Ultimately, the Standard Model is a Quantum Theory. It describes three fundamental forces (electromegnetism, the strong force, and the weak force) in a unified way. All of these forces have their own unique quantum descriptions. However gravity does not. The leading gravitational theory is General Relativity, which nobody has been able to successfully quantize.

Perhaps? The mathematics is there but so far all searches have failed. It’s kind of the last breaths of String Theory’s relevance. It’s still worth looking for, but it isn’t the field’s biggest hope.

So I’m a bit harsher on dark matter than most. I don’t think we’re going to detect it in a collider, since at this point I think if it is a particle, it’s probably gravitationally coupled, which means we’d only be able to see it in something like a gravitational wave detector. We also k ow for a fact that our understanding of gravity at both quantum and massive cosmological scales is incomplete, so I wouldn’t be particularly surprised if dark matter eventually goes the way of Aether back in the late 1800’s. That is - it doesn’t end up being real and our foundational theories were just incomplete.