Related papers: Cosmic Rays and Spectral Distortions from Collapsi…
A variety of beyond the standard model scenarios contain very light hidden sector U(1) gauge bosons undergoing kinetic mixing with the photon. The resulting oscillation between ordinary and hidden photons leads to spectral distortions of…
We obtain the photon spectrum induced by a cosmic background of unstable neutrinos. We study the spectrum in a variety of cosmological scenarios and also we allow for the neutrinos having a momentum distribution (only a critical matter…
The energy at which cosmic rays from extra-galactic sources begin to dominate over those from galactic sources is an important open question in astroparticle physics. A natural candidate is the energy at the 'ankle' in the approximately…
We calculate the $\mu$- and \textit{y}-type spectral distortions of Cosmic Microwave Background (CMB), taking a non-standard interaction between baryons and viscous dark matter. Using the CMB spectral distortion observations, we can…
We investigate the observable consequences of creating cosmic texture by breaking a global SU(3) symmetry, rather than the SU(2) case which is generally studied. To this end, we study the nonlinear sigma model for a totally broken SU(3)…
We study the effects that the diffusion of the cosmic rays in the magnetic field of the Local Supercluster can have on the spectrum of a nearby extragalactic source at ultrahigh energies. We find that the strong enhancement of the flux…
Using simulation methods, distortion effects on energy spectra caused by errors in the energy determination have been investigated. For cosmic ray proton spectra, falling steeply with kinetic energy E as E-2.7, significant effects appear.…
We present a new model for the formation of spherically symmetric clusters in an expanding Universe. Both the Universe and the collapsing cluster are governed by the same pressure less fluid equations for which a uniform initial density…
Global, symmetry-breaking phase transitions in the early universe can generate scaling seed networks which lead to metric perturbations. The acoustic waves in the photon-baryon plasma sourced by these metric perturbations, when Silk damped,…
Current observational data favor cosmological models which differ from the standard model due to the presence of some form of dark energy and, perhaps, by additional contributions to the more familiar dark matter. Primordial nucleosynthesis…
Axion production due to photon-axion mixing in tangled magnetic field(s) prior to recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, contribution of both…
The neutrino telescopes have firmly established the existence of ultra-high-energy (UHE) neutrinos. Observations of these neutrinos offer a unique probe of neutrino self-interactions. This work investigates how the self-interacting…
We calculate the flux of neutrinos generated by the propagation of ultra-high energy nuclei over cosmological distances. The propagation takes into account the interactions with cosmic background radiations including the CMB and the most…
One of the most powerful tools to probe the existence of cosmic defects in the early universe is through the Cosmic Microwave Background (CMB) radiation. It is well known that computations with causal sources are more involved than the…
We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge $Z$)…
According to present cosmological views the energy density of CMB (Cosmic Microwave Background) photons, freely propagating through the expanding cosmos, varies proportional to 1/S^4 with S being the scale factor of the universe. This…
Departures of the energy spectrum of the cosmic microwave background (CMB) from a perfect blackbody probe a fundamental property of the universe -- its thermal history. Current upper limits, dating back some 25 years, limit such spectral…
The interactions of ultra-high-energy cosmic rays (UHECRs) in extragalactic space with photons of the cosmic microwave background (CMB) and extragalactic background light (EBL) can generate high-energy neutrinos and photons. Simulations of…
Perturbations from inflation evolve into large scale structure of the late universe, and encode abundant cosmic structure formation physics. We allow freedom in the primordial power spectrum, rather than assuming a power law scale…
The Milky Way can act as a large-scale weak gravitational lens of the cosmic microwave background (CMB). We study this effect using a photon ray-tracing code and a Galactic mass distribution with disk, bulge and halo components. For an…