Dark Matter: A Hidden Threat to Neutron Stars ⚡ экспресс
We considered hydrostatic configurations of asymmetric fermionic dark matter spheres in multidimensional scenarios, where dark matter particles can propagate into extra spatial dimensions while Standard Model fields remain confined to a three-dimensional subspace. As the number of dimensions increases, the effective equation of state for nonrelativistic matter softens, and even small clumps of dark matter inside neutron stars become prone to gravitational collapse into black holes that live in the higher-dimensional space. These multidimensional black holes have longer lifetimes compared to ordinary ones and can accrete stellar material until the star is fully consumed, forming solar-mass black holes. Analysis using geometric interaction cross sections shows that dark matter with masses above O(10 TeV) can be ruled out already for more than two extra dimensions with sizes of O(fm). This result stands in stark contrast to the standard three-dimensional case, where comparable limits appear only for masses ≳10^5 TeV at a typical halo density of 0.3 GeV/cm³.
A neutron star is the compressed remnant of a sun: a mountain of matter the size of a thimble. If dark matter—the invisible substance that holds galaxies together—accumulates inside, under certain conditions it spells doom. In ordinary space, an incredible mass is needed, but hidden dimensions change the rules.
Gravity is curved spacetime, like a stretched trampoline. Dark matter particles, like tiny ball bearings, slightly dent it. Extra dimensions roll them into a leaden marble that tears the fabric—a black hole forms. Zwicky predicted neutron stars, Rubin proved the reality of dark matter; now their ideas converge in a terrifying scenario.
A twist: the miniature hole doesn't evaporate instantly—extra dimensions slow down the radiation. It devours the star whole, imposing strict limits on the properties of dark matter: particles heavier than tens of TeV are ruled out if the dimensions are real. In flat three-dimensional space, the threshold would be orders of magnitude higher—by millions.
🎯 Extra dimensions could be no larger than an atomic nucleus—about a femtometer, which is a billion times thinner than a hair.
🎬 Like in 'Interstellar,' where five-dimensional space helped survive a black hole—only here, hidden dimensions create that hole in the first place.