The elusive ghost particle that might hold the universe's mass
In short: Neutrinos are nearly invisible particles that stream through your body by the billions every second. Because they rarely interact with normal matter, they share a striking resemblance to dark matter—the mysterious substance that makes up most of the universe's mass but remains almost entirely undetectable.
While both neutrinos and dark matter are characterized by their lack of interaction with light or electromagnetic radiation, physicists distinguish them primarily by their behavior in the early universe. Standard neutrinos are considered 'hot' dark matter because they move at relativistic speeds. This high velocity would prevent them from clumping together effectively enough to form the large-scale structures, like galaxies and clusters, that we observe today. These particles are produced when protons and electrons in a nucleus combine to form neutrons. This process releases most of the energy during a collapsing supernova.
However, a new mathematical model suggests a different possibility: the sterile neutrino. Unlike active neutrinos, which are produced in events like supernovae or solar fusion, sterile neutrinos do not interact via the weak force; they only interact through gravity. This makes them 'non-interacting' candidates for dark matter. To connect small neutrino masses with larger equivalents, a 'seesaw mechanism' is employed by a framework created by Arunansu Sil's research group at Guwahati's Indian Institute of Technology. The seesaw mechanism specifically predicts heavier counterparts for lightweight active neutrinos. These abundant particles currently stream out of our Sun.
The research suggests that these sterile neutrinos could have emerged after the Big Bang from the decay of elementary particles like W and Z bosons. Estimates from the group place the lightest sterile neutrino's mass within a kilo to mega electron-volt range. Beyond providing a candidate for dark matter, the model proposes that two other sterile neutrinos might explain one of physics' greatest mysteries: why the universe contains significantly more matter than antimatter. This model identifies these sterile neutrinos as contributing to the total mass of dark matter. The research team included physicists Arghyajit Datta and Rishav Roshan.
Opens the Intellect+ feed with this card first. Swipe up for the next one.
Sources
- Summary by Intellect · source: Are neutrinos dark matter? | Even Bananas
- Also: Neutrinos may solve the mystery of dark matter
To cite this card, link to https://intellectplus.co.uk/app/space-are-neutrinos-dark-matter-even-bananas.
How we source, check and correct cards: Editorial standards.
General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.
Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?
Related
More in Dark matter · More in Space · Latest · A–Z · All topics
