Orateur
ALESSIO NOTARI
(Universita di Roma Sapienza)
Description
I will present a framework to reproduce any cosmological background via energy exchange between dark energy and dark matter, where a quintessence field controls the DM mass. This setup achieves a phantom-crossing background without introducing ghosts. As a proof of concept, I will reproduce the background that best fits the recent DESI+CMB+DESY5 data. While the background expansion is identical, the perturbations differ, altering late-time structure growth while preserving early-universe predictions. I will discuss the resulting $\mathcal{O}(10\%)$ signatures in the matter power spectrum, CMB lensing, and the ISW effect, which provide clear, testable signatures for future surveys.
Auteur
ALESSIO NOTARI
(Universita di Roma Sapienza)