Cursed technique Limitless: (Convergence) Negative energy is used with his CT to SLOW things down TOWARDS him infinitesimally - this is his base technique.

Cursed technique reversal Red: (Divergence) Positive energy does the complete opposite and SPEEDS things up at an “infinite” rate AWAY from him (red). It makes sense because when you use RCT you are reversing the effects of ur cursed technique. The technique reverses, from slowing down towards gojo (base technique), to speeding up away from him (red). This is how Jogo got sent flying all the way to the forest.

Cursed technique amplification Blue: He uses negative energy to amplify limitless and creates a void. Then the universe immediately recognises this foreign space and creates a violent pull force to fill the void.

Hollow technique Purple: The foreign space created from amplification is being ripped apart by the infinity that has been brought into reality via red. It’s hard to explain but if you constantly rip space infinitely, ur left with nothing, nothing cannot be defined so it’s imaginary mass. And because this a manga full of cool characters he gets to shoot that imaginary mass off like a projectile, deleting anything it comes into contact with. This is just an observation, but I think his six eyes plays a crucial role in this as he needs to use the exact same amount of negative and positive energy. Think of it as 5-5=0. The two numbers representing positive and negative energy used for red and blue respectively, and the 0 representing the imaginary mass. With the six eyes allowing him to precisely manipulate his powers as well as controlling it at an atomic level, he is able to output the same amount cursed energy for red and blue to make purple.