相关论文: Magnetic Fields from Compensated Isocurvature Pert…

We derive the minimal seed magnetic field which unavoidably arises in the radiation and matter eras, prior to recombination, by the rotational velocity of ions and electrons, gravitationally induced by the non-linear evolution of primordial…

We consider the possibility of inflationary magnetogenesis due to dynamical couplings of the electromagnetic fields to gravity. We find that large primordial magnetic fields can be generated during inflation without the strong coupling…

Several accurate analyses of the CMB temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed a set of anomalous results, at large angular scales, that appears inconsistent with the statistical isotropy expected…

Inflationary cosmology has proved to be the most successful at predicting the properties of the anisotropies observed in the cosmic microwave background (CMB). In this essay we show that quantum field renormalization significantly…

In this paper, we investigate the primordial perturbations of inflation model induced from the multi-field mimetic gravity, where there are two field during inflation, and thus both adiabatic and isocurvature perturbation modes are…

If cosmic magnetic fields are indeed produced during inflation, they are likely to be correlated with the scalar metric perturbations that are responsible for the Cosmic Microwave Background anisotropies and Large Scale Structure. Within an…

While the cosmic microwave background (CMB) dipole is largely assumed entirely kinematic, there appears evidence that a part of it is primordial. Such possibility arises in models implying a tilt, interpreted as a dark flow, across the…

Measurements of CMB temperature fluctuations by the Wilkinson Microwave Anisotropy Probe (WMAP) indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry…

Magnetic fields appear to be present in all galaxies and galaxy clusters. Recent measurements indicate that a weak magnetic field may be present even in the smooth low density intergalactic medium. One explanation for these observations is…

Generation of large-scale magnetic fields is studied in dilaton electromagnetism in noncommutative inflationary cosmology, taking into account the effects of the spacetime uncertainty principle motivated by string theory. We show that it is…

Causal seed models, such as cosmological defects, generically predict a distinctly different structure to the CMB power spectrum than inflation, due to the behavior of the perturbations outside the horizon. We provide a general analysis of…

In order to gain new insights into the gauge field couplings in the early universe, we consider the constraints on gauge field production during inflation imposed by requiring that their effect on the CMB anisotropies are subdominant. In…

The mimetic gravity theory is one of the interesting modified gravity theories, which aims to unify the matter component of our universe within the power of gravity. The mimetic-like theory can also be responsible for primordial…

We present a method for the study of second-order superhorizon perturbations in multi field inflationary models with non trivial kinetic terms. We utilise a change of coordinates in field space to separate isocurvature and adiabatic…

The effects of initially uniform magnetic fields on the formation and evolution of dense pillars and cometary globules at the boundaries of H II regions are investigated using 3D radiation-magnetohydrodynamics simulations. It is shown, in…

Observations of cosmic infrared background (CIB) radiation exhibit significant fluctuations on small angular scales. A number of explanations have been put forth, but there is currently no consensus on the origin of these large…

We compute the spectral distortions of the Cosmic Microwave Background (CMB) polarization induced by non-linear effects in the Compton interactions between CMB photons and cold intergalactic electrons. This signal is of the $y$-type and is…

It is shown that the standard cosmological model predicts {\it ab initio} generation of large-scale but very small-amplitude cosmic magnetic fields at the epoch of recombination of the primeval plasma. Matter velocities dominated by…

We present a detailed calculation of our previous short paper [M. Shiraishi, D. Nitta, S. Yokoyama, K. Ichiki, and K. Takahashi, Phys. Rev. D 82, 121302 (2010).] in which we have investigated a constraint on the magnetic field strength…

We investigate the generation of magnetic field by the Biermann battery in cosmological ionization fronts, using new simulations of the reionization of the universe by stars in protogalaxies. Two mechanisms are primarily responsible for…