Related papers: Gravitational waves, CMB polarization, and the Hub…
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…
If the linear polarization of the cosmic microwave background (CMB) is rotated in a frequency-independent manner as it propagates from the surface of last scatter, it may introduce a B-mode polarization. Here I show that measurement of…
The search for primordial gravitational waves is a central goal of cosmic microwave background (CMB) surveys. Isolating the characteristic $B$-mode polarization signal sourced by primordial gravitational waves is challenging for several…
We review current observational constraints on the polarization of the Cosmic Microwave Background (CMB), with a particular emphasis on detecting the signature of primordial gravitational waves. We present an analytic solution to the…
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…
Ever since the Planck satellite measured the the cosmic microwave background (CMB) down to arcminute angular scales, the mismatch between the CMB-inferred value of the Hubble constant and the value inferred from the distance ladder (i.e.,…
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 discuss how one can reconstruct the thermal history of the Universe by combining cosmic microwave background (CMB) measurements and gravitational wave (GW) direct detection experiments. Assuming various expansion eras to take place after…
The cosmic microwave background (CMB) temperature, $T$, surely the most precisely measured cosmological parameter, has been inferred from {\it local} measurements of the blackbody spectrum to an exquisite precision of 1 part in $\sim 4700$.…
The polarization of the Cosmic Microwave Background (CMB) provides a plethora of information about the early universe. Most notably, gravitational waves from the Inflationary epoch (the leading explanation of the origin of the universe)…
Circular polarization in the cosmic microwave background (CMB) offers a promising probe of the parity-violating physics of the early universe. In this paper, we propose a novel method to constrain the primordial circular polarization of…
The detection of B-modes in the Cosmic Microwave Background (CMB) polarization by the BICEP2 experiment, if interpreted as evidence for a primordial gravitational wave background, has enormous ramifications for cosmology and physics. It is…
The detection of primordial gravitational waves in Cosmic Microwave Background B-mode polarization observations requires accurate and robust subtraction of astrophysical contamination. We show, using a blind Spectral Matching Independent…
We discuss the future detectability of gravitational-wave induced lensing from high-sensitivity cosmic microwave background (CMB) experiments. Gravitational waves can induce a rotational component of the weak-lensing deflection angle,…
The B-Mode of the Cosmic Microwave Background Polarization (CMBP) promises to detect the gravitational wave background left by Inflation and explore this very early period of the Universe. In spite of its importance, however, the cosmic…
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…
Primordial gravitational waves leave a characteristic imprint on the cosmic microwave background (CMB) in the form of $B$-mode polarization. Photons are also deflected by large scale gravitational waves which intervene between the source…
We present a follow-up study to the method recently proposed by Namikawa and Sherwin (2023) to probe gravitational waves using cross-correlations between two cosmic microwave background (CMB) $B$-modes and a large-scale structure tracer. We…
The scattering of cosmic microwave background (CMB) radiation in galaxy clusters induces polarization signals according to the quadrupole anisotropy in the photon distribution at the cluster location. This `remote quadrupole' derived from…
Polarimetry of the Cosmic Microwave Background (CMB) represents one of the possible diagnostics aimed at testing large-scale magnetism at the epoch of the photon decoupling. The propagation of electromagnetic disturbances in a magnetized…