A note on some homology spheres which are 2-fold coverings of inequivalent knots
Abstract
We construct a family of closed 3--manifolds
, which are homeomorphic to the Brieskorn homology spheres
, where
and both
and
are odd. We show that
can be represented as 2--fold covering of the 3--sphere branched over two inequivalent knots. Our proofs follow immediately from two different symmetries of a genus 2 Heegaard diagram of
, and generalize analogous results proved in [BGM], [IK], [SIK] and [T].
![M_{\alpha,r}](http://212.189.136.205/plugins/generic/latexRender/cache/42800b3374e008832d5f67b14ad5a0a5.png)
![\Sigma(2, \alpha+1, q+2r-1)](http://212.189.136.205/plugins/generic/latexRender/cache/db2d6caa9baf4dac09975b4e86c2ccc3.png)
![q=\alpha(r-1)](http://212.189.136.205/plugins/generic/latexRender/cache/e6f56f74bf654faced67eed0f404f63d.png)
![\alpha \ge 1](http://212.189.136.205/plugins/generic/latexRender/cache/eb4c22fa8a0f5dd41d7d6a96ab068b32.png)
![q \ge 3](http://212.189.136.205/plugins/generic/latexRender/cache/2c216a92ed7a7c68f1b45e580dd75c0b.png)
![M_{\alpha,r}](http://212.189.136.205/plugins/generic/latexRender/cache/42800b3374e008832d5f67b14ad5a0a5.png)
![\Sigma(2, \alpha+1, q+2r-1)](http://212.189.136.205/plugins/generic/latexRender/cache/373247e71421c07f4f9c8b580918e62e.png)
DOI Code:
10.1285/i15900932v30n1p41
Keywords:
3–manifold; branched covering; orbifold; fundamental group; homology 3–sphere; (1, 1)-knot; torus knot
3–manifold; branched covering; orbifold; fundamental group; homology 3–sphere; (1, 1)-knot; torus knot
Classification:
57M05; 57M12; 57R65
Full Text: PDF