Outputs (5)

Soft theorems for boostless amplitudes (2024)
Journal Article
Du, Z.-Z., & Stefanyszyn, D. (2024). Soft theorems for boostless amplitudes. Journal of High Energy Physics, 2024(7), Article 11. https://doi.org/10.1007/jhep07%282024%29011

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 derive constraints that must be satisfied by the corresponding scattering... Read More about Soft theorems for boostless amplitudes.

Cosmological correlators through the looking glass: reality, parity, and factorisation (2024)
Journal Article
Stefanyszyn, D., Tong, X., & Zhu, Y. (2024). Cosmological correlators through the looking glass: reality, parity, and factorisation. Journal of High Energy Physics, 2024, Article 196. https://doi.org/10.1007/jhep05%282024%29196

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 Universe are purely real when the external states are massless sca... Read More about Cosmological correlators through the looking glass: reality, parity, and factorisation.

The graviton four-point function in de Sitter space (2023)
Journal Article
Bonifacio, J., Goodhew, H., Joyce, A., Pajer, E., & Stefanyszyn, D. (2023). The graviton four-point function in de Sitter space. Journal of High Energy Physics, 2023(6), Article 212. https://doi.org/10.1007/jhep06%282023%29212

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 derive this result in several ways: by direct calculation, using the in-in... Read More about The graviton four-point function in de Sitter space.

Parity violation in the scalar trispectrum: no-go theorems and yes-go examples (2023)
Journal Article
Cabass, G., Jazayeri, S., Pajer, E., & Stefanyszyn, D. (2023). Parity violation in the scalar trispectrum: no-go theorems and yes-go examples. Journal of High Energy Physics, 2023(2), Article 21. https://doi.org/10.1007/jhep02%282023%29021

We derive a set of no-go theorems and yes-go examples for the parity-odd primordial trispectrum of curvature perturbations. We work at tree-level in the decoupling limit of the Effective Field Theory of Inflation and assume scale invariance and a Bun... Read More about Parity violation in the scalar trispectrum: no-go theorems and yes-go examples.

On graviton non-Gaussianities in the Effective Field Theory of Inflation (2022)
Journal Article
Cabass, G., Stefanyszyn, D., Supeł, J., & Thavanesan, A. (2022). On graviton non-Gaussianities in the Effective Field Theory of Inflation. Journal of High Energy Physics, 2022(10), Article 154. https://doi.org/10.1007/JHEP10%282022%29154

We derive parity-even graviton bispectra in the Effective Field Theory of Inflation (EFToI) to all orders in derivatives. Working in perturbation theory, we construct all cubic interactions that can contribute to tree-level graviton bispectra, showin... Read More about On graviton non-Gaussianities in the Effective Field Theory of Inflation.