universality classes from experimental data
While there have been important theoretical advances in understanding the
universality classes of interfaces moving in porous media, the developed tools
cannot be directly applied to experiments. Here we introduce a method that can
identify the universality class from snapshots of the interface profile. We
test the method on discrete models whose universality class is well known, and
use it to identify the universality class of interfaces obtained in experiments
on fluid flow in porous media.Comment: 4 pages, 5 figure
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