- 00-133 PONNO A.,GALGANI L., GUERRA F.
- An analytical estimate of stochasticity thresholds in Fermi-Pasta-Ulam
and $\phi^4$ models.
Mar 29, 00
(auto. generated ps),
of related papers
Abstract. We consider an infinitely extended FPU model, and we show that the slow
modulating amplitude of a narrow wave packet asymptotically satisfies
the Nonlinear Schrodinger equation (NLS). It is well known that NLS
presents a threshold below which the packet width remains narrow.
We give an analytical estimate of such a threshold; we also make a
comparison with the numerical results known to us, and show they are
in remarkable agreement with our estimate. Analogous results are found
for the $\phi^4$ model.