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While the simplest inflationary models predict the primordial perturbations to be near scale-invariant, the primordial power spectrum (PPS) can exhibit oscillatory features in many physically well-motivated models. We search for hints of…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Wuhyun Sohn , Arman Shafieloo , Dhiraj Kumar Hazra

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 early dark energy models in the context of the lensing anomaly by considering two different Cosmic Microwave Background (CMB) datasets: a complete Planck, and a second one primarily based on SPTPol and Planck temperature…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-20 Balakrishna S. Haridasu , Hasti Khoraminezhad , Matteo Viel

The inflationary paradigm provides a mechanism to generate the primordial perturbations needed to explain the observed large scale structures in the universe. Inflation traces back all the inhomogeneities to quantum fluctuations although…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-18 Suratna Das , Kinjalk Lochan , Satyabrata Sahu , T. P. Singh

The CMB is a powerful probe of early-universe physics but is only observed after passing through large-scale structure, which changes the observed spectra in important model-dependent ways. This is of particular concern given recent claims…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-17 Pablo Lemos , Antony Lewis

Current observational data is consistent with the universe being slightly closed. We investigate families of singular and non-singular closed instantons that could describe the beginning of a closed inflationary universe. We calculate the…

Astrophysics · Physics 2009-11-07 Steven Gratton , Antony Lewis , Neil Turok

The perturbations in the early universe are generated as a result of the interplay between quantum field theory and gravitation. Since these primordial perturbations lead to the anisotropies in the cosmic microwave background and eventually…

General Relativity and Quantum Cosmology · Physics 2021-07-29 D. Jaffino Stargen , V. Sreenath , L. Sriramkumar

We study the capability of future measurements of the galaxy clustering power spectrum to probe departures from a power-law spectrum for primordial fluctuations. On considering the information from the galaxy clustering power spectrum up to…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-05 Mario Ballardini , Fabio Finelli , Cosimo Fedeli , Lauro Moscardini

The characterization and modeling of polarized foregrounds has become a critical issue in the quest for primordial $B$-modes. A typical method to proceed is to factorize and parametrize the spectral properties of foregrounds and their scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 S. Azzoni , M. H. Abitbol , D. Alonso , A. Gough , N. Katayama , T. Matsumura

It is commonly assumed that the stochastic background of gravitational waves on cosmological scales follows an almost scale-independent power spectrum, as generically predicted by the inflationary paradigm. However, it is not inconceivable…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Jan Hamann , Ameek Malhotra

Cosmological defects result from cosmological phase transitions in the early Universe and the dynamics reflects their symmetry-breaking mechanisms. These cosmological defects may be probed through weak lensing effects because they interact…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Shohei Saga , Kouichirou Horiguchi , Kiyotomo Ichiki

Future Cosmic Microwave Background (CMB) experiments will deliver extremely accurate measurements of the E-modes pattern of the CMB polarization field. Given the sharpness of the E-modes transfer functions, such surveys make for a powerful…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra , Lucas Pinol

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Noriaki Kitazawa

The form of the primordial power spectrum (PPS) of cosmological scalar (matter density) perturbations is not yet constrained satisfactorily in spite of the tremendous amount of information from the Cosmic Microwave Background (CMB) data.…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Benjamin L'Huillier , Arman Shafieloo , Dhiraj Kumar Hazra , George F. Smoot , Alexei A. Starobinsky

The detection of primordial B-modes, a key probe of cosmic inflation, is increasingly challenged by contamination from weak gravitational lensing B-modes induced by large-scale structure (LSS). We present a delensing pipeline designed to…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-27 Wen-Zheng Chen , Yang Liu , Yi-Ming Wang , Hong Li

Current measurements of the temperature and polarization anisotropy power spectra of the Cosmic Microwave Background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Victor Miralles , Héctor Ramírez , Lotfi Boubekeur

The Cosmic Microwave Background (CMB) radiation lensing is a promising tool to study the physics of early universe. In this work we probe the imprints of deviations from isotropy and scale invariance of primordial curvature perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-01 Farbod Hassani , Shant Baghram , Hassan Firouzjahi

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-20 Takashi Hiramatsu , Eiichiro Komatsu , Masashi Hazumi , Misao Sasaki

We discuss the discordance between the estimated values of the cosmological parameters from Planck assuming the concordance $\Lambda$CDM model and low-redshift measurements. In particular, we consider the Hubble constant mismatch between…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-16 M. Remazeilles , C. Dickinson , H. K. K. Eriksen , I. K. Wehus