Results 41 to 50 of about 33,682 (168)

Sub-Laplacian eigenvalue bounds on sub-Riemannian manifolds [PDF]

, 2015
We study eigenvalue problems for intrinsic sub-Laplacians on regular sub-Riemannian manifolds. We prove upper bounds for sub-Laplacian eigenvalues λk of conformal sub-Riemannian metrics that are asymptotically sharp as k→+∞. For Sasakian manifolds with a
Hassannezhad, A, Kokarev, G
core   +3 more sources

The rolling problem: overview and challenges

, 2012
In the present paper we give a historical account -ranging from classical to modern results- of the problem of rolling two Riemannian manifolds one on the other, with the restrictions that they cannot instantaneously slip or spin one with respect to the ...
A Agrachev, A Agrachev, A Agrachev, A Chelouah, A Marigo, A Marigo, AM Bloch, AV Borisov, Cartan, Cartan, DJ Montana, DW Stroock, E Grong, EP Hsu, F Alouges, G Bor, H Sussmann, I Zelenko, I Zelenko, IM Singer, J Zimmerman, J-M Bismut, K Hüper, K Hüper, K Nomizu, M Godoy Molina, M Godoy Molina, P Rouchon, PB Gilkey, PE Jupp, R Bryant, R Montgomery, R Murray, RW Sharpe, S Kobayashi, SA Chaplygin, SA Chaplygin, T Sakai, V Jurdjevic, V Jurdjevic, V Jurdjevic, Y Chitour, Y Chitour, Y Chitour, Z Li   +44 more
core   +3 more sources

Sub-Riemannian geometry

Journal of Differential Geometry, 1986
A sub-Riemannian or singular Riemannian geometry is given by a smoothly varying positive definite quadratic form defined only on a subbundle \(S\) of the tangent bundle \(TM\) of a differentiable manifold, \(S\) being bracket-generating, that is sections of \(S\) together with their Lie brackets generate the \(C^{\infty}(M)\)-module \(V(M)\) of vector ...
openaire   +2 more sources

Cortical-inspired image reconstruction via sub-Riemannian geometry and hypoelliptic diffusion

ESAIM: Proceedings and Surveys, 2018
In this paper we review several algorithms for image inpainting based on the hypoelliptic diffusion naturally associated with a mathematical model of the primary visual cortex. In particular, we present one algorithm that does not exploit the information
Boscain Ugo, Chertovskih Roman, Gauthier Jean-Paul, Prandi Dario, Remizov Alexey   +4 more
doaj   +1 more source

Symplectic integrators for index one constraints [PDF]

, 2012
We show that symplectic Runge-Kutta methods provide effective symplectic integrators for Hamiltonian systems with index one constraints. These include the Hamiltonian description of variational problems subject to position and velocity constraints ...
Hairer E., Klas Modin, Matt Wilkins, Olivier Verdier, Robert I. McLachlan, Vershik A. M.   +5 more
core   +1 more source

A New Subject-Specific Discriminative and Multi-Scale Filter Bank Tangent Space Mapping Method for Recognition of Multiclass Motor Imagery

Frontiers in Human Neuroscience, 2021
Objective: Tangent Space Mapping (TSM) using the geometric structure of the covariance matrices is an effective method to recognize multiclass motor imagery (MI).
Fan Wu, Fan Wu, Anmin Gong, Hongyun Li, Hongyun Li, Lei Zhao, Lei Zhao, Wei Zhang, Yunfa Fu, Yunfa Fu, Yunfa Fu, Yunfa Fu   +11 more
doaj   +1 more source

Invariants of contact sub-pseudo-Riemannian structures and Einstein-Weyl geometry

, 2015
We consider local geometry of sub-pseudo-Riemannian structures on contact manifolds. We construct fundamental invariants of the structures and show that the structures give rise to Einstein-Weyl geometries in dimension 3, provided that certain additional
Grochowski, Marek, Krynski, Wojciech
core   +1 more source

Screen Cauchy–Riemann (SCR)-lightlike submanifolds of metallic semi-Riemannian manifolds [PDF]

Arab Journal of Mathematical Sciences
PurposeThe screen Cauchy–Riemann (SCR)-lightlike submanifold is an important class of submanifolds of semi-Riemannian manifolds. It contains various other classes of submanifolds as its sub-cases. It has been studied under various ambient space.
Gauree Shanker, Ankit Yadav, Ramandeep Kaur   +2 more
doaj   +1 more source

Quantum geometric tensors from sub-bundle geometry [PDF]

Quantum
The geometric properties of quantum states are crucial for understanding many physical phenomena in quantum mechanics, condensed matter physics, and optics. The central object describing these properties is the quantum geometric tensor, which unifies the
Marius A. Oancea, Thomas B. Mieling, Giandomenico Palumbo   +2 more
doaj   +1 more source

Sub-Riemannian geometry of parallelizable spheres

Revista Matemática Iberoamericana, 2011
The first aim of the present paper is to compare various sub-Riemannian structures over the three dimensional sphere S^3 originating from different constructions. Namely, we describe the sub-Riemannian geometry of S^3 arising through
Godoy Molina , Mauricio, Markina , Irina
openaire   +5 more sources