The search for dark matter ( DM ) is one of the most active and challenging areas of current research .
Possible DM candidates are ultralight fields such as axions and weak interacting massive particles ( WIMPs ) .
Axions piled up in the center of stars are supposed to generate matter/DM configurations with oscillating geometries at a very rapid frequency , which is a multiple of the axion mass m _ { B } [ Brito et al . ( 2015 ) ; Brito et al . ( 2016 ) ] .
Borra and Trottier ( 2016 ) recently found peculiar ultrafast periodic spectral modulations in 236 main sequence stars in the sample of 2.5 million spectra of galactic halo stars of the Sloan Digital Sky Survey ( \sim 1 \% of main sequence stars in the F–K spectral range ) that were interpreted as optical signals from extraterrestrial civilizations , suggesting them as possible candidates for the search for extraterrestrial intelligence ( SETI ) program .
We argue , instead , that this could be the first indirect evidence of bosonic axion-like DM fields inside main sequence stars , with a stable radiative nucleus , where a stable DM core can be hosted .
These oscillations were not observed in earlier stellar spectral classes probably because of the impossibility of starting a stable oscillatory regime due to the presence of chaotic motions in their convective nuclei .
The axion mass values , ( 50 < m _ { B } < 2.4 \times 10 ^ { 3 } ) ~ { } \mathrm { \mu eV } , obtained from the frequency range observed by Borra and Trottier , ( 0.6070 < f < 0.6077 ) THz , agree with the recent theoretical results from high-temperature lattice quantum chromodynamics [ Borsanyi et al . ( 2016 ) ; Borsanyi et al . ( 2016b ) ] .