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In a recently proposed approach to testing models of inflation by Cosmic Microwave Background (CMB) radiation the reheating temperature is directly expressed in terms of the CMB observables. Its model independent bounds translate in a given…

High Energy Physics - Phenomenology · Physics 2026-04-21 Michał Marciniak , Marek Olechowski , Stefan Pokorski

The accurate reconstruction of Cosmic Microwave Background (CMB) maps and the measurement of its power spectrum are crucial for studying the early universe. In this paper, we implement a convolutional neural network to apply the Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-07 Belén Costanza , Claudia G. Scóccola , Matías Zaldarriaga

Polarization of the cosmic microwave background (CMB) can help probe cosmic inflation (via primordial $B$ modes) and test parity-violating physics (via cosmic birefringence), but realizing the potential of these opportunities requires…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-17 Marta Monelli

The Quadratic Maximum Likelihood estimator can be used to reconstruct the Cosmic Microwave Background (CMB) power spectra with minimal error bars. Still, it requires an accurate estimate of the datasets noise covariance matrix in order to…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-28 S. Vanneste , S. Henrot-Versillé , T. Louis , M. Tristram

We introduce a pixel space method to detect dipole modulation or hemispherical power asymmetry in the cosmic microwave background (CMB) polarization. The method relies on the use of squared total polarized flux whose ensemble average picks…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Shamik Ghosh , Pankaj Jain

In forthcoming years, connections between cosmology and particle physics will be made increasingly important with the advent of a new generation of cosmic microwave background (CMB) experiments. Here, we review a number of these links. Our…

Astrophysics · Physics 2008-11-26 Marc Kamionkowski , Arthur Kosowsky

In addition to its spectrum and temperature anisotropy, the 2.7K Cosmic Microwave Background is also expected to exhibit a low level of polarization. The spatial power spectrum of the polarization can provide details about the formation of…

Astrophysics · Physics 2009-10-30 Brian Keating , Peter Timbie , Alexander Polnarev , Julia Steinberger

Future arcminute resolution polarization data from ground-based Cosmic Microwave Background (CMB) observations can be used to estimate the contribution to the temperature power spectrum from the primary anisotropies and to uncover the…

The statistical properties of a map of the primary fluctuations in the cosmic microwave background (CMB) may be specified to high accuracy by a few thousand power spectra measurements, provided the fluctuations are gaussian, yet the number…

Astrophysics · Physics 2009-11-07 Sujata Gupta , Alan F. Heavens

In the standard inflationary scenario, primordial perturbations are adiabatic. The amplitudes of most types of isocurvature perturbations are generally constrained by current data to be small. If, however, there is a baryon-density…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-24 Julian B. Muñoz , Daniel Grin , Liang Dai , Marc Kamionkowski , Ely D. Kovetz

Weak lensing distortion of the background cosmic microwave background (CMB) temperature and polarization patterns by the foreground density fluctuations is well studied in the literature. We discuss the gravitational lensing modification to…

Astrophysics · Physics 2009-11-11 Chao Li , Asantha Cooray

In the recent years, the internal-linear-combination (ILC) method was investigated extensively in the context of reconstruction of Cosmic Microwave Background (CMB) temperature anisotropy signal using observations obtained by WMAP and…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-06 Ujjal Purkayastha , Vipin Sudevan , Rajib Saha

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

We update the search for features, due to transient reductions in inflaton's speed of sound, in the Cosmic Microwave Background (CMB) angular power spectrum using Planck 2018 temperature, polarization and lensing data. We develop a new…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Guadalupe Cañas-Herrera , Jesús Torrado , Ana Achúcarro

The angular power spectrum of the cosmic microwave background (CMB) contains information on virtually all cosmological parameters of interest, including the geometry of the Universe ($\Omega$), the baryon density, the Hubble constant ($h$),…

Astrophysics · Physics 2009-10-28 Gerard Jungman , Marc Kamionkowski , Arthur Kosowsky , David N. Spergel

The current available CMB data show an anomalously low value of the CMB temperature fluctuations at large angular scales (l < 40). This lack of power is not explained by the minimal LCDM model, and one of the possible mechanisms explored in…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 Simony Santos da Costa , Micol Benetti , Jailson Alcaniz

Thermal inflation is a second epoch of exponential expansion at typical energy scales $V^{1/4} \sim 10^{6 \sim 8} \mathrm{GeV}$. If the usual primordial inflation is followed by thermal inflation, the primordial power spectrum is only…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-09 Kihyun Cho , Sungwook E. Hong , Ewan D. Stewart , Heeseung Zoe

We present a methodology to recover cosmic microwave background (CMB) polarization in which the quantity $P = Q+ iU$ is linearly combined at different frequencies using complex coefficients. This is the most general linear combination of…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-06 R. Fernández-Cobos , A. Marcos-Caballero , P. Vielva , E. Martínez-González , R. B. Barreiro

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Stefano Gariazzo

In this thesis we investigate several aspects related to the theory of fluctuations in the Cosmic Microwave Background. We develop a new algorithm to calculate the angular power spectrum of the anisotropies which is two orders of magnitude…

Astrophysics · Physics 2007-05-23 Matias Zaldarriaga
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