Messengers from the cosmos — what neutrinos tell us about the universe.
Cosmic neutrinos arriving from blazars, supernova explosions, and the Big Bang itself. Plus solar neutrinos, geo-neutrinos, and the multi-messenger revolution.
A tidal disruption event happens when a star wanders too close to a supermassive black hole and gets pulled apart. The aftermath blazes in light for months — and, in a small but growing number of cases, IceCube has caught neutrinos coincident in time and direction with the optical flare. This is one of the freshest chapters in neutrino astronomy.
Off Vancouver Island, physicists are designing a cubic-kilometre neutrino telescope that draws power and data straight from an existing seafloor cable. It would complete a planet-spanning detector network.
A decade after the first IceCube astrophysical detections, neutrino alerts have become a routine part of the global multi-messenger response. Here is how the system works in 2026 — who sends, who receives, what counts as a follow-up — and where neutrinos sit alongside photons and gravitational waves.
A single horizontal muon track in the Mediterranean, reconstructed at 30 times higher energy than anything previously observed. What it might mean — and what comes next.
For the first time, humanity has seen its own galaxy in neutrinos. IceCube's 2023 announcement: a diffuse glow of cosmic neutrinos tracing the galactic disk at 4.5σ significance.
A statistical analysis of 10 years of IceCube data revealed NGC 1068 — a relatively nearby Seyfert galaxy whose jet is not aimed at us — as the second identified extragalactic neutrino source.
September 22, 2017: a single IceCube alert triggered observations by 18 telescopes worldwide, identifying a flaring blazar as the first individually-resolved extragalactic cosmic neutrino source.
Two PeV-scale neutrino cascades detected by IceCube in 2012 established cosmic high-energy neutrinos as a real astrophysical phenomenon.
The three landmark multi-messenger events and what each one taught us. Plus what the next event might look like.
Why neutrinos are the most informative messenger of all — and the hardest to catch. What they can tell us that photons and gravitational waves cannot.
How LIGO and Virgo opened a new branch of astronomy — and what gravitational waves can and cannot tell us about compact-object mergers.
Why charged particles, despite being magnificent natural accelerators of energy, are limited messengers — and what they still tell us about the universe.
From radio to gamma rays — the foundational messenger of astronomy. How the electromagnetic spectrum lets us see, and what it can't tell us alone.
A single neutrino event in the Mediterranean Sea, with reconstructed energy 30 times higher than anything previously detected. What it means — and what it doesn't.
How astrophysical neutrinos with TeV to PeV energies trace the extreme accelerators of the universe — and how IceCube made cosmic neutrino astronomy a working science.
How a core-collapse supernova releases 99% of its energy as neutrinos in ten seconds — and how the diffuse glow of all past supernovae has shaped a new branch of neutrino astronomy.
How cosmic rays striking Earth's atmosphere produce a steady drizzle of neutrinos — and how studying those neutrinos led directly to the 1998 discovery of oscillation.
How the Sun produces neutrinos in fusion reactions in its core, what energy spectrum they have, and how each component has been measured experimentally over six decades.
In rural Mendoza Province, Argentina, an array of 1,660 water-Cherenkov tanks and 27 fluorescence telescopes covers an area larger than Rhode Island. The Pierre Auger Observatory has been the leading detector of ultra-high-energy cosmic rays for nearly two decades.
At about 5 × 10¹⁸ eV, the cosmic-ray spectrum flattens noticeably. The 'ankle' is the energy at which the dominant cosmic-ray sources transition from galactic accelerators to extragalactic ones — and from one set of neutrino-production scenarios to another.
When a neutron star is born spinning and magnetized, its rotational energy escapes as a wind of charged particles that piles up against the surrounding supernova ejecta. The resulting nebulae are some of the brightest gamma-ray sources in our galaxy — and they may be major cosmic-ray and neutrino accelerators.
Over the next decade, a network of telescopes at the South Pole and in the Chilean Andes will map the cosmic microwave background with unprecedented precision. Among the consequences: a measurement of the total neutrino mass to within 30 meV, possibly closing the question for good.
If ultra-high-energy cosmic rays really do come from extragalactic sources, then they must, on their way to Earth, produce a small but unavoidable flux of neutrinos at energies far higher than anything detected yet. Several experiments are now hunting for them.
In the late 2010s, astronomy quietly became a multi-messenger discipline. Cosmic events now generate alerts that send telescopes scrambling — and the combined information from light, neutrinos, and gravitational waves is producing answers that no single channel could give.
In 1960, Sheldon Glashow predicted that electron antineutrinos at exactly 6.3 PeV should annihilate with electrons through a W boson resonance. Sixty-one years later, IceCube caught one.
Every core-collapse supernova ever, anywhere in the universe, has released a torrent of neutrinos. Those neutrinos are still streaming through space. A new generation of detectors is finally close to seeing the accumulated glow.
In 2022, IceCube identified a nearby Seyfert galaxy as the second confirmed point source of high-energy cosmic neutrinos — and the first one that emits a steady glow rather than a transient flare.
At about 3 PeV of cosmic-ray energy, the spectrum of particles arriving at Earth steepens noticeably. The kink is called the 'knee.' It probably marks the upper limit of what our own galaxy's accelerators can produce — and therefore the upper limit on neutrinos of galactic origin.
On February 23, 1987, three underground detectors registered an unexplained burst of neutrinos within 23 seconds of each other. Three hours later, a telescope in Chile saw a supernova in the Large Magellanic Cloud. It was the first — and so far only — detection of neutrinos from a stellar explosion.
In September 2017, IceCube caught a 300-TeV neutrino arriving from a specific spot in the sky. Within hours, telescopes around the world traced it back to a flaring blazar four billion light-years away.
One second after the Big Bang, the universe became transparent to neutrinos. Those neutrinos are still here — about 336 per cubic centimeter — but no detector has yet seen them directly. Several experiments are trying.
After ten years of cosmic neutrino measurements, IceCube produced the first observation of neutrinos coming from our own Milky Way — a diffuse galactic glow at energies a million times higher than any star can produce.
About half of Earth's internal heat comes from radioactive decay. Geo-neutrino experiments at KamLAND and Borexino are slowly turning that fact into a measurement — and revealing the planet's hidden chemistry.
Solar neutrinos come from fusion in our own Sun at MeV energies; cosmic neutrinos come from distant accelerators across the universe at TeV-to-PeV energies. The same particle, vastly different sources and roles.
No. Neutrinos contribute only about 0.1-1% of the total dark matter in the universe. The rest is something else — most likely a yet-undiscovered particle. Both are 'invisible' but they're different physics.
In April 2013, the IceCube collaboration announced two extraordinarily energetic neutrinos, nicknamed after Sesame Street characters. They were the first cosmic neutrinos ever caught — and the start of high-energy neutrino astronomy.
Ray Davis's Homestake experiment kept finding only a third of the solar neutrinos the Sun should be sending. It took three decades and a Canadian heavy-water detector to figure out why.
A burst of two dozen neutrinos in 1987 confirmed half a century of theory in 13 seconds — and started a new branch of astronomy.
When a single high-energy neutrino was traced back to a faraway flaring galaxy in 2017, it opened a new way of looking at the universe. Here's where that story stands today.
Updated May 10, 07:01 PM UTC · 53 items aggregated
The scotogenic model defines a framework for radiative neutrino masses and provides a viable dark matter candidate. Since the scotogenic dark matter is leptophilic, indirect searches appear as an especially interesting…
We explore the coincidence of scales between cosmic inflation and right-handed neutrinos in seesaw models. We show that inflation models, which will be tested by next-generation CMB experiments, can produce…
Some high-mass stars likely end their lives in underluminous implosions that leave behind a black hole, known as failed supernovae (FSNe). However, neutrinos radiated during proto-neutron star formation generate a weak…
The singlet-doublet dark matter (SDDM) model is a well-motivated WIMP framework that accommodates viable dark matter over a broad range of parameter space. In this work, we explore the possibility of TeV-scale…
Neutrino processes are important in the modeling of supernova explosions, proto-neutron star evolution, and binary neutron star mergers. We study neutrino production and absorption in proto-neutron star and supernova…
The collapse of supermassive stars (SMSs, $M\gtrsim10^4\,M_\odot$) to black holes is accompanied by a prodigious flux of neutrinos of all flavors. These are produced thermally via $e^\pm$ annihilations, mostly in the…
Ultralight dark matter (ULDM) couplings to matter fields and ULDM self-interactions are typically treated as independent probes. However, since the ULDM-matter couplings unavoidably induce self-interactions through…
Particles that decouple relativistically from the Standard Model bath during reheating represent a versatile class of well-motivated cold dark matter candidates. In fact, ultrarelativistic decoupling ($T_{\rm FO}\gg…
In this talk I discuss how neutrinos might help solving or alleviating different anomalies and tensions in cosmology. Invisible decays of the heaviest relic neutrinos might provide a way to solve the neutrino mass…
The pristine underdense patches of the Universe, cosmic voids, are powerful cosmological laboratories, uniquely sensitive to dark energy, modified gravity, and neutrino masses, yet their baryonic content remains…
We simulate a self-interacting three-flavor neutrino system within a core-collapse supernova using a hybrid classical-quantum algorithm on a qutrit computer. Based on the Dirac-Frenkel evolution equations, we employ a…
We investigate the physical origin and location of high-energy neutrino emission in active galactic nuclei (AGN) using the blazar GB6 J1542+6129 as a case study, testing whether neutrinos are produced in compact…
Black holes are expected to end their lifetime in a burst of Hawking radiation, emitting all Standard Model particles at ultra-high energies. The evaporation of a nearby primordial black hole (PBH) has been proposed as…
We explore the possibility of explaining dark matter through six-dimensional (6D) primordial black holes (PBHs) in a theory with two extra dimensions. Interestingly, in this scenario the fundamental energy scale is of…
The KM3NeT research infrastructure instruments a large volume of seawater using photomultiplier tubes, which are sensitive to the Cherenkov radiation stimulated by the products of neutrino interactions in the water, as…
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