PIRSA:22010087

De Sitter scattering amplitudes in the Born approximation

APA

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

MLA

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

BibTex

          @misc{ pirsa_22010087,
            doi = {},
            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.