Résumé / Abstract Journal-club_GReCO

Séminaire / Seminar GReCO

« Harvesting primordial black holes from stochastic trees with FOREST »

Pierre Auclair
Institut d'Astrophysique de Paris (Paris, France)

Starting with the basic principles of the stochastic inflation formalism
-- an effective theory for the long-wavelengths of quantum fields during
inflation -- I introduce a novel framework to implement stochastic
inflation on stochastic trees, modelling the inflationary expansion as a
branching process. This new approach allows us to generate real-space
maps of the curvature perturbation that fully capture quantum diffusion
and its non-perturbative backreaction during inflation. Unlike lattice
methods, trees do not proceed on a fixed background since new spacetime
units emerge dynamically as trees unfold, naturally incorporating metric
fluctuations. The usage of stochastic trees offers remarkable numerical
efficiency, and I developed the FOrtran Recursive Exploration of
Stochastic Trees (FOREST) tool to demonstrate the performance of this
approach. I show how primordial black holes blossom at unbalanced nodes
of the trees, and how their mass distribution can be obtained while
automatically accounting for the "cloud-in-cloud" effect.
lundi 12 janvier 2026 - 14:00
Salle des séminaires Évry Schatzman
Institut d'Astrophysique de Paris
Pages web du séminaire / Seminar's webpage