English
Related papers

Related papers: Non-Gaussianity in Cosmic Microwave Background Tem…

200 papers

The leading candidate for the very early universe is described by a period of rapid expansion known as inflation. While the standard paradigm invokes a single slow-rolling field, many different models may be constructed which fit the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-30 D. M. Regan

The strong beams of high-frequency gravitational waves (GW) emitted by cusps and kinks of cosmic strings are studied in detail. As a consequence of these beams, the stochastic ensemble of GW's generated by a cosmological network of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Thibault Damour , Alexander Vilenkin

We account for particle emission and gravitational radiation from cosmic string loops to determine their effect on the loop distribution and observational signatures of strings. The effect of particle emission is that the number density of…

High Energy Physics - Phenomenology · Physics 2020-04-15 P. Auclair , D. A. Steer , T. Vachaspati

We calculate the bispectrum of the gravitational field fluctuations generated during warm inflation, where dissipation of the vacuum potential during inflation is the mechanism for structure formation. The bispectrum is non--zero because of…

Astrophysics · Physics 2011-05-10 S. Gupta , A. Berera , A. F. Heavens , S. Matarrese

COBE has provided us with a whole-sky map of the CBR anisotropies. However, even if the noise level is negligible when the four year COBE data are available, the cosmic variance will prevent us from obtaining information about the Gaussian…

Astrophysics · Physics 2016-08-30 Xiaochun Luo

Using analytical methods and Monte Carlo simulations, we analyze a new statistic designed to detect isolated step-like discontinuities which are coherent over large areas of Cosmic Microwave Background (CMB) pixel maps. Such coherent…

Astrophysics · Physics 2007-05-23 Leandros Perivolaropoulos

We develop an analytic approach to calculation of the temperature and polarisation power spectra of the cosmic microwave background due to inflationary gravitational waves. This approach complements the more precise numerical results by…

Astrophysics · Physics 2009-11-10 Jonathan R. Pritchard , Marc Kamionkowski

We examine the two-point correlation function of local maxima in temperature fluctuations at the last scattering surface when this stochastic field is modified by the additional fluctuations produced by straight cosmic strings via the…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-15 M. Sadegh Movahed , B. Javanmardi , Ravi K. Sheth

We extend and develop our previous work on the evolution of a network of cosmic strings. The new treatment is based on an analysis of the probability distribution of the end-to-end distance of a randomly chosen segment of left-moving string…

High Energy Physics - Phenomenology · Physics 2016-09-01 Daren Austin , E. J. Copeland , T. W. B. Kibble

In previous work, we constructed a convolutional neural network used to estimate the location of cosmic strings in simulated cosmic microwave background temperature anisotropy maps. We derived a connection between the estimates of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-11 Razvan Ciuca , Oscar F. Hernández

We present a new tool for relating theory and experiment suited for non-Gaussian theories: non-Gaussian spectra. It does for non-Gaussian theories what the angular power spectrum $C_\ell$ does for Gaussian theories. We then show how…

Astrophysics · Physics 2007-05-23 Joao Magueijo , Alex Lewin

We compute the contribution of kinks on cosmic string loops to stochastic background of gravitational waves (SBGW).We find that kinks contribute at the same order as cusps to the SBGW.We discuss the accessibility of the total background due…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-19 S. Olmez , V. Mandic , X. Siemens

We present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third…

Astrophysics · Physics 2015-05-13 P. Vielva , J. L. Sanz

We analyze statistical properties of the separate multipole moments of the CMB temperature maps and find that the distribution tails are slightly non-Gaussian. Moreover, the deviation from Gaussianity peaks sharply at around $l\sim45\pm10$.…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-01 Vitaly Vanchurin

We consider contributions to non-Gaussianity of the Cosmic Microwave Background (CMB) from remnants of post-inflationary phase transitions in the very early universe. Such signatures can optimistically be used to discover evidence of new…

Astrophysics · Physics 2010-01-11 Alessandra Silvestri , Mark Trodden

We investigate the statistical anisotropy and Gaussianity of temperature fluctuations of Cosmic Microwave Background radiation (CMB) data from {\it Wilkinson Microwave Anisotropy Probe} survey, using the multifractal detrended fluctuation…

Astrophysics · Physics 2011-08-04 M. Sadegh Movahed , F. Ghasemi , Sohrab Rahvar , M. Reza Rahimi Tabar

To take into account the temperature fluctuation in the Planck distribution, we calculate convolution integral with several probability distributions. Using these formula as well the Planck distribution and a formula in the non-extensive…

Statistical Mechanics · Physics 2007-05-23 M. Biyajima , M. Kaneyama , Y. Kurashima , T. Yamashita , T. Mizoguchi

Tighter constraints on measurements of primordial non-Gaussianity will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum-the standard method of measuring the local non-Gaussianity-is limited by…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-15 Zahra Gomes , Stefano Camera , Matt J. Jarvis , Catherine Hale , José Fonseca

Magnetic field fluctuations in the vicinity of the Earth's bow shock have been investigated with the aim to characterize the intermittent behaviour of strong plasma turbulence. The observed small-scale intermittency may be the signature of…

comp-gas · Physics 2020-01-29 T. Dudok de Wit , V. V. Krasnosel'skikh

We calculate the cosmic microwave background temperature bispectrum from cosmic strings, for the first time including the contributions from the last scattering surface, using a well-established Gaussian model for the string energy-momentum…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-21 Donough Regan , Mark Hindmarsh