10 papers
Decay of a square pulse to Sine-Gordon breathers
G. Ka"lbermann
We investigate numerically and analytically the existence of thresholds for the production of Sine-Gordon single and multiple breathers from simple initial pulses.
Stationary finger solutions in the Hele-Shaw cell
G. Ka"lbermann, R. Wallach
We solve numerically the nonlinear differential equation for the Hele-Shaw, Saffman-Taylor problem derived in the preceding work. Stationary solutions with no free phenomenological…
A differential equation for the Saffman-Taylor finger
G. Ka"lbermann
We develop a stream function approach for the horizontal Hele-Shaw, Saffman-Taylor finger. The model yields a nonlinear time-dependent differential equation. The finger widths deri…
The Sine-Gordon Wobble
German Ka"lbermann
Nonperturbative, oscillatory, winding number one solutions of the Sine-Gordon equation are presented and studied numerically. We call these nonperturbative shape modes {\sl wobble}…
A nonlinear differential approach to the Saffman-Taylor finger
G. Kälbermann, R. Wallach
Nonlinear time-dependent differential equations for the Hele-Shaw, Saffman-Taylor problem are derived. The equations are obtained using a separable ansatz expansion for the stream…
Diffraction of wave packets in space and time in three dimensions
G. Kälbermann
A simple formula for the scattering of wave packets from a square well at long times is derived. The expression shows that the phenomenon of wave packet diffraction in space and ti…