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Forthcoming cosmic microwave background experiments (CMB) will provide precise new tests of structure-formation theories. The geometry of the Universe may be determined robustly, and the classical cosmological parameters, such as the…

Astrophysics · Physics 2007-05-23 Marc Kamionkowski

We discuss a method for a model independent reconstruction of the CMB temperature fluctuation power spectrum on small and intermediate scales that is geared to individual experiments. The importance of off-diagonal correlations for…

Astrophysics · Physics 2009-09-25 Martin White

We present the status of our study into the feasibility of estimating the parameters of inflation from planned satellite observations of the anisotropy of the cosmic microwave background (CMB).We describe a perturbative procedure for…

Cosmic microwave background observations are most commonly analyzed by estimating the power spectrum. In the limit where the CMB statistics are perfectly Gaussian, this extracts all the information, but the CMB also contains detectable…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-09 Kendrick M. Smith

We update constraints on the Hubble function H(phi) during inflation, using the most recent cosmic microwave background (CMB) and large scale structure (LSS) data. Our main focus is on a comparison between various commonly used methods of…

Astrophysics · Physics 2009-06-23 Jan Hamann , Julien Lesgourgues , Wessel Valkenburg

The lack of large-angle correlations in the fluctuations of the cosmic microwave background (CMB) conflicts with predictions of slow-roll inflation. But though probabilities (< 0.24%) for the missing correlations disfavor the conventional…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Fulvio Melia , Martin Lopez-Corredoira

We discuss the issue of how precisely we can measure the primordial power spectrum by using future observations of 21 cm fluctuations and cosmic microwave background (CMB). For this purpose, we investigate projected constraints on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Kazunori Kohri , Yoshihiko Oyama , Toyokazu Sekiguchi , Tomo Takahashi

Minkowski functionals are summary statistics that capture the geometric and morphological properties of fields. They are sensitive to all higher order correlations of the fields and can be used to complement more conventional statistics,…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-06 Jan Hamann , Yuqi Kang

We reconstruct the primordial spectrum of the curvature perturbation, $P(k)$, from the observational data of the Wilkinson Microwave Anisotropy Probe (WMAP) by the cosmic inversion method developed recently. In contrast to conventional…

Astrophysics · Physics 2009-10-09 Noriyuki Kogo , Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama

We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of $e$-folds and four phenomenological parameters. This approach captures a number of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Hector Ramirez , Lotfi Boubekeur

We discuss the algorithmic information approach to the analysis of the observational data on the Universe. Kolmogorov complexity is proposed as a descriptor of the Cosmic Microwave Background (CMB) radiation maps. An algorithm of…

Astrophysics · Physics 2017-08-23 V. G. Gurzadyan

In order to reconstruct the initial conditions of the universe it is important to devise a method that can efficiently constrain the shape of the power spectrum of primordial matter density fluctuations in a model-independent way from data.…

Astrophysics · Physics 2009-11-10 Pia Mukherjee , Yun Wang

The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation.…

Astrophysics · Physics 2009-10-22 Alejandro Gangui

CMB and lensing reconstruction power spectra are powerful probes of cosmology. However they are correlated, since the CMB power spectra are lensed and the lensing reconstruction is constructed using CMB multipoles. We perform a full…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-20 Julien Peloton , Marcel Schmittfull , Antony Lewis , Julien Carron , Oliver Zahn

Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Cheng Cheng , Qing-Guo Huang

Inflationary models within string theory exhibit unusual scalar field dynamics involving non-minimal kinetic terms and generically referred to as k-inflation. In this situation, the standard slow-roll approach used to determine the behavior…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-08 Christophe Ringeval

Bursts of particle production during inflation provide a well-motivated mechanism for creating bump like features in the primordial power spectrum. Current data constrains these features to be less than about 5% the size of the featureless…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 Teeraparb Chantavat , Christopher Gordon , Joseph Silk

Spectral features in the CMB energy spectrum contain a wealth of information about the physical processes in the early Universe, z < 2 x 10^6. The CMB spectral distortions are complementary to all other probes of cosmology. In fact, most of…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-12 Rashid A. Sunyaev , Rishi Khatri

Although the cosmic microwave background (CMB) is largely understood to be homogeneous and isotropic, the CMB angular power spectra present anomalies that seem to break down parity symmetry at large angular scales. We argue that the…

General Relativity and Quantum Cosmology · Physics 2024-11-12 K. Sravan Kumar , João Marto

The observed angular power spectrum of the cosmic microwave background temperature anisotropy, $C_l$, is a convolution of a cosmological radiative transport kernel with an assumed primordial power spectrum of inhomogeneities. Exquisite…

Astrophysics · Physics 2009-11-10 Arman Shafieloo , Tarun Souradeep