Formality of Floer complex of the ideal boundary of hyperbolic knot complement

This is a sequel to the authors' article [BKO](arXiv:1901.02239). We consider a hyperbolic knot $K$ in a closed 3-manifold $M$ and the cotangent bundle of its complement $M \setminus K$. We equip $M \setminus K$ with a hyperbolic metric $h$ and its cotangent bundle $T^*(M \setminus K)$ with the induced kinetic energy Hamiltonian $H_h = \frac{1}{2} |p|_h^2$ and Sasakian almost complex structure $J_h$, and associate a wrapped Fukaya category to $T^*(M\setminus K)$ whose wrapping is given by $H_h$. We then consider the conormal $\nu^*T$ of a horo-torus $T$ as its object. We prove that all non-constant Hamiltonian chords are transversal and of Morse index 0 relative to the horo-torus $T$, and so that the structure maps satisfy $\widetilde{\mathfrak m}^k = 0$ unless $k \neq 2$ and an $A_\infty$-algebra associated to $\nu^*T$ is reduced to a noncommutative algebra concentrated to degree 0. We prove that the wrapped Floer cohomology $HW(\nu^*T; H_h)$ with respect to $H_h$ is well-defined and isomorphic to the Knot Floer cohomology $HW(\partial_\infty(M \setminus K))$ that was introduced in [BKO] for arbitrary knot $K \subset M$. We also define a reduced cohomology, denoted by $\widetilde{HW}^d(\partial_\infty(M \setminus K))$, by modding out constant chords and prove that if $\widetilde{HW}^d(\partial_\infty(M \setminus K))\neq 0$ for some $d \geq 1$, then $K$ cannot be hyperbolic. On the other hand, we prove that all torus knots have $\widetilde{HW}^1(\partial_\infty(M \setminus K)) \neq 0$.

[1]  Wilhelm Klingenberg,et al.  Lectures on closed geodesics , 1978 .

[2]  William D. Brewer,et al.  Vol. II , 2020, The Works of Mary Robinson.

[3]  C. Vafa,et al.  Topological Strings, D-Model, and Knot Contact Homology , 2013, 1304.5778.

[4]  Knot and braid invariants from contact homology I , 2003, math/0302099.

[5]  K. N. Dollman,et al.  - 1 , 1743 .

[6]  Y. Oh Symplectic topology as the geometry of action functional. I. Relative Floer theory on the cotangent bundle , 1997 .

[7]  A. Portaluri,et al.  The homology of path spaces and Floer homology with conormal boundary conditions , 2008, 0810.1977.

[8]  K. Allegaert,et al.  (Preprint) , 2018 .

[9]  On the Floer homology of cotangent bundles , 2006 .

[10]  Y. Oh Symplectic Topology and Floer Homology , 2015 .

[11]  M. Abouzaid On the wrapped Fukaya category and based loops , 2009, 0907.5606.

[12]  Y. Oh Fredholm theory of holomorphic discs under the perturbation of boundary conditions , 1996 .

[13]  O. Yong-Geun Floer mini-max theory, the Cerf diagram, and the spectral invariants , 2004, math/0406449.

[14]  Knot and braid invariants from contact homology II , 2003, math/0303343.

[15]  T. Ekholm,et al.  A complete knot invariant from contact homology , 2016, 1606.07050.

[16]  R. C. Penner,et al.  Euclidean decompositions of noncompact hyperbolic manifolds , 1988 .

[17]  P. Seidel A biased view of symplectic cohomology , 2007, 0704.2055.

[18]  Y. Oh,et al.  Lagrangian intersection floer theory : anomaly and obstruction , 2009 .

[19]  W. Fenchel Elementary Geometry in Hyperbolic Space , 1989 .

[20]  P. Seidel,et al.  An open string analogue of Viterbo functoriality , 2007, 0712.3177.

[21]  John B. Etnyre,et al.  Knot contact homology , 2011, 1109.1542.

[22]  P. Steerenberg,et al.  Targeting pathophysiological rhythms: prednisone chronotherapy shows sustained efficacy in rheumatoid arthritis. , 2010, Annals of the rheumatic diseases.

[23]  H. Hofer,et al.  Symplectic homology I open sets in ℂn , 1994 .