# Observatorio de I+D+i UPM

Memorias de investigación
Artículos en revistas:
Roundoff-induced attractors and reversibility in conservative two-dimensional maps
Año:2007
Áreas de investigación
• Electrónica
Datos
Descripción
We numerically study two conservative two-dimensional maps, namely the baker map (whose Lyapunov exponent is known to be positive), and a typical one (exhibiting a vanishing Lyapunov exponent) chosen from the generalized shift family of maps introduced by C. Moore [Phys Rev Lett {\bf 64}, 2354 (1990)] in the context of undecidability. We calculated the time evolution of the entropy $S_q \equiv \frac{1-\sum_{i=1}^Wp_i^q}{q-1}$ ($S_1=S_{BG}\equiv -\sum_{i=1}^Wp_i \ln p_i$), and exhibited the dramatic effect introduced by numerical precision. Indeed, in spite of being area-preserving maps, they present, {\it well after} the initially concentrated ensemble has spread virtually all over the phase space, unexpected {\it pseudo-attractors} (fixed-point like for the baker map, and more complex structures for the Moore map). These pseudo-attractors, and the apparent time (partial) reversibility they provoke, gradually disappear for increasingly large precision. In the case of the Moore map, they are related to zero Lebesgue-measure effects associated with the frontiers existing in the definition of the map. In addition to the above, and consistently with the results by V. Latora and M. Baranger [Phys. Rev. Lett. {\bf 82}, 520 (1999)], we find that the rate of the far-from-equilibrium entropy production of baker map, numerically coincides with the standard Kolmogorov-Sinai entropy of this strongly chaotic system
Internacional
No
JCR del ISI
No
Título de la revista
Physica A
ISSN
0378-4371
Factor de impacto JCR
0
Información de impacto
Volumen
2
DOI
Número de revista
386
Desde la página
720
Hasta la página
728
Mes
SIN MES
Ranking
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Participantes
• Participante: C. Tsallis
• Autor: Guiomar Ruiz Lopez (UPM)
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