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Smooth vector fields on $\mathbb{R}^n$ can be decomposed into the sum of a gradient vector field and divergence-free (solenoidal) vector field under suitable hypotheses. This is called the Helmholtz-Hodge decomposition (HHD), which has been…

Dynamical Systems · Mathematics 2020-07-17 Tomoharu Suda

RNA's diverse biological functions stem from its structural versatility, yet accurately predicting and designing RNA sequences given a 3D conformation (inverse folding) remains a challenge. Here, I introduce a deep learning framework that…

Quantitative Methods · Quantitative Biology 2026-01-06 Annabelle Yao

We examine holographic renormalization by the singular value decomposition (SVD) of matrix data generated by the Monte Carlo snapshot of the 2D classical Ising model at criticality. To take the continuous limit of the SVD enables us to find…

Statistical Mechanics · Physics 2016-11-03 Hiroaki Matsueda

We generalize Y. Nievergelt's inversion method for the Radon transform on lines in the 2-plane to the $k$-plane Radon transform of continuous and $L^p$ functions on $R^n$ for all $1\leq k<n$.

Functional Analysis · Mathematics 2009-08-05 Elena Ournycheva , Boris Rubin

We consider an inverse problem arising in thermo-/photo- acoustic tomography that amounts to reconstructing a function $f$ from its circular or spherical means with the centers lying on a given measurement surface. (Equivalently, these…

Analysis of PDEs · Mathematics 2015-09-02 Leonid Kunyansky

Zeeman-Doppler Imaging (ZDI) is a powerful inversion method to reconstruct stellar magnetic surface fields. The reconstruction process is usually solved by translating the inverse problem into a regularized least-square or optimization…

Solar and Stellar Astrophysics · Physics 2009-11-13 T. A. Carroll , M. Kopf , K. G. Strassmeier , I. Ilyin

The theory of contractions of multivectors, and star duality, was reorganized in a previous article, and here we present some applications. First, we study inner and outer spaces associated to a general multivector $M$ via the equations $v…

General Mathematics · Mathematics 2024-10-30 André L. G. Mandolesi

We study the integral transform over a general family of broken rays in $\mathbb{R}^2$. It is natural for broken rays to have conjugate points, for example, when they are reflected from a curved boundary. If there are conjugate points, we…

Analysis of PDEs · Mathematics 2018-03-02 Yang Zhang

Generic singularities of line fields have been studied for lines of principal curvature of embedded surfaces. In this paper we propose an approach to classify generic singularities of general line fields on 2D manifolds. The idea is to…

Differential Geometry · Mathematics 2016-05-23 Ugo Boscain , Ludovic Sacchelli , Mario Sigalotti

We solve the problem of constructing a genus-zero full conformal field theory (a conformal field theory on genus-zero Riemann surfaces containing both chiral and antichiral parts) from representations of a simple vertex operator algebra…

Quantum Algebra · Mathematics 2008-11-26 Yi-Zhi Huang , Liang Kong

In this paper, the photon stationary transport equation has been extended from $\mathbb{R}^3$ to $\mathbb{C}^3$. A solution of the inverse problem is obtained on a hyper-sphere and a hyper-cylinder as X-ray and Radon transform,…

Mathematical Physics · Physics 2015-03-19 Seyed Majid Saberi Fathi

A real vector space combined with an inverse for vectors is sufficient to define a vector continued fraction whose parameters consist of vector shifts and changes of scale. The choice of sign for different components of the vector inverse…

Mathematical Physics · Physics 2009-11-10 Roger Haydock , C. M. M. Nex , Geoffrey Wexler

The normal form theory for polynomial vector fields is extended to those for $C^\infty$ vector fields vanishing at the origin. Explicit formulas for the $C^\infty$ normal form and the near identity transformation which brings a vector field…

Dynamical Systems · Mathematics 2024-06-19 Hayato Chiba

One of the main computational drawbacks in the application of 3-D iterative inversion techniques is the requirement of solving the field quantities for the updated contrast in every iteration. In this paper, the 3-D electromagnetic inverse…

Signal Processing · Electrical Eng. & Systems 2019-06-27 Shilong Sun , Bert Jan Kooij , Alexander G. Yarovoy

We introduce a rotation-invariant representation of planar shapes. In particular, this representation encodes shapes as vectors such that the Euclidean distance between them serves as a valid shape distance. For standardized, star-shaped…

Computational Geometry · Computer Science 2026-05-28 Hamid Shafieasl , Jeff M. Phillips

We give a global geometric decomposition of continuously differentiable vector fields on $\mathbb{R}^n$. More precisely, given a vector field of class $\mathcal{C}^{1}$ on $\mathbb{R}^{n}$, and a geometric structure on $\mathbb{R}^n$, we…

Dynamical Systems · Mathematics 2019-05-31 Razvan M. Tudoran

The results on the inversion of convolution operators and Toeplitz matrices in the 1-D (one dimensional) case are classical and have numerous applications. We consider a 2-D case of Toeplitz-block Toeplitz matrices, describe a minimal…

Classical Analysis and ODEs · Mathematics 2020-07-03 Alexander Sakhnovich

In 1927 Philomena Mader derived elegant inversion formulas for the hyperplane Radon transform on $\bbr^n$. These formulas differ from the original ones by Radon and seem to be forgotten. We generalize Mader's formulas to totally geodesic…

Complex Variables · Mathematics 2011-03-14 Yuri A. Antipov , Boris Rubin

We consider the inhomogeneous div-curl system (i.e.\ to find a vector field with prescribed div and curl) in a bounded star-shaped domain in $\mathbb{R}^3$. An explicit general solution is given in terms of classical integral operators,…

Mathematical Physics · Physics 2024-10-15 Briceyda B. Delgado , R. Michael Porter

We propose a novel formulation for the second-order total generalized variation (TGV) of the normal vector on an oriented, triangular mesh embedded in $\R^3$. The normal vector is considered as a manifold-valued function, taking values on…

Computer Vision and Pattern Recognition · Computer Science 2025-10-27 Lukas Baumgärtner , Ronny Bergmann , Roland Herzog , Stephan Schmidt , Manuel Weiß