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Related papers: Comparison of Spectral Index Determinations

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We derive the primordial power spectrum of density fluctuations in the framework of quantum cosmology. For this purpose we perform a Born-Oppenheimer approximation to the Wheeler-DeWitt equation for an inflationary universe with a scalar…

General Relativity and Quantum Cosmology · Physics 2012-01-17 Claus Kiefer , Manuel Kraemer

Upcoming and existing large-scale surveys of galaxies require accurate theoretical predictions of the dark matter clustering statistics for thousands of mock galaxy catalogs. We demonstrate that this goal can be achieve with our new…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Anatoly Klypin , Francisco Prada

Recent data from the WMAP, ACT and SPT experiments provide precise measurements of the cosmic microwave background temperature power spectrum over a wide range of angular scales. The combination of these observations is well fit by the…

The spectral fluctuations of complex quantum systems, in appropriate limit, are known to be consistent with that obtained from random matrices. However, this relation between the spectral fluctuations of physical systems and random matrices…

Quantum Physics · Physics 2020-09-16 S. Harshini Tekur , M. S. Santhanam

Recently the second phase of Background Imaging of Cosmic Extragalactic Polarization (BICEP2) claimed a detection of the tensor-to-scalar ratio ($r$) of primordial fluctuation at $5\sigma$ confidence level. If it is true, this large and…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-06 Yi Wang , Yin-Zhe Ma

We derive a non-perturbative, closed, analytic equation for the non-linear power spectrum of cosmic density fluctuations. This result is based on our kinetic field theory (KFT) of cosmic structure formation and on evaluating particle…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-23 Matthias Bartelmann , Felix Fabis , Sara Konrad , Elena Kozlikin , Robert Lilow , Carsten Littek , Johannes Dombrowski

We compute the decay spectrum for dark matter (DM) with masses above the scale of electroweak symmetry breaking, all the way to the Planck scale. For an arbitrary hard process involving a decay to the unbroken standard model, we determine…

High Energy Physics - Phenomenology · Physics 2021-07-07 Christian W. Bauer , Nicholas L. Rodd , Bryan R. Webber

To test a theory of cosmic microwave background fluctuations, it is natural to expand an anisotropy map in an uncorrelated basis of linear combinations of pixel amplitudes --- statistically-independent for both the noise and the signal.…

Astrophysics · Physics 2009-01-23 J. Richard Bond

I review a number of tests of theories for structure formation. Large-scale flows and IRAS galaxies indicate a high density parameter $\Omega \simeq 1$, in accord with inflationary predictions, but it is not clear how this meshes with the…

Astrophysics · Physics 2007-05-23 Nick Kaiser

We propose a new approximated expression for non-linear Dark Matter power spectrum much beyond BAO scales. The proposed expression agrees with the result of N-body simulation with the accuracy better than 2 % up to k=1.0 [h/Mpc] and k=0.7…

General Relativity and Quantum Cosmology · Physics 2012-12-03 Naonori S. Sugiyama , Toshifumi Futamase

We consider the running of the spectral index as a probe of both inflation itself, and of the overall evolution of the very early universe. Surveying a collection of simple single field inflationary models, we confirm that the magnitude of…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Peter Adshead , Richard Easther , Jonathan Pritchard , Abraham Loeb

We introduce the cosmic momentum field as a new measure of the large-scale peculiar velocity and matter fluctuation fields. The momentum field is defined as the peculiar velocity field traced and weighted by galaxies, and is equal to the…

Astrophysics · Physics 2009-10-31 Changbom Park

The spectral principle of Connes and Chamseddine is used as a starting point to define a discrete model for Euclidean quantum gravity. Instead of summing over ordinary geometries, we consider the sum over generalized geometries where…

High Energy Physics - Theory · Physics 2009-11-10 Luiz C. de Albuquerque , Jorge L. deLyra , Paulo Teotonio-Sobrinho

Using the temperature data from Planck we search for departures from a power-law primordial power spectrum, employing Bayesian model-selection and posterior probabilities. We parametrize the spectrum with $n$ knots located at arbitrary…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-28 Grigor Aslanyan , Layne C. Price , Kevork N. Abazajian , Richard Easther

We provide predictions on small-scale cosmological density power spectrum from supernova lensing dispersion. Parameterizing the primordial power spectrum with running $\alpha$ and running of running $\beta$ of the spectral index, we exclude…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-11 Ido Ben-Dayan , Ryuichi Takahashi

We calculate the power spectrum of vacuum fluctuations of a generic scalar field in a quantum cosmological setting that is manifestly singularity-free. The power spectrum is given in terms of the usual scale invariant spectrum plus scale…

Astrophysics · Physics 2007-05-23 S. Hofmann , O. Winkler

The angular power spectra of the infrared maps obtained by the DIRBE (Diffuse InfraRed Background Experiment) instrument on the COBE satellite have been obtained by two methods: the Hauser-Peebles method previously applied to the DMR maps,…

Astrophysics · Physics 2009-10-30 Edward L. Wright

We study the spectral tilt of primordial perturbations in Horava-Lifshitz cosmology. The uniform approximation, which is a generalization of the familiar Wentzel-Kramers-Brillouin (WKB) method, is employed to compute the spectral index both…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-24 Kazuhiro Yamamoto , Tsutomu Kobayashi , Gen Nakamura

Precision measurements of anisotropies in the cosmic microwave background and of the clustering of large-scale structure have supposedly confirmed that the primordial density perturbation has a (nearly) scale-invariant spectrum. However…

High Energy Physics - Phenomenology · Physics 2011-02-16 Subir Sarkar

For the inflaton perturbations it is shown that the evolution of the difference between the spectral indices can be translated into information on the scale dependence of the tensor to scalar amplitudes ratio, $r$, and how the scalar field…

Astrophysics · Physics 2009-11-07 C. A. Terrero-Escalante