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Related papers: A Bayesian Monte-Carlo Analysis of the M-sigma Rel…

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We explore the stability of the variance and skewness of the cosmic gravitational convergence field, using two different approaches: first we simulate a whole MEGACAM survey (100 sq. degrees). The reconstructed mass map, obtained from a…

Astrophysics · Physics 2007-05-23 A. Thion , Y. Mellier , F. Bernardeau , E. Bertin , T. Erben , L. van Waerbeke

We present measurements of the specific angular momentum $j_\star$ of 41 star-forming galaxies at $1.5<z<2.5$. These measurements are based on radial profiles inferred from near-IR \textit{HST} photometry, along with multi-resolution…

We present a study of the statistical properties of three velocity dispersion and mass estimators, namely biweight, gapper and standard deviation, in the small number of galaxies regime ($N_{\rm gal} \le 75$). Using a set of 73 numerically…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-09 A. Ferragamo , J. A. Rubiño-Martín , J. Betancort-Rijo , E. Munari , B. Sartoris , R. Barrena

In many polarimetry applications, including observations in the X-ray band, the measurement of a polarization signal can be reduced to the detection and quantification of a deviation from uniformity of a distribution of measured angles. We…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Tod E. Strohmayer , Tim R. Kallman

Given a real symmetric positive semi-definite matrix E, and an approximation S that is a sum of n independent matrix-valued random variables, we present bounds on the relative error in S due to randomization. The bounds do not depend on the…

Numerical Analysis · Mathematics 2018-01-03 John T. Holodnak , Ilse C. F. Ipsen , Ralph C. Smith

In predictive modeling with simulation or machine learning, it is critical to accurately assess the quality of estimated values through output analysis. In recent decades output analysis has become enriched with methods that quantify the…

Methodology · Statistics 2023-10-27 Kimia Vahdat , Sara Shashaani

To synthesize diffusion MR measurements from Monte-Carlo simulation using tissue models with sizes comparable to those of scan voxels. Larger regions enable restricting structures to be modeled in greater detail and improve accuracy and…

Computational Physics · Physics 2017-01-16 Matt G Hall , Gemma Nedjati-Gilani , Daniel C Alexander

Upcoming X-ray surveys like eROSITA require precise calibration between X-ray observables and mass down to the low mass regime to set tight constraints on the fundamental cosmological parameters. Since an individual mass measurement is only…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-14 Lorenzo Lovisari , Thomas Reiprich , Gerrit Schellenberger

This paper investigates the impact of Malmquist bias on the distance to the Virgo cluster determined by the H_0 Key Project using M100, and consequently on the derived value of H_0. Malmquist bias is a volume-induced statistical effect…

Astrophysics · Physics 2009-10-30 Anthony H. Gonzalez , S. M. Faber

The velocity dispersion of galaxies on scales of $r\sim1h^{-1}$ Mpc, $\sigma_{12}(r)$, may be estimated from the anisotropy of the galaxy-galaxy correlation function in redshift space. We present a reanalysis of the CfA1 survey, correct an…

Astrophysics · Physics 2009-10-28 Rachel S. Somerville , Marc Davis , Joel R. Primack

Monte Carlo (MC) algorithms are commonly employed to explore high-dimensional parameter spaces constrained by data. All the statistical information obtained in the output of these analyses is contained in the Markov chains, which one needs…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Adrià Gómez-Valent

The influence of various factors on the statistical properties of the Galactic center distance ($R_0$) estimate obtained by solving the general problem of determining the geometric parameters of a Galactic spiral arm from its segment with…

Astrophysics of Galaxies · Physics 2018-11-19 I. I. Nikiforov , A. V. Veselova

To investigate the $M_\bullet -\sigma$ relation, we consider realistic elliptical galaxy profiles that are taken to follow a single power law density profile given by $\rho(r) = \rho_{0}(r/ r_{0})^{-\gamma}$ or the Nuker intensity profile.…

Astrophysics of Galaxies · Physics 2020-04-14 Dipanweeta Bhattacharyya , A. Mangalam

The radio surface brightness-to-diameter ({\Sigma} - D) relation for supernova remnants (SNRs) in the starburst galaxy M82 is analyzed in a statistically more robust manner than in the previous studies that mainly discussed sample quality…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-27 D. Urosevic , B. Vukotic , B. Arbutina , M. Sarevska

Importance-weighting is a popular and well-researched technique for dealing with sample selection bias and covariate shift. It has desirable characteristics such as unbiasedness, consistency and low computational complexity. However,…

Machine Learning · Statistics 2019-03-12 Wouter M. Kouw , Marco Loog

The contact values $g(\sigma,\sigma')$ of the radial distribution functions of a fluid of (additive) hard spheres with a given size distribution $f(\sigma)$ are considered. A ``universality'' assumption is introduced, according to which, at…

Statistical Mechanics · Physics 2007-05-23 A. Santos , S. B. Yuste , M. Lopez de Haro

Most studies of correlations between X-ray and optical properties of galaxy clusters have used the largest samples of data available, regardless of the morphological types of clusters included. Given the increasing evidence that morphology…

Astrophysics · Physics 2009-10-28 Christina M. Bird , Richard F. Mushotzky , Christopher A. Metzler

This paper presents a theoretical analysis of sample selection bias correction. The sample bias correction technique commonly used in machine learning consists of reweighting the cost of an error on each training point of a biased sample to…

Machine Learning · Computer Science 2008-12-18 Corinna Cortes , Mehryar Mohri , Michael Riley , Afshin Rostamizadeh

Large differences between the properties of the known sample of cataclysmic variable stars (CVs) and the predictions of the theory of binary star evolution have long been recognised. However, because all existing CV samples suffer from…

Astrophysics · Physics 2008-11-26 Magaretha L. Pretorius , Christian Knigge , Ulrich Kolb

Recent high-resolution interferometric images of submillimetre galaxies (SMGs) reveal fascinatingly complex morphologies. This raises a number of questions: how does the relative orientation of a galaxy affect its observed submillimetre…

Astrophysics of Galaxies · Physics 2022-08-31 C. C. Lovell , J. E. Geach , R. Davé , D. Narayanan , K. E. K. Coppin , Q. Li , M. Franco , G. C. Privon