Subleading Chern-Simons soft factors in perturbative de Sitter

@misc{chattopadhyay2026subleading,
  title = {{Subleading Chern-Simons soft factors in perturbative de Sitter}},
  author = {Pratik Chattopadhyay and Avi Wadhwa},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2605.05130},
  eprint = {2605.05130},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.05130},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Subleading Chern-Simons soft factors in perturbative de Sitter
AU  - Pratik Chattopadhyay
AU  - Avi Wadhwa
PY  - 2026
DA  - 2026/11/01
PB  - arXiv
DO  - 10.48550/arxiv.2605.05130
UR  - https://arxiv.org/abs/2605.05130
AB  - Chern--Simons perturbations introduce corrections to soft theorems for gauge theories at subleading 𝒪(ω^0) order in soft momenta. We investigate these soft theorems in flat spacetime with perturbative 1/ℓ^2 de Sitter corrections. Following previous works, we define the perturbative scattering matrix in a compact region in the static patch of de Sitter. We start with computing the soft theorem for an n-gluon amplitude in pure Yang--Mills. We then add a Chern--Simons perturbation and compute the correction to the subleading soft theorem. We show that Chern--Simons corrections do not mix with the 1/ℓ^2 de Sitter curvature corrections at subleading order 𝒪(ω^0). Alternatively, one can say that the subleading Chern--Simons soft factors are insensitive to the de Sitter curvature at this order, indicating their topological nature at the level of amplitudes. This also suggests a universal behavior of these Chern--Simons soft factors.
ER  -