Related papers: Decoding the cosmological baryonic fluctuations us…
Fast Radio Bursts (FRBs) are a unique probe of the cosmos, owing to dispersion caused by free electrons in the intergalactic medium (IGM). Two of the main quantities of interest are degenerate: the density of matter…
It has been known for decades that the observed number of baryons in the local universe falls about 30-40% short of the total number of baryons predicted by Big-Bang Nucleosynthesis, as inferred from density fluctuations of the Cosmic…
Searches for transient astrophysical sources often reveal unexpected classes of objects that are useful physical laboratories. In a recent survey for pulsars and fast transients we have uncovered four millisecond-duration radio transients…
The frequency-dependent time delays in fast radio bursts (FRBs) can be used to constrain the photon mass, if the FRB redshifts are known, but the similarity between the frequency dependences of dispersion due to plasma effects and a photon…
Constrained measurements of fundamental physical constants using astronomical observational data represent a powerful method for investigating potential new physics. In particular, the dispersion measure (DM) of fast radio bursts (FRBs),…
A new model of the Milky Way (MW) halo component of the dispersion measure (DM) for extragalactic sources, such as fast radio bursts (FRBs), is presented in light of recent diffuse X-ray observations. In addition to the spherical component…
Critical phenomena in phase transitions of strongly interacting matter, governed by quantum chromodynamics, are inherently encoded in the fluctuations of conserved charges. In this work, we study the net-baryon number density fluctuations,…
Observations of clusters of galaxies suggest that they contain significantly fewer baryons (gas plus stars) than the cosmic baryon fraction. This `missing baryon' puzzle is especially surprising for the most massive clusters which are…
A key tool astronomers have to investigate the nature of extragalactic transients is their position on their host galaxies. Galactocentric offsets, enclosed fluxes and the fraction of light statistic are widely used at different wavelengths…
Cosmological and astrophysical surveys in various wavebands, in particular from the radio to the far-infrared, offer a unique view of the universe's properties and the formation and evolution of its structures. After a preamble on the…
The flux ratios in the multiple images of gravitationally lensed quasars can provide evidence for dark matter substructure in the halo of the lensing galaxy if the flux ratios differ from those predicted by a smooth model of the lensing…
The $\Lambda$CDM model successfully explains the majority of cosmological observations. However, the $\Lambda$CDM model is challenged by Hubble tension, a remarkable difference of Hubble constant $H_0$ between measurements from local probe…
Recent observations of FRB 20190520B have revealed rapid fluctuation of its Dispersion Measure within apparently fixed bounds, as well as a reversal of its Rotation Measure. The fluctuations of Dispersion Measure are uncorrelated with the…
Six cases of fast radio bursts (FRBs) have recently been discovered. The FRBs are bright (~0.1 - 1 Jy) and brief (~ 1 ms) pulses of radio emission with dispersion measures (DMs) that exceed Galactic values, and hence FRBs have been…
Fast Radio Bursts (FRBs) are a promising tool for studying the low-density universe as their dispersion measures (DM) are extremely sensitive probes of electron column density. Active Galactic Nuclei (AGN) inject energy into the…
Linear cosmological observables can be used to probe elastic scattering of dark matter (DM) with baryons. Availability of high-precision data requires a critical reassessment of any assumptions that may impact the accuracy of constraints.…
We introduce a new technique to constrain the line-of-sight integrated electron density of our Galactic halo $\text{DM}_\text{MW,halo}$ through analysis of the observed dispersion measure distributions of pulsars $\text{DM}_\text{pulsar}$…
The evolution of small scale cosmological perturbations is carefully re-examined. Through the interaction with photons via electrons, baryon perturbations show interesting behavior in some physical scales. Characteristic features of the…
For each photon wave packet of extragalactic light, the dispersion by line-of-sight intergalactic plasma causes an increase in the envelope width and a chirp (drift) in the carrier frequency. It is shown that for continuous emission of many…
We performed a fluctuation analysis of the Hubble Extremely Deep Field (XDF) at four optical wavelength bands and found large fluctuations that are significantly brighter than those expected for ordinary galaxies. Good cross-correlations…