68 citations · 220 across the 13 of their papers we have counts for
13 papers
Ultra slow-turn inflation
Ana Achúcarro, Perseas Christodoulidis, Jinn-Ouk Gong +1
In standard multi-field models, tachyonic isocurvature perturbations generally indicate the presence of an instability. We revisit the stability of some known counterexamples and s…
Gravitational open effective field theory of inflation
Perseas Christodoulidis, Jinn-Ouk Gong
We construct a gravitational open extension of the effective field theory of inflation in the Schwinger-Keldysh framework. While physical symmetries allow many open operators in th…
Emergent structures in open EFTs
Perseas Christodoulidis
Open effective field theories provide a systematic framework for describing systems coupled to an environment, where dissipation, noise, and modified conservation laws naturally ar…
Robust non-minimal attractors in many-field inflation
Perseas Christodoulidis, Robert Rosati, Evangelos I. Sfakianakis
Multi-field inflation can be inherently non-predictive, with the exception of models with strong attractors. In this work, we focus on models with multiple scalar fields that are n…
New shape for cross-bispectra in Chern-Simons gravity
Perseas Christodoulidis, Jinn-Ouk Gong, Wei-Chen Lin +2
Chern-Simons gravity is known to suffer from graviton ghost production during inflation, which suppresses the parity-violating power spectrum at scales relevant to cosmic microwave…
Enhanced power spectra from multi-field inflation
Perseas Christodoulidis, Jinn-Ouk Gong
We investigate the enhancement of the power spectra large enough to produce primordial black holes in models with multiple scalar fields. We present analytic solutions for the pert…
(Slow-)Twisting inflationary attractors
Perseas Christodoulidis, Robert Rosati
We explore in detail the dynamics of multi-field inflationary models. We first revisit the two-field case and rederive the coordinate independent expression for the attractor solut…
-field cosmology in hyperbolic field space: stability and general solutions
Perseas Christodoulidis, Andronikos Paliathanasis
We study the dynamics of a cosmological model with a perfect fluid and fields on a hyperbolic field space interacting via a symmetric potential. We list all late-time…
Many-field Inflation: Universality or Prior Dependence?
Perseas Christodoulidis, Diederik Roest, Robert Rosati
We investigate the observational signatures of many-field inflation and present analytic expressions for the spectral index as a function of the prior. For a given prior we employ…
Scaling attractors in multi-field inflation
Perseas Christodoulidis, Diederik Roest, Evangelos I. Sfakianakis
Multi-field inflation with a curved scalar geometry has been found to support background trajectories that violate the slow-roll, slow-turn conditions and thus have the potential t…
Attractors, Bifurcations and Curvature in Multi-field Inflation
Perseas Christodoulidis, Diederik Roest, Evangelos I. Sfakianakis
Recent years have seen the introduction of various multi-field inflationary scenarios in which the curvature and geodesics of the scalar manifold play a crucial role. We outline a…
General solutions to -field cosmology with exponential potentials
Perseas Christodoulidis
We construct the general analytical solution for the -field product-exponential potential in an expanding FLRW background. We demonstrate the relevance of this analyti…
Angular inflation in multi-field -attractors
Perseas Christodoulidis, Diederik Roest, Evangelos I. Sfakianakis
We explore the dynamics of multi-field models of inflation in which the field-space metric is a hyperbolic manifold of constant curvature. Such models are known as -attractors a…