If gravitational waves formed interference patterns, or just simply interfere as normal waves, couldn't that result in gravitational anomalies in absence of mass? Destructive interference could be thought of as negative gravity(dark energy), leading to expansive "forces", whilst constructive interference could emulate the presence of mass, i.e. dark matter. And perhaps the current shapes of galaxies are due to some resonance effect. Sorry if I'm reviving some old discussion, or got the wrong forum section. I got this idea after reading an article about dark matter on physorg and I'm just curious if anyone has pursued this train of thought before, if it's a valid one. My knowledge is thoroughly limited and my approach is "by the ear", so I may have just proposed something very silly.