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Can I read Heegaard Genus, Degree-one Maps, and Amalgamation of 3-Manifolds on EtoBox?
Heegaard Genus, Degree-one Maps, and Amalgamation of 3-Manifolds by Li, Tao is a scholarly article available to read on EtoBox.
What is Heegaard Genus, Degree-one Maps, and Amalgamation of 3-Manifolds about?
Let $M=W\cup_T V$ be an amalgamation of two compact 3-manifolds along a torus, where $W$ is the exterior of a knot in a homology sphere. Let $N$ be the manifold obtained by replacing $W$ with a solid torus such that the boundary of a Seifert surface in $W$ is a meridian of the solid torus. This means that there is a degree-one map $f\colon M\to N$, pinching $W$ into a solid torus while fixing $V$. We prove that $g(M)\ge g(N)$, where $g(M)$ denotes the Heegaard genus. An immediate corollary is that the tunnel number of a satellite knot is at least as large as the tunnel number of its pattern knot.
- Author
- Li, Tao
- Published
- 2020
- Language
- EN