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| Main Authors: | , , , , , |
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| Format: | Preprint |
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2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2512.07933 |
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| _version_ | 1866912968096088064 |
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| author | Marcuzzo, Elena Porciani, Cristiano Romano-Díaz, Emilio Dizgah, Azadeh Moradinezhad Khatri, Prachi Viel, Matteo |
| author_facet | Marcuzzo, Elena Porciani, Cristiano Romano-Díaz, Emilio Dizgah, Azadeh Moradinezhad Khatri, Prachi Viel, Matteo |
| contents | The nature of dark matter (DM) is still debated. While cold DM (CDM) is the standard paradigm, warm DM (WDM) may ease some small-scale tensions in the $Λ$CDM framework. Line-intensity mapping (LIM) offers a novel probe of DM properties. To explore the potential of LIM surveys in constraining the WDM particle mass ($m_\mathrm{WDM}$) by means of the [C II] power spectrum (PS), we provide forecasts for the Deep Spectroscopic Survey (DSS) at $z\simeq3.6$ and extend the analysis to larger sky coverage, higher sensitivity, and/or increased spectral resolution. We developed a formulation for the [C II] PS based on the halo-model approach, incorporating the uncertainty in the luminosity function (LF) through two alternative parameterisations. We performed a Bayesian analysis on mock data to derive constraints on $m_\mathrm{WDM}$. In a CDM universe, the DSS yields lower limits on $m_\mathrm{WDM}$, at a $95\%$ credibility level, of $1.10$ keV and $0.58$ keV when considering the optimistic and pessimistic LF ($α= -1.1$), respectively. Ambitious surveys can improve these figures to $5.82$ keV and $1.90$ keV, and assuming a steeper faint-end slope ($α= -1.9$) further boosts these limits. A fivefold increase in spectral resolution enhances sensitivity to the damping scale associated with redshift-space distortions, tightening the constraints on $m_\mathrm{WDM}$ by a factor of up to $\sim1.8$. Finally, Bayesian inference on mock data with $m_\mathrm{WDM}=3$ keV results in a well-constrained and unbiased posterior only in futuristic survey setups. Upcoming LIM surveys can provide meaningful limits on $m_\mathrm{WDM}$, although the negligible contribution from small haloes reduces the constraining power of the [C II] PS. Future progress will benefit from combining multiple redshifts and emission lines, opening the way to competitive constraints on the nature of DM. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_07933 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Probing the warm dark matter mass with [C II] intensity mapping Marcuzzo, Elena Porciani, Cristiano Romano-Díaz, Emilio Dizgah, Azadeh Moradinezhad Khatri, Prachi Viel, Matteo Cosmology and Nongalactic Astrophysics The nature of dark matter (DM) is still debated. While cold DM (CDM) is the standard paradigm, warm DM (WDM) may ease some small-scale tensions in the $Λ$CDM framework. Line-intensity mapping (LIM) offers a novel probe of DM properties. To explore the potential of LIM surveys in constraining the WDM particle mass ($m_\mathrm{WDM}$) by means of the [C II] power spectrum (PS), we provide forecasts for the Deep Spectroscopic Survey (DSS) at $z\simeq3.6$ and extend the analysis to larger sky coverage, higher sensitivity, and/or increased spectral resolution. We developed a formulation for the [C II] PS based on the halo-model approach, incorporating the uncertainty in the luminosity function (LF) through two alternative parameterisations. We performed a Bayesian analysis on mock data to derive constraints on $m_\mathrm{WDM}$. In a CDM universe, the DSS yields lower limits on $m_\mathrm{WDM}$, at a $95\%$ credibility level, of $1.10$ keV and $0.58$ keV when considering the optimistic and pessimistic LF ($α= -1.1$), respectively. Ambitious surveys can improve these figures to $5.82$ keV and $1.90$ keV, and assuming a steeper faint-end slope ($α= -1.9$) further boosts these limits. A fivefold increase in spectral resolution enhances sensitivity to the damping scale associated with redshift-space distortions, tightening the constraints on $m_\mathrm{WDM}$ by a factor of up to $\sim1.8$. Finally, Bayesian inference on mock data with $m_\mathrm{WDM}=3$ keV results in a well-constrained and unbiased posterior only in futuristic survey setups. Upcoming LIM surveys can provide meaningful limits on $m_\mathrm{WDM}$, although the negligible contribution from small haloes reduces the constraining power of the [C II] PS. Future progress will benefit from combining multiple redshifts and emission lines, opening the way to competitive constraints on the nature of DM. |
| title | Probing the warm dark matter mass with [C II] intensity mapping |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2512.07933 |