@physicists, this seems highly innovative, and highly interesting. What do you think?

This particular paper I haven’t read (it’s 62 pages long), but it seems to be using amplituhedron to compute cosmological quantities.

The amplituhedron is a powerful mathematical book-keeping device (similar to the Feynman diagrams in particle physics) that allows really complex equations to be represented in a much simpler form. However, it itself carries no physics - it’s just a new way of representing the mathematics. It seems that they used this formalism to perform some cosmological computations that was previously too challenging to tackle.

Note that the first author, Nima Arkani-Hamed (who also invented the amplituhedron), is not just any random physicist. He is probably the most well respected astroparticle physicist alive at the moment.

Can you give us a high level primer? How does it represent the math?