🗑️ 🧵 Help me understand particle physics

Anonymous at Sat, 23 Mar 2024 10:02:20 UTC No. 16092349

So im trying to get a grasp on particle physics and many textbooks say something along the lines of "elementary particles correspond to irreducible unitary representations of the Lorentz group".
Now, the most common representation of this group is just the old Lorentz transformation matrices, but this is just one out of infinite possible representations, out of which only some are unitary, some are irreducible and even less are unitary and irreducible. All of these sets are infinite anyway.
Well, how do you actually find these? And related, why are these specific representations said to represent elementary particles?
I try to follow the explanations in textbooks and internet articles but they go too fast and skip over details. I get the Lorentz group is related to SU(2) x SU(2) but i get lost in the details, i need this explained like a friend would i he sat with you for an hour to explain you a difficult topic. Any help would be greatly appreciated.