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Related papers: The Spherical Cap Discrepancy of HEALPix Points

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Pach showed that every $d+1$ sets of points $Q_1,\dotsc,Q_{d+1} \subset \mathbb{R}^d$ contain linearly-sized subsets $P_i\subset Q_i$ such that all the transversal simplices that they span intersect. We show, by means of an example, that a…

Combinatorics · Mathematics 2019-11-20 Boris Bukh , Alfredo Hubard

We study random spherical harmonics at shrinking scales. We compare the mass assigned to a small spherical cap with its area, and find the smallest possible scale at which, with high probability, the discrepancy between them is small…

Probability · Mathematics 2017-11-07 Matthew de Courcy-Ireland

We study stable immersed capillary hypersurfaces $\Sigma$ in domains B of R n+1 bounded by hyperplanes. When B is a half-space, we show $\Sigma$ is a spherical cap. When B is a domain bounded by k hyperplanes P 1 ,. .. , P k , 2 $\le$ k…

Differential Geometry · Mathematics 2022-01-12 Rabah Souam

Recent years have witnessed the surge of learned representations that directly build upon point clouds. Though becoming increasingly expressive, most existing representations still struggle to generate ordered point sets. Inspired by…

Computer Vision and Pattern Recognition · Computer Science 2023-02-06 Jiaxin Wei , Lige Liu , Ran Cheng , Wenqing Jiang , Minghao Xu , Xinyu Jiang , Tao Sun , Soren Schwertfeger , Laurent Kneip

Understanding how particles are arranged on the sphere is not only central to numerous physical, biological, and materials systems but also finds applications in mathematics and in analysis of geophysical and meteorological measurements. In…

Soft Condensed Matter · Physics 2019-03-06 Anže Lošdorfer Božič , Simon Čopar

Let m>1 and n>1 be any pair of integers. In this paper we prove that if H is between the numbers \cot(\frac{\pi}{m}) and b_{m,n}=\frac{(m^2-2)\sqrt{n-1}}{n\sqrt{m^2-1}}, then, there exists a non isoparametric, compact embedded hypersurface…

Differential Geometry · Mathematics 2009-03-10 Oscar Perdomo

In this paper, we show that the total area of two distinct surfaces with Gaussian curvature equal to 1, which are also conformal to the Euclidean unit disk with the same conformal factor on the boundary, must be at least 4{\pi}. In other…

Analysis of PDEs · Mathematics 2016-10-28 Changfeng Gui , Amir Moradifam

A fast and exact algorithm is developed for the spin +-2 spherical harmonics transforms on equi-angular pixelizations on the sphere. It is based on the Driscoll and Healy fast scalar spherical harmonics transform. The theoretical exactness…

Astrophysics · Physics 2008-11-26 Y. Wiaux , L. Jacques , P. Vandergheynst

We consider capillarity functionals which measure the perimeter of sets contained in a Euclidean half-space assigning a constant weight $\lambda \in (-1,1)$ to the portion of the boundary that touches the boundary of the half-space.…

Analysis of PDEs · Mathematics 2024-10-01 Giulio Pascale , Marco Pozzetta

Spherical $t$-designs are finite point sets on the unit sphere that enable exact integration of polynomials of degree at most $t$ via equal-weight quadrature. This concept has recently been extended to spherical $t$-design curves by the use…

Combinatorics · Mathematics 2025-03-05 Martin Ehler

Image segmentation plays a central role in computer vision. However, widely used evaluation metrics, whether pixel-wise, region-based, or boundary-focused, often struggle to capture the structural and topological coherence of a…

Computer Vision and Pattern Recognition · Computer Science 2026-01-21 Serena Grazia De Benedictis , Amedeo Altavilla , Nicoletta Del Buono

The parameterization of open and closed anatomical surfaces is of fundamental importance in many biomedical applications. Spherical harmonics, a set of basis functions defined on the unit sphere, are widely used for anatomical shape…

Computational Geometry · Computer Science 2022-06-30 Gary P. T. Choi , Amita Giri , Lalan Kumar

In this paper, we study curvature estimates for nodal sets of harmonic functions in the plane. We prove that at any point $p$, the curvature of each nodal curve of any harmonic function $u$ is upper bounded by…

Analysis of PDEs · Mathematics 2024-09-06 Jin Sun

Visual scene decomposition into semantic entities is one of the major challenges when creating a reliable object grasping system. Recently, we introduced a bottom-up hierarchical clustering approach which is able to segment objects and…

Computer Vision and Pattern Recognition · Computer Science 2017-01-18 Dominik Alexander Klein , Boris Illing , Bastian Gaspers , Dirk Schulz , Armin Bernd Cremers

We study the problem of compression for the purpose of similarity identification, where similarity is measured by the mean square Euclidean distance between vectors. While the asymptotical fundamental limits of the problem - the minimal…

Information Theory · Computer Science 2014-05-13 Fabian Steiner , Steffen Dempfle , Amir Ingber , Tsachy Weissman

It is known that the infimum of the sectional curvatures (on the regular part) of orbit spaces of isometric actions on unit spheres in bounded above by $4$. We show that the infimum is $1$ for "most" actions, and determine the cases in…

Differential Geometry · Mathematics 2018-09-11 Claudio Gorodski

We demonstrate spectroscopy of incoherent light with sub-diffraction resolution. In a proof-of-principle experiment we analyze the spectrum of a pair of incoherent point-like sources whose separation is below the diffraction limit. The two…

Topological consistency plays a crucial role in the task of boundary segmentation for reticular images, such as cell membrane segmentation in neuron electron microscopic images, grain boundary segmentation in material microscopic images and…

Computer Vision and Pattern Recognition · Computer Science 2026-05-27 Chuni Liu , Boyuan Ma , Xiaojuan Ban , Yujie Xie , Hao Wang , Weihua Xue , Jingchao Ma , Ke Xu

In recent years, considerable interest has been drawn by the analysis of geometric functionals for the excursion sets of random eigenfunctions on the unit sphere (spherical harmonics). In this paper, we extend those results to proper…

Probability · Mathematics 2020-09-30 Anna Paola Todino

Several image pattern recognition tasks rely on superpixel generation as a fundamental step. Image analysis based on superpixels facilitates domain-specific applications, also speeding up the overall processing time of the task. Recent…

Computer Vision and Pattern Recognition · Computer Science 2018-02-19 Marcelo Santos , Luciano Oliveira