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We determine the best-fit values and confidence limits for dynamical dark energy parameters together with other cosmological parameters on the basis of different datasets which include WMAP9 or Planck-2013 results on CMB anisotropy, BAO…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 B. Novosyadlyj , O. Sergijenko , R. Durrer , V. Pelykh

We propose a new high dimensional semiparametric principal component analysis (PCA) method, named Copula Component Analysis (COCA). The semiparametric model assumes that, after unspecified marginally monotone transformations, the…

Machine Learning · Statistics 2014-02-20 Fang Han , Han Liu

Late time cosmic acceleration may be achieved by modifying gravity on large scales. This should also have consequences on the evolution of perturbations. We thus extend our study of exponential infrared $f(T)$ teleparallel gravity to…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Mahmoud Hashim , Amr A. El-Zant , Waleed El Hanafy , Alexey Golovnev

The recent WMAP data represents a milestone in cosmology and helps constrain cosmological parameters with unprecedented accuracy. In this work we combine the WMAP data with previous CMB anisotropy measurements at smaller angular scales to…

Astrophysics · Physics 2015-06-24 C. J. Odman

We study the accuracy with which cosmological parameters can be determined from real space power spectrum of matter density contrast at weakly nonlinear scales using analytical approaches. From power spectra measured in $N$-body simulations…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 Ken Osato , Takahiro Nishimichi , Francis Bernardeau , Atsushi Taruya

By confronting the two independent Boltzmann codes CLASS and CAMB, we establish that for concordance cosmology and for a given recombination history, lensed CMB and matter power spectra can be computed by current codes with an accuracy of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Julien Lesgourgues

We present a method for ultra-fast confrontation of the WMAP cosmic microwave background observations with theoretical models, implemented as a publicly available software package called CMBfit, useful for anyone wishing to measure…

Astrophysics · Physics 2013-08-07 Havard B. Sandvik , Max Tegmark , Xiaomin Wang , Matias Zaldarriaga

Constraints on the main cosmological parameters using CMB or large scale structure data are usually based on power-law assumption of the primordial power spectrum (PPS). However, in the absence of a preferred model for the early universe,…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-14 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

Predictive coding (PC) is a biologically plausible alternative to standard backpropagation (BP) that minimises an energy function with respect to network activities before updating weights. Recent work has improved the training stability of…

Machine Learning · Computer Science 2026-05-25 Francesco Innocenti , El Mehdi Achour , Rafal Bogacz

We present a sample-variance-limited measurement of the temperature power spectrum ($TT$) of the cosmic microwave background (CMB) using observations of a $\sim\! 1500 \,\mathrm{deg}^2$ field made by SPT-3G in 2018. We report multifrequency…

We present a self-contained description of everything needed to write a program that calculates the CMB power spectrum for the standard model of cosmology (LCDM). This includes the equations used, assumptions and approximations imposed on…

Astrophysics · Physics 2007-05-23 Petter Callin

We introduce a noise-aware extension to the parametric maximum-likelihood framework for component separation by modeling correlated $1/f^\alpha$ noise as a harmonic-space power law. This approach addresses a key limitation of existing…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-07 Goureesankar Sathyanathan , Josquin Errard , Soumen Basak

Cosmological analyses can be accelerated by approximating slow calculations using a training set, which is either precomputed or generated dynamically. However, this approach is only safe if the approximations are well understood and…

Instrumentation and Methods for Astrophysics · Physics 2015-09-03 Grigor Aslanyan , Richard Easther , Layne C. Price

To improve the accuracy and efficiency of high-dimensional stellar parameter inference in large spectroscopic datasets, we propose a projection-assisted parameter-inference framework -- Projected-Space Inference of Stellar Parameters…

A peak has been unambiguously detected in the cosmic microwave background (CMB) angular spectrum. Here we characterize its properties with fits to phenomenological models. We find that the TOCO and BOOM/NA data determine the peak location…

Astrophysics · Physics 2009-10-31 Lloyd Knox , Lyman Page

VPIC is a general purpose Particle-in-Cell simulation code for modeling plasma phenomena such as magnetic reconnection, fusion, solar weather, and laser-plasma interaction in three dimensions using large numbers of particles. VPIC's…

Distributed, Parallel, and Cluster Computing · Computer Science 2021-06-16 Robert Bird , Nigel Tan , Scott V. Luedtke , Stephen Lien Harrell , Michela Taufer , Brian Albright

Reconstructing the shape of the primordial power spectrum in a model independent way from cosmological data is a useful consistency check on what is usually assumed regarding early universe physics. It is also our primary window to unknown…

Astrophysics · Physics 2008-11-26 Pia Mukherjee , Yun Wang

Line intensity mapping (LIM) is an emerging technique with a unique potential to probe a wide range of scales and redshifts. Realizing the full potential of LIM, however, relies on accurate modeling of the signal. We introduce an extended…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-23 Azadeh Moradinezhad Dizgah , Farnik Nikakhtar , Garrett K. Keating , Emanuele Castorina

Sampling-based motion planners (SBMPs) are effective for planning with complex kinodynamic constraints in high-dimensional spaces, but they still struggle to achieve real-time performance, which is mainly due to their serial computation…

Robotics · Computer Science 2025-02-06 Nicolas Perrault , Qi Heng Ho , Morteza Lahijanian

Accurate measurements of angular power spectrum of Cosmic Microwave Background (CMB) radiation has lead to marked improvement in the estimates of different cosmological parameters. This has required removal of foreground contamination as…

Astrophysics · Physics 2009-11-13 Rajib Saha , Pankaj Jain , Tarun Souradeep