The late-time entropy production by the massive particle decay induces the various cosmological effects in the early epoch and modify the standard scenario. We investigate the thermalization process of the neutrinos after the entropy production by solving the Boltzmann equations numerically. We find that if the large entropy are produced at t ∼ 1 sec, the neutrinos are not thermalized very well...

Nature abhors an infinity. The limits of general relativity are often signaled by infinities: infinite curvature as in the center of a black hole, the infinite energy of the singular big bang. We might be inclined to add an infinite universe to the list of intolerable infinities. Theories that move beyond general relativity naturally treat space as finite. In this review we discuss the mathemat...

In an analysis of the gravitational lensing by two relativistic cosmic strings, we argue that the formation of closed time-like curves proposed by Gott is unstable in the presence of particles (e.g. the cosmic microwave background radiation). Due to the attractor-like behavior of the closed time-like curve, we argue that this instability is very generic. A single graviton or photon in the vicin...

We present the first results of observations of the intrinsic anisotropy of the cosmic microwave background radiation with the Cosmic Background Imager from a site at 5080 m altitude in northern Chile. Our observations show a sharp decrease in Cl in the range l = 400–1500. The broadband amplitudes we have measured are δTband = 58.7+7.7 −6.3 μK for l = 603 +180 −166 and δTband = 29.7 +4.8 −4.2 μ...

We describe the results of a hybrid matrix{Monte Carlo calculation of cascading of UHE cosmic rays and-rays through the cosmic background radiation elds over cosmological distances. We calculate the-ray and neutrino emission that results from the cascade, as well as the eeect of cascading on the primary spectrum. We discuss the results for various cosmic ray injection spectra and primary specie...

We utilize the principle of conservation of energy in a model which explains the cosmological redshift, Olbers’ paradox and the cosmic background radiation. The model is based on a hypothesis of absorption and emission of light by galactic and intergalactic matter, and a mean temperature of matter in the Universe compatible with the background radiation. We also discuss the early works of Regen...

The power spectra of the scalarand tensor-type structures generated in an inflation model based on nonminimally coupled scalar field are derived. The contributions of these structures to the anisotropy of the cosmic microwave background radiation are derived, and are compared with the four year COBE DMR data. The constraints on the ratio of the self-coupling and nonmimimal coupling constants, t...

The M-theory which is the strong-coupling heterotic string theory brings various interesting new phenomenologies to us. The M-theory bulk axion is one of them, whose decay constant is estimated as Fa ≃ 10GeV. Direct searches for the M-theory axion seem impossible because of the large decay constant. However, we point out that large isocurvature fluctuations of the Mtheory axion are obtained in ...

The detection of compact sources embedded in a background is a very common problem in many fields of Astronomy. In these lecture notes we present a review of different techniques developed for the detection and extraction of compact sources, with a especial focus on their application to the field of the cosmic microwave background radiation. In particular, we will consider the detection of extr...

The results of EPR experiments performed in Geneva are analyzed in the frame of the cosmic microwave background radiation, generally considered as a good candidate for playing the role of preferred frame. We set a lower bound for the speed of quantum information in this frame at 1.5× 10c.