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We present a simple model that accurately describes various statistical properties of peculiar velocities of dark matter halos. We pay particular attention to the following two effects; first, the evolution of the halo peculiar velocity…

Astrophysics · Physics 2009-11-07 Takashi Hamana , Issha Kayo , Naoki Yoshida , Yasushi Suto , Y. P. Jing

As a planet transits the face of a star, it accelerates along the line-of-sight. The changing delay in the propagation of photons produces an apparent deceleration of the planet across the sky throughout the transit. This persistent…

Astrophysics · Physics 2009-11-10 Abraham Loeb

We study the averaging of fronts moving with positive oscillatory normal velocity, which is periodic in space and stationary ergodic in time. The problem can be reformulated as the homogenization of coercive level set Hamilton-Jacobi…

Analysis of PDEs · Mathematics 2014-08-12 W. Jing , P. E. Souganidis , H. V. Tran

Intermittency as it occurs in fast dynamos in the MHD framework is evaluated through the examination of relations between normalized moments at third order (skewness S) and fourth order (kurtosis K) for both the velocity and magnetic field,…

Plasma Physics · Physics 2025-03-11 Yannick Ponty , Helene Politano , Annick Pouquet

The Event Horizon Telescope is preparing to produce time sequences of black hole images, or movies. In anticipation, we developed an autocorrelation technique to measure apparent rotational motion using the image-domain pattern speed…

High Energy Astrophysical Phenomena · Physics 2025-10-13 Nicholas S. Conroy , Michi Bauböck , Vedant Dhruv , Daeyoung Lee , Chi-kwan Chan , Abhishek V. Joshi , Ben Prather , Charles F. Gammie

We study the effects of Lorentz non-invariance on the physical pion velocity at the critical temperature $T_c$ in an effective theory of hidden local symmetry (HLS) with the "vector manifestation" fixed point. We match at a "matching scale"…

High Energy Physics - Phenomenology · Physics 2015-06-25 Masayasu Harada , Youngman Kim , Mannque Rho , Chihiro Sasaki

We examine models in which the accelerated expansion of the universe is driven by a scalar field rolling near an inflection point in the potential. For the simplest such models, in which the potential is of the form V(\phi) = V_0 + V_3…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Hui-Yiing Chang , Robert J. Scherrer

A spherically symmetric and static metric that describes physical coordinates is introduced. It is defined to be a metric that gives coordinate independent results for physically observable quantities without a further coordinate…

Astrophysics · Physics 2007-05-23 Yukio Tomozawa

A hierarchical Bayesian model is applied to the Cosmicflows-3 catalog of galaxy distances in order to derive the peculiar velocity field and distribution of matter within $z \sim 0.054$. The model assumes the $\Lambda$CDM model within the…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 R. Graziani , H. M. Courtois , G. Lavaux , Y. Hoffman , R. B. Tully , Y. Copin , D. Pomarède

We consider an anisotropic inhomogeneous model to simulate measured vertical-seismic-profile traveltimes. In this model, we assume that velocity increases linearly with depth and anisotropy is the result of elliptical velocity dependence.…

Geophysics · Physics 2020-12-08 Ayiaz Kaderali , Theodore Stanoev

We introduce a global quantity $\delta$ that characterizes turbulent fluctuations in inhomogeneous anisotropic flows. This time-dependent quantity is based on spatial averages of global velocity fields rather than classical temporal…

The longitudinal Doppler shift is a measure of hyperbolic distance. Transformations of uniform motion are determined by the Doppler shift, while its square root transforms to a uniformly accelerated frame. A time-velocity space metric is…

General Physics · Physics 2008-05-16 B. H. Lavenda

A standard approach to propulsion velocities of autophoretic colloids with thin interaction layers uses a reciprocity relation applied to the slip velocity. But the surface flux (chemical, electrical, thermal, etc.), which is the source of…

Soft Condensed Matter · Physics 2016-08-24 Paul E. Lammert , Vincent H. Crespi , Amir Nourhani

This paper is devoted to a statistical analysis of the velocity fluctuations arising from a random distribution of point vortices in two-dimensional turbulence. Exact results are derived for the correlations in the velocities occurring at…

Statistical Mechanics · Physics 2009-10-31 Pierre-Henri Chavanis , Clément Sire

A new method for the formal solution of the 2D radiative transfer equation in axial symmetry in the presence of arbitrary velocity fields is presented. The combination of long and short characteristics methods is used to solve the radiative…

Astrophysics · Physics 2016-08-16 D. Korčáková , J. Kubát

We consider the convergence of kinetic Langevin dynamics to its ergodic invariant measure, which is Gibbs distribution. Instead of the standard setup where the friction coefficient is a constant scalar, we investigate position-dependent…

Probability · Mathematics 2024-07-02 Keunwoo Lim , Molei Tao

We study numerically the one-dimensional Allen-Cahn equation with the spectral fractional Laplacian $(-\Delta)^{\alpha/2}$ on intervals with homogeneous Neumann boundary conditions. In particular, we are interested in the speed of sharp…

Dynamical Systems · Mathematics 2024-07-25 Franz Achleitner , Christian Kuehn , Jens Markus Melenk , Alexander Rieder

In this paper we consider a telegraph equation with time-dependent coefficients, governing the persistent random walk of a particle moving on the line with a time-varying velocity $c(t)$ and changing direction at instants distributed…

Probability · Mathematics 2020-01-09 Luca Angelani , Roberto Garra

We consider the so-called G-equation, a level set Hamilton-Jacobi equation, used as a sharp interface model for flame propagation, perturbed by an oscillatory advection in a spatio-temporal periodic environment. Assuming that the advection…

Analysis of PDEs · Mathematics 2011-02-16 Pierre Cardaliaguet , James Nolen , Panagiotis E. Souganidis

Two motions in the galactic plane have been detected and characterized, based on the determination of a common systematic component in Hipparcos catalogue proper motions. The procedure is based only on positions, proper motions and…

Astrophysics · Physics 2007-05-23 Carlos Abad , Katherine Vieira