9 March 2026
Joan Najita (NOIRLab) and Andrea Muñoz-Gutiérrez (UNAM)
Two DESI scientists were recently awarded first place in the 2025 Annual Review of Nuclear and Particle Science Video Contest for their contribution, “Neutrino masses, from ghost particles to cosmological tensions,” which explains DESI’s results on the neutrino mass. We sat down with the winners, Hernán Noriega and Bernardita Ried Guachalla, to learn more about their research interests and their contest experience.
Q: Can you tell us a little about your research interests?
Hernán: My research focuses on the large-scale structure of the Universe. I work on perturbation theory and effective field theory methods to model galaxy clustering, with a particular emphasis on how massive neutrinos shape cosmic structure formation. More recently, I’ve also been exploring modified gravity scenarios.
Berni: My research interests scrutinize fundamental questions about our Universe: What is the physical origin and evolution of the cosmos? What astrophysical knowledge can be inferred from astronomical surveys? What are dark matter and dark energy? And more specifically, what can we learn from the cosmic microwave background data when combining it with observations of the large-scale structure?
Q: Can you tell us about the video contest you entered?
Hernán: The contest was organized by Annual Reviews as part of the Annual Review of Nuclear and Particle Science (ARNPS). The goal was to encourage early-career researchers to translate cutting-edge nuclear or particle physics into a short, engaging, and accessible video for a broad audience. Participants submitted brief videos explaining a concept they have expertise in, and the winning entries were selected to be featured by Annual Reviews to reach researchers, educators, and science enthusiasts. More details about the contest are available on the ARNPS Video Contest page.
Q: What ideas and messages were you hoping share with the public? The idea of a negative neutrino mass seems crazy!
Berni: The video explores one of the most intriguing questions in modern physics: the total neutrino mass. Once thought massless, neutrinos are now known to have mass, but recent results from cosmology suggest limits so tight they even hint at “negative” values. We explain what neutrinos are, how oscillation and direct experiments like KATRIN measure their mass, and why cosmology offers a powerful but indirect probe. Current results from DESI, Planck, ACT, and SPT push constraints to unprecedented levels, exposing tensions between particle physics and cosmology. Could this mean that neutrinos hold the key to new physics, or even a revision of the ΛCDM model?
Q: What was DESI’s role in these results?
Hernán: DESI provides extremely precise measurements of large-scale structure through galaxy redshift surveys. These data tighten cosmological constraints by improving our handle on the expansion history and the growth of structure, which in turn helps constrain parameters like the sum of neutrino masses when combined with CMB datasets. Importantly, DESI can also place competitive neutrino-mass constraints on its own, with minimal external inputs, providing an independent cross-check that can be directly compared against other probes.
Q: …And you won first place! What was your reaction?
Hernán: I was truly thrilled…. especially because we are proud of the final result. We had a strong feeling it could do well, and after the final edit we thought the video was genuinely compelling. Winning first place was incredibly exciting.
Berni: Since I saw the contest I thought that we could win it. Hernán is a great colleague who knows a lot about neutrinos and he was visiting Stanford when we decided to do it. It was an amazing experience which allowed us to further explore ways of communicating DESI results in a different format.
To learn more, see Bernadita and Hernán’s 5-minute prize winning video, available here.
