About

Professor Graciela Gelmini has been working on astro-particle physics, especially in the problem of dark matter, where she has studied different dark matter particle candidates. She is also interested in different aspects of the physics of neutrinos. Her educational background includes a Ph.D. from U. Nacional de La Plata, obtained in 1981.

Research topics

• Optics
• Physics
• Quantum mechanics
• Atomic physics
• Particle physics

Selected publications

• Multiple populations of the same sterile neutrino as dark matter

  Journal of Cosmology and Astroparticle Physics · 2026-05-01

  preprintOpen access

  Abstract Sterile neutrinos produced in the early Universe that mix with active neutrinos of the Standard Model are typically considered to consist of a single population resulting from one dominant production mechanism. We show that the same sterile neutrino species can naturally emerge with multiple population components, yielding a multi-modal relic momentum spectrum. We consider four distinct production scenarios: active-sterile non-resonant oscillations following resonant oscillations in the presence of a primordial lepton asymmetry, gravitational production through sterile neutrinogenesis from populations of evaporating primordial black holes, and heavy singlet Higgs or inflaton decays combined with non-resonant active-sterile oscillations or neutrinogenesis. We identify sterile neutrino mass ranges where colder and warmer populations can be present and contribute non-negligibly to the dark matter relic abundance. We discuss some potential consequences of such a multi-population framework.

  PublisherDOI

• Gravitational wave detection with plasma haloscopes

  Physical review. D/Physical review. D. · 2025-09-09 · 9 citations

  articleOpen access

  Searches for high frequency gravitational waves using cavities based on the Gertsenshtein effect were recently proposed, building off existing axion dark matter experiments. In particular, the sensitivity of axion dark matter experiments using metamaterial plasmas (tunable plasma haloscopes) to gravitational waves has not been explored in detail. Here we perform a full analysis of gravitational wave detection in plasma haloscopes, showing that the baseline design of experiments such as ALPHA is several orders of magnitude less sensitive than previously thought. We show how simple changes to the experiment can recover that sensitivity and lead to a powerful gravitational wave detector in the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi mathvariant="script">O</a:mi><a:mo stretchy="false">(</a:mo><a:mn>10</a:mn><a:mi>–</a:mi><a:mn>50</a:mn><a:mo stretchy="false">)</a:mo><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi>GHz</a:mi></a:math> frequency range.

  PublisherOA PDFDOI

• Spin-dependent dark matter interactions at loop-level in Ar and Xe

  Journal of Cosmology and Astroparticle Physics · 2025-04-01

  articleOpen access

  Abstract Xenon and argon are the two noble gases used in tonne scale dark matter direct detection experiments. We compare the detection capability of both target elements for interactions due to a pseudoscalar mediator including loop-level contributions to the cross section. At tree-level this type of interaction depends on the nuclear spin and would thus not be detectable in argon-based detectors, since Ar has spin zero. However, at the loop-level the same interaction yields spin-independent contributions that would be detectable in an argon target and are not negligible with respect to the tree-level interactions in xenon, because these are momentum suppressed. In fact, the loop-level contributions are also important for xenon-based experiments at low recoil energies, which could change their discovery reach for this interaction.

  PublisherDOI

• Primordial black hole sterile neutrinogenesis: sterile neutrino dark matter production independent of couplings

  Journal of Cosmology and Astroparticle Physics · 2024-07-01 · 10 citations

  article

  Abstract Sterile neutrinos ( ν s s) are well-motivated and actively searched for hypothetical neutral particles that would mix with the Standard Model active neutrinos. They are considered prime warm dark matter (DM) candidates, typically when their mass is in the keV range, although they can also be hot or cold DM components. We discuss in detail the characteristics and phenomenology of ν s s that minimally couple only to active neutrinos and are produced in the evaporation of early Universe primordial black holes (PBHs), a process we called “PBH sterile neutrinogenesis”. Contrary to the previously studied ν s production mechanisms, this novel mechanism does not depend on the active-sterile mixing. The resulting ν s s have a distinctive spectrum and are produced with larger energies than in typical scenarios. This characteristic enables ν s s to be WDM in the unusual 0.3 MeV to 0.3 TeV mass range, if PBHs do not matter-dominate the Universe before evaporating. When PBHs matter-dominate before evaporating, the possible coincidence of induced gravitational waves associated with PBH evaporation and astrophysical X-ray observations from ν s decays constitutes a distinct signature of our scenario.

  PublisherDOI

• Spin-dependent dark matter interactions at loop-level in Ar and Xe

  arXiv (Cornell University) · 2024-08-24

  preprintOpen access

  Xenon and argon are the two noble gases used in tonne scale dark matter direct detection experiments. We compare the detection capability of both target elements for interactions due to a pseudoscalar mediator including loop-level contributions to the cross section. At tree-level this type of interaction depends on the nuclear spin and would thus not be detectable in argon-based detectors, since Ar has spin zero. However, at the loop-level the same interaction yields spin-independent contributions that would be detectable in an argon target and are not negligible with respect to the tree-level interactions in xenon, because these are momentum suppressed. In fact, the loop-level contributions are also important for xenon-based experiments at low recoil energies, which could change their discovery reach for this interaction.

  PublisherOA PDFDOI

• Primordial black hole neutrinogenesis of sterile neutrino dark matter

  Physics Letters B · 2024-03-27 · 13 citations

  articleOpen accessCorresponding

  Sterile neutrinos are well-motivated and actively searched for new particles that would mix with the active neutrinos. We study their phenomenology when they are produced in the evaporation of early Universe black holes, a novel production mechanism that differs from all others and does not depend on the active-sterile mixing. The resulting hotter sterile neutrinos have a distinct spectrum and could be warm dark matter in the 0.3 MeV to 0.3 TeV mass range, distinct from the typical keV range. The possible coincidence of X-rays and gravitational waves is a unique novel signature of our scenario.

  PublisherDOI

• Primordial black hole dark matter from catastrogenesis with unstable pseudo-Goldstone bosons

  arXiv (Cornell University) · 2023-03-24

  preprintOpen access1st authorCorresponding

  We propose a new scenario for the formation of asteroid-mass primordial black holes (PBHs). Our mechanism is based on the annihilation of the string-wall network associated with the breaking of a $U(1)$ global symmetry into a discrete $Z_N$ symmetry. If the potential has multiple local minima ($N&gt;1$) the network is stable, and the annihilation is guaranteed by a bias among the different vacua. The collapse of the string-wall network is accompanied by catastrogenesis, a large production of pseudo-Goldstone bosons (pGBs) -- e.g. axions, ALPs, or majorons -- gravitational waves, and PBHs. If pGBs rapidly decay into products that thermalize, as predicted e.g. in the high-quality QCD axion and heavy majoron models, they do not contribute to the dark matter population, but we show that PBHs can constitute 100\% of the dark matter. The gravitational wave background produced by catastrogenesis with heavy unstable axions, ALPs, or majorons could be visible in future interferometers.

  PublisherOA PDFDOI

• Halo-independent dark matter electron scattering analysis with in-medium effects

  Physics Letters B · 2023-04-19 · 10 citations

  articleOpen access

  Dark matter (DM)-electron scattering is a prime target of a number of direct DM detection experiments and constitutes a promising avenue for exploring interactions of DM in the sub-GeV mass-range, challenging to probe with nuclear recoils. We extend the recently proposed halo-independent analysis method for DM-electron scattering, which allows to infer the local DM halo properties without any additional assumptions about them, to include in-medium effects through dielectric functions of the target material. We show that in-medium effects could significantly affect halo-independent analysis response functions for germanium and silicon and thus are essential for proper inference of local DM halo characteristics from direct DM detection data.

  PublisherDOI

• Primordial black hole dark matter from catastrogenesis with unstable pseudo-Goldstone bosons

  Journal of Cosmology and Astroparticle Physics · 2023-06-01 · 35 citations

  articleOpen access1st authorCorresponding

  Abstract We propose a new scenario for the formation of asteroid-mass primordial black holes (PBHs). Our mechanism is based on the annihilation of the string-wall network associated with the breaking of a U(1) global symmetry into a discrete Z N symmetry. If the potential has multiple local minima ( N &gt; 1) the network is stable, and the annihilation is guaranteed by a bias among the different vacua. The collapse of the string-wall network is accompanied by catastrogenesis , a large production of pseudo-Goldstone bosons (pGBs) — e.g. axions, ALPs, or majorons — gravitational waves, and PBHs. If pGBs rapidly decay into products that thermalize, as predicted e.g. in the high-quality QCD axion and heavy majoron models, they do not contribute to the dark matter population, but we show that PBHs can constitute 100% of the dark matter. The gravitational wave background produced by catastrogenesis with heavy unstable axions, ALPs, or majorons could be visible in future interferometers.

  PublisherOA PDFDOI

• Catastrogenesis with unstable ALPs as the origin of the NANOGrav 15 yr gravitational wave signal

  Physics Letters B · 2023-11-24 · 17 citations

  articleOpen access1st authorCorresponding

  In post-inflation axion-like particle (ALP) models, a stable domain wall network forms if the model's potential has multiple minima. This system must annihilate before dominating the Universe's energy density, producing ALPs and gravitational waves (a process we dub “catastrogenesis,” or “creation via annihilation”). We examine the possibility that the gravitational wave background recently reported by NANOGrav is due to catastrogenesis. For the case of ALP decay into two photons, we identify the region of ALP mass and coupling, just outside current limits, compatible with the NANOGrav signal.

  PublisherDOI

Frequent coauthors

• D. Allard

  Laboratoire AstroParticule et Cosmologie

  127 shared

• C. Lachaud

  Centre National de la Recherche Scientifique

  116 shared

• D. Semikoz

  Laboratoire AstroParticule et Cosmologie

  101 shared

• S. Dagoret-Campagne

  Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

  82 shared

• M. D. Rodríguez-Friás

  80 shared

• J. N. Capdevielle

  Université Paris Cité

  78 shared

• C. Blaksley

  RIKEN

  70 shared

• Alexander Kusenko

  67 shared