Seminario di Analisi Matematica

Lunedì 8 giugno alle ore 15:00, Stefano Pasquali (SISSA, Trieste) terrà un Seminario di Analisi Matematica dal titolo "Modulational instability of internal gravity waves for a 2D Boussinesq system".

Abstract:
We consider a two-dimensional incompressible inviscid fluid with variable density, under the action of gravity. We assume that the equilibrium density profile is stable, and we consider the so-called Boussinesq approximation, which neglects density variations in terms which do not involve gravity; this system has been widely used in physical literature to describe internal gravity waves. We prove a modulational instability result for such system, namely that the linearization at a small-amplitude travelling wave admits at least an eigenvalue with positive real part. This can be regarded as a rigorous proof of the phenomenon of Parametric Subharmonic Instability (PSI) for inviscid fluids, in which one observes a transfer of energy between a primary initially excited wave and two secondary waves with different frequencies.
This is a joint work with R. Bianchini (CNR) and A. Maspero (SISSA).

Il seminario si svolgerà in presenza presso il Dipartimento di Matematica e Fisica, Largo S. Leonardo Murialdo 1, aula B308.