@article{oai:oist.repo.nii.ac.jp:00002312,
 author = {Albrychiewicz, Emil and Neiman, Yasha and Tsulaia, Mirian},
 issue = {9},
 journal = {Journal of High Energy Physics},
 month = {Sep},
 note = {We study the scattering problem in the static patch of de Sitter space, i.e. the problem of field evolution between the past and future horizons of a de Sitter observer. We formulate the problem in terms of off-shell fields in Poincare coordinates. This is especially convenient for conformal theories, where the static patch can be viewed as a flat causal diamond, with one tip at the origin and the other at timelike infinity. As an important example, we consider Yang-Mills theory at tree level. We find that static-patch scattering for Yang-Mills is subject to BCFW-like recursion relations. These can reduce any staticpatch amplitude to one with N-1MHV helicity structure, dressed by ordinary Minkowski amplitudes. We derive all the N-1MHV static-patch amplitudes from self-dual Yang-Mills field solutions. Using the recursion relations, we then derive from these an infinite set of MHV amplitudes, with arbitrary number of external legs.},
 title = {MHV amplitudes and BCFW recursion for Yang-Mills theory in the de Sitter static patch},
 volume = {2021},
 year = {2021}
}