Sunny Vagnozzi

Sunny Vagnozzi is an Italian cosmologist. He is an associate professor at the University of Trento.^[1][2]

Vagnozzi is known for his contributions at the interface of cosmology, particle physics, and astrophysics, with a primary focus on determining the fundamental nature of dark matter and dark energy. He has been awarded the Buchalter Cosmology Prize for his work on dark energy,^[3] is the recipient of the 2023 SIGRAV Prize,^[4] and has been included in the Clarivate Highly Cited Researchers list in 2025.^[5] Additionally, he is an editor of the journal Physics of the Dark Universe.^[6]

Vagnozzi earned a Bachelor of Science in Physics from the University of Trento in 2012, followed by a Master of Science in Physics from the University of Melbourne in 2014. Later in 2019, he completed a Ph.D. in Theoretical Physics from Stockholm University.^[7]

Following his PhD, Vagnozzi joined the Kavli Institute for Cosmology at the University of Cambridge as a Newton-Kavli Fellow.^[8] In 2022, he returned to the University of Trento, where he has served as assistant professor until 2025, when he received tenure and was promoted to associate professor.^[1]

Vagnozzi's work has been highlighted by various news websites and science magazines, including Science, Science News, Quanta Magazine, New Scientist, National Geographic (Poland), Esquire, Forbes, and Scientific American.^{[9][10][11][12][13][14][15][16]}

Vagnozzi has worked on a broad array of problems at the interface of cosmology and astroparticle physics. His work has contributed to investigating the nature of dark matter and dark energy,^[17][18] testing cosmic inflation,^[19][20] determining the shape of the universe,^[21] understanding the origins of cosmic tensions (including the Hubble tension),^[22][18] using black hole observations to test gravity and fundamental physics,^[23] and searching for signatures of neutrino masses in cosmological observations.^[24] Additionally, his research has identified new ways for detecting dark energy in experiments on Earth,^[25] and has proposed new techniques for testing gravity and searching for fifth forces by analyzing asteroid trajectories.^[26] As of 2025, his work has been cited more than 14,000 times, with an h-index of 61, according to Google Scholar.^[2]

• 2021 – Alfredo di Braccio Prize, Accademia dei Lincei
• 2022 – Buchalter Cosmology Prize (third prize)^[3]
• 2022 – Marie Skłodowska-Curie Fellowship
• 2023 – SIGRAV Prize^[4]
• 2025 – Clarivate Highly Cited Researcher^[5]

Vagnozzi is first cousin of tennis coach and former tennis player Simone Vagnozzi.^[27][28]

He has stated that his research interests have been strongly influenced by Philip Pullman's His Dark Materials trilogy.^[27]

• Foot, R., & Vagnozzi, S. (2015). Dissipative hidden sector dark matter. Physical Review D, 91(2), 023512. https://doi.org/10.1103/PhysRevD.91.023512
• Vagnozzi, S., Giusarma, E., Mena, O., Freese, K., Gerbino, M., Ho, S., & Lattanzi, M. (2017). Unveiling ν secrets with cosmological data: Neutrino masses and mass hierarchy. Physical Review D, 96(12), 123503. https://doi.org/10.1103/PhysRevD.96.123503
• Vagnozzi, S. (2020). New physics in light of the H₀ tension: An alternative view. Physical Review D, 102(2), 023518. https://doi.org/10.1103/PhysRevD.102.023518
• Vagnozzi, S. (2020). Implications of the NANOGrav results for inflation. Monthly Notices of the Royal Astronomical Society Letters, 502(1), L11–L15. https://doi.org/10.1093/mnrasl/slaa203
• Vagnozzi, S., Loeb, A., & Moresco, M. (2021). Eppur è piatto? The Cosmic Chronometers Take on Spatial Curvature and Cosmic Concordance. Astrophysical Journal, 908(1), 84. https://doi.org/10.3847/1538-4357/abd4df
• Vagnozzi, S., Visinelli, L., Brax, P., Davis, A.-C., & Sakstein, J. (2021). Direct detection of dark energy: The XENON1T excess and future prospects. Physical Review D, 104(6), 063023. https://doi.org/10.1103/PhysRevD.104.063023
• Vagnozzi, S., & Loeb, A. (2022). The Challenge of Ruling Out Inflation via the Primordial Graviton Background. Astrophysical Journal Letters, 939(2), L22. https://doi.org/10.3847/2041-8213/ac9b0e
• Vagnozzi, S., Roy, R., Tsai, Y.-D., Visinelli, L., Afrin, M., Allahyari, A., Bambhaniya, P., Dey, D., Ghosh, S. G., Joshi, P. S., Jusufi, K., Khodadi, M., Walia, R. K., Övgün, A., & Bambi, C. (2023). Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A*. Classical and Quantum Gravity, 40(16), 165007. https://doi.org/10.1088/1361-6382/acd97b
• Vagnozzi, S. (2023). Seven Hints That Early-Time New Physics Alone Is Not Sufficient to Solve the Hubble Tension. Universe, 9(9), 393. https://doi.org/10.3390/universe9090393
• Tsai, Y.-D., Farnocchia, D., Micheli, M., Vagnozzi, S., & Visinelli, L. (2024). Constraints on fifth forces and ultralight dark matter from OSIRIS-REx target asteroid Bennu. Communications Physics, 7(1), 311. https://doi.org/10.1038/s42005-024-01779-3