activity
20242026
collaborators

10 papers

astro-ph.CO2026

Pure Natural Inflation Passes the ACT

Cristóbal Zenteno Gatica, Alexandros Papageorgiou, Matteo Fasiello

Pure natural inflation is a compelling effectively single-field model of inflation stemming from a top-down approach to the acceleration mechanism. In this short letter we show tha…

hep-th2026

Tachyonic Encore: A universal shift of inflationary observables

Diogo S. Gorgulho, Margherita Putti, Rodrigo Gonzalez Quaglia +3

We propose a generic, largely inflaton-potential-independent mechanism in which a light axion spectator, initialized near the hilltop of its potential, reshapes inflationary observ…

astro-ph.CO2026

Primordial Gravitational Waves from Scalar Backreaction in Axion-SU(2) Inflation

Mattia Cielo, Ema Dimastrogiovanni, Matteo Fasiello +1

In this work, we perform the first numerical study of strong scalar backreaction in spectator chromo-natural inflation (SCNI) in the case where the spectator sector decays during i…

astro-ph.CO2025

Closing in on -attractors

Laura Iacconi, Sukannya Bhattacharya, Matteo Fasiello +1

Recent observations of cosmic microwave background (CMB) anisotropies combined with large-scale structure may point towards higher values of the scalar spectral index, . This…

astro-ph.CO2025

On the prospects of thermalization of axion-SU(2) inflation

Sukannya Bhattacharya, Matteo Fasiello, Alexandros Papageorgiou +1

Axion inflation models coupled to a gauge sector via a Chern-Simons term exhibit an array of interesting phenomenology including a chiral gravitational wave spectrum and primordial…

astro-ph.CO2025

Kinetic Fragmentation of the QCD Axion on the Lattice

Matteo Fasiello, Joanes Lizarraga, Alexandros Papageorgiou +1

Kinetic misalignment, one of the most compelling scenarios for the non-thermal generation of axion dark matter, is generally accompanied by axion fragmentation, a process in which…