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Related papers: Almost Equivariance via Lie Algebra Convolutions

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Let $J$ be an almost complex structure on a 4-dimensional and unimodular Lie algebra $\mathfrak{g}$. We show that there exists a symplectic form taming $J$ if and only if there is a symplectic form compatible with $J$. We also introduce…

Symplectic Geometry · Mathematics 2015-06-04 Tian-Jun Li , Adriano Tomassini

Let $\Gamma=(\mathcal{V},\mathcal{E})$ be a graph, whose vertices $v\in \mathcal{V}$ are colored black and white and labeled with invertible elements $\lambda_v$ from a commutative and associative ring $R$ containing $\pm 1$. Then we…

Rings and Algebras · Mathematics 2026-04-02 Hans Cuypers

The translation equivariance of convolutional layers enables convolutional neural networks to generalize well on image problems. While translation equivariance provides a powerful inductive bias for images, we often additionally desire…

Machine Learning · Statistics 2020-09-25 Marc Finzi , Samuel Stanton , Pavel Izmailov , Andrew Gordon Wilson

We propose Equivariance by Contrast (EbC) to learn equivariant embeddings from observation pairs $(\mathbf{y}, g \cdot \mathbf{y})$, where $g$ is drawn from a finite group acting on the data. Our method jointly learns a latent space and a…

Machine Learning · Computer Science 2025-10-27 Tobias Schmidt , Steffen Schneider , Matthias Bethge

We study almost inner derivations of Lie algebras, which were introduced by Gordon and Wilson in their work on isospectral deformations of compact solvmanifolds. We compute all almost inner derivations for low-dimensional Lie algebras, and…

Rings and Algebras · Mathematics 2017-04-21 Dietrich Burde , Karel Dekimpe , Bert Verbeke

This monograph introduces a framework for genuine proper equivariant stable homotopy theory for Lie groups. The adjective `proper' alludes to the feature that equivalences are tested on compact subgroups, and that the objects are built from…

Algebraic Topology · Mathematics 2023-08-15 Dieter Degrijse , Markus Hausmann , Wolfgang Lück , Irakli Patchkoria , Stefan Schwede

In this article, we provide a general set-up for arbitrary linear Lie groups $H\leq \mathrm{GL}(n,\mathbb{R})$ which allows to characterise the almost Abelian Lie algebras admitting a torsion-free $H$-structure. In more concrete terms,…

Differential Geometry · Mathematics 2025-05-27 Marco Freibert

Convolution is conventionally defined as a linear operation on functions of one or more variables which commutes with shifts. Group convolution generalizes the concept to linear operations on functions of group elements representing more…

Computer Vision and Pattern Recognition · Computer Science 2022-03-16 Xinhua Zhang , Lance R. Williams

In many real-world applications of regression, conditional probability estimation, and uncertainty quantification, exploiting symmetries rooted in physics or geometry can dramatically improve generalization and sample efficiency. While…

Machine Learning · Computer Science 2025-05-28 Daniel Ordoñez-Apraez , Vladimir Kostić , Alek Fröhlich , Vivien Brandt , Karim Lounici , Massimiliano Pontil

Physical theories grounded in mathematical symmetries are an essential component of our understanding of a wide range of properties of the universe. Similarly, in the domain of machine learning, an awareness of symmetries such as rotation…

The Exel-Loring formula asserts that two topological invariants associated to a pair of almost commuting unitary matrices coincide. Such a pair can be viewed as a quasi-representation of $\mathbb{Z}^2$. We give a generalization of this…

Operator Algebras · Mathematics 2022-04-20 Marius Dadarlat

Convolutional neural networks have been extremely successful in the image recognition domain because they ensure equivariance to translations. There have been many recent attempts to generalize this framework to other domains, including…

Machine Learning · Statistics 2018-11-13 Risi Kondor , Shubhendu Trivedi

Equivariant neural networks are designed to respect symmetries through their architecture, boosting generalization and sample efficiency when those symmetries are present in the data distribution. Real-world data, however, often departs…

Machine Learning · Computer Science 2025-12-12 Andrei Manolache , Luiz F. O. Chamon , Mathias Niepert

Many successful deep learning architectures are equivariant to certain transformations in order to conserve parameters and improve generalization: most famously, convolution layers are equivariant to shifts of the input. This approach only…

Machine Learning · Computer Science 2021-03-31 Allan Zhou , Tom Knowles , Chelsea Finn

We introduce the class of almost symmetric submanifolds of Euclidean space, a close relative of symmetric submanifolds and (contact) sub-Riemannian symmetric spaces. More specifically, we prove that every full irreducible almost symmetric…

Differential Geometry · Mathematics 2025-12-18 Claudio Gorodski , Carlos Olmos

Regular Lie groups are infinite dimensional Lie groups with the property that smooth curves in the Lie algebra integrate to smooth curves in the group in a smooth way (an `evolution operator' exists). Up to now all known smooth Lie groups…

Differential Geometry · Mathematics 2007-05-23 Andreas Kriegl , Peter W. Michor

It is proposed to use the Lie group theory of symmetries of differential equations to investigate the system of equations describing a static star in a radiative and convective equilibrium. It is shown that the action of an admissible group…

Astrophysics · Physics 2008-11-26 Marek Szydlowski , Andrzej J. Maciejewski

We introduce the notion of almost representations of Lie algebras and quantum tori, and establish an Ulam-stability type phenomenon: every irreducible almost representation is close to a genuine irreducible representation. As an…

Mathematical Physics · Physics 2022-02-01 Louis Ioos , David Kazhdan , Leonid Polterovich

Let $S$ be the affine plane $\C^2$ together with an appropriate $\mathbb T = \C^*$ action. Let $\hil{m,m+1}$ be the incidence Hilbert scheme. Parallel to \cite{LQ}, we construct an infinite dimensional Lie algebra that acts on the direct…

Algebraic Geometry · Mathematics 2008-02-13 Wei-Ping Li , Zhenbo Qin

A simple Almost-Riemmanian Structure on a Lie group G is defined by a linear vector field and dim(G)-1 left-invariant ones. We state results about the singular locus, the abnormal extremals and the desingularization of such ARS's, and these…

Differential Geometry · Mathematics 2015-11-02 Victor Ayala , Philippe Jouan