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I discuss an issue arising in analyzing data from astronomical surveys: accounting for measurement uncertainties in the properties of individual sources detected in a survey when making inferences about the entire population of sources.…

Astrophysics · Physics 2009-11-10 Thomas J. Loredo

We study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty…

Astrophysics · Physics 2008-12-30 M. Liguori , A. Riotto

CMB anisotropy data could put powerful constraints on theories of the evolution of our Universe. Using the observations of the large number of CMB experiments, many studies have put constraints on cosmological parameters assuming different…

Astrophysics · Physics 2015-06-24 Marian Douspis

We present a neural net algorithm for parameter estimation in the context of large cosmological data sets. Cosmological data sets present a particular challenge to pattern-recognition algorithms since the input patterns (galaxy redshift…

Astrophysics · Physics 2007-05-23 Nicholas G. Phillips , A. Kogut

Modern cosmology relies on the assumption of large-scale isotropy and homogeneity of the Universe. However, locally the Universe is inhomogeneous and anisotropic. So, how can local measurements (at the 100 Mpc scale) be used to determine…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-21 Alexander Wiegand , Dominik J. Schwarz

We estimate how clustering in large-scale redshift surveys can constrain various cosmological parameters. Depth and sky coverage of modern redshift surveys are greater than ever, opening new possibilities for statistical analysis. We have…

Astrophysics · Physics 2009-11-07 Takahiko Matsubara , Alexander S. Szalay

Empirical estimates of the band power covariance matrix are commonly used in cosmic microwave background (CMB) power spectrum analyses. While this approach easily captures correlations in the data, noise in the resulting covariance estimate…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 L. Balkenhol , C. L. Reichardt

In the absence of any compelling physical model, cosmological systematics are often misrepresented as statistical effects and the approach of marginalising over extra nuisance systematic parameters is used to gauge the effect of the…

Astrophysics · Physics 2009-10-20 T. D. Kitching , A. Amara , F. B. Abdalla , B. Joachimi , A. Refregier

The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, {\it i.e.} aberration, and a shift in their frequency, {\it i.e.} Doppler effect. Both effects distort the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Riccardo Catena , Alessio Notari

We provide an efficient method to approximate the covariance between decision variables and uncertain parameters in solutions to a general class of stochastic nonlinear complementarity problems. We also develop a sensitivity metric to…

Optimization and Control · Mathematics 2018-10-10 Sriram Sankaranarayanan , Felipe Feijoo , Sauleh Siddiqui

We propose a modification of a maximum likelihood procedure for tuning parameter values in models, based upon the comparison of their output to field data. Our methodology, which uses polynomial approximations of the sample space to…

Data Analysis, Statistics and Probability · Physics 2013-07-03 Nusret Balci , Juan M. Restrepo , Shankar C. Venkataramani

Over the last decade, cosmological observations have attained a level of precision which allows for detailed comparison with theoretical predictions. In this paper, we briefly review some studies of the current and prospected constraints…

Popular Physics · Physics 2007-05-23 Monique Signore , Denis Puy

We assess the accuracy with which future galaxy surveys can measure cosmological parameters by deriving a handy approximation that we validate numerically. We find that galaxy surveys are quite complementary to future Cosmic Microwave…

Astrophysics · Physics 2009-10-07 Max Tegmark

Astrophysics and cosmology are rich with data. The advent of wide-area digital cameras on large aperture telescopes has led to ever more ambitious surveys of the sky. Data volumes of entire surveys a decade ago can now be acquired in a…

Instrumentation and Methods for Astrophysics · Physics 2017-04-18 Jan Kremer , Kristoffer Stensbo-Smidt , Fabian Gieseke , Kim Steenstrup Pedersen , Christian Igel

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Janis Fluri , Aurelien Lucchi , Tomasz Kacprzak , Alexandre Refregier , Thomas Hofmann

The estimation of cosmological constraints from observations of the large scale structure of the Universe, such as the power spectrum or the correlation function, requires the knowledge of the inverse of the associated covariance matrix,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Dante J. Paz , Ariel G. Sanchez

A grand challenge of the 21st century cosmology is to accurately estimate the cosmological parameters of our Universe. A major approach to estimating the cosmological parameters is to use the large-scale matter distribution of the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Siamak Ravanbakhsh , Junier Oliva , Sebastien Fromenteau , Layne C. Price , Shirley Ho , Jeff Schneider , Barnabas Poczos

Relying on recent advances in statistical estimation of covariance distances based on random matrix theory, this article proposes an improved covariance and precision matrix estimation for a wide family of metrics. The method is shown to…

Machine Learning · Statistics 2021-02-03 Malik Tiomoko , Florent Bouchard , Guillaume Ginholac , Romain Couillet

Exclusion zones in the cross-correlations between critical points (peak-void, peak-wall, filament-wall, filament-void) of the density field define quasi-standard rulers that can be used to constrain dark matter and dark energy cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-19 Junsup Shim , Christophe Pichon , Dmitri Pogosyan , Stephen Appleby , Corentin Cadiou , Juhan Kim , Katarina Kraljic , Changbom Park

Current and upcoming cosmological surveys will produce unprecedented amounts of high-dimensional data, which require complex high-fidelity forward simulations to accurately model both physical processes and systematic effects which describe…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-11 Aizhan Akhmetzhanova , Carolina Cuesta-Lazaro , Siddharth Mishra-Sharma
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