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We simulate CMB maps including non-Gaussianity arising from cubic order perturbations of the primordial gravitational potential, characterized by the non-linearity parameter $g_{NL}$. The maps are used to study the characteristic nature of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Pravabati Chingangbam , Changbom Park

Weak lensing of galaxies and CMB photons through the large-scale structure of the Universe is one of the most promising cosmological probes with upcoming experiments dedicated to its measurements such as Euclid/LSST and CMB Stage 4…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Alexandre Barthelemy , Sandrine Codis , Francis Bernardeau

Recent tentative findings of non-Gaussian structure in the COBE-DMR dataset have triggered renewed attention to candidate models from which such intrinsic signature could arise. In the framework of slow roll inflation with built-in non…

Astrophysics · Physics 2009-10-31 Alejandro Gangui , Jerome Martin

We calculate the fluctuations in the current and energy densities for the case of a quantized, minimally coupled, massless, complex scalar field around a straight and infinitesimally thin cosmic string carrying magnetic flux. At zero…

General Relativity and Quantum Cosmology · Physics 2009-10-31 L. Sriramkumar

We study the topology generated by the temperature fluctuations of the Cosmic Microwave Background (CMB) radiation, as quantified by the number of components and holes, formally given by the Betti numbers, in the growing excursion sets. We…

We introduce an exact Bayesian approach to search for non-Gaussianity of local type in Cosmic Microwave Background (CMB) radiation data. Using simulated CMB temperature maps, the newly developed technique is compared against the…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-15 Franz Elsner , Benjamin D. Wandelt

We present cosmic microwave background (CMB) power spectra from recent numerical simulations of cosmic strings in the Abelian Higgs model and compare them to CMB power spectra measured by Planck. We obtain revised constraints on the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-28 Joanes Lizarraga , Jon Urrestilla , David Daverio , Mark Hindmarsh , Martin Kunz

We perform high resolution ray-tracing simulations to investigate probability distribution functions (PDFs) of lensing convergence, shear, and magnification on distant sources up to the redshift of $z_s=20$. We pay particular attention to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ryuichi Takahashi , Masamune Oguri , Masanori Sato , Takashi Hamana

We study how the presence of world-sheet currents affects the evolution of cosmic string networks, and their impact on predictions for the cosmic microwave background (CMB) anisotropies generated by these networks. We provide a general…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 I. Yu. Rybak , A. Avgoustidis , C. J. A. P. Martins

Using an analytic model we show that the predictions of the cosmic string model for the peculiar velocities and the microwave background (MBR) anisotropy depend on similar combinations of string evolution parameters. Normalizing from the…

High Energy Physics - Phenomenology · Physics 2009-10-22 L. Perivolaropoulos , T. Vachaspati

Considerable recent attention has focussed on the prospects to use the cosmic microwave background (CMB) trispectrum to probe the physics of the early universe. Here we evaluate the probability distribution function (PDF) for the standard…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Tristan L. Smith , Marc Kamionkowski

We re-examine the constraints on the cosmic string tension from Cosmic Microwave Background (CMB) and matter power spectra, and also from limits on a stochastic background of gravitational waves provided by pulsar timing. We discuss the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Richard Battye , Adam Moss

We present a new calculation for the evolution of the 1-point Probability Distribution Function (PDF) of the cosmological density field based on an exact statistical treatment. Using the Chapman-Kolmogorov equation and second-order Eulerian…

Astrophysics · Physics 2009-10-31 Andrew Taylor , Peter Watts

Non-Gaussian distributions of cosmic microwave background (CMB) anisotropies have been proposed to reconcile the discrepancies between different experiments at half-degree scales (Coulson et al. 1994). Each experiment probes a different…

Astrophysics · Physics 2009-10-22 Xiaochun Luo

Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-09 Christophe Ringeval , Daisuke Yamauchi , Jun'ichi Yokoyama , Francois R. Bouchet

We present ray tracing simulations combined with sets of large N-body simulations. Experiments were performed to explore, for the first time, statistical properties of fluctuations in angular separations of nearby light ray pairs (the…

Astrophysics · Physics 2016-08-30 Takashi Hamana , Yannick Mellier

The presence of axion strings in the Universe after recombination can leave an imprint on the polarization pattern of the cosmic microwave background radiation through the phenomenon of axion-string-induced birefringence via the hyperlight…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-19 Ray Hagimoto , Andrew J. Long

We introduce a new technique to detect the discrete temperature steps that cosmic strings might have left in the cosmic microwave background (CMB) anisotropy map. The technique provides a validity test on the pattern search of cosmic…

Astrophysics · Physics 2009-11-11 E. Jeong , G. F. Smoot

We continue our studies of the evolution and cosmological consequences of current-carrying cosmic string networks, described by a charge-velocity-dependent one scale (CVOS) model. We present a detailed calculation of the effects of these…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-23 I. Yu. Rybak , C. J. A. P. Martins , Patrick Peter , E. P. S. Shellard

Information about the physical processes that generate the primordial fluctuations in the early universe can be gained by testing the Gaussian nature of the fluctuations through cosmic microwave background radiation (CBR) temperature…

Astrophysics · Physics 2009-12-30 Xiaochun Luo
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