Questions de topologie en biologie moléculaire
Nous considérons l’action de la monodromie sur l’homologie de la fibre de Milnor d’une singularité complexe. Cette action est plus compliquée que prévu : en effet nous montrons que, sur , elle n’est, en général, pas somme directe de modules cycliques. Nous donnons également des exemples prouvant que la monodromie rationnelle ne détermine pas la monodromie entière et que la monodromie entière ne détermine pas la topologie.
Let be a non-trivial knot in the -sphere, its exterior, its group, and its peripheral subgroup. We show that is malnormal in , namely that for any with , unless is in one of the following three classes: torus knots, cable knots, and composite knots; these are exactly the classes for which there exist annuli in attached to which are not boundary parallel (Theorem 1 and Corollary 2). More generally, we characterise malnormal peripheral subgroups in the fundamental group of a...
Malnormal subgroups occur in various contexts. We review a large number of examples, and compare the general situation to that of finite Frobenius groups of permutations.
In a companion paper [
In this paper we are interested in symmetries of alternating knots, more precisely in those related to achirality. We call the following statement
Page 1