4 papers
Large deviations for halos and voids: beyond perturbative non-gaussianities
Martin Teuscher, Ruth Durrer, Julien Grain +2
The excursion-set formalism provides a key connection between primordial density fluctuations and the abundance of cosmic structures such as dark matter halos and voids, traditiona…
Recoherence, adiabaticity, and Markovianity in Gaussian maps
Dimitrios Kranas, Julien Grain, Vincent Vennin
Motivated by the recent discovery of situations where cosmological fluctuations recohere during inflation, we investigate the relationship between quantum recoherence (late-time pu…
Separate universe in multifield inflation: a phase-space approach
Julien Grain, Hugo Holland
In this article we extend a study of the validity conditions of the separate-universe approach of cosmological perturbations to models of inflation with multiple fields. The separa…
Hamiltonian formalism for cosmological perturbations: fixing the gauge
Danilo Artigas, Julien Grain, Vincent Vennin
Cosmological perturbation theory is an example of a gauge theory, where gauge transformations correspond to changes in the space-time coordinate system. To determine physical quant…