38 citations · 89 across the 7 of their papers we have counts for
15 papers · 1 filter
Massive Spinning Fields During Inflation: Feynman rules and correlator comparison
Trevor Cheung, David Stefanyszyn
We consider the dynamics of massive spinning fields during inflation and the resulting signatures in the cosmological correlators of inflaton perturbations computed in the Poincaré…
New Exceptional EFTs in de Sitter Space from Generalised Energy Conservation
Zong-Zhe Du, David Stefanyszyn
We discover a surprising relationship between exceptional effective field theories (EFTs) in de Sitter space and a notion of \textit{generalised energy conservation} (GEC) of an S-…
A Match Made in Heaven: Linking Observables in Inflationary Cosmology
David Stefanyszyn, Xi Tong, Yuhang Zhu
Cosmological correlation functions of inflaton and graviton perturbations are the fundamental observables of early universe cosmology and remain a primary target for observations.…
Soft Theorems for Boostless Amplitudes
Zongzhe Du, David Stefanyszyn
We consider effective field theories (EFTs) of scalar fields with broken Lorentz boosts, which arise by taking the decoupling and flat-space limits of the EFT of inflation, and der…
Cosmological Correlators Through the Looking Glass: Reality, Parity, and Factorisation
David Stefanyszyn, Xi Tong, Yuhang Zhu
We consider the evolution of quantum fields during inflation, and show that the total-energy singularities appearing in the perturbative expansion of the late-time Wavefunction of…
The graviton four-point function in de Sitter space
James Bonifacio, Harry Goodhew, Austin Joyce +2
We compute the tree-level late-time graviton four-point correlation function, and the related quartic wavefunction coefficient, for Einstein gravity in de Sitter spacetime. We deri…