Related papers: Multimessenger Cosmology: correlating CMB and SGWB…

We present a 1+3 covariant discussion of the contribution of gravitational waves to the anisotropy of the CMB in an almost-Friedmann-Robertson-Walker universe. Our discussion is based in the covariant approach to perturbations in cosmology,…

The recent NANOGrav finding of a common-spectrum process has invited interpretations as possible evidence of a primordial stochastic gravitational-wave background (SGWB) stronger than predicted by standard inflation+LCDM. Such an SGWB would…

One of the guaranteed features of the stochastic gravitational wave background (SGWB) is the presence of Doppler anisotropies induced by the motion of the detector with respect to the rest frame of the SGWB source. We point out that…

Working toward a model independent understanding of cosmic microwave background (CMB) anisotropies and their significance, we undertake a comprehensive and self-contained study of scalar perturbation theory. Initial conditions, evolution,…

We study Gravitational Waves (GWs) in the context of Massive Gravity, an extension to General Relativity (GR) where the fluctuations of the metric have a nonzero mass, and specifically investigate the effect of the tensor modes on the…

We study the properties of the stochastic gravitational wave background (SGWB) resulting from the mergers of primordial black holes (PBH) that formed from the collapse of sub-horizon regions in the early universe. We adopt a…

The cosmic microwave background (CMB), the relic radiation from the early Universe, offers a unique window into both primordial conditions and the intervening large-scale structure (LSS) it traverses. Interactions between CMB photons and…

We investigate the cosmic variance of the skewness of the cosmic microwave background (CMB) anisotropies in an inflationary model which leads to the baryon isocurvature scenario for the cosmic structure formation. In this model, the baryon…

Motivated by the fact that cosmological perturbations of inflationary quantum origin were born Gaussian, the search for non-Gaussianities in the cosmic microwave background (CMB) anisotropies is considered as the privileged probe of…

The ability to test and constrain theories of cosmic inflation will advance substantially over the next decade. Key data sources include cosmic microwave background (CMB) measurements and observations of the distribution of matter at…

We study the large scale power spectrum of gravitational wave perturbations of the microwave background in the context of single-bubble open inflation models. We compute the ratio of tensor to scalar contributions to the CMB anisotropies as…

The cosmic microwave background (CMB) encodes information about the content and evolution of the universe. The presence of light, weakly interacting particles impacts the expansion history of the early universe, which alters the temperature…

I discuss how parameters describing inflation in the very early universe may be related to primordial perturbation spectra. Precision observations of anisotropies in the cosmic microwave background (CMB) such as those provided by the WMAP…

Recently, the NANOGrav, PPTA, EPTA, and CPTA collaborations independently reported their evidence of the Stochastic Gravitational Waves Background (SGWB). While the inferred gravitational-wave background amplitude and spectrum are…

Long-wavelength gravitational waves can induce significant temperature anisotropy in the cosmic microwave background. Distinguishing this from anisotropy induced by energy density fluctuations is critical for testing inflationary cosmology…

In the light of the recent results concerning CMB observations and GW detection we address the question of whether it is possible, in a self-consistent inflationary framework, to simultaneously generate a spectrum of scalar metric…

We describe the subject of Cosmic Microwave Background (CMB) analysis - its past, present and future. The theory of Gaussian primary anisotropies, those arising from linear physics operating in the early Universe, is in reasonably good…

We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the…

Searching for the signal of primordial gravitational waves in the B-modes (BB) power spectrum is one of the key scientific aims of the cosmic microwave background (CMB) polarization experiments. However, this could be easily contaminated by…

We argue that the lack of power exhibited by cosmic microwave background (CMB) anisotropies at large angular scales might be linked to the onset of inflation. We highlight observational features and theoretical hints that support this view,…