[notaustinpowers]

No, they are not caused by the galactic filaments. We don't know exactly yet what all is causing gravitational wave background (GWB), but a theory is that it could be caused by supermassive black holes, or primordial black holes from the early universe, etc.

[Zoadian]

I asked the reverse. If the filaments are caused by gravitational waves.

[notaustinpowers]

No to that as well. The galactic filaments are just aggregations of gravitationally-massive objects in space.