4 papers
The separate universe approach with non minimal coupling to gravity
Hugo Holland, Julien Grain
In this paper we extend a study of the validity conditions of the separate universe approach of cosmological perturbations to models of inflation with multiple fields that are non…
Explicit gauge-invariant variables in multifield inflation beyond linear order and Hamiltonian dynamics
Julien Grain, Hugo Holland, Lucas Pinol
General relativity coupled to multiple scalar fields is a diffeomorphism-invariant constrained system. Consequently, a naive counting of the perturbative degrees of freedom unavoid…
Further Comments on Yablo's Construction
Karl Schlechta
We continue our analysis of Yablo's coding of the liar paradox by infinite acyclic graphs. The present notes are based on and continue the author's previous results on the problem.…
The Separate Universe approach for multifield inflation models
Hugo Holland
Primordial black holes could constitute part or all of dark matter but they require large inhomogeneities to form in the early universe. These inhomogeneities can strongly backreac…