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The inflationary paradigm is extremely successful regarding predictions of temperature anisotropies in the CMB. However, inflation also makes predictions for a CMB B-mode polarization, which has not been detected. Moreover, the standard…

General Relativity and Quantum Cosmology · Physics 2018-07-24 Gabriel León , Abhishek Majhi , Elias Okon , Daniel Sudarsky

We explore a novel analysis framework for parameter inference with large-scale CMB polarization data. Our method uses simulation-based inference combined with the needlet internal linear combination (NILC) algorithm and…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-19 Adriaan J. Duivenvoorden , Kristen Surrao , Adrian E. Bayer , Alexandre E. Adler , Nadia Dachlythra , Susanna Azzoni , J. Colin Hill

In this work we consider the realization of a variant emergent Universe scenario in the context of $f(R)$ gravity. We use well-known reconstruction techniques existing in the literature, and we find the approximate form of the vacuum $f(R)$…

General Relativity and Quantum Cosmology · Physics 2024-03-18 V. K. Oikonomou , Gregory K. Kafanelis

We present a new model for the formation of spherically symmetric clusters in an expanding Universe. Both the Universe and the collapsing cluster are governed by the same pressure less fluid equations for which a uniform initial density…

Astrophysics · Physics 2007-05-23 Y. Dabrowski , M. P. Hobson , A. N. Lasenby , C. Doran

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Craig Hogan , Stephan S. Meyer

Searches for the imprint of primordial gravitational waves in degree-scale CMB $B$-mode polarisation data must account for significant contamination from gravitational lensing. Fortunately, the lensing effects can be partially removed by…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-12 Antón Baleato Lizancos , Anthony Challinor , Julien Carron

Several missions following Planck are currently under development, which will provide high-precision measurements of the Cosmic Microwave Background (CMB) anisotropies. Specifically, measurements of the E modes will become nearly limited by…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Catherine Petretti , Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra , Sonia Paban

The observation of the polarised emission from the Cosmic Microwave Background (CMB) from future ground-based and satellite-borne experiments holds the promise of indirectly detecting the elusive signal from primordial tensor fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-22 Susanna Azzoni , David Alonso , Maximilian H. Abitbol , Josquin Errard , Nicoletta Krachmalnicoff

We consider a bouncing Universe model which explains the flatness of the primordial scalar spectrum via complex scalar field that rolls down its negative quartic potential and dominates in the Universe. We show that in this model, there…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Sergey Mironov

The recent measurements of the power spectrum of Cosmic Microwave Background anisotropies are consistent with the simplest inflationary scenario and big bang nucleosynthesis constraints. However, these results rely on the assumption of a…

In this letter, we propose a model of inflationary cosmology with a bounce preceded and study its primordial curvature perturbations. Our model gives rise to a primordial power spectrum with a feature of oscillation on large scales compared…

Astrophysics · Physics 2009-02-02 Yi-Fu Cai , Tao-tao Qiu , Jun-Qing Xia , Xinmin Zhang

We explore the possibility of emergent cosmology using the effective potential formalism. We discover new models of emergent cosmology which satisfy the constraints posed by the cosmic microwave background (CMB). We demonstrate that, within…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Satadru Bag , Varun Sahni , Yuri Shtanov , Sanil Unnikrishnan

We build upon previous analytical treatments of scalar perturbations in curved inflationary universes to obtain analytical templates for the primordial tensor power spectrum in models with non-zero primordial spatial curvature. These…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Ezra Msolla , Ayngaran Thavanesan

We study the generation of primordial perturbations in a (single-field) slow-roll inflationary universe. In momentum space, these (Gaussian) perturbations are characterized by a zero mean and a non-zero variance $\Delta^2(k, t)$. However,…

High Energy Physics - Theory · Physics 2010-04-06 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

We explore the potential of the B-mode anisotropies of the Cosmic Microwave Background radiation (CMB) to constrain the shape of the primordial tensor power spectrum in a model-independent way. We expand possible perturbations to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-09 M. Farhang , A. Vafaei Sadr

Diffusion damping of the cosmic microwave background (CMB) power spectrum results from imperfect photon-baryon coupling in the pre-recombination plasma. At redshift $5 \times 10^4 < z < 2 \times 10^6$, the plasma acquires an effective…

In this work we investigate the standard deviation of the Cosmic Microwave Background (CMB) temperature gradient field as a signature for a multiply connected nature of the Universe. CMB simulations of a spatially infinite universe model…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-02 Ralf Aurich , Thomas Buchert , Martin J. France , Frank Steiner

We have developed a fast method for predicting the angular power spectrum, C_l, of the cosmic microwave background given cosmological parameters and a primordial power spectrum of perturbations. After pre--computing the radiation…

Astrophysics · Physics 2009-11-07 Manoj Kaplinghat , Lloyd Knox , Constantinos Skordis

Loop quantum cosmology allows to replace the original singularity by a quantum bounce followed by a phase of fast expansion called super-inflation. In this paper, we use a simple analytic description of super-inflation using the equation of…

General Relativity and Quantum Cosmology · Physics 2015-03-19 J. Ribassin , E. Huguet , K. Ganga

Acoustic peaks in the Cosmic Microwave Background (CMB) temperature spectrum as observed by the Planck satellite appear to be smoother than our expectation from the standard model lensing effect. This anomalous effect can be also mimicked…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Dhiraj Kumar Hazra , Akhil Antony , Arman Shafieloo
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