Astronomers observe the Radcliffe Wave oscillating
phys.org
phys.org
> A few years ago, astronomers uncovered one of the Milky Way's greatest secrets: An enormous, wave-shaped chain of gaseous clouds in our sun's backyard, giving birth to clusters of stars along the spiral arm of the galaxy we call home.
Tldr: the clouds both look like a wave and move like waves too (analogized to wave-like motions in stadiums). Which is pretty neat. They speculate it's because of gravitational interactions.
visible matter moving interacting with specific dark matter gravitational sources, in effect static wrt the galactic rotation of the visible, would explain the "origin" sought.
I.e., don't need oscillation to continue, but it's a premise for how it got started.