25 research outputs found
The mechanics of shuffle products and their siblings
We carry on the investigation initiated in [15] : we describe new shuffle
products coming from some special functions and group them, along with other
products encountered in the literature, in a class of products, which we name
-shuffle products. Our paper is dedicated to a study of the latter
class, from a combinatorial standpoint. We consider first how to extend
Radford's theorem to the products in that class, then how to construct their
bi-algebras. As some conditions are necessary do carry that out, we study them
closely and simplify them so that they can be seen directly from the definition
of the product. We eventually test these conditions on the products mentioned
above
The heparin-Ca2+ interaction: metal influence characterized by MS/MS and UVPD experiments
Communication par afficheInternational audienc
The contrivances of shuffle products and their siblings
In order to calculate and effectively represent special functions on the one hand, work on the other hand, we analyze a class of mixed product. We analyze in particular how to extend the maximum theorem of Radford and compare its applicability to pre-mentioned product
Heparin-like disaccharides: effect of metallic complexation in fragmentation pathways as characterized by MS/MS and UVPD experiments
Communication par afficheNational audienc
Bounds for Completely Decomposable Jacobians
A curve over the eld of two elements with completely decomposable Jacobian is shown to have at most six rational points and genus at most 26. The previous upper bound for the genus was 145
Jacobiennes et cryptographie
L'objectif premier de cette thèse est d'étudier le problème du logarithme discret dans des groupes constitués de jacobiennes généralisées de courbes irréductibles non singulières. Nous donnons tout d'abord un état de l'art de ce problème et de ses diverses attaques connues. Nous étudions ensuite les jacobiennes généralisées et exhibons leurs liens avec des groupes de classes d'ordres. Nous reportons alors nos visées cryptographiques à ces groupes de classes : nous donnons des applications cryptographiques utilisant des corps quadratiques, et nous utilisons les groupes de classes pour construire des exemples permettant de tester les attaques connues. Nous finissons par l'étude des courbes utilisées. Nous donnons des majorations du genre et du nombre de points rationnels de certaines de ces courbes, ainsi que des conditions permettant de localiser leurs angles de Frobenius.LIMOGES-BU Sciences (870852109) / SudocSudocFranceF