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We investigate discrete spin transformations, a geometric framework to manipulate surface meshes by controlling mean curvature. Applications include surface fairing -- flowing a mesh onto say, a reference sphere -- and mesh extrusion --…

Computational Geometry · Computer Science 2019-06-11 Loic Le Folgoc , Daniel C. Castro , Jeremy Tan , Bishesh Khanal , Konstantinos Kamnitsas , Ian Walker , Amir Alansary , Ben Glocker

Upper-ocean flows are a multi-scale jigsaw puzzle of turbulence and waves. Characterizing these flows is essential for understanding their role in redistributing heat, carbon, and nutrients, yet power spectral analysis cannot always…

Atmospheric and Oceanic Physics · Physics 2025-05-05 J. W. Skinner , A. Lawrence , J. Callies

In a number of geophysical or planetological settings (Earth's inner core, a silicate mantle crystallizing from a magma ocean, or an ice shell surrounding a deep water ocean) a convecting crystalline layer is in contact with a layer of its…

Geophysics · Physics 2013-03-20 Renaud Deguen

Many real-world networks are characterized by directionality; however, the absence of an appropriate Fourier basis hinders the effective implementation of graph signal processing techniques. Inspired by discrete signal processing, where…

Information Theory · Computer Science 2024-07-30 Ali Bagheri Bardi , Taher Yazdanpanah , Milos Dakovic , Ljubisa Stankovic

Transformers have significantly advanced the field of natural language processing, but comprehending their internal mechanisms remains a challenge. In this paper, we introduce a novel geometric perspective that elucidates the inner…

Computation and Language · Computer Science 2023-09-20 Raul Molina

Coordinated cilia are used throughout the natural world for micronscale fluid transport. They are often modelled with regular filament arrays on fixed, planar surfaces. Here, we simulate hundreds of interacting active filaments on spherical…

Fluid Dynamics · Physics 2021-12-01 Timothy A Westwood , Eric E Keaveny

The Dirac wave function in a curved spacetime is usually defined as a quadruplet of scalar fields. It can alternatively be defined as a four-vector field. We describe these two representations in a common geometrical framework and we prove…

General Relativity and Quantum Cosmology · Physics 2011-10-05 Mayeul Arminjon , Frank Reifler

We introduce a novel analysis technique for pulsar secondary spectra. The power spectrum of pulsar scintillation (referred to as the "secondary spectrum") shows differential delays and Doppler shifts due to interference from multi-path…

Instrumentation and Methods for Astrophysics · Physics 2020-12-02 Tim Sprenger , Olaf Wucknitz , Robert Main , Daniel Baker , Walter Brisken

Convolutional dictionary learning (CDL) estimates shift invariant basis adapted to multidimensional data. CDL has proven useful for image denoising or inpainting, as well as for pattern discovery on multivariate signals. As estimated…

Machine Learning · Computer Science 2019-01-29 Thomas Moreau , Alexandre Gramfort

We introduce the concepts of the Fourier transform and convolution generated by an arbitrary restriction of the differentiation operator in the space $L_{2}(0,b).$ In contrast to the classical convolution, the introduced convolution…

Analysis of PDEs · Mathematics 2013-02-07 Baltabek Kanguzhin , Niyaz Tokmagambetov

Visual place recognition is challenging because there are so many factors that can cause the appearance of a place to change, from day-night cycles to seasonal change to atmospheric conditions. In recent years a large range of approaches…

Computer Vision and Pattern Recognition · Computer Science 2020-07-31 Sourav Garg , Ben Harwood , Gaurangi Anand , Michael Milford

Vector displacements expressed in spherical coordinates are proposed. They correspond to electromagnetic fields in vacuum that globally rotate about an axis and display many circular patterns on the surface of a sphere. The fields basically…

Classical Physics · Physics 2021-06-11 Daniele Funaro

Finding semantic correspondences is a challenging problem. With the breakthrough of CNNs stronger features are available for tasks like classification but not specifically for the requirements of semantic matching. In the following we…

Computer Vision and Pattern Recognition · Computer Science 2019-06-18 Nikolai Ufer , Kam To Lui , Katja Schwarz , Paul Warkentin , Björn Ommer

Using convolutional neural networks for 360images can induce sub-optimal performance due to distortions entailed by a planar projection. The distortion gets deteriorated when a rotation is applied to the 360image. Thus, many researches…

Computer Vision and Pattern Recognition · Computer Science 2022-02-14 Sungmin Cho , Raehyuk Jung , Junseok Kwon

We analyse a system in which, due to entanglement between the spin and spatial degrees of freedom, the reduced transmitted state has the shape of the freely propagating pulse translated in the complex co-ordinate plane. In the case an…

Quantum Physics · Physics 2015-05-14 D. Sokolovski , R. Sala Mayato

The introduction of convolutional layers greatly advanced the performance of neural networks on image tasks due to innately capturing a way of encoding and learning translation-invariant operations, matching one of the underlying symmetries…

Computer Vision and Pattern Recognition · Computer Science 2016-12-15 Nicholas Guttenberg , Nathaniel Virgo , Olaf Witkowski , Hidetoshi Aoki , Ryota Kanai

No existing spherical convolutional neural network (CNN) framework is both computationally scalable and rotationally equivariant. Continuous approaches capture rotational equivariance but are often prohibitively computationally demanding.…

Computer Vision and Pattern Recognition · Computer Science 2023-01-31 Jeremy Ocampo , Matthew A. Price , Jason D. McEwen

Surface-consistent deconvolution is a standard processing technique in land data to uniformize the wavelet across all sources and receivers. The required wavelet estimation step is generally done in the homomorphic domain since this is a…

Information Theory · Computer Science 2012-09-18 Roberto H. Herrera , Mirko van der Baan

Metaplectic operators form a relevant class of operators appearing in different applications, in the present work we study their Schwartz kernels. Namely, diagonality of a kernel is defined by imposing rapid off-diagonal decay conditions,…

Analysis of PDEs · Mathematics 2025-10-16 Gianluca Giacchi , Luigi Rodino

At present the theory of skew-symmetric exterior differential forms has been developed. The closed exterior forms possess the invariant properties that are of great importance. The operators of the exterior form theory lie at the basis of…

Mathematical Physics · Physics 2007-05-23 L. I. Petrova