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We compute the metric associated to noncommutative spaces described by a tensor product of spectral triples. Well known results of the two-sheets model (distance on a sheet, distance between the sheets) are extended to any product of two…

High Energy Physics - Theory · Physics 2009-11-07 P. Martinetti , R. Wulkenhaar

Starting from the classical notion of an oriented congruence (i.e. a foliation by oriented curves) in $R^3$, we abstract the notion of an oriented congruence structure. This is a 3-dimensional CR manifold $(M,H, J)$ with a preferred…

Differential Geometry · Mathematics 2008-08-14 C Denson Hill , Pawel Nurowski

Developments in dynamical systems theory provides new support for the discretisation of \pde{}s and other microscale systems. By systematically resolving subgrid microscale dynamics the new approach constructs asymptotically accurate,…

Numerical Analysis · Mathematics 2009-04-07 Tony MacKenzie , A. J. Roberts

The Bures--Wasserstein geometry of covariance matrices provides a canonical distance on the statistical manifold of centred Gaussian measures and lies at the intersection of information geometry, quantum information, and optimal transport.…

Differential Geometry · Mathematics 2026-03-31 Leonardo Marconi

We introduce the concept of Hypoelliptic Diffusion Maps (HDM), a framework generalizing Diffusion Maps in the context of manifold learning and dimensionality reduction. Standard non-linear dimensionality reduction methods (e.g., LLE,…

Statistics Theory · Mathematics 2015-03-19 Tingran Gao

We reduce CR-structures on smooth elliptic and hyperbolic manifolds of CR-codimension 2 to parallelisms thus solving the problem of global equivalence for such manifolds. The parallelism that we construct is defined on a sequence of two…

Complex Variables · Mathematics 2007-05-23 V. V. Ezhov , A. V. Isaev , G. Schmalz

We consider a generalization of Riemannian geometry that naturally arises in the framework of control theory. Let $X$ and $Y$ be two smooth vector fields on a two-dimensional manifold $M$. If $X$ and $Y$ are everywhere linearly independent,…

Optimization and Control · Mathematics 2007-05-23 Andrei A. Agrachev , Ugo Boscain , Mario Sigalotti

We establish an exact bidirectional map between interior Friedmann density of a collapsing star and exterior static spherically symmetric metric in generalized Oppenheimer-Snyder collapse. This reduces Einstein's differential…

General Relativity and Quantum Cosmology · Physics 2026-05-12 H. Khodabakhshi , Zhi-Chao Li , H. Lu , F. Shojai

Let M be a compact Riemannian manifold without boundary and let E be a Riemannian vector bundle over M. If $\sigma$ denotes the sphere subbundle of E, we look for embeddings of $\sigma$ into E admitting a prescribed mean curvature.

Differential Geometry · Mathematics 2016-01-25 Pascal Cherrier , Abdellah Hanani

We present new exact solutions for two-dimensional geometries generated by continuous distributions of topological defects within a conformal metric framework. By reformulating Einstein's equations in two dimensions as a Poisson equation…

General Relativity and Quantum Cosmology · Physics 2025-07-09 A. M. de M. Carvalho , G. Q. Garcia , C. Furtado

The deformation principle admits one to obtain a very broad class of nonuniform geometries as a result of deformation of the proper Euclidean geometry. The Riemannian geometry is also obtained by means of a deformation of the Euclidean…

General Mathematics · Mathematics 2007-05-23 Yuri A. Rylov

The curvature discussed in this paper is a rather far going generalization of the Riemannian sectional curvature. We define it for a wide class of optimal control problems: a unified framework including geometric structures such as…

Differential Geometry · Mathematics 2018-11-30 Andrei Agrachev , Davide Barilari , Luca Rizzi

Let $n$ be a positive integer. We provide an explicit geometrically motivated $1$-Lipschitz map from the space of persistence diagrams on $n$ points (equipped with the Bottleneck distance) into the Hilbert space $\ell^2$. Such maps are a…

Metric Geometry · Mathematics 2025-10-28 Atish Mitra , Ziga Virk

We disclose the mathematical structure underlying the gauge field sector of the recently constructed non-abelian superconformal models in six spacetime dimensions. This is a coupled system of 1-form, 2-form, and 3-form gauge fields. We show…

Mathematical Physics · Physics 2015-01-13 Sylvain Lavau , Henning Samtleben , Thomas Strobl

Subspace representation is a fundamental technique in various fields of machine learning. Analyzing a geometrical relationship among multiple subspaces is essential for understanding subspace series' temporal and/or spatial dynamics. This…

Machine Learning · Computer Science 2024-09-16 Kazuhiro Fukui , Pedro H. V. Valois , Lincon Souza , Takumi Kobayashi

We constructed a simple cosmological model which approximates the Einstein-de Sitter background with periodically distributed dust inhomogeneities. By taking the metric as a power series up to the third order in some perturbative parameter…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Szymon Sikora , Krzysztof Głód

The quantization of the most general Bianchi Type II geometry -with all six scale factors, as well as the lapse function and the shift vector, present- is considered. In an earlier work, a first reduction of the initial 6-dimensional…

General Relativity and Quantum Cosmology · Physics 2009-10-09 T. Christodoulakis , G. O. Papadopoulos

In this paper, we provide a notion of $\infty$-bicategories fibred in $\infty$-bicategories which we call 2-Cartesian fibrations. Our definition is formulated using the language of marked biscaled simplicial sets: Those are scaled…

Algebraic Topology · Mathematics 2021-06-08 Fernando Abellán García , Walker H. Stern

Utilizing recently developed abstract notions of sectional curvature, we introduce a method for constructing a curvature-based geometric profile of discrete metric spaces. The curvature concept that we use here captures the metric relations…

Computer Vision and Pattern Recognition · Computer Science 2025-09-18 Charlotte Beylier , Parvaneh Joharinad , Jürgen Jost , Nahid Torbati

Motivated by persistent homology and topological data analysis, we consider formal sums on a metric space with a distinguished subset. These formal sums, which we call persistence diagrams, have a canonical 1-parameter family of metrics…

Algebraic Topology · Mathematics 2025-02-19 Peter Bubenik , Iryna Hartsock