Low-redshift IGM measured to be extremely hot (T0 ≈ 28,000 K) and nearly isothermal at z=0.1, with Gamma_HI lower than UV-background models, possibly due to 15 km/s turbulence.
Constraining the mass of light bosonic dark matter using SDSS Lyman-$\alpha$ forest
10 Pith papers cite this work. Polarity classification is still indexing.
abstract
If a significant fraction of the dark matter in the Universe is made of an ultra-light scalar field, named fuzzy dark matter (FDM) with a mass $m_a$ of the order of $10^{-22}-10^{-21}$ eV, then its de Broglie wavelength is large enough to impact the physics of large scale structure formation. In particular, the associated cut-off in the linear matter power spectrum modifies the structure of the intergalactic medium (IGM) at the scales probed by the Lyman-$\alpha$ forest of distant quasars. We study this effect by making use of dedicated cosmological simulations which take into account the hydrodynamics of the IGM. We explore heuristically the amplitude of quantum pressure for the FDM masses considered here and conclude that quantum effects should not modify significantly the non-linear evolution of matter density at the scales relevant to the measured Lyman-$\alpha$ flux power, and for $m_a \geq 10^{-22}$ eV. We derive a scaling law between $m_a$ and the mass of the well-studied thermal warm dark matter (WDM) model that is best adapted to the Lyman-$\alpha$ forest data, and differs significantly from the one infered by a simple linear extrapolation. By comparing FDM simulations with the Lyman-$\alpha$ flux power spectra determined from the BOSS survey, and marginalizing over relevant nuisance parameters, we exclude FDM masses in the range $10^{-22} \leq m_a < 2.3\times 10^{-21}$ eV at 95 % CL. Adding higher-resolution Lyman-$\alpha$ spectra extends the exclusion range up to $2.9\times 10^{-21}$ eV. This provides a significant constraint on FDM models tailored to solve the "small-scale problems" of $\Lambda$CDM.
citation-role summary
citation-polarity summary
years
2026 10representative citing papers
A semiclassical tunneling model shows that two-field ultralight DM halos have stability bounds that can be relaxed for some density-mass ratios but become more stringent across much of the parameter space compared to single-field cases.
Stochastic inflationary fluctuations cannot supply the large dark-Higgs displacement required for broad parametric resonance production of vector dark matter, but a classically sourced Hubble-induced minimum can, with distinct relic scaling and consistency conditions.
An EFT-based field-level forward model for the Lyman-alpha forest matches simulations at the percent level on quasi-linear scales and generates mocks for DESI and DESI-II analyses.
Vortex reconnections in BEC/superfluid dark-matter cores can transfer at most 0.06–4.5% of the virial energy in 10 Gyr under fiducial assumptions, so they cannot appreciably restructure the core.
Lyman-alpha forest data yield m_FDM > 1.9e-21 eV (95% CL) for pure FDM and f_FDM upper limits of 0.07-0.65 for mixed FDM at log10(m_FDM/eV) = -23 to -21.
New upper limits on ultralight axion dark matter fraction (<1.5% at 10^{-26} eV, <9% at 10^{-25} eV at 95% CL) from combined CMB lensing data, plus marginal 2.1σ preference at 10^{-24.5} eV driven by few points.
Self-interaction bounds from cosmology constrain ultralight dark matter couplings to neutrinos, electrons, and light quarks via unavoidable quantum loop corrections.
MUST is a new 6.5 m telescope designed to deliver simultaneous optical spectra for over 20,000 targets across a 5 deg² field, enabling the largest 3D spectroscopic map of the Universe with redshifts for more than 100 million objects over an 8-year survey.
Fisher forecasts indicate joint post-reionization LSS cross-spectra and CMB-S4-like data can reach O(10^{-4}) uncertainty on ultra-light axion fraction for m_a ≲ 10^{-28} eV, with peak sensitivity near 10^{-25} eV.
citing papers explorer
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A Measurement of the Thermal and Ionization State of the IGM at $z < 0.5$
Low-redshift IGM measured to be extremely hot (T0 ≈ 28,000 K) and nearly isothermal at z=0.1, with Gamma_HI lower than UV-background models, possibly due to 15 km/s turbulence.
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Tunneling and tidal stripping in multifield ultralight dark matter halos
A semiclassical tunneling model shows that two-field ultralight DM halos have stability bounds that can be relaxed for some density-mass ratios but become more stringent across much of the parameter space compared to single-field cases.
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Parametric Resonance of Higgsed Vector Dark Matter: Inflationary Initial Conditions and Sourced Displacements
Stochastic inflationary fluctuations cannot supply the large dark-Higgs displacement required for broad parametric resonance production of vector dark matter, but a classically sourced Hubble-induced minimum can, with distinct relic scaling and consistency conditions.
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Lyman-Alpha Forest and its Cross-Correlation with High-Redshift Galaxies in Effective Field Theory at the Field Level
An EFT-based field-level forward model for the Lyman-alpha forest matches simulations at the percent level on quasi-linear scales and generates mocks for DESI and DESI-II analyses.
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Vortex-reconnection energy bounds in Bose-Einstein-condensed and superfluid dark matter halos
Vortex reconnections in BEC/superfluid dark-matter cores can transfer at most 0.06–4.5% of the virial energy in 10 Gyr under fiducial assumptions, so they cannot appreciably restructure the core.
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Lyman-$\alpha$ forest constraints on pure and mixed fuzzy dark matter
Lyman-alpha forest data yield m_FDM > 1.9e-21 eV (95% CL) for pure FDM and f_FDM upper limits of 0.07-0.65 for mixed FDM at log10(m_FDM/eV) = -23 to -21.
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The Atacama Cosmology Telescope: Probing new signatures of ultralight axions with gravitational lensing
New upper limits on ultralight axion dark matter fraction (<1.5% at 10^{-26} eV, <9% at 10^{-25} eV at 95% CL) from combined CMB lensing data, plus marginal 2.1σ preference at 10^{-24.5} eV driven by few points.
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Self-Interaction Bounds on Ultralight Dark Matter Couplings to Matter
Self-interaction bounds from cosmology constrain ultralight dark matter couplings to neutrinos, electrons, and light quarks via unavoidable quantum loop corrections.
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From Large Telescopes to the MUltiplexed Survey Telescope (MUST)
MUST is a new 6.5 m telescope designed to deliver simultaneous optical spectra for over 20,000 targets across a 5 deg² field, enabling the largest 3D spectroscopic map of the Universe with redshifts for more than 100 million objects over an 8-year survey.
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Tracing Ultra Light Axions in Post-reionization, Lyman-$\alpha$ and CMB Missions
Fisher forecasts indicate joint post-reionization LSS cross-spectra and CMB-S4-like data can reach O(10^{-4}) uncertainty on ultra-light axion fraction for m_a ≲ 10^{-28} eV, with peak sensitivity near 10^{-25} eV.