Related papers: Constraining primordial vector mode from B-mode po…
We study temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation sourced from primordial cross-bispectra between metric perturbations and vector fields, which are generated from the inflation model where…
We study the degree to which the cosmic microwave background (CMB) can be used to constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on the correlation of one polarization $B$ mode with two…
In a recent publication, we used the data from WMAP and SDSS to constrain the primordial perturbations and to predict the B-mode polarization sourced by cosmic string networks. We have been alerted by A. Slosar to the existence of errors in…
We consider a novel contribution to the polarization of the Cosmic Microwave Background induced by vector and tensor modes generated by the non-linear evolution of primordial scalar perturbations. Our calculation is based on relativistic…
We present new constraints on gravitational vector perturbations ($\mathcal{V}$-modes) using Cosmic Microwave Background (CMB) data, including temperature and $E$-mode polarization from SPT-3G D1, ACT-DR6, and $Planck$, as well as $B$-mode…
Primordial vector modes describe vortical fluid perturbations in the early universe. A regular solution exists with constant non-zero radiation vorticities on super-horizon scales. Baryons are tightly coupled to the photons, and the baryon…
Given observations of B-mode polarization power spectrum of the cosmic microwave background (CMB), we can reconstruct power spectra of primordial tensor modes from the early Universe without assuming their functional form such as a…
Primordial inhomogeneous magnetic fields of the right strength can leave a signature on the CMB temperature anisotropy and polarization. Potentially observable contributions to polarization B-modes are generated by vorticity and…
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…
Probing primordial curvature perturbations on small scales, beyond those accessible using cosmic microwave background (CMB) primary anisotropies and Lyman-$\alpha$ forest data, remains a major open challenge. Current constraints on the…
The BICEP2 collaboration reports a detection of primordial cosmic microwave background (CMB) B-mode with a tensor-scalar ratio $r=0.20^{+0.07}_{-0.05}$ (68% C.L.). However, this result is in tension with the recent Planck limit, $r<0.11$…
I will discuss to what degree the cosmic microwave background (CMB) can be used to constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on the correlation of one $B$-mode polarization fluctuation…
Many models of the early universe predict that there should be primordial tensor perturbations. These leave an imprint into the temperature and polarisation anisotropies of the cosmic microwave background (CMB). The differential equation…
The temperature perturbations of the cosmic microwave background radiation (CMB) appear systematically suppressed, at large angular scales, with respect to the prediction of the LambdaCDM concordance model. This behavior might be a glimpse…
The BICEP2 collaboration reported recently a B-mode polarization of the cosmic microwave background (CMB) radiation inconsistent with the null hypothesis at a significance of > 5 {\sigma}. This result has been often interpreted as a…
We investigate the observational signatures of three models of the early Universe in the $B$-mode polarization of the Cosmic Microwave Background (CMB) radiation. In addition to the standard single field inflationary model, we also consider…
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…
Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…
We revisit regular primordial vector modes sustained by the anisotropic stress of free-streaming neutrinos. We consider two classes of neutrino-sector initial conditions, the neutrino velocity isocurvature mode ($\nu\mathrm{VI}$) and the…
The measurement of the large-scale B-mode polarization in the cosmic microwave background (CMB) is a fundamental goal of future CMB experiments. However, because of unprecedented sensitivity, future CMB experiments will be much more…