Data di Pubblicazione:
2006
Citazione:
On metastability in FPU / D.P. Bambusi, A. Ponno. - In: COMMUNICATIONS IN MATHEMATICAL PHYSICS. - ISSN 0010-3616. - 264:2(2006), pp. 539-561.
Abstract:
We present an analytical study of the Fermi--Pasta--Ulam (FPU) $\alpha$--model with periodic boundary conditions. We analyze the dynamics corresponding to initial data with one low frequency Fourier mode excited. We show that, correspondingly, a pair of KdV equations constitute the resonant normal form of the
system. We also use such a normal form in order to prove the existence of a metastability phenomenon. More precisely, we show that the time
average of the modal energy spectrum rapidly attains a well defined distribution corresponding to a packet of low frequencies modes. Subsequently, the distribution remains unchanged up to the time scales of validity of our approximation. The phenomenon is controlled
by the specific energy.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
D.P. Bambusi, A. Ponno
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