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We consider the inverse problem of determining the metric-measure structure of collapsing manifolds from local measurements of spectral data. In the part I of the paper, we proved the uniqueness of the inverse problem and a continuity…

Analysis of PDEs · Mathematics 2024-04-26 Matti Lassas , Jinpeng Lu , Takao Yamaguchi

The classical theory of $G$-structures, which include almost-complex structures, explains the relationship between the curvature of compatible connections and integrability. This note is an effort to understand how the curvature of…

Differential Geometry · Mathematics 2023-01-31 Gabriella Clemente

Curvature properties of a metric connection with totally skew-symmetric torsion are investigated. It is shown that if either the 3-form $T$ is harmonic, $dT=\delta T=0$ or the curvature of the torsion connection $R\in S^2\Lambda^2$ then the…

Differential Geometry · Mathematics 2024-10-08 Stefan Ivanov , Nikola Stanchev

Group lattices (Cayley digraphs) of a discrete group are in natural correspondence with differential calculi on the group. On such a differential calculus geometric structures can be introduced following general recipes of noncommutative…

Mathematical Physics · Physics 2015-06-26 Aristophanes Dimakis , Folkert Muller-Hoissen

The Gaussian curvature of a two-dimensional Riemannian manifold is uniquely determined by the choice of the metric. The formulas for computing the curvature in terms of components of the metric, in isothermal coordinates, involve the…

Differential Geometry · Mathematics 2013-11-11 Haakan Hedenmalm , Yolanda Perdomo

This is the first half of a two-part paper dealing with the geometry of color perception. Here we analyze in detail the seminal 1974 work by H.L. Resnikoff, who showed that there are only two possible geometric structures and Riemannian…

Neurons and Cognition · Quantitative Biology 2025-04-23 Edoardo Provenzi

It is well-known that the Einstein condition on warpedgeometries requires the fibres to be necessarily Einstein. However, exact warped solutions have often been obtained using one- and two-dimensional bases. In this paper, keeping the…

General Relativity and Quantum Cosmology · Physics 2012-11-08 M. M. Akbar

In a Riemannian manifold, the existence of a new connection is proved. In particular cases, this connection reduces to several symmetric, semi-symmetric and quarter-symmetric connections; even some of them are not introduced so far. We also…

Differential Geometry · Mathematics 2008-02-06 Mukut Mani Tripathi

In this paper we consider the isentropic compressible Euler equations in two space dimensions together with particular initial data. The latter consists only of two constant states, where one state lies on the lower and the other state on…

Analysis of PDEs · Mathematics 2017-10-09 Christian Klingenberg , Simon Markfelder

Work consists of introduction, two chapters, conclusion and four applications. In this work is examined the condition, with which the wave space metrics of Riemann- Cartan is the solution of Einstein equation in the void. Geometric…

Differential Geometry · Mathematics 2008-06-25 Vladimir N. Shcherban , Olga V. Baburova

If a (non-constant) polynomial has no zero, then a certain Riemannian metric is constructed on the two dimensional sphere. Several geometric arguments are then shown to contradict this fact.

Differential Geometry · Mathematics 2011-06-07 J. M. Almira , A. Romero

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

Given two compact Riemannian manifolds with boundary $M_1$ and $M_2$ such that their respective boundaries $\Sigma_1$ and $\Sigma_2$ admit neighborhoods $\Omega_1$ and $\Omega_2$ which are isometric, we prove the existence of a constant…

Spectral Theory · Mathematics 2019-01-21 Bruno Colbois , Alexandre Girouard , Asma Hassannezhad

The Riemann curvature tensor fully encodes local geometry, but its Ricci contraction retains only limited information: only the Ricci tensor and the scalar curvature survive, while the Weyl curvature vanishes identically. We show that…

Differential Geometry · Mathematics 2026-01-07 Mohammed Larbi Labbi

We consider a three-dimensional Riemannian manifold equipped with two circulant structures - a metric g and a structure q, which is an isometry with respect to g and the third power of q is minus identity. We discuss some curvature…

Differential Geometry · Mathematics 2017-09-19 Iva Dokuzova

We uncover some connections between the topology of a complete Riemannian surface M and the minimum number of vertices, i.e., critical points of geodesic curvature, of closed curves in M. In particular we show that the space forms with…

Differential Geometry · Mathematics 2010-06-23 Mohammad Ghomi

We revisit, qualify, and objectively resolve the seemingly controversial question about what is the number of dimensional fundamental constants in Nature. For this purpose, we only assume that all we can directly measure are space and time…

Classical Physics · Physics 2007-12-04 George E. A. Matsas , Vicente Pleitez , Alberto Saa , Daniel A. T. Vanzella

I classify the Finsler structures on the 2-sphere that have constant Finsler-Gauss curvature and whose geodesics are the great circles. Modulo diffeomorphism, there is a 2-parameter family of such Finsler structures, only one of which is…

dg-ga · Mathematics 2008-02-03 Robert L. Bryant

In Riemannian geometry the prescribed Ricci curvature problem is as follows: given a smooth manifold $M$ and a symmetric 2-tensor $r$, construct a metric on $M$ whose Ricci tensor equals $r$. In particular, DeTurck and Koiso proved the…

Differential Geometry · Mathematics 2015-11-17 Sergey Stepanov

Let M be an almost Hermitian manifold of dimension greater or equal to 6. The following theorems are proved: Theorem 1. If M is of pointwise constant {\theta}-holomorphic sectional curvature for a number {\theta} in (0,{\pi}/2) then M is of…

Differential Geometry · Mathematics 2010-09-15 Ognian Kassabov