Kartik Prabhu
@JeffreyM for some context:
The infrared structure here refers to the symmetries of asymptotic flat spacetimes given by the BMS group. This has been known for a long time in classical GR. Some recent work by Strominger relates these symmetries to the so-called “soft theorems” in scattering calculations (involving gravitons) in perturbative QFT. In essence, what it says is, since the BMS group is infinite-dimensional, there is an infinite-dimensional degeneracy in what one would like to call the “asymptotic ground state”.
How this shakes out for the information “paradox” remains to be seen.