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In this manuscript, we investigate the patterns satisfied by the cosmological anisotropy under the hypothesis of the observers being co-moving with a perfect fluid whose induced space sections are homogeneous with vanishing scalar…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Leandro G. Gomes

This paper investigates the problem of time-harmonic acoustic scattering in an inhomogeneous medium with a complex topological structure. Specifically, the medium is anisotropic and contains several disjoint sound-soft obstacles. This model…

Mathematical Physics · Physics 2025-09-30 Huaian Diao , Qingle Meng , Zhiying Sun

We extend a well-studied ODE model for collective behaviour by considering anisotropic interactions among individuals. Anisotropy is modelled by limited sensorial perception of individuals, that depends on their current direction of motion.…

Classical Analysis and ODEs · Mathematics 2014-06-05 Joep H. M. Evers , Razvan C. Fetecau , Lenya Ryzhik

There is no universal model for thixotropy, and comparing thixotropic effects between different fluids is a subtle yet challenging problem. We introduce a generalized (model-insensitive) framework for comparing thixotropic properties based…

Soft Condensed Matter · Physics 2023-11-28 Samya Sen , Randy H. Ewoldt

We analyze the velocity anisotropy of stars in real and energy space for a sample of Milky Way-like galaxies in the TNG50 simulation. We employ different selection criteria, including spatial, kinematic and metallicity cuts, and make three…

In this paper, we consider the travel time tomography problem for conformal metrics on a bounded domain, which seeks to determine the conformal factor of the metric from the lengths of geodesics joining boundary points. We establish forward…

Differential Geometry · Mathematics 2024-05-28 Ashwin Tarikere , Hanming Zhou

When the elastic properties of structured materials become direction-dependent, the number of their descriptors increases. For example, in two-dimensions, the anisotropic behavior of materials is described by up to 6 independent elastic…

Materials Science · Physics 2023-12-14 Jagannadh Boddapati , Moritz Flaschel , Siddhant Kumar , Laura De Lorenzis , Chiara Daraio

We present a new method of constraining the mass and velocity anisotropy profiles of galaxy clusters from kinematic data. The method is based on a model of the phase space density which allows the anisotropy to vary with radius between two…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Radoslaw Wojtak , Ewa L. Lokas , Gary A. Mamon , Stefan Gottloeber

In this paper, we consider the problem of estimating parameters of a linear regression model. Using a hybrid systems framework, a hybrid algorithm is proposed allowing the estimate to converge to the exact value of the unknown parameters in…

Systems and Control · Electrical Eng. & Systems 2026-03-04 Adnane Saoud , Ryan S. Johnson , Ricardo G. Sanfelice

We present an optimization-based method for the joint estimation of system parameters and noise covariances of linear time-variant systems. Given measured data, this method maximizes the likelihood of the parameters. We solve the…

Optimization and Control · Mathematics 2023-03-21 Léo Simpson , Andrea Ghezzi , Jonas Asprion , Moritz Diehl

Concepts of high precision studies of the one-way speed of light anisotropy are discussed. The high energy particle beam allows measurement of a one-way speed of light anisotropy (SOLA) via analysis of the beam momentum variation with…

General Relativity and Quantum Cosmology · Physics 2017-06-06 B. Wojtsekhowski

The effective anisotropic stresses induced by the scalar modes of the geometry depend on the coordinate system so that the comparison of the competing results is ultimately determined by the evolution of the pivotal variables in each…

High Energy Physics - Theory · Physics 2021-02-24 Massimo Giovannini

The density profile of simulated dark matter structures is fairly well-established, and several explanations for its characteristics have been put forward. In contrast, the radial variation of the velocity anisotropy has still not been…

Astrophysics · Physics 2014-11-18 Steen H. Hansen

In this paper we present an analysis of information transfer time based on holomorphism, causality and the classical principle of stationary phase. We also make a preliminary study of the effect of noise on information transfer time, and…

Optics · Physics 2007-05-23 Michael C. Parker , Stuart D. Walker

Linear regressions with endogeneity are widely used to estimate causal effects. This paper studies a framework that involves two common practical issues: endogeneity of the regressors and heteroskedasticity that depends on endogenous…

Econometrics · Economics 2025-12-10 Javier Alejo , Antonio F. Galvao , Julian Martinez-Iriarte , Gabriel Montes-Rojas

We consider an inhomogeneous model and independently an anisotropic model of primordial power spectrum in order to describe the observed hemispherical anisotropy in Cosmic Microwave Background Radiation. This anisotropy can be parametrized…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-31 Rahul Kothari , Shamik Ghosh , Pranati K. Rath , Gopal Kashyap , Pankaj Jain

The viscosity parameters play a fundamental role in applications involving stochastic primitive equations (SPE), such as accurate weather predictions, climate modeling, and ocean current simulations. In this paper, we develop several novel…

Probability · Mathematics 2025-04-21 Igor Cialenco , Ruimeng Hu , Quyuan Lin

We developed a novel contactless frequency-domain approach to study thermal transport, which is particularly convenient when thermally anisotropic materials are considered. The method is based on a similar line-shaped heater geometry as…

We consider parameter estimation, hypothesis testing and variable selection for partially time-varying coefficient models. Our asymptotic theory has the useful feature that it can allow dependent, nonstationary error and covariate…

Statistics Theory · Mathematics 2012-08-20 Ting Zhang , Wei Biao Wu

We introduce directional regularity, a new definition of anisotropy for multivariate functional data. Instead of taking the conventional view, which determines anisotropy as a notion of smoothness along a dimension, directional regularity…

Methodology · Statistics 2026-05-05 Omar Kassi , Sunny G. W. Wang