13 citations · 63 across the 35 of their papers we have counts for
44 papers
Discovering PDEs equivariant under rigid motions
Francesco Ballerin, Erlend Grong
We consider the problem of PDE discovery from possibly noisy observations under the hypothesis that the underlying dynamic is symmetric in all rigid motions. Rather than using a ge…
Equivariant nonlinear partial differential operators on constant curvature spaces
Francesco Ballerin, Erlend Grong
Motivated by PDE-learning, we give a classifying space for nonlinear partial differential operators equivariant under the action of isometries. This classifying space is for operat…
Effective normalization of sub-Riemannian connections
Erlend Grong, Jan Slovak
We give a new normalization condition for connections on sub-Riemannian manifolds with constant symbols. The condition is formulated in terms of Cartan connections and depends only…
SO(3)-Equivariant Neural Networks for Learning from Scalar and Vector Fields on Spheres
Francesco Ballerin, Nello Blaser, Erlend Grong
Analyzing scalar and vector fields on the sphere, such as temperature or wind speed and direction on Earth, is a difficult task. Models should respect both the rotational symmetrie…
Boundary values of diffeomorphisms of simple polytopes, and controllability
Helge Glöckner, Erlend Grong, Alexander Schmeding
We consider the Lie group of smooth diffeomorphisms Diff of a simple polytope in the euclidean space. Simple polytopes are special cases of manifolds with corners. The geo…
Score matching for sub-Riemannian bridge sampling
Erlend Grong, Karen Habermann, Stefan Sommer
Simulation of conditioned diffusion processes is an essential tool in inference for stochastic processes, data imputation, generative modelling, and geometric statistics. Whilst si…