401 citations · 3.9k across the 71 of their papers we have counts for
27 papers · 1 filter
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…
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…
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 Univers…
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…
Loops in inflation with strongly non-geodesic motion
Sebastian Garcia-Saenz, Yizhou Lu, Sébastien Renaux-Petel
We study loop corrections in the effective field theory of inflation with imaginary speed of sound, which has been shown to provide an effective description of multi-field inflatio…
Non-perturbative Wavefunction of the Universe in Inflation with (Resonant) Features
Paolo Creminelli, Sébastien Renaux-Petel, Giovanni Tambalo +1
We study the statistics of scalar perturbations in models of inflation with small and rapid oscillations in the inflaton potential (resonant non-Gaussianity). We do so by deriving…
Parity Violation from Emergent Non-Locality During Inflation
Sadra Jazayeri, Sébastien Renaux-Petel, Xi Tong +2
Parity violation in the early universe holds great promise for uncovering new physics. In particular, the primordial scalar four-point correlation function is allowed to develop a…
Shapes of the Cosmological Low-Speed Collider
Sadra Jazayeri, Sébastien Renaux-Petel, Denis Werth
Massive particles produced during inflation leave specific signatures in soft limits of correlation functions of primordial fluctuations. When the Goldstone boson of broken time tr…
Cosmological Flow of Primordial Correlators
Denis Werth, Lucas Pinol, Sébastien Renaux-Petel
Correlation functions of primordial density fluctuations provide an exciting probe of the physics governing the earliest moments of our Universe. However, the standard approach to…
Cosmological Bootstrap in Slow Motion
Sadra Jazayeri, Sébastien Renaux-Petel
Speed matters. How the masses and spins of new particles active during inflation can be read off from the statistical properties of primordial density fluctuations is well understo…
Inflationary flavor oscillations and the cosmic spectroscopy
Lucas Pinol, Shuntaro Aoki, Sébastien Renaux-Petel +1
Inflationary scenarios motivated by high-energy physics generically contain a plethora of degrees of freedom beyond the primordial curvature perturbation. The latter interacts in a…
Turning in the landscape: a new mechanism for generating Primordial Black Holes
Jacopo Fumagalli, Sébastien Renaux-Petel, John W. Ronayne +1
We propose a new model-independent mechanism for producing primordial black holes from a period of multi-field inflation. This requires an enhancement of primordial fluctuations at…
Revisiting non-Gaussianity in multifield inflation with curved field space
Sebastian Garcia-Saenz, Lucas Pinol, Sébastien Renaux-Petel
Recent studies of inflation with multiple scalar fields have highlighted the importance of non-canonical kinetic terms in novel types of inflationary solutions. This motivates a th…
Hyper non-Gaussianities in inflation with strongly non-geodesic motion
Jacopo Fumagalli, Sebastian Garcia-Saenz, Lucas Pinol +2
Several recent proposals to embed inflation into high-energy physics rely on inflationary dynamics characterized by a strongly non-geodesic motion in negatively curved field space.…
Flattened non-Gaussianities from the effective field theory of inflation with imaginary speed of sound
Sebastian Garcia-Saenz, Sébastien Renaux-Petel
Inflationary perturbations in multi-field theories can exhibit a transient tachyonic instability as a consequence of their non-trivial motion in the internal field space. When an e…
Aspects of massive gravity
Sébastien Renaux-Petel
We report here on two works on Lorentz invariant massive gravity. In the first part, we derive the decoupling limit of massive gravity on de Sitter, relying on embedding de Sitter…
On the Vainshtein mechanism in the minimal model of massive gravity
Sebastien Renaux-Petel
We reinvestigate the fate of the Vainhstein mechanism in the minimal model of dRGT massive gravity. As the latter is characterised by the complete absence of interactions in the de…
Massive Gravity on de Sitter and Unique Candidate for Partially Massless Gravity
Claudia de Rham, Sebastien Renaux-Petel
We derive the decoupling limit of Massive Gravity on de Sitter in an arbitrary number of space-time dimensions d. By embedding d-dimensional de Sitter into d+1-dimensional Minkowsk…
Combined local and equilateral non-Gaussianities from multifield DBI inflation
Sébastien Renaux-Petel
We study multifield aspects of Dirac-Born-Infeld (DBI) inflation. More specifically, we consider an inflationary phase driven by the radial motion of a D-brane in a conical throat…
Multifield Cosmological Perturbations at Third Order and the Ekpyrotic Trispectrum
Jean-Luc Lehners, Sébastien Renaux-Petel
Using the covariant formalism, we derive the equations of motion for adiabatic and entropy perturbations at third order in perturbation theory for cosmological models involving two…
Multi-field DBI inflation: introducing bulk forms and revisiting the gravitational wave constraints
David Langlois, Sebastien Renaux-Petel, Daniele A. Steer
We study multi-field Dirac-Born-Infeld (DBI) inflation models, taking into account the NS-NS and R-R bulk fields present in generic flux compactifications. We compute the second-or…