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In material testing applications, Computed Tomography is a well established imaging technique that allows the recovery of the attenuation map of an object. Conventional modalities exploit only primary radiation and although in the energy…

Medical Physics · Physics 2020-07-07 Cécilia Tarpau , Javier Cebeiro , Mai K. Nguyen , Gevneviève Rollet , Laurent Dumas

In this paper, we study the problem of a batch of linearly correlated image alignment, where the observed images are deformed by some unknown domain transformations, and corrupted by additive Gaussian noise and sparse noise simultaneously.…

Computer Vision and Pattern Recognition · Computer Science 2022-12-14 Sijia Xia , Duo Qiu , Xiongjun Zhang

Recovering high-resolution structural and compositional information from coherent X-ray measurements involves solving coupled, nonlinear, and ill-posed inverse problems. Ptychography reconstructs a complex transmission function from…

Numerical Analysis · Mathematics 2026-05-13 Chengru Eric Zou , Elle Buser , Zichao Wendy Di , Yuanzhe Xi

A generalized covariant method of analysis applicable to frames for which time is not orthogonal to space, such as spacetime around a star possessing angular momentum or on a rotating disk, is presented. Important aspects of such an…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robert D. Klauber

Transformation optics offers an unconventional approach to the control of electromagnetic fields. A transformation optical structure is designed by first applying a form-invariant coordinate transform to Maxwell's equations, in which part…

The tensor decomposition addressed in this paper may be seen as a generalisation of Singular Value Decomposition of matrices. We consider general multilinear and multihomogeneous tensors. We show how to reduce the problem to a truncated…

Algebraic Geometry · Mathematics 2012-10-17 Alessandra Bernardi , Jerome Brachat , Pierre Comon , Bernard Mourrain

We consider geodesics on the surfaces obtained by weak deformations of the standard 2D-sphere. The dynamics of a particle on the surface can be asymptotically described by the averaged evolution of the particle's angular momentum. It is…

Mathematical Physics · Physics 2010-03-30 D. O. Sinitsyn

A spherical tensor expansion is carried out to express the resonant inelastic scattering cross-section as a sum of products of fundamental spectra with tensors involving wavevectors and polarization vectors of incident and scattered…

Strongly Correlated Electrons · Physics 2014-05-20 Amélie Juhin , Christian Brouder , Frank De Groot

The second fundamental form of Riemannian geometry is generalised to the case of a manifold with a linear connection and an integrable distribution. This bilinear form is generally not symmetric and its skew part is the torsion. The form…

Differential Geometry · Mathematics 2023-07-20 G. E. Prince

On a manifold with boundary, we deform the metric conformally. This induces a deformation of the Schouten tensor. We fix the metric at the boundary and realize a prescribed value for the product of the eigenvalues of the Schouten tensor in…

Analysis of PDEs · Mathematics 2007-05-23 Oliver C. Schnuerer

In this paper, we introduce tensor involved peridynamics, a unified framework for simulating both isotropic and anisotropic materials. While traditional peridynamics models effectively simulate isotropic materials, they face challenges with…

Materials Science · Physics 2024-12-23 Hao Tian , Jinlong Shao , Chenguang Liu , Shuo Liu , Xu Guo

Diffusion encoding along multiple spatial directions per signal acquisition can be described in terms of a b-tensor. The benefit of tensor-valued diffusion encoding is that it unlocks the "shape of the b-tensor" as a new encoding dimension.…

Medical Physics · Physics 2020-11-18 Filip Szczepankiewicz , Carl-Fredrik Westin , Markus Nilsson

A tensor form of phenomenological damping is derived for small magnetization motions. This form reflects basic physical relaxation processes for a general uniformly magnetized particle or film. Scalar Landau-Lifshitz damping is found to…

Statistical Mechanics · Physics 2009-11-07 Vladimir L. Safonov

We propose a new model to describe diffusion processes within active deformable media. Our general theoretical framework is based on physical and mathematical considerations, and it suggests to use diffusion tensors directly coupled to…

Tissues and Organs · Quantitative Biology 2021-03-03 Christian Cherubini , Simonetta Filippi , Alessio Gizzi , Ricardo Ruiz-Baier

We present novel equivalences in random matrix and tensor models between complex and self-adjoint theories with nontrivial quadratic terms in the action, established through an intermediate field representation. More precisely, we show that…

Mathematical Physics · Physics 2026-03-31 Juan Abranches , Alicia Castro , Reiko Toriumi

Low rank tensor decompositions are a powerful tool for learning generative models, and uniqueness results give them a significant advantage over matrix decomposition methods. However, tensors pose significant algorithmic challenges and…

Data Structures and Algorithms · Computer Science 2014-01-21 Aditya Bhaskara , Moses Charikar , Ankur Moitra , Aravindan Vijayaraghavan

We study thin self-assembled columns constrained to lie on a curved, rigid substrate. The curvature presents no local obstruction to equally spaced columns in contrast to curved crystals for which the crystalline bonds are frustrated.…

Soft Condensed Matter · Physics 2011-11-09 Christian D. Santangelo , Vincenzo Vitelli , Randall D. Kamien , David R. Nelson

Using a multiple scattering technique, we derived closed-form expressions for effective constitutive parameters and electro/magneto-strictive tensor components for 2D bi-anisotropic metamaterials. Using the principle of virtual work, we…

Optics · Physics 2018-08-01 Neng Wang , Shubo Wang , Zhao-Qing Zhang , C. T. Chan

Diffusion-attenuated MR signal for heterogeneous media has been represented as a sum of signals from anisotropic Gaussian sub-domains. Any effect of macroscopic (global or ensemble) anisotropy in the signal can be removed by averaging the…

Applied Physics · Physics 2020-01-03 Magnus Herberthson , Cem Yolcu , Hans Knutsson , Carl-Fredrik Westin , Evren Özarslan

The cosine transforms of functions on the unit sphere play an important role in convex geometry, the Banach space theory, stochastic geometry and other areas. Their higher-rank generalization to Grassmann manifolds represents an interesting…

Functional Analysis · Mathematics 2007-05-23 E. Ournycheva , B. Rubin