Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,695 papers · 148 categories

Trend · papers per month

74148222296 · Jun 202019922001200920172026
48 results for discrete transforms

New method linearizes Darboux transformations of discrete curves.

problem Linearizing Darboux transformations of discrete curves.
method Expressing Darboux transformations as parallel sections of discrete connections in quaternionic formalism.
result Closed-form discrete parametrisations of all Darboux transforms and bicycle correspondences.

Geometric approach uses Bäcklund transformations to create integrable discrete analogs of surface nets.

problem Creating integrable discrete analogs of surface nets and conjugate nets.
method Interpreting classical differential geometry results through Bäcklund transformations and applying permutability properties.
result Integrable discrete analogs of asymptotic and conjugate nets are constructed.

We study the dynamics of the discrete bicycle (Darboux, Backlund) transformation of polygons in n-dimensional Euclidean space. This transformation is a discretization of the continuous bicycle transformation, recently studied by Foote, Levi, and Tabachnikov. We prove that the respective monodromy is a Moebius transform…

2012-11-10abs ↗pdf ↗

A new method for discrete data normalizing flows using latent transformations.

problem Challenges in parameterizing bijective transformations for discrete data.
method Predict a distribution over latent transformations to make the marginal likelihood differentiable.
result Discrete-data normalizing flows can be trained using gradient-based learning with unbiased score function estimation.

New Bäcklund transformations for discrete pseudospherical surfaces of revolution are found.

problem Constructing new non-rotational discrete pseudospherical surfaces.
method Explicit parametrizations and Bäcklund transformations for discrete constant negative Gaussian curvature surfaces of revolution.
result Conditions for Bäcklund transformations to preserve periodicity are provided.

A Darboux transformation for polarized space curves is introduced and its properties are studied, in particular, Bianchi permutability. Semi-discrete isothermic surfaces are described as sequences of Darboux transforms of polarized curves in the conformal n-sphere and their transformation theory is studied. Semi-discre…

2015-06-15abs ↗pdf ↗

New discrete models for constant mean curvature surfaces and tori.

problem Creating discrete models for constant mean curvature surfaces and tori.
method Integrable theory of discrete polarised curves and Darboux transforms.
result Closed-form discrete parametrisations of discrete isothermic cylinders, discrete constant mean curvature cylinders, and discrete isothermic tori.

The asymptotic lattices and their transformations are studied within the line geometry approach. It is shown that the discrete asymptotic nets are represented by isotropic congruences in the Plucker quadric. On the basis of the Lelieuvre-type representation of asymptotic lattices and of the discrete analog of the Mouta…

1999-09-16abs ↗pdf ↗

We introduce the Koenigs lattice, which is a new integrable reduction of the quadrilateral lattice (discrete conjugate net) and provides natural integrable discrete analogue of the Koenigs net. We construct the Darboux-type transformations of the Koenigs lattice and we show permutability of superpositions of such trans…

2002-03-07abs ↗pdf ↗

We construct explicit solutions to the discrete motion of discrete plane curves that has been introduced by one of the authors recently. Explicit formulas in terms the ττ function are presented. Transformation theory of the motions of both smooth and discrete curves is developed simultaneously.

2010-08-17abs ↗pdf ↗

Calculates affine transformations for specific homogeneous spaces.

problem Computing groups of affine transformations on homogeneous spaces.
method Analyzes conditions for affine connections and uses them to establish group isomorphisms.
result Groups of affine transformations are locally isomorphic under specified conditions.

We study Christoffel and Darboux transforms of discrete isothermic nets in 4-dimensional Euclidean space: definitions and basic properties are derived. Analogies with the smooth case are discussed and a definition for discrete Ribaucour congruences is given. Surfaces of constant mean curvature are special among all iso…

1996-11-25abs ↗pdf ↗

DNFS trains efficient samplers for discrete distributions using locally equivariant Transformers.

problem Sampling from unnormalised discrete distributions.
method DNFS learns a rate matrix to satisfy the Kolmogorov equation, using control variates and locally equivariant Transformers.
result DNFS achieves efficient and effective sampling across various applications.

Skew parallelogram nets factorize, encompassing discrete differential geometry.

problem Factorization of polynomials in discrete differential geometry.
method Lax representation, Bäcklund transformations, factorization of polynomials.
result Skew parallelogram nets encompass all systems with polynomial representations.

Weingarten transformations which, by definition, preserve the asymptotic lines on smooth surfaces have been studied extensively in classical differential geometry and also play an important role in connection with the modern geometric theory of integrable systems. Their natural discrete analogues have been investigated…

2013-05-21abs ↗pdf ↗

The paper connects quantum 6j6j-symbols to tetrahedra volumes via discrete Fourier transforms.

problem Understanding the asymptotic behavior of quantum 6j6j-symbols and their relation to 3-manifold invariants.
method Proposing and proving a conjecture linking discrete Fourier transforms of quantum 6j6j-symbols to the volumes of deeply truncated tetrahedra.
result Supporting evidence for the conjecture in specific cases, with numerical calculations for larger dihedral angles.

In this paper, we study robust tensor completion by using transformed tensor singular value decomposition (SVD), which employs unitary transform matrices instead of discrete Fourier transform matrix that is used in the traditional tensor SVD. The main motivation is that a lower tubal rank tensor can be obtained by usin…

2019-07-02abs ↗pdf ↗

Discrete conjugate systems are quadrilateral nets with all planar faces. Discrete orthogonal systems are defined by the additional property of all faces being concircular. Their geometric properties allow one to consider them as proper discretization of conjugate, resp. orthogonal coordinate systems of classical differ…

2003-03-26abs ↗pdf ↗

New discrete curves defined in space forms with geometric properties.

problem Defining discrete elastic and constrained elastic curves in space forms.
method Extending discrete Euclidean curvature to space forms and using Bäcklund transformations.
result Discrete elastic and constrained elastic curves are elements of a curve hierarchy.

We introduce (binary) Darboux transformation for general differential equation of the second order in two independent variables. We present a discrete version of the transformation for a 6-point difference scheme. The scheme is appropriate to solving a hyperbolic type initial-boundary value problem. We discuss several …

2006-06-08abs ↗pdf ↗

Neural networks' feature geometry evolves like discrete Ricci flow.

problem Understanding neural feature representations and their geometric transformations.
method Approximating input manifold with geometric graphs and analyzing their evolution during training.
result Neural feature geometry evolves like discrete Ricci flow, with nonlinear activations playing a crucial role.

Study identifies and analyzes three types of errors in learning Fourier operators.

problem Statistical, discretization, and truncation errors in learning Fourier operators.
method Analysis of a Discrete Fourier Transform (DFT) based least squares estimator.
result Established upper and lower bounds on statistical, discretization, and truncation errors.

Discrete linear Weingarten surfaces in space forms are characterized as special discrete ΩΩ-nets, a discrete analogue of Demoulin's ΩΩ-surfaces. It is shown that the Lie-geometric deformation of ΩΩ-nets descends to a Lawson transformation for discrete linear Weingarten surfaces, which coincides with the well-known L…

2014-06-05abs ↗pdf ↗

We discuss results for the Ribaucour transformation of curves or of higher dimensional smooth and discrete submanifolds. In particular, a result for the reduction of the ambient dimension of a submanifold is proved and the notion of Ribaucour coordinates is derived using a Bianchi permutability result. Further, we disc…

2017-11-13abs ↗pdf ↗

A method for vectorizing persistence diagrams simplifies topological data analysis.

problem Challenges in integrating persistence diagrams into machine learning pipelines.
method Quantized Persistence and Integral transforms of Diagrams (Qupid) using binning and discrete transforms.
result Qupid preserves highly competitive performances compared to state-of-the-art methods across various classification tasks.

The paper develops a computational method for efficient online filtering of diffusion processes.

problem Online filtering of discretely observed nonlinear diffusion processes.
method The approach involves Doob's hh-transforms approximated by solving backward Kolmogorov equations using nonlinear Feynman-Kac formulas and neural networks.
result The proposed method can be orders of magnitude more efficient than state-of-the-art particle filters.

Study preserves symplectic structure in forced discrete mechanical systems.

problem Preserving symplectic structure in forced discrete mechanical systems.
method Analyzes a specific type of forced discrete mechanical system (Q,Ld,fd)(Q,L_d,f_d), preserving a symplectic structure on QimesQQ imes Q.
result The preserved symplectic structure can be seen as Marsden-Weinstein reduction of the canonical symplectic structure.

We extend the Fourier cosine method to discrete probability distributions, achieving faster convergence rates.

problem Extending Fourier cosine method to discrete probability distributions.
method Spectral filters and convergence rates analysis.
result Spectral filters achieve one order faster convergence rates than previously recognized.