Differentiating CDM and Baryon Isocurvature Models with 21 cm Fluctuations
arXiv:1104.5591 · doi:10.1088/1475-7516/2011/10/028
Abstract
We discuss how one can discriminate models with cold dark matter (CDM) and baryon isocurvature fluctuations. Although current observations such as cosmic microwave background (CMB) can severely constrain the fraction of such isocurvature modes in the total density fluctuations, CMB cannot differentiate CDM and baryon modes by the shape of its power spectra. However, the evolution of CDM and baryon density fluctuations are different for each model, thus it would be possible to discriminate those isocurvature modes by extracting information on the fluctuations of CDM/baryon itself. We discuss that observations of 21 cm fluctuations can in principle differentiate these modes and demonstrate to what extent we can distinguish them with future 21 cm surveys. We show that, when the isocurvature mode has a large blue-tilted initial spectrum, 21 cm survey can clearly probe the difference.
25 pages, 6 figures, 1 table; (v2) constraints are reanalyzed using a tomography 21cm survey, conclusions unchanged, some references added, accepted for publication in JCAP
References in corpus (11)
- CMBPol Mission Concept Study: Probing Inflation with CMB Polarization
- How accurately can 21 cm tomography constrain cosmology?
- The 21cm angular-power spectrum from the dark ages
- The Fast Fourier Transform Telescope
- Constraining Isocurvature Initial Conditions with WMAP 3-year data
- Axion isocurvature fluctuations with extremely blue spectrum
- Compensated Isocurvature Perturbations and the Cosmic Microwave Background
- Forecasted 21 cm constraints on compensated isocurvature perturbations
- Hints of Isocurvature Perturbations in the Cosmic Microwave Background?
- Cold Dark Matter Isocurvature Perturbations: Constraints and Model Selection
- Cold Dark Matter Isocurvature Perturbations: Cosmological Constraints and Applications
Cited by in corpus (19)
- Observational implications of mattergenesis during inflation
- Baryons do trace dark matter 380,000 years after the big bang: Search for compensated isocurvature perturbations with WMAP 9-year data
- Compensated isocurvature perturbations in the curvaton model
- Isocurvature modes in the CMB bispectrum
- Baryon isocurvature constraints on the primordial hypermagnetic fields
- Cosmological signatures of tilted isocurvature perturbations: reionization and 21cm fluctuations
- Isocurvature perturbations in extra radiation
- Warming up for Planck
- Fermionic Isocurvature Perturbations
- Compensation for large tensor modes with iso-curvature perturbations in CMB anisotropies
- Constraining isocurvature perturbations with the 21cm emission from minihaloes
- Searching for blue in the dark
- Probing the primordial Universe with 21-cm line from cosmic dawn/epoch of reionization
- Extended analysis of CMB constraints on non-Gaussianity in isocurvature perturbations
- CDM/baryon isocurvature perturbations in a sneutrino curvaton model
- Nambu-Goldstone Affleck-Dine Baryogenesis
- Isocurvature modes: joint analysis of the CMB power spectrum and bispectrum
- Probing isocurvature perturbations with 21-cm global signal in the light of HERA result
- Non-Gaussianity in Cosmology: from Inflation to the CMB