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Related papers: Ray Velocity Derivatives in Anisotropic Elastic Me…

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In Part I of this study, we obtained the ray (group) velocity gradients and Hessians with respect to the ray locations, directions and the anisotropic model parameters, at nodal points along ray trajectories, considering general anisotropic…

Geophysics · Physics 2021-12-01 Igor Ravve , Zvi Koren

The form of the Lagrangian proposed in Part I of this study has been previously used for obtaining stationary ray paths between two endpoints in isotropic media. We extended it to general anisotropy by replacing the isotropic medium…

Geophysics · Physics 2020-03-23 Zvi Koren , Igor Ravve

We present a new ray bending approach, referred to as the Eigenray method, for solving two-point boundary-value kinematic and dynamic ray tracing problems in 3D smooth heterogeneous general anisotropic elastic media. The proposed Eigenray…

Geophysics · Physics 2020-03-23 Zvi Koren , Igor Ravve

In Part V of this study, we presented an original Lagrangian approach for computing the dynamic characteristics along stationary rays, by solving the linear, second-order Jacobi differential equation, considering four sets of initial…

Geophysics · Physics 2020-03-24 Igor Ravve , Zvi Koren

Parts V, VI and VII of this study are dedicated to the computation of paraxial rays and dynamic characteristics along the stationary rays obtained numerically in Part III. In this part (Part V), we formulate the linear, second-order, Jacobi…

Geophysics · Physics 2020-03-24 Igor Ravve , Zvi Koren

Wavefield travel time tomography is used for a variety of purposes in acoustics, geophysics and non-destructive testing. Since the problem is non-linear, assessing uncertainty in the results requires many forward evaluations. It is…

Geophysics · Physics 2023-08-21 James Ludlam , Katherine Tant , Victorita Dolean , Andrew Curtis

Considering 3D heterogeneous anisotropic media, in Part III of this study we obtain the finite-element solution for the stationary ray path between two fixed endpoints using the finite element approach. It involves computation of the global…

Geophysics · Physics 2020-03-24 Igor Ravve , Zvi Koren

In this part, we apply the same finite-element approach, used in Part III for the vanishing first traveltime variation (to obtain the stationary rays), for the second traveltime variation, in order to compute the dynamic characteristics…

Geophysics · Physics 2020-03-26 Igor Ravve , Zvi Koren

Using curvature and torsion to describe Lagrangian trajectories gives a full description of these as well as an insight into small and large time scales as temporal derivatives up to order 3 are involved. One might expect that the…

We lay down the foundations of particle dynamics in mechanical theories that satisfy the relativity principle and whose kinematics can be formulated employing reference frames of the type usually adopted in special relativity. Such…

General Relativity and Quantum Cosmology · Physics 2009-06-30 Sebastiano Sonego , Massimo Pin

In seismic imaging, understanding the relationship between wavefront-propagation velocity and time-interval velocity is crucial for achieving optimal resolution. However, this task becomes even more challenging when considering anisotropic…

Geophysics · Physics 2025-04-28 Tiago A. Coimbra , Rodrigo Bloot , Jorge H. Faccipieri

We establish a Lagrangian variational framework for general relativistic continuum theories that permits the development of the process of Lagrangian reduction by symmetry in the relativistic context. Starting with a continuum version of…

Mathematical Physics · Physics 2024-09-23 François Gay-Balmaz

The 'vertical modes and horizontal rays' method, commonly applied for simulating acoustic wave propagation in shallow water is advanced in this research. Our approach to this method involves the use of the so-called space-time rays, which…

Mathematical Physics · Physics 2025-01-08 Aleksandr Kaplun , Boris Katsnelson

We consider the scattering of elastic waves by highly oscillating anisotropic periodic media with bounded support. Applying the two-scale homogenization, we first obtain a constant coefficient second-order partial differential elliptic…

Analysis of PDEs · Mathematics 2018-02-06 Yi-Hsuan Lin , Shixu Meng

Lagrangian statistics of passive tracers in rotating turbulence is investigated by Particle Tracking Velocimetry. A confined and steadily-forced turbulent flow is subjected to five different rotation rates. The PDFs of the velocity…

Fluid Dynamics · Physics 2013-07-24 Lorenzo Del Castello , Herman J. H. Clercx

This work presents a generalized physical interpretation of unconventional dispersion asymmetries associated moving elastic solids. By shifting the notion from systems with time-variant material fields to physically traveling materials, the…

Applied Physics · Physics 2019-01-15 M. A. Attarzadeh , M. Nouh

In this work we study the generalization of the problem, considered in [{\it Phys. Rev. E} {\bf 91}, 013002 (2015)], to the case of {\it finite} correlation time of the environment (velocity) field. The model describes a vector (e.g.,…

Statistical Mechanics · Physics 2015-10-27 N. V. Antonov , N. M. Gulitskiy

This chapter describes briefly the key aspects behind the derivation of precise radial velocities. I start by defining radial velocity precision in the context of astrophysics in general and exoplanet searches in particular. Next I discuss…

Earth and Planetary Astrophysics · Physics 2017-11-23 Pedro Figueira

We prove quantitative estimates for flows of vector fields subject to anisotropic regularity conditions: some derivatives of some components are (singular integrals of) measures, while the remaining derivatives are (singular integrals of)…

Analysis of PDEs · Mathematics 2014-12-09 Anna Bohun , Francois Bouchut , Gianluca Crippa

A two-point ray-tracing technique for 3D smoothly heterogeneous, weakly transversely-isotropic media is based on Fermat's principle and takes advantage of global Chebyshev approximation of both the model and curved rays. This approximation…

Geophysics · Physics 2019-02-07 Vladimir Grechka , George A. McMechan
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