PIRSA:22010087 Scientific Series Quantum Gravity

DOI10.48660/22010087

Series: Quantum Gravity

Ripken, C. (2022). De Sitter scattering amplitudes in the Born approximation. Perimeter Institute. https://pirsa.org/22010087

Ripken, Chris. De Sitter scattering amplitudes in the Born approximation. Perimeter Institute, Jan. 20, 2022, https://pirsa.org/22010087 

@misc{ pirsa_PIRSA:22010087,
  doi = {10.48660/22010087},
  url = {https://pirsa.org/22010087},
  author = {Ripken, Chris},
  keywords = {Quantum Gravity},
  language = {en},
  title = {De Sitter scattering amplitudes in the Born approximation},
  publisher = {Perimeter Institute},
  year = {2022},
  month = {jan},
  note = {PIRSA:22010087 see, \url{https://pirsa.org}}
}

Abstract

A basic calculation in QFT is the construction of the Yukawa potential from a tree-level scattering amplitude. In the massless limit, this reproduces the 1/r potential. For gravity, scattering mediated by a massless graviton is thus consistent with the Newtonian potential.

In de Sitter spacetime, the cosmological constant gives rise to a mass-like term in the graviton propagator. This raises the question what the classical potential looks like when taking into account curvature effects.

In this talk, I will introduce an operator-based formalism to compute scattering amplitudes in curved spacetime, and I will show how to construct the Newtonian potential in a dS background. Remarkably, the potential gives rise to an additional repulsive force, and encodes the de Sitter horizon in a novel and non-trivial way.

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