اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدConstraint on Matter Power Spectrum on $10^6-10^9M_odot$ Scales from ${largetau_e}$
72
0
0.0
(
0
)
تأليف
Renyue Cen
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
An analysis of the physics-rich endgame of reionization at $z=5.7$ is performed, utilizing jointly the observations of the Ly$alpha$ forest, the mean free path of ionizing photons, the luminosity function of galaxies and new physical insight. We find that an upper limit on ${rm tau_e}$ provides a constraint on the minimum mean free path (of ionizing photons) that is primarily due to dwarf galaxies, which in turn yields a new and yet the strongest constraint on the matter power spectrum on $10^6-10^9M_odot$ scales. With the latest Planck measurements of ${rm tau_e = 0.055 pm 0.009}$, we can place an upper limit of $(8.9times 10^6, 3.8times 10^7, 4.2times 10^8)M_odot$ on the lower cutoff mass of the halo mass function, or equivalent a lower limit on warm dark matter particle mass ${rm m_x ge (15.1, 9.8, 4.6)keV}$ or on sterile neutrino mass ${rm m_s ge (161, 90, 33)keV}$, at $(1, 1.4, 2.2)sigma$ confidence level, respectively.
قيم البحث
اقرأ أيضاً
Using the Reduced Relativistic Gas (RRG) model, we analytically determine the matter power spectrum for Warm Dark Matter (WDM) on small scales, $k>1 htext{/Mpc}$. The RRG is a simplified model for the ideal relativistic gas, but very accurate in the
cosmological context. In another work, we have shown that, for typical allowed masses for dark matter particles, $m>5 text{keV}$, the higher order multipoles, $ell>2$, in the Einstein-Boltzmann system of equations are negligible on scales $k<10 htext{/Mpc}$. Hence, we can follow the perturbations of WDM using the ideal fluid framework, with equation of state and sound speed of perturbations given by the RRG model. We derive a Meszaros like equation for WDM and solve it analytically in radiation, matter and dark energy dominated eras. Joining these solutions, we get an expression that determines the value of WDM perturbations as a function of redshift and wavenumber. Then we construct the matter power spectrum and transfer function of WDM on small scales and compare it to some results coming from Lyman-$alpha$ forest observations. Besides being a clear and pedagogical analytical development to understand the evolution of WDM perturbations, our power spectrum results are consistent with the observations considered and the other determinations of the degree of warmness of dark matter particles.
We present a new compilation of inferences of the linear 3D matter power spectrum at redshift $z,{=},0$ from a variety of probes spanning several orders of magnitude in physical scale and in cosmic history. We develop a new lower-noise method for per
forming this inference from the latest Ly$alpha$ forest 1D power spectrum data. We also include cosmic microwave background (CMB) temperature and polarization power spectra and lensing reconstruction data, the cosmic shear two-point correlation function, and the clustering of luminous red galaxies. We provide a Dockerized Jupyter notebook housing the fairly complex dependencies for producing the plot of these data, with the hope that groups in the future can help add to it. Overall, we find qualitative agreement between the independent measurements considered here and the standard $Lambda$CDM cosmological model fit to the {it Planck} data
We examine the projected correlation of galaxies with mass from small scales (<few hundred kpc) where individual dark matter halos dominate, out to 15 Mpc where correlated large-scale structure dominates. We investigate these profiles as a function o
f galaxy luminosity and redshift. Selecting 0.8 million galaxies in the Deep Lens Survey, we use photometric redshifts and stacked weak gravitational lensing shear tomography out to radial scales of 1 degree from the centers of foreground galaxies. We detect correlated mass density from multiple halos and large-scale structure at radii larger than the virial radius, and find the first observational evidence for growth in the galaxy-mass correlation on 10 Mpc scales with decreasing redshift and fixed range of luminosity. For a fixed range of redshift, we find a scaling of projected halo mass with rest-frame luminosity similar to previous studies at lower redshift. We control systematic errors in shape measurement and photometric redshift, enforce volume completeness through absolute magnitude cuts, and explore residual sample selection effects via simulations.
We discuss an analytical approximation for the matter power spectrum covariance matrix and its inverse on translinear scales, $k sim 0.1h - 0.8h/textrm{Mpc}$ at $z = 0$. We proceed to give an analytical expression for the Fisher information matrix of
the nonlinear density field spectrum, and derive implications for its cosmological information content. We find that the spectrum information is characterized by a pair of upper bounds, plateaux, caused by the trispectrum, and a knee in the presence of white noise. The effective number of Fourier modes, normally growing as a power law, is bounded from above by these plateaux, explaining naturally earlier findings from $N$-body simulations. These plateaux limit best possible measurements of the nonlinear power at the percent level in a $h^{-3}textrm{Gpc}^3$ volume; the extraction of model parameters from the spectrum is limited explicitly by their degeneracy to the nonlinear amplitude. The value of the first, super-survey (SS) plateau depends on the characteristic survey volume and the large scale power; the second, intra-survey (IS) plateau is set by the small scale power. While both have simple interpretations within the hierarchical textit{Ansatz}, the SS plateau can be predicted and generalized to still smaller scales within Takada and Hus spectrum response formalism. Finally, the noise knee is naturally set by the density of tracers.
We compare primordial black hole (PBH) constraints on the power spectrum and mass distributions using the traditional Press Schechter formalism, peaks theory, and a recently developed version of peaks theory relevant to PBHs. We show that, provided t
he PBH formation criteria and the power spectrum smoothing are treated consistently, the constraints only vary by $sim$10% between methods (a difference that will become increasingly important with better data). Our robust constraints from PBHs take into account the effects of critical collapse, the non-linear relation between $zeta$ and $delta$, and the shift from the PBH mass to the power spectrum peak scale. We show that these constraints are remarkably similar to the pulsar timing array (PTA) constraints impacting the black hole masses detected by the LIGO and Virgo, but that the $mu$-distortion constraints rule out supermassive black hole (SMBH) formation and potentially even the much lighter mass range of $sim$(1-100) $mathrm{M}_odot$ that LIGO/Virgo probes.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
