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If I understand this right, they are hypothesizing that a super high energy photon encountering a magnetic field near its origin supernova got converted into a
by throwaway81523 4y ago
If I understand this right, they are hypothesizing that a super high energy photon encountering a magnetic field near its origin supernova got converted into a dark matter particle. That let it travel 2.4 billion light years to earth without interacting with stray photons during that intergalactic journey. Then somewhere near here, it hit another magnetic field and got converted back to a normal photon that set off all our detectors.
Does that mean we get hit with unconverted dark matter particles all the time? Do they just sail through the earth, like neutrinos supposedly do most of the time? Could they be converted to regular photons using magnetic fields? Could we reproduce the conversion to and from dark matter in the LHC, which reaches comparable energy levels to this photon? This is big brain stuff, I guess.
- andrewflnr 4y agoI'm confused at the magnetic field aspect. The point of dark matter is that it doesn't interact electromagnetically, at least not strongly. Is the idea that this interaction is such a rare one that it has escaped all the earth-based experiments so far?
- throwaway81523 4y agoIt sounded like this interaction was special because of the super high energy of the photon and the super strong magnetic field near the supernova. At lower energies there would not have been an interaction. Presumably another occasion when those conditions existed was the Big Bang. So a lot of the universe's dark matter would have been created then, under this picture.
- lamontcg 4y agoAxions can't be perfectly dark matter, they're very weakly interacting with electrons and the EM field. They would be the Higgs field of the strong force (Axions were initially also named a "higglet") and would be an electrically neutral scalar particle like the Higgs, and that would interact with magnetic fields by the Primakoff effect: https://en.wikipedia.org/wiki/Primakoff_effect https://en.wikipedia.org/wiki/Primakoff_effect
- throwaway81523 4y agoRight, it said "axion-like particle" as distinct from an axion.
- ssivark 4y agoYes. Dark matter is typically modeled as approximately dark… dark enough to have evaded experiments so far, and bright enough to have a footprint on phenomena (newly) observed at a fine level of sensitivity. I’m glossing over important technical details, but roughly imagine that anything can typically interact with electromagnetism at least indirectly/weakly (very difficult to screen absolutely).