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According to the perturbed Friedmann model, the difference between Hubble constant measurements in two rest frames, at leading order in velocity, is determined solely by the relative motion of the observers and remains unaffected by the…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-24 Xiaoyun Shao , Carlos A. P. Bengaly

This paper presents a least mean square (LMS) algorithm for the joint estimation of acoustic and mean flow velocities from laser doppler velocimetry (LDV) measurements. The usual algorithms used for measuring with LDV purely acoustic…

Classical Physics · Physics 2009-07-08 Laurent Simon , Olivier Richoux , Anne Degroot , Louis Lionet

In this study, we employ the maximum likelihood estimator (MLE) to investigate the relationship between initial-state fluctuations and final-state anisotropies in relativistic heavy-ion collisions. The granularity of the initial state,…

Nuclear Theory · Physics 2025-02-11 Shui-Fa Shen , Chong Ye , Dan Wen , Lina Bao , Jin Li , Yutao Xing , Jiaming Jiang , Wei-Liang Qian

Churn flow-the chaotic, oscillatory regime in vertical two-phase flow-has lacked a quantitative mathematical definition for over $40$ years. We introduce the first topology-based characterization using Euler Characteristic Surfaces (ECS).…

Machine Learning · Computer Science 2026-04-08 Brady Koenig , Sushovan Majhi , Atish Mitra , Abigail Stein , Burt Todd

The peculiar radial velocities of eight clusters of galaxies, as determined from a variety of distance indicators, are consistent with a bulk flow not greatly different in direction and magnitude from the velocity vector of the Local Group…

Astrophysics · Physics 2007-05-23 Donald H. Gudehus

An accurate determination of the Hubble constant remains a puzzle in observational cosmology. The possibility of a new physics has emerged with a significant tension between the current expansion rate of our Universe measured from the…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , G. Pordeus-da-Silva , S. H. Pereira

The maximum likelihood amplitude estimation algorithm (MLAE) is a practical solution to the quantum amplitude estimation problem with Heisenberg limit error convergence. We improve MLAE by using random depths to avoid the so-called critical…

Quantum Physics · Physics 2023-11-20 Xi Lu , Hongwei Lin

The knowledge of the main features of the bulk flow in the Local Universe is important for a better determination of the relative motions there, an information that would contribute to a precise calculation of the Hubble-Lema\^{\i}tre law…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-13 Felipe Avila , Jezebel Oliveira , Mariana L. S. Dias , Armando Bernui

A new method for the localization of the regions where small scale turbulent fluctuations are present in hypersonic flows is applied to the large-eddy simulation (LES) of a compressible turbulent jet with an initial Mach number equal to 5.…

Fluid Dynamics · Physics 2015-06-12 D. Tordella , M. Iovieno , S. Massaglia , A. Mignone

This is a brief progress report on a long-term collaborative project to measure the power spectrum (PS) of mass density fluctuations from the Mark III and the SFI catalogs of peculiar velocities. The PS is estimated by applying maximum…

Astrophysics · Physics 2007-05-23 Idit Zehavi

This work studies the properties of the maximum likelihood estimator (MLE) of a non-linear model with Gaussian errors and multidimensional parameter. The observations are collected in a two-stage experimental design and are dependent since…

Statistics Theory · Mathematics 2019-11-01 Nancy Flournoy , Caterina May , Chiara Tommasi

The systemic velocity or redshift of galaxies is a convenient tool to calculate their distances in the absence of primary methods, but the uncertainties on these flow distances may be substantial due to galaxy peculiar motions. Here, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-23 Konstantin Haubner , Federico Lelli , Enrico Di Teodoro , Francis Duey , Stacy McGaugh , James Schombert

Recent measurements of the parameters of the Concordance Cosmology Model ($\Lambda$CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done with Cosmic Microwave Background (CMB) imply different…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 B. Czerny , M. L. Martínez-Aldama , G. Wojtkowska , M. Zajaček , P. Marziani , D. Dultzin , M. H. Naddaf , S. Panda , R. Prince , R. Przyluski , M. Ralowski , M. Śniegowska

(abridged) We perform a reconstruction of the cosmological large scale flows in the nearby Universe using two complementary observational sets. The first, the SFI++ sample of Tully-Fisher (TF) measurements of galaxies, provides a direct…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Marc Davis , Adi Nusser , Karen Masters , Christopher Springob , John P. Huchra , Gerard Lemson

The k-monotone classes of densities defined on (0, \infty) have been known in the mathematical literature but were for the first time considered from a statistical point of view by Balabdaoui and Wellner (2007, 2010). In these works, the…

Statistics Theory · Mathematics 2013-01-16 Fadoua Balabdaoui , Simon Foucart , Jon A. Wellner

This paper introduces the Variational Determinant Estimator (VDE), a variational extension of the recently proposed determinant estimator discovered by arXiv:2005.06553v2. Our estimator significantly reduces the variance even for low sample…

Machine Learning · Computer Science 2021-01-11 Simon Passenheim , Emiel Hoogeboom

Cosmological perturbations of sufficiently long wavelength admit a fluid dynamic description. We consider modes with wavevectors below a scale $k_m$ for which the dynamics is only mildly non-linear. The leading effect of modes above that…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 Diego Blas , Stefan Floerchinger , Mathias Garny , Nikolaos Tetradis , Urs Achim Wiedemann

An approximate mean square error (MSE) expression for the performance analysis of implicitly defined estimators of non-random parameters is proposed. An implicitly defined estimator (IDE) declares the minimizer/maximizer of a selected…

Signal Processing · Electrical Eng. & Systems 2025-12-02 Erdal Mehmetcik , Umut Orguner , Çağatay Candan

We use laser-Doppler velocimetry (LDV) experiments and Reynolds-averaged Navier--Stokes (RANS) simulations to study the characteristic flow patterns downstream of a standardized clockwise swirl disturbance generator. After quantifying the…

Fluid Dynamics · Physics 2015-10-27 Diego del Olmo Díaz , Denis F. Hinz

All previous experiments in open turbulent flows (e.g. downstream of grids, jet and atmospheric boundary layer) have produced quantitatively consistent values for the scaling exponents of velocity structure functions. The only measurement…

Chaotic Dynamics · Physics 2018-02-14 E-W. Saw , P. Debue , D. Kuzzay , F. Daviaud , B. Dubrulle