Fundamental Group and Covering Properties of Hyperbolic Surgery Manifolds

الملخص EN

We study a family of closed connected orientable 3-manifolds obtained by Dehn surgeries with rational coefficients along the oriented components of certain links.

This family contains all the manifolds obtained by surgery along the (hyperbolic) 2-bridge knots.

We find geometric presentations for the fundamental group of such manifolds and represent them as branched covering spaces.

As a consequence, we prove that the surgery manifolds, arising from the hyperbolic 2-bridge knots, have Heegaard genus 2 and are 2-fold coverings of the 3-sphere branched over well-specified links.