Snowmass2021 - Letter of interest cosmology intertwined IV: The age of the universe and its curvature


Eleonora Di Valentino, The University of Manchester
Luis A. Anchordoqui, City University of New York
Özgür Akarsu, İstanbul Teknik Üniversitesi
Yacine Ali-Haimoud, New York University
Luca Amendola, Universität Heidelberg
Nikki Arendse, Niels Bohr Institute
Marika Asgari, The University of Edinburgh
Mario Ballardini, Alma Mater Studiorum Università di Bologna
Spyros Basilakos, National Observatory of Athens
Elia Battistelli, Sapienza Università di Roma
Micol Benetti, Università degli Studi di Napoli Federico II
Simon Birrer, Stanford University
François R. Bouchet, Sorbonne Universite
Marco Bruni, Institute of Cosmology and Gravitation
Erminia Calabrese, Cardiff University
David Camarena, Federal University of Espirito Santo
Salvatore Capozziello, Università degli Studi di Napoli Federico II
Angela Chen, University of Michigan, Ann Arbor
Jens Chluba, The University of Manchester
Anton Chudaykin, Institute for Nuclear Research
Eoin Colgáin, Asia Pacific Center for Theoretical Physics (APCTP)
Francis Yan Cyr-Racine, The University of New Mexico
Paolo de Bernardis, Sapienza Università di Roma
Javier de Cruz Pérez, Universitat de Barcelona
Jacques Delabrouille, Commissariat a L'Energie Atomique CEA
Celia Escamilla-Rivera, Universidad Nacional Autónoma de México
Agnès Ferté, Jet Propulsion Laboratory
Fabio Finelli, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
Wendy Freedman, The University of Chicago
Noemi Frusciante, Lisboa
Elena Giusarma, Michigan Technological UniversityFollow
Adrià Gómez-Valent, Universität Heidelberg

Document Type


Publication Date



Department of Physics


A precise measurement of the curvature of the Universe is of prime importance for cosmology since it could not only confirm the paradigm of primordial inflation but also help in discriminating between different early-Universe scenarios. Recent observations, while broadly consistent with a spatially flat standard Λ Cold Dark Matter (ΛCDM) model, show tensions that still allow (and, in some cases, even suggest) a few percent deviations from a flat universe. In particular, the Planck Cosmic Microwave Background power spectra, assuming the nominal likelihood, prefer a closed universe at more than 99% confidence level. While new physics could be at play, this anomaly may be the result of an unresolved systematic error or just a statistical fluctuation. However, since positive curvature allows a larger age of the Universe, an accurate determination of the age of the oldest objects provides a smoking gun in confirming or falsifying the current flat ΛCDM model.

Publication Title

Astroparticle Physics