相关论文: White Noise from Dark Matter: 21 cm Observations o…

The temperature of baryons at the end of the cosmic dark ages can be inferred from observations of the 21-cm hyperfine transition in neutral hydrogen. Any energy injection from the dark sector can therefore be detected through these…

If the symmetry breaking inducing the axion occurs after the inflation, the large axion isocurvature perturbations can arise due to a different axion amplitude in each causally disconnected patch. This causes the enhancement of the…

Recently, Tseliakhovich and Hirata (2010) showed that during the cosmic Dark Ages the baryons were typically moving supersonically with respect to the dark matter with a spatially variable Mach number. Such supersonic motion may source…

In the standard Cold Dark Matter (CDM) theory of structure formation, virialized minihalos (with T_vir = 10,000 K or less) form in abundance at high redshift (z > 6), during the cosmic "dark ages." The hydrogen in these minihalos, the first…

We investigate the suppression of the baryon density fluctuations compared to the dark matter in the linear regime. Previous calculations predict that the suppression occurs up to a characteristic mass scale of ~ 1,000,000 solar masses,…

Before reionization, the intergalactic medium (IGM) may have been sufficiently cold for low-mass "minihalos" to condense out of the gas and subsequently affect reionization. Previous work has shown that minihalos generate reasonably large…

In the standard Cold Dark Matter (CDM) theory of structure formation, virialized minihalos (with T_vir}<10^4 K) form in abundance at high redshift (z>6), during the cosmic ``dark ages.'' The hydrogen in these minihalos, the first nonlinear…

The post-recombination streaming of baryons through dark matter keeps baryons out of low mass (<10^6 solar masses) halos coherently on scales of a few comoving Mpc. It has been argued that this will have a large impact on the 21-cm signal…

Studies of the growth of cosmic perturbations are typically focused on galactic scales and above. In this paper we investigate the evolution of perturbations in baryons, photons, and dark matter for masses below 10^6 M_\odot (or wavenumbers…

Fluctuations of the 21 cm brightness temperature before the formation of the first stars hold the promise of becoming a high-precision cosmological probe in the future. The growth of over densities is very well described by perturbation…

Warm dark matter (WDM) with mass m_WDM = O(1) keV has long been discussed as a promising solution for discrepancies between cosmic structures observed at small scales and predications of the concordance CDM model. Though several…

We investigate the redshift evolution of the concentration-mass relationship of dark matter haloes in state-of-the-art cosmological hydrodynamic simulations and their dark-matter-only counterparts. By combining the IllustrisTNG suite and…

We investigate the hypothesis that Coulomb-type interactions between dark matter (DM) and baryons explain the anomalously low 21cm brightness-temperature minimum at redshift z ~ 17 that was recently measured by the EDGES experiment. In…

The origin and composition of the cosmological dark matter remain a mystery. However, upcoming 21-cm measurements during cosmic dawn, the period of the first stellar formation, can provide new clues on the nature of dark matter. During this…

The epoch of the formation of the first stars, known as the cosmic dawn, has emerged as a new arena in the search for dark matter. In particular, the first claimed 21-cm detection exhibits a deeper global absorption feature than expected,…

We consider the influence of decaying dark matter (DM) particles on the characteristics of 21 cm absorption in spectra of distant radio-loud sources - "21 cm forest" - from minihaloes with masses $M=10^5-10^7\msun$ virialized at $z_{vir} =…

Measurements of the temperature of the baryons at the end of the cosmic dark ages can potentially set very precise constraints on energy injection from exotic sources, such as annihilation or decay of the dark matter. However, additional…

We demonstrate that elastic scattering between dark matter (DM) and baryons can affect the thermal evolution of the intergalactic medium at early epochs and discuss the observational consequences. We show that, due to the interaction…

Primordial magnetic fields (PMF) can enhance baryon perturbations on scales below the photon mean free path. However, a magnetically driven baryon fluid becomes turbulent near recombination, thereby damping out baryon perturbations below…

Scalar modifications of gravity have an impact on the growth of structure. Baryon and Cold Dark Matter (CDM) perturbations grow anomalously for scales within the Compton wavelength of the scalar field. In the late time Universe when…