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The curl (B) modes of cosmic microwave background (CMB) polarization anisotropies are a unique probe of the primordial background of inflationary gravitational waves (IGWs). Unfortunately, the B-mode polarization anisotropies generated by…

Astrophysics · Physics 2007-05-23 Kris Sigurdson , Asantha Cooray

We show that cosmological quantum relaxation predicts an anisotropic primordial power spectrum with a specific dependence on wavenumber k. We explore some of the consequences for precision measurements of the cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-12 Antony Valentini

In the context of inflationary scenarios, the observed large angle anisotropy of the Cosmic Microwave Background (CMB) temperature is believed to probe the primordial metric perturbations from inflation. Although the perturbations from…

Astrophysics · Physics 2019-08-17 Somnath Bharadwaj , Dipak Munshi , Tarun Souradeep

The first observations of the cosmic microwave background (CMB) from NASA's \emph{Wilkinson Microwave Anisotropy Probe} (WMAP) led to finding `alignment' anomalies not expected from fluctuations in the isotropic cosmological model. We study…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Sanjeet Kumar Patel , Pavan Kumar Aluri , John P. Ralston

We review aspects of Cosmic Microwave Background (CMB) spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-13 G. De Zotti , M. Negrello , G. Castex , A. Lapi , M. Bonato

We derive an expression for the non-Gaussian cosmic-microwave-background (CMB) statistic $I_l^3$ defined recently by Ferreira, Magueijo, and G\'orski in terms of the slow-roll-inflation parameters $\epsilon$ and $\eta$. This result shows…

Astrophysics · Physics 2011-02-02 Limin Wang , Marc Kamionkowski

The tremendous experimental progress in cosmic microwave background (CMB) temperature and polarization anisotropy studies over the last few years has helped establish a standard paradigm for cosmology at intermediate epochs and has…

Astrophysics · Physics 2011-05-12 Wayne Hu

Non-Gaussianity in the inflationary perturbations can couple observable scales to modes of much longer wavelength (even superhorizon), leaving as a signature a large-angle modulation of the observed cosmic microwave background (CMB) power…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Fabian Schmidt , Lam Hui

In this paper we propose a novel unified cosmological model that connects a pre-inflationary epoch, starting at the Planckian time, with the onset of inflation within a single scalar-field framework. The pre-inflationary phase is…

General Relativity and Quantum Cosmology · Physics 2026-05-20 M. Montes , José Edgar Madriz Aguilar , A. Bernal , Diego Allan Reyna

The breakdown of statistical homogeneity and isotropy of cosmic perturbations is a generic feature of ultra large scale structure of the cosmos, in particular, of non trivial cosmic topology. The statistical isotropy (SI) of the Cosmic…

Astrophysics · Physics 2007-05-23 Amir Hajian , Tarun Souradeep

Recent analyses of the cosmic microwave background (CMB) maps from the WMAP satellite have uncovered evidence for a hemispherical power anomaly, i.e. a dipole modulation of the CMB power spectrum at large angular scales with an amplitude of…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 Christopher M. Hirata

We study the angular distribution of temperature fluctuations in the cosmic microwave background (CMB) to probe the statistical isotropy of the universe by using precise full-sky CMB data with a model-independent approach. We investigated…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-01 C. E. Kester , A. Bernui , W. S. Hipólito-Ricaldi

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,…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 A. Gruppuso , A. Sagnotti

The Cosmic Microwave Background (CMB) anisotropies measurements can provide many clues about the Universe. Although the common belief is that they will allow a very precise measurement of the cosmological parameters (that is, the current…

Astrophysics · Physics 2007-05-23 Alain Riazuelo , David Langlois

We propose that several of the anomalies that have been observed at large angular scales in the CMB have a common origin in a cosmic bounce that took place before the inflationary era. The bounce introduces a new physical scale in the…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Ivan Agullo , Dimitrios Kranas , V. Sreenath

We study the cosmic microwave background (CMB) anisotropy in the scenario where the baryon asymmetry of the universe is generated from a condensation of a scalar field. In such a scenario, the scalar condensation may acquire fluctuation…

High Energy Physics - Phenomenology · Physics 2009-09-29 Takeo Moroi , Hitoshi Murayama

Search for the statistical anisotropy in the CMB data is a powerful tool for constraining models of the early Universe. In this paper we focus on the recently proposed cosmological scenario with conformal rolling. We consider two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 S. R. Ramazanov , G. I. Rubtsov

In the gravitational effective theories including higher curvature terms, cosmological solutions can have nontrivial de Sitter fixed points. We study phenomenological implications of such points, focusing on a theory in which a massive…

High Energy Physics - Phenomenology · Physics 2021-09-07 Shinsuke Kawai , Jinsu Kim

Secondary anisotropies in the cosmic microwave background (CMB) contain information that can be used to test both cosmological models and models of galaxy formation. Starting from lightcone-based HEALPix maps and catalogues, we present a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-22 Tianyi Yang , Ian G. McCarthy , Fiona McCarthy , Boris Bolliet , Jens Chluba , William Coulton , John C. Helly , Matthieu Schaller , Joop Schaye

Non-linear effects in the early Universe generate non-zero bispectra of the cosmic microwave background (CMB) temperature and polarization, even in the absence of primordial non-Gaussianity. In this paper, we compute the contributions from…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-09 Pedro Carrilho , Karim A. Malik