I would like this Journal Club to be a discussion between Amplitudes-type people and Cosmology people! I will present some stuff on the board to begin with but would like to open the floor halfway through to get input from others. Feel free to add content to this section if you have a relevant paper which people may want to read up on beforehand.
Topic:
In particle physics, there are 'Soft Theorems' of Goldstone Bosons, which are relations between correlation functions of operators in which one or more of the external momenta is 'soft' i.e. it's magnitude is much less than the magnitude of the other 'hard' external momenta. I would like to know how other people use soft limits in their work.
These soft limits also arise in Cosmology, when one considers soft limits of correlations of the comoving curvature perturbation. I would like to review the relevant cosmology to bring everyone up to speed on this.
I think this is a cool area and would like to work on it in the future, and perhaps this is a good area of overlap for our group!
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