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Last year we argued that if slow-roll inflation followed the decay of a false vacuum in a large landscape, the steepening of the scalar potential between the inflationary plateau and the barrier generically leads to a potentially observable…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Raphael Bousso , Daniel Harlow , Leonardo Senatore

We study scalar mode perturbations (magnetosonic waves) induced by a helical stochastic cosmological magnetic field and derive analytically the corresponding cosmic microwave background (CMB) temperature and polarization anisotropy angular…

Astrophysics · Physics 2008-11-26 Tina Kahniashvili , Bharat Ratra

Combining the latest Planck, Wilkinson Microwave Anisotropy Probe (WMAP), and baryon acoustic oscillation (BAO) data, we exploit the recent cosmic microwave background (CMB) B-mode power spectra data released by the BICEP2 collaboration to…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-10 Fengquan Wu , Yichao Li , Youjun Lu , Xuelei Chen

A non-cosmological origin for the CMB low-order multipoles and associated anomalies is suggested in this paper. We discuss the possibility that these features of the power spectrum originate in the termination shock (TS) region of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-27 H. N. Sharpe

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…

High Energy Physics - Phenomenology · Physics 2025-09-03 Aurora Ireland , Kuver Sinha , Tao Xu

Following the paper of K. Shimizu et al. (2011) we consider the Bonhoeffer-van der Pol oscillator with non-autonomous periodic perturbation. We show that the presence of mixed mode oscillations reported in that paper can be explained using…

Mathematical Physics · Physics 2013-11-21 E. Kutafina

The 21-cm global signal is obscured by very bright galactic and extra galactic foreground emissions. Typical single-spectrum fit (SSF) based methods for foreground/signal separation can result in biased estimates of the cosmological signal…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 Yordan D. Ignatov , Jonathan R. Pritchard

We explore the possibility that both the suppression of the $\ell = 2$ multipole moment of the power spectrum of cosmic microwave background temperature fluctuations and the possible dip for $\ell = 10-30$ can be explained as well as a…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Mayukh R. Gangopadhyay , Grant J. Mathews , Kiyotomo Ichiki , Toshitaka Kajino

Cosmic microwave background measurements show an agreement with the concordance cosmology model except for a few notable anomalies: Power Suppression, the lack of large scale power in the temperature data compared to what is expected in the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-20 Shabbir Shaikh , Suvodip Mukherjee , Santanu Das , Benjamin D. Wandelt , Tarun Souradeep

The recently detected polarization of the cosmic microwave background (CMB) holds the potential for revealing the physics of inflation and gravitationally mapping the large-scale structure of the universe, if so called B-mode signals below…

Astrophysics · Physics 2011-05-12 Wayne Hu , Matthew M. Hedman , Matias Zaldarriaga

We introduce the real space correlation function of $B$-mode polarization of the cosmic microwave background (CMB) as a probe of superhorizon tensor perturbations created by inflation. By causality, any non-inflationary mechanism for…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Daniel Baumann , Matias Zaldarriaga

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…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Yin-Zhe Ma , Wen Zhao , Michael L. Brown

The anisotropy of the redshift space bispectrum contains a wealth of cosmological information. This anisotropy depends on the orientation of three vectors ${\bf k_1,k_2,k_3}$ with respect to the line of sight. Here we have decomposed the…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-12 Somnath Bharadwaj , Arindam Mazumdar , Debanjan Sarkar

Bipolar spherical harmonics (BiPoSHs) provide a general formalism for quantifying departures in the cosmic microwave background (CMB) from statistical isotropy (SI) and from Gaussianity. However, prior work has focused only on BiPoSHs with…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Laura G. Book , Marc Kamionkowski , Tarun Souradeep

Recent developments in the search for inflationary gravitational waves in the cosmic microwave background (CMB) polarization motivate the search for new diagnostics to distinguish the Galactic foreground contribution to B modes from the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Marc Kamionkowski , Ely D. Kovetz

We consider a model in which a pseudo-scalar field $\sigma$ rolls for some e-folds during inflation, sourcing one helicity of a gauge field. These fields are only gravitationally coupled to the inflaton, and therefore produce scalar and…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Ryo Namba , Marco Peloso , Maresuke Shiraishi , Lorenzo Sorbo , Caner Unal

We show that perturbations generated during the anisotropic pre-inflationary stage of cosmic evolution may affect cosmological observations today for a certain range of parameters. Due to the anisotropic nature of the universe during such…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-15 Pavan K. Aluri , Pankaj Jain

We compute the full cosmic microwave background temperature bispectrum generated by nonlinearities after single-field inflation. By integrating the photon temperature at second order along a perturbed geodesic in Newtonian gauge, we derive…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-22 Zhiqi Huang , Filippo Vernizzi