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2009 Surgery formulae for finite type invariants of rational homology $3$–spheres
Christine Lescop
Algebr. Geom. Topol. 9(2): 979-1047 (2009). DOI: 10.2140/agt.2009.9.979


We first present four graphic surgery formulae for the degree n part Zn of the Kontsevich–Kuperberg–Thurston universal finite type invariant of rational homology spheres.

Each of these four formulae determines an alternate sum of the form

I N ( 1 ) I Z n ( M I )

where N is a finite set of disjoint operations to be performed on a rational homology sphere M, and MI denotes the manifold resulting from the operations in I. The first formula treats the case when N is a set of 2n Lagrangian-preserving surgeries (a Lagrangian-preserving surgery replaces a rational homology handlebody by another such without changing the linking numbers of curves in its exterior). In the second formula, N is a set of n Dehn surgeries on the components of a boundary link. The third formula deals with the case of 3n surgeries on the components of an algebraically split link. The fourth formula is for 2n surgeries on the components of an algebraically split link in which all Milnor triple linking numbers vanish. In the case of homology spheres, these formulae can be seen as a refinement of the Garoufalidis–Goussarov–Polyak comparison of different filtrations of the rational vector space freely generated by oriented homology spheres (up to orientation preserving homeomorphisms).

The presented formulae are then applied to the study of the variation of Zn under a pq–surgery on a knot K. This variation is a degree n polynomial in qp when the class of qp in is fixed, and the coefficients of these polynomials are knot invariants, for which various topological properties or topological definitions are given.


Download Citation

Christine Lescop. "Surgery formulae for finite type invariants of rational homology $3$–spheres." Algebr. Geom. Topol. 9 (2) 979 - 1047, 2009.


Received: 1 April 2009; Accepted: 2 April 2009; Published: 2009
First available in Project Euclid: 20 December 2017

zbMATH: 1171.57014
MathSciNet: MR2511138
Digital Object Identifier: 10.2140/agt.2009.9.979

Primary: 57M27
Secondary: 55R80, 57M25, 57N10

Rights: Copyright © 2009 Mathematical Sciences Publishers


Vol.9 • No. 2 • 2009
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