http://arxiv.org/abs/2210.15983
In our previous work [Tamburini and Licata (2017)] we discussed the hypothesis that the ultrafast periodic spectral modulations with frequency $f_S \simeq 0.61$ THz found by Borra and Trottier (2016) in $236$ main sequence stars from a sample of $2.5$ million spectra of galactic halo stars of the Sloan Digital Sky Survey were due to axion-like dark matter piled up in the center of these stars. These temporary matter/dark matter structures are characterized by a spacetime geometry rapidly oscillating at frequencies that depend on the axion mass $m_a$ [Brito {\it et~al.} (2015); Brito {\it et~al.} (2016)]. Borra (2013) found two additional frequencies, $ f_{1,G} \simeq 9.5$ THz and $f_{2,G} \simeq 8.9$ THz, in the Sloan dataset of galaxies, redshifted by the cosmological expansion and, for any redshift value, $f_S + f_{2,G} = f_{1,G}$ is found. Hippke (2019) showed that $f_{2,G}$ is spurious and introduced by the data analysis procedure due to the nonrandom spacing of the spectral absorption lines. This was not even found by Isaacson (2019) when re-observed four of these stars with different instrumentation and data reduction procedure. Interestingly, Hippke found $f_S$ in the solar spectrum but not in the Kurucz (2005) artificial solar spectrum whilst its spectral power estimated by Isaacson resulted below the accepted error $(1\%)$. From these results, we discuss the validity of our ansatz by analyzing the common features present in all the spectra. In the worst case, if all the three frequencies are not real the oscillating axion core models is not valid. Assuming, instead, the validity of $f_S$ from the results from the analysis of the solar spectra, those oscillating modes may be transient modes favoring the axion hypothesis in the mass range $(10^{- 3} < m_a < 2.4 \times 10^{3})~ \mathrm{\mu eV}$, also according to the recent limits from the gamma ray burst GRB221009A.
F. Tamburini and I. Licata
Mon, 31 Oct 22
44/60
Comments: 9 pages, 1 table