Related papers: Primordial Magnetic Helicity Constraints from WMAP…
Cosmic birefringence is the in-vacuo, frequency independent rotation of the polarization plane of linearly polarized radiation, induced by a parity-violating term in the electromagnetic Lagrangian. We implement an harmonic estimator for the…
Polarization results from the Cosmic Anisotropy Polarization MAPper (CAPMAP) experiment are reported. These are based upon 433 hours, after cuts, observing a 2 square degree patch around the North Celestial Pole (NCP) with four 90 GHz…
Measuring the primordial matter power spectrum is our primary means of probing unknown physics in the very early universe. We allow the primordial power spectrum to be an arbitrary function, and parametrize it in terms of wavelet band…
In this paper, we investigate the effects of helical primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) reduced bispectrum. We derive the full three-point statistics of helical magnetic fields and numerically…
We investigate the generation of helical magnetic fields and address the baryon asymmetry of the universe from an inflationary magnetogenesis scenario, in which the conformal and parity symmetries of the electromagnetic field are broken…
It is shown that small-scale magnetic fields present before recombination induce baryonic density inhomogeneities of appreciable magnitude. The presence of such inhomogeneities changes the ionization history of the Universe, which in turn…
Any attempt to understand the ubiquitous nature of the magnetic field in the present universe seems to lead us towards its primordial origin. For large-scale magnetic fields, however, their strength and length scale may not necessarily…
Primordial magnetic fields could provide an explanation for the galactic magnetic fields observed today, in which case they may also leave interesting signals in the CMB and the small-scale matter power spectrum. We discuss how to…
The pseudoscalar-photon mixing in presence of large scale magnetic field induces polarization in light from distant cosmological sources. We study the effect of these pseudoscalars or axion like particles (ALPs) on Cosmic Microwave…
Polarization of the cosmic microwave background (CMB) can probe new parity-violating physics such as cosmic birefringence (CB), which requires exquisite control over instrumental systematics. The non-idealities of the half-wave plate (HWP)…
We use the cosmic microwave background angular power spectra to place upper limits on the degree to which global defects may have aided cosmic structure formation. We explore this under the inflationary paradigm, but with the addition of…
In this work, we constrain the spectral index $n_t$ of the primordial gravitational wave power spectrum in a universe with sterile neutrinos by using the Planck temperature data, the WMAP 9-year polarization data, the baryon acoustic…
Microwave background temperature and polarization observations are a powerful way to constrain cosmological parameters if the likelihood function can be calculated accurately. The temperature and polarization fields are correlated, partial…
The temperature and polarization inhomogeneities of the Cosmic Microwave Background might bear the mark of pre-decoupling magnetism. The parameters of a putative magnetized background are hereby estimated from the observed temperature…
The angular power spectrum of the cosmic microwave background temperature anisotropy observed by WMAP has an anomalous dip at l~20 and bump at l~40. One explanation for this structure is the presence of features in the primordial curvature…
We confront predictions of inflationary scenarios with the WMAP data, in combination with complementary small-scale CMB measurements and large-scale structure data. The WMAP detection of a large-angle anti-correlation in the…
Parity violation is expected to generate an asymmetry between the amplitude of left and right-handed gravitational-wave modes which leads to a circularly polarized stochastic gravitational-wave background (SGWB). Due to the three…
Galactic magnetic fields are observed of order $\sim 10^{-6}G$, but their origin is not definitely known yet. In this paper we consider the primordial magnetic fields generated in the early universe and analyse their effects on the density…
The temperature fluctuations and polarization of the Cosmic Microwave Background (CMB) are now a well-known probe of the Universe at an infant age of 400,000 years. During the transit to us from the surface of last scattering, the CMB…
We estimate Cosmic Microwave Background (CMB) polarisation power spectra, and temperature-polarisation cross-spectra, from the 9-year data of the Wilkinson Microwave Anisotropy Probe (WMAP). Foreground cleaning is implemented using minimum…