@article {2011,
	title = {The sphere and the cut locus at a tangency point in two-dimensional almost-Riemannian geometry},
	journal = {Journal of Dynamical and Control Systems },
	volume = {17 },
	number = {arXiv:1009.2612;},
	year = {2011},
	pages = {141-161},
	publisher = {Springer},
	abstract = {<p>We study the tangential case in 2-dimensional almost-Riemannian geometry. We\\r\\nanalyse the connection with the Martinet case in sub-Riemannian geometry. We\\r\\ncompute estimations of the exponential map which allow us to describe the\\r\\nconjugate locus and the cut locus at a tangency point. We prove that this last\\r\\none generically accumulates at the tangency point as an asymmetric cusp whose branches are separated by the singular set.</p>},
	doi = {10.1007/s10883-011-9113-4},
	url = {http://hdl.handle.net/1963/4914},
	author = {Bernard Bonnard and Gr{\'e}goire Charlot and Roberta Ghezzi and Gabriel Janin}
}
