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Consider the geometric inverse problem: There is a set of delta-sources in spacetime that emit waves travelling at unit speed. If we know all the arrival times at the boundary cylinder of the spacetime, can we reconstruct the space, a…

Differential Geometry · Mathematics 2023-08-09 Maarten V. de Hoop , Joonas Ilmavirta , Matti Lassas , Teemu Saksala

This paper looks at how changes of coordinates on a pseudo-Riemannian manifold induce homogeneous linear transformations on its tangent spaces. We see that a pseudo-orthonormal frame in a given tangent space is the basis for a set of…

General Physics · Physics 2022-11-15 Tom Lawrence

We construct a tangent bundle exponential map and locally autoparallel coordinates for geometries based on a general connection on the tangent bundle of a manifold. As concrete application we use these new coordinates for Finslerian…

Mathematical Physics · Physics 2016-03-10 Christian Pfeifer

In this paper, we propose a generalization of the Riemann curvature tensor on manifolds (of dimension two or higher) endowed with a Regge metric. Specifically, while all components of the metric tensor are assumed to be smooth within…

Numerical Analysis · Mathematics 2026-01-12 Jay Gopalakrishnan , Michael Neunteufel , Joachim Schöberl , Max Wardetzky

A 4-dimensional relativistic positioning system for a general spacetime is constructed by using the so called "emission coordinates". The results apply in a small region around the world line of an accelerated observer carrying a Fermi…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Donato Bini , Andrea Geralico , Matteo Luca Ruggiero , Angelo Tartaglia

Special coordinate systems are constructed in a neighborhood of a point or of a curve. Taylor expansions can then be easily inferred for the metric, the connection, or the Finsler Lagrangian in terms of curvature invariants. These…

General Relativity and Quantum Cosmology · Physics 2017-02-27 E. Minguzzi

Two-dimensional almost-Riemannian structures are generalized Riemannian structures on surfaces for which a local orthonormal frame is given by a Lie bracket generating pair of vector fields that can become collinear. Generically, there are…

Optimization and Control · Mathematics 2011-12-23 Ugo Boscain , Grégoire Charlot , Roberta Ghezzi

We show that for a generic Riemannian or reversible Finsler metric on a compact differentiable manifold $M$ of dimension at least three all closed geodesics are simple and do not intersect each other. Using results by Contreras~\cite{C2010}…

Differential Geometry · Mathematics 2023-08-10 Hans-Bert Rademacher

The Riemannian metric on the manifold of positive definite matrices is defined by a kernel function $\phi$ in the form $K_D^\phi(H,K)=\sum_{i,j}\phi(\lambda_i,\lambda_j)^{-1} Tr P_iHP_jK$ when $\sum_i\lambda_iP_i$ is the spectral…

Mathematical Physics · Physics 2008-11-08 F. Hiai , D. Petz

Motivated by the geometrical structures of quantum mechanics, we introduce an almost-complex structure $J$ on the product $M\times M$ of any parallelizable statistical manifold $M$. Then, we use $J$ to extract a pre-symplectic form and a…

Quantum Physics · Physics 2020-05-19 Florio M. Ciaglia , Fabio Di Cosmo , Armando Figueroa , Giuseppe Marmo , Luca Schiavone

Fermi coordinates are constructed as exact functions of the Schwar\-zschild coordinates around the world line of a static observer in the equatorial plane of the Schwarzschild spacetime modulo a single impact parameter determined implicitly…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Donato Bini , Andrea Geralico , Robert T. Jantzen

We introduce a generalization of structured manifolds as the most general Riemannian metric g associated to an affinor (tensor field of (1,1)-type) F and initiate a study of their semi-invariant submanifolds. These submanifolds are…

Differential Geometry · Mathematics 2011-09-06 Novac-Claudiu Chiriac , Mircea Crasmareanu

A central part of geometric statistics is to compute the Fr\'echet mean. This is a well-known intrinsic mean on a Riemannian manifold that minimizes the sum of squared Riemannian distances from the mean point to all other data points. The…

Machine Learning · Statistics 2025-11-07 Frederik Möbius Rygaard , Søren Hauberg , Steen Markvorsen

The study of recently introduced Fedosov supermanifolds is continued. Using normal coordinates, properties of even and odd symplectic supermanifolds endowed with a symmetric connection respecting given sympletic structure are studied.

High Energy Physics - Theory · Physics 2009-11-10 Bodo Geyer , Peter Lavrov

General covariant expressions for measurable angles, distances, velocities, and accelerations are provided in terms of fundamental parameters that can be applied in any setup. The relativistic aberration of light relationship is presented…

General Relativity and Quantum Cosmology · Physics 2026-05-25 Dmitri Lebedev , Kayll Lake

In this paper, we study Riemannian zeroth-order optimization in settings where the underlying Riemannian metric $g$ is geodesically incomplete, and the goal is to approximate stationary points with respect to this incomplete metric. To…

Machine Learning · Computer Science 2026-04-14 Shaocong Ma , Heng Huang

We define the notion of sub-Finsler geometry as a natural generalization of sub-Riemannian geometry with applications to optimal control theory. We compute a complete set of local invariants, geodesic equations, and the Jacobi operator for…

Differential Geometry · Mathematics 2007-05-23 Jeanne N. Clelland , Christopher G. Moseley

A natural extension of a homogeneous geodesic in homogeneous Riemannian spaces $G/H$, known as a two-step homogeneous geodesic, can be expressed of the form $\gamma(t)=\pi(\exp(tx)\exp(ty))$, where $x$ and $y$ are elements of the Lie…

Differential Geometry · Mathematics 2026-04-30 Masoumeh Hosseini , Hamid Reza Salimi Moghaddam

The geodesics for a sub-Riemannian metric on a three-dimensional contact manifold $M$ form a 1-parameter family of curves along each contact direction. However, a collection of such contact curves on $M$, locally equivalent to the solutions…

Differential Geometry · Mathematics 2007-05-23 Thomas A. Ivey

The equivalence problem of curves with values in a Riemannian manifold, is solved. The domain of validity of Frenet's theorem is shown to be the spaces of constant curvature. For a general Riemannian manifold new invariants must thus be…

Differential Geometry · Mathematics 2012-07-20 M. Castrillon Lopez , V. Fernandez Mateos , J. Munoz Masque