Related papers: Hunting for Statistical Anisotropy in Tensor Modes…
We examine the contribution of tensor modes, in addition to the dominant scalar ones, on the temperature anisotropies of the cosmic microwave background (CMB). To this end, we analyze in detail the temperature two-point angular correlation…
The detection of a stochastic background of long-wavelength gravitational waves (tensors) in the cosmic microwave background (CMB) anisotropy would be an invaluable probe of the high energy physics of the early universe. Unfortunately a…
It is known that in contrast with the E-mode polarization, the B-mode polarization of the Cosmic Microwave Background cannot be generated by the Compton scattering in the case of scalar mode of metric perturbation. However it is possible to…
The detection of large angular scale $B$-mode in the Cosmic Microwave Background (CMB) polarization signal will open a direct window into not only the primary CMB anisotropies caused by the primordial gravitational waves (PGW) originating…
Possible signatures of primordial magnetic fields on the Cosmic Microwave Background (CMB) temperature and polarization anisotropies are reviewed. The signals that could be searched for include excess temperature anisotropies particularly…
Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial vector fields in inflationary theories…
Distortions in the primordial cosmic microwave background (CMB) along the line-of-sight can be modeled and described using 11 fields. These distortion fields correspond to various cosmological signals such as weak gravitational lensing of…
The cosmic microwave background (CMB) contains perturbations that are close to Gaussian and isotropic. This means that its information content, in the sense of the ability to constrain cosmological models, is closely related to the number…
This PhD thesis (defended in 2014) is focused on the estimation of the CMB polarised anisotropies power spectra on a masked sky and on forecasts of constraints set on the primordial universe physics thanks to these anisotropies. After an…
Besides expanding anisotropically, the universe can also be anisotropic at the level of its (spatial) curvature. In particular, models with anisotropic curvature and isotropic expansion leads both to a $\Lambda$CDM-like phenomenology and to…
We report the detection of polarized anisotropy in the Cosmic Microwave Background radiation with the Degree Angular Scale Interferometer (DASI), located at the Amundsen-Scott South Pole research station. Observations in all four Stokes…
Recently, BICEP2 measurements of the cosmic microwave background (CMB) $B$-mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of $r=0.2$ when assuming nearly…
The effect of weak gravitational lensing on the cosmic microwave background (CMB) temperature anisotropies and polarization will provide access to cosmological information that cannot be obtained from the primary anisotropies alone. We…
We consider the weak lensing effect induced by linear cosmological perturbations on the cosmic microwave background (CMB) polarization anisotropies. We find that the amplitude of the lensing peak in the BB mode power spectrum is a faithful…
Low multipoles ($l$) in cosmic microwave background (CMB) temperature anisotropies have shown some `peculiarities' when examined since the release of the full sky CMB maps, using a variety of tests. In this paper, we concern ourselves with…
We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or M-theory generically yield parity violating…
Observations of the polarization of the cosmic microwave backround (CMB) have the potential to place much tighter constraints on cosmological parameters than observations of the fluctuations in temperature alone. We discuss using CMB…
In the measurements of cosmic microwave background polarizations, three frequency channels are necessary for discriminating the primordial B-modes from the polarized dust and the synchrotron emission. We carry out an optimistic estimate on…
If the seed magnetic fields exist in the early Universe, tensor components of their anisotropic stresses are not compensated prior to neutrino decoupling and the tensor metric perturbations generated from them survive passively.…
We investigate the anisotropies in the cosmic microwave background in a class of models which possess a positive cosmic energy density but negative pressure, with a constant equation of state w = p/rho < -1. We calculate the temperature and…