Role of the neutral X-fermion in describing the dark matter of the universe
Abstract Decades of progress culminating in the optical interferometry developed in the Keck Observatory and VLT GRAVITY facility led to the determination of the mass of the compact object in Sgr A* in $$4.3\times 10^6 \,M_{\odot }$$ 4.3 × 10 6 M ⊙ and firm limits on its angular momentum. The most s...
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SpringerOpen
2025-07-01
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| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-025-14404-6 |
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| author | Remo Ruffini Gregory Vereshchagin |
| author_facet | Remo Ruffini Gregory Vereshchagin |
| author_sort | Remo Ruffini |
| collection | DOAJ |
| description | Abstract Decades of progress culminating in the optical interferometry developed in the Keck Observatory and VLT GRAVITY facility led to the determination of the mass of the compact object in Sgr A* in $$4.3\times 10^6 \,M_{\odot }$$ 4.3 × 10 6 M ⊙ and firm limits on its angular momentum. The most straightforward interpretation of these observations is a Schwarzschild black hole (BH). Considering that the S cluster of stars orbiting the Galactic Center does not probe distances closer than 1400 its Schwarzschild radius, several alternatives were proposed. Among them the self-gravitating system of Dark Matter (DM) fermions (here referred to as X-fermion) having a quantum degenerate core and extended to non-degenerate isothermal halo. Application of this model to our Galaxy results in a bound on X-fermion mass $$m_X>56$$ m X > 56 keV. Upon accreting baryonic matter the degenerate fermionic core may collapse into a BH providing seeds to Active Galactic Nuclei (AGNs) and SuperMassive Black Holes (SMBHs). We address the implications of DM X-fermions with mass $$m_X\sim 300$$ m X ∼ 300 keV endowed with a large and negative chemical potential here evaluated on structure formation and its evolution with redshift. The Jeans mass of X-fermions peaks at $$10^{10}\,M_{\odot }$$ 10 10 M ⊙ at redshift $$z\sim 10^9$$ z ∼ 10 9 , which sets the scale of galactic structures. The degenerate cores forming as early as $$z\sim 14$$ z ∼ 14 are consistent with recent observations of the James Web Space Telescope (JWST) disclosing the Little Red Dots (LRDs) at cosmological redshifts $$4<z<12$$ 4 < z < 12 harboring SMBHs in the range $$10^6\text{- }10^9\,M_{\odot }$$ 10 6 - 10 9 M ⊙ . Assuming that Sgr A* is not yet a BH, the lower limit on SMBH mass of $$4.3\times 10^6 \,M_{\odot }$$ 4.3 × 10 6 M ⊙ and the corresponding upper limit on the X-fermion mass of $$m_X<381$$ m X < 381 keV are established, which acquires relevance given ongoing JWST observations of the Galactic Center and the planning of new accelerators for the scrutiny of DM in CERN. |
| format | Article |
| id | doaj-art-0aed172c3b674eeb9305575f876f2f82 |
| institution | Kabale University |
| issn | 1434-6052 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | SpringerOpen |
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| series | European Physical Journal C: Particles and Fields |
| spelling | doaj-art-0aed172c3b674eeb9305575f876f2f822025-08-20T03:46:29ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60522025-07-018571810.1140/epjc/s10052-025-14404-6Role of the neutral X-fermion in describing the dark matter of the universeRemo Ruffini0Gregory Vereshchagin1ICRANetICRANetAbstract Decades of progress culminating in the optical interferometry developed in the Keck Observatory and VLT GRAVITY facility led to the determination of the mass of the compact object in Sgr A* in $$4.3\times 10^6 \,M_{\odot }$$ 4.3 × 10 6 M ⊙ and firm limits on its angular momentum. The most straightforward interpretation of these observations is a Schwarzschild black hole (BH). Considering that the S cluster of stars orbiting the Galactic Center does not probe distances closer than 1400 its Schwarzschild radius, several alternatives were proposed. Among them the self-gravitating system of Dark Matter (DM) fermions (here referred to as X-fermion) having a quantum degenerate core and extended to non-degenerate isothermal halo. Application of this model to our Galaxy results in a bound on X-fermion mass $$m_X>56$$ m X > 56 keV. Upon accreting baryonic matter the degenerate fermionic core may collapse into a BH providing seeds to Active Galactic Nuclei (AGNs) and SuperMassive Black Holes (SMBHs). We address the implications of DM X-fermions with mass $$m_X\sim 300$$ m X ∼ 300 keV endowed with a large and negative chemical potential here evaluated on structure formation and its evolution with redshift. The Jeans mass of X-fermions peaks at $$10^{10}\,M_{\odot }$$ 10 10 M ⊙ at redshift $$z\sim 10^9$$ z ∼ 10 9 , which sets the scale of galactic structures. The degenerate cores forming as early as $$z\sim 14$$ z ∼ 14 are consistent with recent observations of the James Web Space Telescope (JWST) disclosing the Little Red Dots (LRDs) at cosmological redshifts $$4<z<12$$ 4 < z < 12 harboring SMBHs in the range $$10^6\text{- }10^9\,M_{\odot }$$ 10 6 - 10 9 M ⊙ . Assuming that Sgr A* is not yet a BH, the lower limit on SMBH mass of $$4.3\times 10^6 \,M_{\odot }$$ 4.3 × 10 6 M ⊙ and the corresponding upper limit on the X-fermion mass of $$m_X<381$$ m X < 381 keV are established, which acquires relevance given ongoing JWST observations of the Galactic Center and the planning of new accelerators for the scrutiny of DM in CERN.https://doi.org/10.1140/epjc/s10052-025-14404-6 |
| spellingShingle | Remo Ruffini Gregory Vereshchagin Role of the neutral X-fermion in describing the dark matter of the universe European Physical Journal C: Particles and Fields |
| title | Role of the neutral X-fermion in describing the dark matter of the universe |
| title_full | Role of the neutral X-fermion in describing the dark matter of the universe |
| title_fullStr | Role of the neutral X-fermion in describing the dark matter of the universe |
| title_full_unstemmed | Role of the neutral X-fermion in describing the dark matter of the universe |
| title_short | Role of the neutral X-fermion in describing the dark matter of the universe |
| title_sort | role of the neutral x fermion in describing the dark matter of the universe |
| url | https://doi.org/10.1140/epjc/s10052-025-14404-6 |
| work_keys_str_mv | AT remoruffini roleoftheneutralxfermionindescribingthedarkmatteroftheuniverse AT gregoryvereshchagin roleoftheneutralxfermionindescribingthedarkmatteroftheuniverse |