Here is a very good talk by Sean Carroll on Dark Matter and or modifying Einstein's General Relativity.
https://www.youtube.com/watch?v=4uogQiH5Yx4
This is a very good talk as well on Quantum Field Theory.
https://www.youtube.com/watch?v=gEKSpZPByD0
The Universe consists of Quantum Fields rather than particles.
Bert