相关论文: Suppression of Gravitational Structure Formation b…
Structure formation in the universe can produce high energy gamma-rays from shock-accelerated electrons, and this process may be the origin of the extragalactic gamma-ray background (EGRB) as well as a part of the unidentified sources…
The homogeneity of the cosmic microwave background radiation (CBR) is one of the most severe constraint for theories of the structure formation in the universe. We investigated the effect of the gravitational scattering (lensing) of…
We investigate the imprint of nonlinear matter condensations on the Cosmic Microwave Background (CMB) in an $\Omega=1$, Cold Dark Matter (CDM) model universe. Temperature anisotropies are obtained by numerically evolving matter…
If dark matter is made up of Weakly Interacting Massive Particles, the annihilation of these particles in halos results in energy being released, some of which is absorbed by gas, causing partial ionization and heating. Dark matter…
We investigate the effect of gravitational lensing by matter distribution in the universe on the cosmic microwave background (CMB) polarization power spectra and temperature-polarization cross-correlation spectrum. As in the case of…
The evolution of nonlinear density fluctuations around the Jeans mass shortly after cosmological recombination is analyzed using a 3D hydrodynamics/dark--matter code. The Cosmic Background Radiation (CBR) exerts Compton friction on free…
We investigate the possible effects of reionization by active sources on the cosmic microwave background. We concentrate on the sources themselves as the origin of reionization, rather than early object formation, introducing an extra…
In the pre-reheating era, following cosmic inflation and preceding radiation domination, the energy density may be dominated by an oscillating massive scalar condensate, such as is the case for quadratic chaotic inflation. We have found in…
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and photoevaporating them. This feedback effect of…
Mounting evidence from $x$-ray observations reveals that bound objects should receive some form of energy in the past injected from non-gravitaional sources. We report that an instantaneous heating scheme, for which gases in dense regions…
We present results on the heating of the inter-cluster medium (ICM) by gravitational potential energy from in-falling satellites. We calculate the available excess energy of baryons once they are stripped from their satellite and added to…
A short introduction to structure formation is given, followed by a discussion of the possible characteristics of the initial perturbations assuming a generic inflationary origin. Observational data related to large-scale structure and the…
Primordial black holes (PBHs) of stellar mass or heavier would accrete baryonic gas, which becomes denser and hotter, injecting energetic photons in the cosmological medium soon after cosmic recombination, in the so-called dark ages. The…
We explore the effects of magnetic energy dissipation on the formation of the first stars. For this purpose, we follow the evolution of primordial chemistry in the presence of magnetic fields in the post-recombination universe until the…
For the first time, the possibility of generation of thermal gravitational waves from warm inflation is investigated with cosmic microwave background. Gravitons produced from the quantum fluctuations during warm inflation are found to carry…
Gravitational lensing, caused by matter perturbations along the line-of-sight to the last scattering surface, can modify the shape of the cosmic microwave background (CMB) anisotropy power spectrum. We discuss the detectability of lensing…
A field with particularly exciting results over the past few years is the study of the interaction of cosmic rays with interstellar matter. For star formation to take place, gas and dust need to be sufficiently cold for gravity to overcome…
We examine stochastic temperature fluctuations of the cosmic background radiation (CBR) arising via the Sachs-Wolfe effect from gravitational wave perturbations produced in the early universe. These temperature fluctuations are described by…
Cosmological inhomogeneities gravitationally deflect radiation propagating from distant sources, transforming the spatial and angular correlation functions of intrinsic source properties. For a gaussian distribution of deflections (e.g.…
We study the effect of a stochastic background of gravitational waves on the gravitational lensing of the Cosmic Microwave Background (CMB) radiation. It has been shown that matter density inhomogeneities produce a smoothing of the acoustic…