On the Ozsváth-Szabó invariant of negative definite plumbed 3-manifolds.
On the Reidemeister torsion of rational homology spheres.
On the rho invariant for manifolds with boundary.
On the slice genus of links.
On Yetter's invariant and an extension of the Dijkgraaf-Witten invariant to categorical groups.
Orderable 3-manifold groups
We investigate the orderability properties of fundamental groups of 3-dimensional manifolds. Many 3-manifold groups support left-invariant orderings, including all compact -irreducible manifolds with positive first Betti number. For seven of the eight geometries (excluding hyperbolic) we are able to characterize which manifolds’ groups support a left-invariant or bi-invariant ordering. We also show that manifolds modelled on these geometries have virtually bi-orderable groups. The question of virtual orderability...
Pachner move and affine volume-preserving geometry in .
Parity biquandle
We use crossing parity to construct a generalization of biquandles for virtual knots which we call parity biquandles. These structures include all biquandles as a standard example referred to as the even parity biquandle. We find all parity biquandles arising from the Alexander biquandle and quaternionic biquandles. For a particular construction named the z-parity Alexander biquandle we show that the associated polynomial yields a lower bound on the number of odd crossings as well as the total number...
Patterns in knot cohomology. I.
Plane curve singularities and carousels
In this paper we give a direct and explicit description of the local topological embedding of a plane curve singularity using the Puiseux expansions of its branches in a given set of coordinates.
Polynomial invariants of links in the projective space
The Homflypt and Kauffman skein modules of the projective space are computed. Both are free and generated by some infinite set of links. This set may be chosen to be {Lₙ: n ∈ ℕ ∪ {0}}, where Lₙ is an arbitrary link consisting of n projective lines for n > 0, and L₀ is an affine unknot.
Pure virtual braids homotopic to the identity braid
Two virtual link diagrams are homotopic if one may be transformed into the other by a sequence of virtual Reidemeister moves, classical Reidemeister moves, and self crossing changes. We recall the pure virtual braid group. We then describe the set of pure virtual braids that are homotopic to the identity braid.
Qualgebras and knotted 3-valent graphs
This paper is devoted to new algebraic structures, called qualgebras and squandles. Topologically, they emerge as an algebraic counterpart of knotted 3-valent graphs, just like quandles can be seen as an "algebraization" of knots. Algebraically, they are modeled after groups with conjugation and multiplication/squaring operations. We discuss basic properties of these structures, and introduce and study the notions of qualgebra/squandle 2-cocycles and 2-coboundaries. Knotted 3-valent graph invariants...
Quantum invariants of periodic links and periodic 3-manifolds
We give criteria for framed links and 3-manifolds to be periodic of prime order. As applications we show that the Poincaré sphere is of periodicity 2, 3, 5 only and the Brieskorn sphere Σ(2,3,7) is of periodicity 2, 3, 7 only.
Quantum link invariant from the Lie superalgebra .
Quantum faithfully detects mapping class groups modulo center.
-matrice universelle pour et invariant d’entrelacs associé
En utilisant la méthode du double quantique, nous construisons une -matrice universelle pour la quantification de la superalgèbre de Lie . Nous utilisons ce résultat pour construire un invariant d’entrelacs et nous montrons qu’il est égal à une spécialisation du polynôme de Dubrovnik introduit par Kauffman.
Rank gradient, cost of groups and the rank versus Heegaard genus problem
We study the growth of the rank of subgroups of finite index in residually finite groups, by relating it to the notion of cost. As a by-product, we show that the ‘rank vs. Heegaard genus’ conjecture on hyperbolic 3-manifolds is incompatible with the ‘fixed price problem’ in topological dynamics.
Reidemeister-Turaev torsion modulo one of rational homology threespheres.
Reshetikhin-Turaev invariants of Seifert 3-manifolds and a rational surgery formula.