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A formalism is presented that allows cosmological experiments to be tested for consistency, and allows a simple frequentist interpretation of the resulting significance levels. As an example of an application, this formalism is used to…

Astrophysics · Physics 2009-10-07 Max Tegmark , Emory Bunn , Wayne Hu

Surveys of galaxy distances and radial peculiar velocities can be used to reconstruct the large scale structure. Other than systematic errors in the zero-point calibration of the galaxy distances the main source of uncertainties of such…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 Yehuda Hoffman , Adi Nusser , Aurelien Valade , Noam I. Libeskind , R. Brent Tully

We compare an autoencoder convolutional neural network (AE-CNN) with a conventional maximum-likelihood estimator (MLE) for inferring cluster virial masses, $M_v$, directly from the galaxy distribution around clusters, without identifying…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Raeed Mundow , Adi Nusser

We investigate the extent to which correlated distortions of the luminosity distance-redshift relation due to large-scale bulk flows limit the precision with which cosmological parameters can be measured. In particular, peculiar velocities…

Astrophysics · Physics 2009-11-11 Asantha Cooray , Robert R. Caldwell

We study nonparametric maximum likelihood estimation of a log-concave density function $f_0$ which is known to satisfy further constraints, where either (a) the mode $m$ of $f_0$ is known, or (b) $f_0$ is known to be symmetric about a fixed…

Statistics Theory · Mathematics 2019-05-15 Charles R. Doss , Jon A. Wellner

Given $n$ independent random vectors with common density $f$ on $\mathbb{R}^d$, we study the weak convergence of three empirical-measure based estimators of the convex $\lambda$-level set $L_\lambda$ of $f$, namely the excess mass set, the…

Statistics Theory · Mathematics 2020-06-04 Philippe Berthet , John H. J. Einmahl

The hot intracluster medium (ICM) provides a unique laboratory to test multi-scale physics in numerical simulations and probe plasma physics. Utilizing archival Chandra observations, we measure density fluctuations in the ICM in a sample of…

High Energy Astrophysical Phenomena · Physics 2024-01-30 Annie Heinrich , Irina Zhuravleva , Congyao Zhang , Eugene Churazov , William Forman , Reinout J. van Weeren

We study the gradient flow for a relaxed approximation to the Kullback-Leibler (KL) divergence between a moving source and a fixed target distribution. This approximation, termed the KALE (KL approximate lower-bound estimator), solves a…

Machine Learning · Statistics 2021-11-01 Pierre Glaser , Michael Arbel , Arthur Gretton

We characterize the radial and angular variance of the Hubble flow in the COMPOSITE sample of 4534 galaxies, on scales in which much of the flow is in the nonlinear regime. With no cosmological assumptions other than the existence of a…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 David L. Wiltshire , Peter R. Smale , Teppo Mattsson , Richard Watkins

Cosmological measurements have revealed tensions within the standard $\Lambda$CDM model, notably discrepancies in the Hubble constant and $S_8$ parameter. A modified recombination scenario involving a time-varying electron mass has been…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-30 Yi-Ying Wang , Lei Lei , Shao-Peng Tang , Yi-Zhong Fan

The Millimeter-wave Intensity Mapping Experiment (mmIME) recently reported a detection of excess spatial fluctuations at a wavelength of 3 mm, which can be attributed to unresolved emission of several CO rotational transitions between…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-20 Patrick C. Breysse , Shengqi Yang , Rachel S. Somerville , Anthony R. Pullen , Gergö Popping , Abhishek S. Maniyar

We propose a new method to measure the possible large-scale bulk flows in the Universe from the cosmic microwave background (CMB) maps from the upcoming missions, MAP and Planck. This can be done by studying the statistical properties of…

Astrophysics · Physics 2009-10-31 A. Kashlinsky , F. Atrio-Barandela

We explore the detectability of bulk motions in the X-ray emitting intracluster medium (ICM) using a catalog of 1,836 mock Astro-E2 observations of simulated clusters of galaxies. We generate high resolution mock spectra for two observing…

Astrophysics · Physics 2009-11-10 Andrew Pawl , August E. Evrard , Renato A. Dupke

To study galactic motions on the largest available scales, we require bulk flow moments whose window functions have as narrow a peak as possible and having as small an amplitude as possible outside the peak. Typically the moments found…

Astrophysics · Physics 2008-05-13 Hume A. Feldman , Michael J. Hudson , Richard Watkins

In this paper we apply to gravitational waves from non-spinning binary systems a recently intro- duced frequentist methodology to calculate analytically the error for a maximum likelihood estimate (MLE) of physical parameters. While…

General Relativity and Quantum Cosmology · Physics 2011-02-02 Salvatore Vitale , Michele Zanolin

We analyze in detail the peculiar velocity field traced by 56 clusters within 120 h^-1 Mpc in the Streaming Motions of Abell Clusters (SMAC) sample. The bulk flow of the SMAC sample is 687 +- 203 km/s, toward l = 260 +- 13, b = 0 +- 11. We…

Astrophysics · Physics 2009-11-10 Michael J. Hudson , Russell J. Smith , John R. Lucey , Enzo Branchini

We study the instantaneous inference of an unbounded planar flow from sparse noisy pressure measurements. The true flow field comprises one or more regularized point vortices of various strength and size. We interpret the true flow's…

Fluid Dynamics · Physics 2024-05-08 Jeff D. Eldredge , Mathieu Le Provost

We present a measurement of the velocity flow of the local universe relative to the CMB rest frame, based on the Jha, Riess & Kirshner (2007) sample of 133 low redshift type Ia supernovae. At a depth of 4500 km/s we find a dipole amplitude…

The mounting evidence for anomalously large peculiar velocities in our Universe presents a challenge for the LCDM paradigm. The recent estimates of the large scale bulk flow by Watkins et al. are inconsistent at the nearly 3 sigma level…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Mark Wyman , Justin Khoury

There is a $\sim 150 km s^{-1}$ discrepancy between the measured motion of the Local Group of galaxies (LG) with respect to the CMB and the linear theory prediction based on the gravitational force field of the large scale structure in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Adi Nusser , Marc Davis , Enzo Branchini
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