Oscillatory sound pulses, with or without axial angular momentum, localized in space and time.

Lekner, John · Phys Rev E · 2025

Where this comes from

Abstract

Results are given for the exact energy and momentum of a family of oscillatory pulses. The pulses are characterized by a length a and a dominant wave number K. Pulses with angular momentum about the direction of propagation are also discussed. The total energy, momentum, and angular momentum of all pulses are simply expressed as integrals over a wave-number weight function, and evaluated explicitly for the Ka family. For large Ka the speed of sound times the net momentum tends to the total energy from below.