arXiv research

New theorem proves convergence of various discrete conformal structures to conformal maps.

The paper proves convergence of discrete maps to Riemann mappings for polyhedral surfaces.

Isothermic nets created from special maps for smooth surfaces.

No stable discrete maps into certain curved spaces exist.

Discrete Flow Maps bypass sequential prediction limits for parallel text generation.

New representations for discrete surfaces derived from dual transforms.

Discrete conformal maps on surfaces with vertex decorations are studied.

Discrete exterior calculus shows natural properties of wedge product and averaging.

Optimal discrete harmonic maps between hyperbolic surfaces are found via minimizing energy.

We establish a connection between recent developments in the study of vortices in the abelian Higgs models, and in the theory of structure-preserving discrete conformal maps. We explain how both are related via conformal mapping problems involving prescribed linear combinations of the curvature and volume form, and sho…

We establish a connection between two previously unrelated topics: a particular discrete version of conformal geometry for triangulated surfaces, and the geometry of ideal polyhedra in hyperbolic three-space. Two triangulated surfaces are considered discretely conformally equivalent if the edge lengths are related by s…

Unified framework for various geometric constructions.

In the previous paper [GLM2018], we showed that the theory of harmonic maps between Riemannian manifolds may be discretized by introducing triangulations with vertex and edge weights on the domain manifold. In the present paper, we study convergence of the discrete theory to the smooth theory when taking finer and fine…

A discrete conformal map (DCM) maps the square lattice to the Riemann sphere such that the image of every irreducible square has the same cross-ratio. This paper shows that every periodic DCM can be determined from spectral data (a hyperelliptic compact Riemann surface, called the spectral curve, equipped with some mar…

Develops TCD maps to relate discrete differential geometry and cluster algebras.

Discrete approximation solves Björling's minimal surface problem.

Maps discrete manifolds to partitions to define new manifolds.

We present effective methods to compute equivariant harmonic maps from the universal cover of a surface into a nonpositively curved space. By discretizing the theory appropriately, we show that the energy functional is strongly convex and derive convergence of the discrete heat flow to the energy minimizer, with explic…

Estimates discontinuous optimal transport maps between a discrete and continuous distribution.

Develops a new method for learning discrete distributions without embedding them in a continuous space.

Maps between Hadamard manifolds are quasi-isometric to harmonic maps.

Accelerators with power-law memory are proposed in the framework of the discrete time approach. To describe discrete accelerators we use the capital stock adjustment principle, which has been suggested by Matthews.The suggested discrete accelerators with memory describe the economic processes with the power-law memory …

Finding appropriate notions of discrete holomorphic maps and, more generally, conformal immersions of discrete Riemann surfaces into 3-space is an important problem of discrete differential geometry and computer visualization. We propose an approach to discrete conformality that is based on the concept of holomorphic l…

New methods use transport maps to improve Langevin dynamics for sampling.

Study shows mapping class groups are one-ended for surfaces with at least one end.

The paper simplifies complex mechanical systems with external forces.

The paper proves a mapping from a space of holonomy varieties to Teichmüller spaces, with a non-empty discrete intersection.

Exact discrete mechanics for nonholonomic systems defined.

Extremal length is a conformal invariant that transfers naturally to the discrete setting, giving square tilings as a natural combinatorial analog of conformal mappings. Recent work by S. Hersonsky has explored generalizing these ideas to three-dimensional cube tilings. The connections between discrete extremal length …

We present a definition of discrete channel surfaces in Lie sphere geometry, which reflects several properties for smooth channel surfaces. Various sets of data, defined at vertices, on edges or on faces, are associated with a discrete channel surface that may be used to reconstruct the underlying particular discrete L…

Skew parallelogram nets factorize, encompassing discrete differential geometry.

We consider discrete nets in Grassmannians $\mathbb{G}^d_r$ which generalize Q-nets (maps $\mathbb{Z}^N\to\mathbb{P}^d$ with planar elementary quadrilaterals) and Darboux nets ($\mathbb{P}^d$-valued maps defined on the edges of $\mathbb{Z}^N$ such that quadruples of points corresponding to elementary squares are all co…

Research proves limits on harmonic map orders into Euclidean buildings.

This paper explores geometric insights into discrete R-congruences and their envelopes.

Earth observation embeddings can convert discrete biome maps into continuous representations that better capture ecological variation.

The image of the branch set of a PL branched cover between PL $n$-manifolds is a simplicial $(n-2)$-complex. We demonstrate that the reverse implication also holds: an open and discrete map $f \colon \mathbb{S}^n \to \mathbb{S}^n$ with the image of the branch set contained in a simplicial $(n-2)$-complex is equivalent …

The paper studies groups formed by two parabolic maps and their properties.

Liouville's theorem says that in dimension greater than two, all conformal maps are Möbius transformations. We prove an analogous statement about simplicial complexes, where two simplicial complexes are considered discretely conformally equivalent if they are combinatorially equivalent and the lengths of corresponding …

Study discretizes Dirac and port-Hamiltonian systems using manifolds.

We use the combinatorial harmonic map theory to study the isometric actions of discrete groups on Hadamard spaces. Given a finitely generated group acting by automorphisms, properly discontinuously and cofinitely on a simplicial complex and its isometric action on a Hadamard space, we formulate criterions for the actio…

Study on Gauss map of anisotropic minimal surfaces with Morse index estimates.

Stochastic optimization improves semi-discrete OT map estimation with a minimax rate.

Riemannian Neural OT maps improve scalability on manifolds.

The paper analyzes rates of convergence for optimal transport map estimators using barycentric projections.

Our aim in this paper is to provide a theory of discrete Riemann surfaces based on quadrilateral cellular decompositions of Riemann surfaces together with their complex structure encoded by complex weights. Previous work, in particular of Mercat, mainly focused on real weights corresponding to quadrilateral cells havin…

By the Riemann-mapping theorem, one can bijectively map the interior of an $n$-gon $P$ to that of another $n$-gon $Q$ conformally. However, (the boundary extension of) this mapping need not necessarily map the vertices of $P$ to those $Q$. In this case, one wants to find the ``best" mapping between these polygons, i.e.…

Let SL(2, $\mathbb H$) be the group of $2 \times 2$ quaternionic matrices $A=\begin{pmatrix} a & b \\ c & d \end{pmatrix}$ with quaternionic determinant $\det A=|ad-aca^{-1} b|=1$. This group acts by the orientation-preserving isometries of the five dimensional (real) hyperbolic space. We obtain discreteness criteria f…

Discrete-time systems can be characterized by simple flat coordinates and their shifts.