7 papers
All Tree-Level Massive Cosmological Correlators via Spectral Gluing
Jonathan Gräfe, Denis Werth
Massive cosmological correlators exhibit a rich hypergeometric structure already at tree level, reflecting the distorted propagation of particles in de Sitter spacetime. In this pa…
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…
Universal Non-Gaussian Signatures from Transient Instabilities
Shuntaro Aoki, Diederik Roest, Denis Werth
We identify universal signatures in the bispectrum arising from a transient tachyonic instability of entropic fluctuations during inflation, a phenomenon that naturally arises in h…
The Exact and Approximate Tales of Boost-Breaking Cosmological Correlators
Zhehan Qin, Sébastien Renaux-Petel, Xi Tong +2
Cosmological correlators offer a remarkable window into the high-energy physics governing Universe's earliest moments, with the tantalising prospect of discovering new particles. H…
Reconstructing Primordial Curvature Perturbations via Scalar-Induced Gravitational Waves with LISA
Jonas El Gammal, Aya Ghaleb, Gabriele Franciolini +17
Many early universe scenarios predict an enhancement of scalar perturbations at scales currently unconstrained by cosmological probes. These perturbations source gravitational wave…