One of the most promising dark matter candidates are light particles, like axions. With JWST, we can rule out many of those options already.
All throughout the Universe, there’s a massive puzzle whose solution remains unknown: the dark matter mystery. Within every large, high-mass system that we examine, including:
- spiral galaxies,
- elliptical galaxies,
- groups of galaxies,
- clusters of galaxies,
- cosmic filaments,
- and the large-scale cosmic web,
there simply isn’t enough normal matter to explain the gravitational signals we observe. From the internal motions of galaxies to the relative motions of galaxies within a cluster to the gravitational lensing signals generated by these objects to the clustering patterns of galaxies on the largest of cosmic scales, some novel type of mass that neither absorbs nor emits light — dark matter — must be present to consistently explain what we observe.
And yet, all of our efforts to directly detect dark matter have come up empty, with key signals from particle colliders, cosmic ray experiments, and possible signatures of…