It was previously shown by the first author that every knot in [Formula: see text] is ambient isotopic to one component of a two-component, alternating, hyperbolic link. In this paper, we define the alternating volume of a knot [Formula: see text] to be the minimum volume of any link [Formula: see text] in a natural class of alternating, hyperbolic links such that [Formula: see text] is ambient isotopic to a component of [Formula: see text]. Our main result shows that the alternating volume of a knot is coarsely equivalent to the twist number of a knot.
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A lower bound on critical points of the electric potential of a knot
Consider a knot [Formula: see text] in [Formula: see text] with charge uniformly distributed on it. From the standpoint of both physics and knot theory, it is natural to try to understand the critical points of the potential and their behavior. We show the number of critical points of the potential is at least [Formula: see text], where [Formula: see text] is the tunnel number, defined as the smallest number of arcs one must add to [Formula: see text] such that its complement is a handlebody. The result is proven using Morse theory and stable manifold theory.
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- Award ID(s):
- 1645643
- PAR ID:
- 10286412
- Date Published:
- Journal Name:
- Journal of Knot Theory and Its Ramifications
- Volume:
- 30
- Issue:
- 04
- ISSN:
- 0218-2165
- Page Range / eLocation ID:
- 2150026
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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