-vectors of 3-manifolds.
Failure of the Dehn Lemma on Contractible 4-Manifolds.
Faithful integral and modular representations of the Klein bottle group
Families of algebraic curves with nodes
Families of polynomials with total Milnor number constant.
Farrell cohomology of low genus pure mapping class groups with punctures.
Fast genügend große irreduzible 3-dimensionale Mannigfaltigkeiten.
Fatgraph models of RNA structure
In this review paper we discuss fatgraphs as a conceptual framework for RNA structures. We discuss various notions of coarse-grained RNA structures and relate them to fatgraphs.We motivate and discuss the main intuition behind the fatgraph model and showcase its applicability to canonical as well as noncanonical base pairs. Recent discoveries regarding novel recursions of pseudoknotted (pk) configurations as well as their translation into context-free grammars for pk-structures are discussed. This...
Fatness of covers.
Feuilletages de -complexes
Feuilletages transversalement projectifs sur les variétés de Seifert
Soit une variété de Seifert de groupe fondamental non virtuellement résoluble. Soit un feuilletage de dimension sur , muni d’une structure projective réelle transverse. On suppose que satisfait la propriété de relèvement des chemins, i.e., que l’espace des feuilles du relèvement de dans le revêtement universel de est séparé au sens de Hausdorff. On montre qu’à revêtements finis près, est soit une fibration projective, soit un feuilletage géodésique convexe, soit un feuilletage horocyclique...
Fibrations and contact structures.
Fibrations sur le cercle et surfaces complexes
Nous donnons des conditions nécessaires et suffisantes pour qu’une variété de dimension 3 se réalise comme bord d’une famille dégénérée de courbes complexes, et pour qu’un entrelacs dans une 3-variété se réalise comme bord d’un germe de fonction analytique en un point d’une surface complexe normale. Ces résultats s’appuient sur une étude des objets topologiques fournis par de telles fonctions holomorphes : soit une variété de Waldhausen et soit une union finie, éventuellement vide, de fibres...
Fibred and virtually fibred hyperbolic 3-manifolds in the censuses.
Fibred closed braids with disc-band fibre surfaces
A classical result by Stallings provides a necessary and sufficient condition to decide whether a given embedded surface is a fibre in . In this paper it is described how to find a candidate fibre surface for a a link presented as a closed braid. Also it is described an implemented algorithm to find the main ingredients of the necessary and sufficient condition of Stallings, namely presentations of the fundamental groups of the surface and of its complement in , and an explicit expression of...
Fibred Knots and Disks with Clasps.
Finite actions on the Klein four-orbifold and prism manifolds
We describe the finite group actions, up to equivalence, which can act on the orbifold , and their quotient types. This is then used to consider actions on prism manifolds which preserve a longitudinal fibering, but do not leave any Heegaard Klein bottle invariant. If is such an action, we show that and fibers over a certain collection of 2-orbifolds with positive Euler characteristic which are covered by . For the standard actions, we compute the fundamental group of and indicate when...
Finite group actions on acyclic -complexes
Finite presentations for the mapping class group via the ordered complex of curves.
Finite subset spaces of graphs and punctured surfaces.