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arXiv · 2509.15863

Projective geodesic extensions by conformal modifications in nonholonomic mechanics

Malika Belrhazi·Tom Mestdag
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Abstract

Projective geodesic extensions are reparametrizations of the trajectories of a nonholonomic mechanical system (with only a kinetic energy Lagrangian), in such a way that they can be interpreted as part of the geodesics of a Riemannian metric. We derive necessary and sufficient conditions for the existence of these extensions, in the case where the constrained Lagrangian remains preserved up to a conformal transformation. When the nonholonomic system has a symmetry group (a Chaplygin system), we clarify the relation between projective geodesic extensions and closely related concepts, such as ${\phi}$-simplicity, invariant measures and Hamiltonization. Throughout the paper, new and relevant examples illustrate the key differences between all these concepts.

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Malika Belrhazi, Tom Mestdag. 2025-09-19. Projective geodesic extensions by conformal modifications in nonholonomic mechanics. https://arxiv.org/abs/2509.15863

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