6 papers
Analytical Cosmological Collider at Strong Mixing in Laplace Space
Nathan Belrhali, Arthur Poisson, Sébastien Renaux-Petel
Primordial non-Gaussianities are at their largest when the curvature perturbation is coupled to a massive field by a mixing too strong to be treated perturbatively. We show that th…
Cosmological Correlators in KLF and the Double-Exchange
Nathan Belrhali, Arthur Poisson, Sébastien Renaux-Petel
In this work, we present the procedure to find series representations of tree-level cosmological correlators using the Kontorovich-Lebedev-Fourier (KLF) space formalism. This frame…
Massive Cosmological Correlators from Flat Space: a Laplace-Space Approach
Nathan Belrhali, Arthur Poisson, Sébastien Renaux-Petel
We develop a new approach to cosmological correlators, built on a simple physical fact: deep inside the Hubble radius every mode oscillates as a flat-space plane wave, the curvatur…
Laplace Space for Cosmological Correlators
Nathan Belrhali, Arthur Poisson, Sébastien Renaux-Petel
Deep inside the horizon, every cosmological mode oscillates as a flat-space plane wave. A Laplace transform turns this fact into a general method: it resolves each curved-space mod…
De Sitter Momentum Space
Nathan Belrhali, Arthur Poisson, Sébastien Renaux-Petel +1
We construct a natural and nonperturbative momentum space for quantum field theory on -dimensional de Sitter (dS) spacetime in the Poincaré slicing, adapted to early Univer…
Kontorovich-Lebedev-Fourier Space for de Sitter Correlators
Nathan Belrhali, Arthur Poisson, Sébastien Renaux-Petel +1
In this work, we build a novel frequency-momentum space for -dimensional de Sitter (dS) correlators from first principles. This construction follows directly from the decomp…