arXiv research

The paper explores a new method for landmark matching using sub-Riemannian geometry and neural networks.

We study completeness properties of the Sobolev diffeomorphism groups $\mathcal D^s(M)$ endowed with strong right-invariant Riemannian metrics when the underlying manifold $M$ is $\mathbb R^d$ or compact without boundary. The main result is that for $s > \dim M/2 + 1$, the group $\mathcal D^s(M)$ is geodesically and me…

Bayesian method learns optimal momentum for landmark matching.

Generative model uses ODEs and RKHSs for measure matching.

We address the following problem: given two smooth densities on a manifold, find an optimal diffeomorphism that transforms one density into the other. Our framework builds on connections between the Fisher-Rao information metric on the space of probability densities and right-invariant metrics on the infinite-dimension…

Registration, which aims to find an optimal 1-1 correspondence between shapes, is an important process in different research areas. Conformal mappings have been widely used to obtain a diffeomorphism between shapes that minimizes angular distortion. Conformal registrations are beneficial since it preserves the local ge…

The paper extends LDDMM framework to include Lie group actions in large deformation shape registration.

Anosov diffeomorphisms with integrable subbundles have coherent dynamics and spectral rigidity.

The geometric approach to diffeomorphic image registration known as "large deformation by diffeomorphic metric mapping" (LDDMM) is based on a left action of diffeomorphisms on images, and a right-invariant metric on a diffeomorphism group, usually defined using a reproducing kernel. We explore the use of left-invariant…

SFM matches flows on statistical manifolds for better discrete generation.

A new layer, funnel, reduces dimensionality in flows for better performance.

New method for partial matching of shapes with Varifolds.

Diffeomorphic Time Warping (DiffTW) is a novel method for time series classification that learns a diffeomorphic mapping between time series.

DiffeoCFM efficiently generates realistic brain connectivity matrices using pullback metrics.

We present a new approach for matching regular surfaces in a Riemannian setting. We use a Sobolev type metric on deformation vector fields which form the tangent bundle to the space of surfaces. In this article we compare our approach with the diffeomorphic matching framework. In the latter approach a deformation is pr…

We study how a gluing construction, which produces compact manifolds with holonomy G_2 from matching pairs of asymptotically cylindrical G_2-manifolds, behaves under deformations. We show that the gluing construction defines a smooth map from a moduli space of gluing data to the moduli space of torsion-free G_2-structu…

Knot Floer homology matches fixed point Floer for fibred knots.

We study gluings of asymptotically cylindrical special Lagrangian submanifolds in asymptotically cylindrical Calabi--Yau manifolds. We prove both that there is a well-defined gluing map, and, after reviewing the deformation theory for special Lagrangians, prove that this gluing map defines a local diffeomorphism from m…

Registration, which aims to find an optimal one-to-one correspondence between different data, is an important problem in various fields. This problem is especially challenging when large deformations occur. In this paper, we present a novel algorithm to obtain diffeomorphic image or surface registrations with large def…

Constructs minimal surfaces over Pitot quadrilaterals using harmonic diffeomorphisms.

This paper presents an overview of recent developments in the analysis of shapes such as curves and surfaces through Riemannian metrics. We show that several constructions of metrics on spaces of submanifolds can be unified through the prism of Riemannian submersions, with shape space metrics being induced from metrics…

In this paper we study a class of Riemannian metrics on the space of unparametrized curves and develop a method to compute geodesics with given boundary conditions. It extends previous works on this topic in several important ways. The model and resulting matching algorithm integrate within one common setting both the …

EGFs use ergodicity to simplify generative flows for easier training and imitation learning.

We survey the role of symmetry in diffeomorphic registration of landmarks, curves, surfaces, images and higher-order data. The infinite dimensional problem of finding correspondences between objects can for a range of concrete data types be reduced resulting in compact representations of shape and spatial structure. Th…

We discretize a cost functional for image registration problems by deriving Taylor expansions for the matching term. Minima of the discretized cost functionals can be computed with no spatial discretization error, and the optimal solutions are equivalent to minimal energy curves in the space of $k$-jets. We show that t…

Smooth manifolds have equivalent diffeomorphism groups if and only if they are diffeomorphic.

Constructs entropy-minimizing pseudo-Anosov diffeomorphisms on K3 surfaces.

We develop some consequences of the connection between Calabi-Yau structures and torsion-free $G_2$ structures on compact and asymptotically cylindrical six- and seven-dimensional manifolds. Firstly, we improve the known proof that matching asymptotically cylindrical Calabi-Yau threefolds can be glued. Secondly, we giv…

The study proves diffeomorphisms can be localized to simpler submanifolds.

Why and how that deep learning works well on different tasks remains a mystery from a theoretical perspective. In this paper we draw a geometric picture of the deep learning system by finding its analogies with two existing geometric structures, the geometry of quantum computations and the geometry of the diffeomorphic…

Paper derives explicit expression of Alekseev-Meinrenken diffeomorphism.

According to Pixton, there are Morse-Smale diffeomorphisms of the 3-sphere which have no energy function, that is a Lyapunov function whose critical points are all periodic points of the diffeomorphism. We introduce the concept of quasi-energy function for a Morse-Smale diffeomorphism as a Lyapunov function with the le…

We determine the Riemannian manifolds for which the group of exact volume preserving diffeomorphisms is a totally geodesic subgroup of the group of volume preserving diffeomorphisms, considering right invariant $L^2$-metrics. The same is done for the subgroup of Hamiltonian diffeomorphisms as a subgroup of the group of…

Generalizes $π_2$-diffeomorphism finiteness to non-zero first homotopy groups.

Study on group cocycles for volume-preserving diffeomorphisms.

Book introduces Hofer's metric on symplectic diffeomorphisms.

Study local diffeomorphisms of conformal circles in pseudo-Riemannian manifolds.

Survey on foliations and diffeomorphism groups.

New exotic 4D spaces found using knot slicing techniques.

The paper proves $n$-transitivity for equivariant diffeomorphisms of manifolds.

New 4-manifolds with exotic diffeomorphisms found.

Study exotic Dehn twists in 4-manifolds, producing first known exotic diffeomorphisms.

New Lie groups found for Poisson diffeomorphisms.

An area-preserving diffeomorphism of an annulus has an "action function" which measures how the diffeomorphism distorts curves. The average value of the action function over the annulus is known as the Calabi invariant of the diffeomorphism, while the average value of the action function over a periodic orbit of the di…

Paper finds exotic diffeomorphisms on specific 4-manifolds.

Theta graph diffeomorphism shows nontrivial mapping class of 4-sphere.

The paper finds diffeomorphic complex intersections with distinct Hodge numbers.

Positive paths connect diffeomorphisms on contact manifolds.