%0 Generic %1 villasenor2022constraints %A Villasenor, Bruno %A Robertson, Brant %A Madau, Piero %A Schneider, Evan %D 2022 %K library %T New Constraints on Warm Dark Matter from the Lyman-$\alpha$ Forest Power Spectrum %U http://arxiv.org/abs/2209.14220 %X The forest of Lyman-$\alpha$ absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. Its main observable -- the 1D flux power spectrum (FPS) -- should exhibit a suppression on small scales and an enhancement on large scales in warm dark matter (WDM) cosmologies compared to standard $Łambda$CDM. Here, we present an unprecedented suite of 1080 high-resolution cosmological hydrodynamical simulations run with the Graphics Processing Unit-accelerated code Cholla to study the evolution of the Lyman-$\alpha$ forest under a wide range of physically-motivated gas thermal histories along with different free-streaming lengths of WDM thermal relics in the early Universe. A statistical comparison of synthetic data with the forest FPS measured down to the smallest velocity scales ever probed at redshifts $4.0z5.2$ (Boera et al. 2019) yields a lower limit $m_WDM>3.1$ keV (95 percent CL) for the WDM particle mass and constrains the amplitude and spectrum of the photoheating and photoionizing background produced by star-forming galaxies and active galactic nuclei at these redshifts. Interestingly, our Bayesian inference analysis appears to weakly favor WDM models with a best-fit thermal relic mass of $m_\rm WDM=4.5_-1.4^+45$ keV (95 percent CL). We find that the suppression of the FPS from free-streaming saturates at $k0.1\,$s km$^-1$ because of peculiar velocity smearing, and this saturated suppression combined with a slightly lower gas temperature provides a moderately better fit to the observed small-scale FPS for WDM cosmologies.

@misc{villasenor2022constraints, abstract = {The forest of Lyman-$\alpha$ absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. Its main observable -- the 1D flux power spectrum (FPS) -- should exhibit a suppression on small scales and an enhancement on large scales in warm dark matter (WDM) cosmologies compared to standard $\Lambda$CDM. Here, we present an unprecedented suite of 1080 high-resolution cosmological hydrodynamical simulations run with the Graphics Processing Unit-accelerated code {\sc Cholla} to study the evolution of the Lyman-$\alpha$ forest under a wide range of physically-motivated gas thermal histories along with different free-streaming lengths of WDM thermal relics in the early Universe. A statistical comparison of synthetic data with the forest FPS measured down to the smallest velocity scales ever probed at redshifts $4.0\lesssim z\lesssim 5.2$ (Boera et al. 2019) yields a lower limit $m_{\rm WDM}>3.1$ keV (95 percent CL) for the WDM particle mass and constrains the amplitude and spectrum of the photoheating and photoionizing background produced by star-forming galaxies and active galactic nuclei at these redshifts. Interestingly, our Bayesian inference analysis appears to weakly favor WDM models with a best-fit thermal relic mass of $m_{\rm WDM}=4.5_{-1.4}^{+45}$ keV (95 percent CL). We find that the suppression of the FPS from free-streaming saturates at $k\gtrsim 0.1\,$s km$^{-1}$ because of peculiar velocity smearing, and this saturated suppression combined with a slightly lower gas temperature provides a moderately better fit to the observed small-scale FPS for WDM cosmologies.}, added-at = {2022-09-29T07:52:06.000+0200}, author = {Villasenor, Bruno and Robertson, Brant and Madau, Piero and Schneider, Evan}, biburl = {https://www.bibsonomy.org/bibtex/2991ef96c1d9d5d7a4cf595e779738357/gpkulkarni}, description = {New Constraints on Warm Dark Matter from the Lyman-$\alpha$ Forest Power Spectrum}, interhash = {139c6e6112e90821f77de5eac041ac0a}, intrahash = {991ef96c1d9d5d7a4cf595e779738357}, keywords = {library}, note = {cite arxiv:2209.14220Comment: Submitted to Phys. Rev. D}, timestamp = {2022-09-29T07:52:06.000+0200}, title = {New Constraints on Warm Dark Matter from the Lyman-$\alpha$ Forest Power Spectrum}, url = {http://arxiv.org/abs/2209.14220}, year = 2022 }