61 results on '"Kimihiko Motegi"'
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2. Vanishing nontrivial elements in a knot group by Dehn fillings
- Author
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Kazuhiro Ichihara, Masakazu Teragaito, and Kimihiko Motegi
- Subjects
010101 applied mathematics ,Combinatorics ,Knot group ,010102 general mathematics ,Geometry and Topology ,0101 mathematics ,Mathematics::Geometric Topology ,01 natural sciences ,Mathematics ,Knot (mathematics) - Abstract
Let K be a nontrivial knot in S 3 with the exterior E ( K ) , and denote π 1 ( E ( K ) ) by G ( K ) . We prove that for any hyperbolic knot K and any nontrivial element g ∈ G ( K ) , there are only finitely many Dehn fillings of E ( K ) which trivialize g. We also demonstrate that there are infinitely many nontrivial elements in G ( K ) which cannot be trivialized by nontrivial Dehn fillings.
- Published
- 2019
3. Nontrivial Elements in a Knot Group That are Trivialized by Dehn Fillings
- Author
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Tetsuya Ito, Kimihiko Motegi, and Masakazu Teragaito
- Subjects
Combinatorics ,010201 computation theory & mathematics ,Knot group ,General Mathematics ,010102 general mathematics ,0102 computer and information sciences ,0101 mathematics ,01 natural sciences ,Mathematics - Abstract
Let $K$ be a nontrivial knot in $S^3$ with the exterior $E(K)$, and $\gamma \in G(K) = \pi _1(E(K), *)$ a slope element represented by an essential simple closed curve on $\partial E(K)$ with base point $* \in \partial E(K)$. Since the normal closure $\langle \!\langle \gamma \rangle \!\rangle $ of $\gamma $ in $G(K)$ coincides with that of $\gamma ^{-1}$, and $\gamma $ and $\gamma ^{-1}$ correspond to a slope $r \in \mathbb{Q} \cup \{ \infty \}$, we write $\langle \!\langle r \rangle \!\rangle = \langle \!\langle \gamma \rangle \!\rangle $. The normal closure $\langle \!\langle r \rangle \!\rangle $ describes elements, which are trivialized by $r$-Dehn filling of $E(K)$. In this article, we prove that $\langle \!\langle r_1 \rangle \!\rangle = \langle \!\langle r_2 \rangle \!\rangle $ if and only if $r_1 = r_2$, and for a given finite family of slopes $\mathcal{S} = \{ r_1, \dots , r_n \}$, the intersection $\langle \!\langle r_1 \rangle \!\rangle \cap \cdots \cap \langle \!\langle r_n \rangle \!\rangle $ contains infinitely many elements except when $K$ is a $(p, q)$-torus knot and $pq \in \mathcal{S}$. We also investigate inclusion relation among normal closures of slope elements.
- Published
- 2019
4. Generalized torsion for knots with arbitrarily high genus
- Author
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Kimihiko Motegi and Masakazu Teragaito
- Subjects
Mathematics - Geometric Topology ,General Mathematics ,FOS: Mathematics ,Geometric Topology (math.GT) ,Group Theory (math.GR) ,Mathematics - Group Theory ,Mathematics::Geometric Topology - Abstract
In a group, a non-trivial element is called a generalized torsion element if some non-empty finite product of its conjugates equals to the identity. We say that a knot has generalized torsion if its knot group admits such an element. For a (2, 2q+1)-torus knot K, we demonstrate that there are infinitely many unknots c such that p-twisting K about c yields a twist family, which consists of hyperbolic knots with generalized torsion whenever |p| > 3. This gives a new infinite class of hyperbolic knots having generalized torsion. In particular, each class contains knots with arbitrarily high genus. We also show that some twisted torus knots, including the (-2, 3, 7)-pretzel knot, have generalized torsion. Since generalized torsion is an obstruction for having bi-order, these knots have non-bi-orderable knot groups., 14 pages, 14 figures
- Published
- 2021
- Full Text
- View/download PDF
5. Generalized Torsion Elements and Bi-orderability of 3-manifold Groups
- Author
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Masakazu Teragaito and Kimihiko Motegi
- Subjects
Pure mathematics ,Conjecture ,Fibonacci number ,Computer Science::Information Retrieval ,General Mathematics ,010102 general mathematics ,57M25, 57M05, 06F15, 20F05, 20F60 ,Geometric Topology (math.GT) ,Torsion element ,Group Theory (math.GR) ,Mathematics::Geometric Topology ,01 natural sciences ,010101 applied mathematics ,Mathematics - Geometric Topology ,Converse ,FOS: Mathematics ,Torsion (algebra) ,0101 mathematics ,Mathematics - Group Theory ,3-manifold ,Mathematics - Abstract
It is known that a bi-orderable group has no generalized torsion element, but the converse does not hold in general. We conjecture that the converse holds for the fundamental groups of 3-manifolds, and verify the conjecture for non-hyperbolic, geometric 3-manifolds. We also confirm the conjecture for some infinite families of closed hyperbolic 3-manifolds. In the course of the proof, we prove that each standard generator of the Fibonacci group F(2,m) (m>2) is a generalized torsion element., 14 pages, no figure
- Published
- 2017
6. A note on L-spaces which are double branched covers of non-quasi-alternating links
- Author
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Kimihiko Motegi
- Subjects
Combinatorics ,Seifert fiber space ,010102 general mathematics ,0103 physical sciences ,Cover (algebra) ,010307 mathematical physics ,Geometry and Topology ,Branched covering ,Link (geometry) ,0101 mathematics ,01 natural sciences ,Mathematics - Abstract
Greene has given an infinite family of non-quasi-alternating links L m , n in which L 2 , 3 is homologically thin and its double branched cover X 2 , 3 is an L-space. In this note we show that the double branched cover X m , n of L m , n is an L-space for all n > m ≥ 2 and L m , n is the unique link whose double branched cover is X m , n .
- Published
- 2017
7. Generalized torsion and Dehn filling
- Author
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Masakazu Teragaito, Tetsuya Ito, and Kimihiko Motegi
- Subjects
Pure mathematics ,Fundamental group ,010102 general mathematics ,Geometric Topology (math.GT) ,Torsion element ,Group Theory (math.GR) ,Mathematics::Geometric Topology ,01 natural sciences ,010101 applied mathematics ,Mathematics - Geometric Topology ,Dehn surgery ,57K10, 57M05, 20F05 ,FOS: Mathematics ,Torsion (algebra) ,Geometry and Topology ,0101 mathematics ,Mathematics - Group Theory ,Mathematics::Symplectic Geometry ,Knot (mathematics) ,Mathematics - Abstract
A generalized torsion element is a non-trivial element such that some non-empty finite product of its conjugates is the identity. We construct a generalized torsion element of the fundamental group of a 3-manifold obtained by Dehn surgery along a knot in the 3-sphere., 15 pages, 9 figures. We fixed the problem in figures
- Published
- 2021
8. The Strong Slope Conjecture for twisted generalized Whitehead doubles
- Author
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Kenneth L. Baker, Toshie Takata, and Kimihiko Motegi
- Subjects
Pure mathematics ,Conjecture ,Degree (graph theory) ,Jones polynomial ,Boundary (topology) ,Geometric Topology (math.GT) ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Surface (topology) ,Mathematics::Geometric Topology ,Mathematics - Geometric Topology ,Linear term ,57M25, 57M27 ,FOS: Mathematics ,Geometry and Topology ,Mathematical Physics ,Knot (mathematics) ,Mathematics - Abstract
The Slope Conjecture proposed by Garoufalidis asserts that the degree of the colored Jones polynomial determines a boundary slope, and its refinement, the Strong Slope Conjecture proposed by Kalfagianni and Tran asserts that the linear term in the degree determines the topology of an essential surface that satisfies the Slope Conjecture. Under certain hypotheses, we show that twisted, generalized Whitehead doubles of a knot satisfies the Slope Conjecture and the Strong Slope Conjecture if the original knot does. Additionally, we provide a proof that there are Whitehead doubles which are not adequate., This version has been accepted for publication in Quantum Topology. We restructured results and presentation to focus on the maximum degree of colored Jones polynomial for improved exposition and clarity. A cancellation error is also corrected. The changes mainly impact sections 1 and 2
- Published
- 2018
9. Seifert fibered surgeries on strongly invertible knots without primitive/Seifert positions
- Author
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Katura Miyazaki, Kimihiko Motegi, Edgar Jasso, and Mario Eudave-Muñoz
- Subjects
Fibered knot ,Geometric Topology (math.GT) ,Mathematics::Geometric Topology ,law.invention ,Combinatorics ,Mathematics - Geometric Topology ,Dehn surgery ,Invertible matrix ,Seifert surface ,law ,Seifert fiber space ,FOS: Mathematics ,Geometry and Topology ,Branched covering ,Geometrization conjecture ,Mathematics::Symplectic Geometry ,57M25, 57M50, 57N10 ,Mathematics ,Trefoil knot - Abstract
We find an infinite family of Seifert fibered surgeries on strongly invertible knots which do not have primitive/Seifert positions. Each member of the family is obtained from a trefoil knot after alternate twists along a pair of seiferters for a Seifert fibered surgery on a trefoil knot., Comment: To appear in Topology Appl
- Published
- 2015
10. Generalized torsion and decomposition of 3-manifolds
- Author
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Kimihiko Motegi, Tetsuya Ito, and Masakazu Teragaito
- Subjects
Fundamental group ,Pure mathematics ,Toroid ,Applied Mathematics ,General Mathematics ,MathematicsofComputing_GENERAL ,Prime decomposition ,Torsion element ,Geometric Topology (math.GT) ,Group Theory (math.GR) ,Graph of groups ,Mathematics - Geometric Topology ,Free product ,Mathematics::K-Theory and Homology ,Prime factor ,Torsion (algebra) ,FOS: Mathematics ,Mathematics - Group Theory ,57M05, 20E06 (Primary)m 06F15, 20F60 (Secondary) ,Mathematics - Abstract
A nontrivial element in a group is a generalized torsion element if some nonempty finite product of its conjugates is the identity. We prove that any generalized torsion element in a free product of torsion-free groups is conjugate to a generalized torsion element in some factor group. This implies that the fundamental group of a compact orientable $3$-manifold $M$ has a generalized torsion element if and only if the fundamental group of some prime factor of $M$ has a generalized torsion element. On the other hand, we demonstrate that there are infinitely many toroidal $3$-manifolds whose fundamental group has a generalized torsion element, while the fundamental group of each decomposing piece has no such elements., Comment: 10 pages, 2 Figures
- Published
- 2018
- Full Text
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11. The Strong Slope Conjecture for cablings and connected sums.
- Author
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Baker, Kenneth L., Kimihiko Motegi, and Toshie Takata
- Subjects
- *
LOGICAL prediction , *CABLES - Abstract
We show that, under some technical conditions, the Strong Slope Conjecture proposed by Kalfagianni and Tran is closed under connect sums and cabling. As an application, we establish the Strong Slope Conjecture for graph knots. [ABSTRACT FROM AUTHOR]
- Published
- 2021
12. Seifert vs slice genera of knots in twist families and a characterization of braid axes
- Author
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Kimihiko Motegi and Kenneth L. Baker
- Subjects
Mathematics::Combinatorics ,General Mathematics ,010102 general mathematics ,Winding number ,Zero (complex analysis) ,Fibered knot ,Geometric Topology (math.GT) ,Disjoint sets ,01 natural sciences ,Mathematics::Geometric Topology ,Combinatorics ,Mathematics - Geometric Topology ,Knot (unit) ,0103 physical sciences ,FOS: Mathematics ,010307 mathematical physics ,0101 mathematics ,Twist ,Unknot ,Primary 57M25, 57M27, Secondary 57R17, 57R58 ,Mathematics ,Slice genus - Abstract
Twisting a knot $K$ in $S^3$ along a disjoint unknot $c$ produces a twist family of knots $\{K_n\}$ indexed by the integers. Comparing the behaviors of the Seifert genus $g(K_n)$ and the slice genus $g_4(K_n)$ under twistings, we prove that if $g(K_n) - g_4(K_n) < C$ for some constant $C$ for infinitely many integers $n > 0$ or $g(K_n) / g_4(K_n) \to 1$ as $n \to \infty$, then either the winding number of $K$ about $c$ is zero or the winding number equals the wrapping number. As a key application, if $\{K_n\}$ or the mirror twist family $\{\overline{K_n}\}$ contains infinitely many tight fibered knots, then the latter must occur. We further develop this to show that $c$ is a braid axis of $K$ if and only if both $\{K_n\}$ and $\{\overline{K_n}\}$ each contain infinitely many tight fibered knots. We also give a necessary and sufficient condition for $\{ K_n \}$ to contain infinitely many L-space knots, and show (modulo a conjecture) that satellite L-space knots are braided satellites., 34 pages, 12 figures
- Published
- 2017
- Full Text
- View/download PDF
13. Networking Seifert surgeries on knots, III
- Author
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Arnaud Deruelle, Katura Miyazaki, and Kimihiko Motegi
- Subjects
Mathematics::Dynamical Systems ,Physics::Medical Physics ,Geometric Topology (math.GT) ,Annulus (mathematics) ,Torus ,Mathematics::Geometric Topology ,57M50 ,Dehn surgery ,Combinatorics ,Seifert fiber space ,band-sum ,57N10 ,Mathematics - Geometric Topology ,Knot (unit) ,Seifert surgery network ,seiferter ,hyperbolic knot ,57M25 ,FOS: Mathematics ,Geometry and Topology ,Twist ,Primary 57M25, 57M50 Secondary 57N10 ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
How do Seifert surgeries on hyperbolic knots arise from those on torus knots? We approach this question from a networking viewpoint. The Seifert Surgery Network is a 1-dimensional complex whose vertices correspond to Seifert surgeries; two vertices are connected by an edge if one Seifert surgery is obtained from the other by a single twist along a trivial knot called a seiferter or along an annulus cobounded by seiferters. Successive twists along a "hyperbolic seiferter" or a "hyperbolic annular pair" produce infinitely many Seifert surgeries on hyperbolic knots. In this paper, we investigate Seifert surgeries on torus knots which have hyperbolic seiferters or hyperbolic annular pairs, and obtain results suggesting that such surgeries are restricted., Comment: To appear in Algebr. Geom. Topol
- Published
- 2014
14. Seifert vs. slice genera of knots in twist families and a characterization of braid axes.
- Author
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Baker, Kenneth L. and Kimihiko Motegi
- Subjects
BRAID ,KNOT theory ,BRAID group (Knot theory) ,AXES ,INTEGERS - Abstract
Twisting a knot K in S³ along a disjoint unknot c produces a twist family of knots {K
n } indexed by the integers. We prove that if the ratio of the Seifert genus to the slice genus for knots in a twist family limits to 1, then the winding number of K about c equals either zero or the wrapping number. As a key application, if {Kn } or the mirror twist family {Kn } contains infinitely many tight fibered knots, then the latter must occur. This leads to the characterization that c is a braid axis of K if and only if both {Kn } and {Kn } each contain infinitely many tight fibered knots. We also give a necessary and sufficient condition for {Kn } to contain infinitely many L-space knots, and apply the characterization to prove that satellite L-space knots have braided patterns, which answers a question of both Baker-Moore and Hom in the positive. This result also implies an absence of essential Conway spheres for satellite L-space knots, which gives a partial answer to a conjecture of Lidman-Moore. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
15. GENERALIZED TORSION AND DECOMPOSITION OF 3-MANIFOLDS.
- Author
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TETSUYA ITO, KIMIHIKO MOTEGI, and MASAKAZU TERAGAITO
- Subjects
- *
COMPACT groups , *GROUP products (Mathematics) , *COMMUTATORS (Operator theory) , *COMMUTATION (Electricity) - Abstract
A nontrivial element in a group is a generalized torsion element if some nonempty finite product of its conjugates is the identity. We prove that any generalized torsion element in a free product of torsion-free groups is conjugate to a generalized torsion element in some factor group. This implies that the fundamental group of a compact orientable 3-manifold M has a generalized torsion element if and only if the fundamental group of some prime factor of M has a generalized torsion element. On the other hand, we demonstrate that there are infinitely many toroidal 3-manifolds whose fundamental group has a generalized torsion element, while the fundamental group of each decomposing piece has no such elements. Additionally, in the course of the proof of the first result, we give an upper bound for the stable commutator length of generalized torsion elements. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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16. Non-characterizing slopes for hyperbolic knots
- Author
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Kenneth L. Baker and Kimihiko Motegi
- Subjects
010102 general mathematics ,Geometric Topology (math.GT) ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Mathematics::Geometric Topology ,Dehn surgery ,Combinatorics ,Mathematics - Geometric Topology ,Knot (unit) ,0103 physical sciences ,57M25 ,FOS: Mathematics ,characterizing slope ,Meridian (astronomy) ,010307 mathematical physics ,Geometry and Topology ,0101 mathematics ,Unknot ,Mathematics - Abstract
A non-trivial slope $r$ on a knot $K$ in $S^3$ is called a characterizing slope if whenever the result of $r$-surgery on a knot $K'$ is orientation preservingly homeomorphic to the result of $r$-surgery on $K$, then $K'$ is isotopic to $K$. Ni and Zhang ask: for any hyperbolic knot $K$, is a slope $r = p/q$ with $|p| + |q|$ sufficiently large a characterizing slope? In this article we answer this question in the negative by demonstrating that there is a hyperbolic knot $K$ in $S^3$ which has infinitely many non-characterizing slopes. As the simplest known example, the hyperbolic knot $8_6$ has no integral characterizing slopes., 13 pages, 7 figures
- Published
- 2016
17. Networking Seifert surgeries on knots II: The Berge's lens surgeries
- Author
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Katura Miyazaki, Kimihiko Motegi, and Arnaud Deruelle
- Subjects
Lens (geometry) ,Pure mathematics ,Berge knot ,Physics::Medical Physics ,Lens space ,Seiferter ,Physics::Optics ,Mathematics::Geometric Topology ,Dehn surgery ,Combinatorics ,Geometry and Topology ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
In [A. Deruelle, K. Miyazaki, K. Motegi, Networking Seifert surgeries on knots, Preprint], we have defined the Seifert Surgery Network consisting of all the integral Dehn surgeries on knots in S 3 yielding Seifert fiber spaces, where Seifert fiber spaces may have fibers of indices zero as a degenerate case. In this paper we focus on lens surgeries, i.e. Dehn surgeries on knots which yield lens spaces. J. Berge [J. Berge, Some knots with surgeries yielding lens spaces, unpublished manuscript] gave a list of twelve infinite families of lens surgeries, which is conjectured to be a complete list of lens surgeries. We locate the Berge's lens surgeries in the Seifert Surgery Network, and show that in the network, they are “close” to Seifert surgeries on torus knots.
- Published
- 2009
- Full Text
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18. HYPERBOLIC SECTIONS IN SEIFERT-FIBERED SURFACE BUNDLES
- Author
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Kimihiko Motegi and Kazuhiro Ichihara
- Subjects
Surface bundle ,Pure mathematics ,General Mathematics ,Mathematical analysis ,Fibered knot ,Surface (topology) ,Mathematics::Geometric Topology ,Torus knot ,Section (fiber bundle) ,Monodromy ,Projection (mathematics) ,Seifert fiber space ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
Let M be a small Seifert fiber space which has also a structure of surface bundle F × [0, 1]/{(x, 0) = (f(x), 1)} over the circle, where f: F → F is a monodromy map with non-empty fixed point set. A typical example of such a manifold appears as the result of 0-surgery on a torus knot. For each section in M, we have a ‘projection’ in F in a natural way. We give a condition assuring that the given section in M is hyperbolic in terms of the ‘projection’ in the fiber surface. By translating the result, we give a condition to obtain pseudo-Anosov automorphisms of once punctured surfaces from a periodic automorphism.
- Published
- 2008
19. Twist families of L-space knots, their genera, and Seifert surgeries
- Author
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Kimihiko Motegi and Kenneth L. Baker
- Subjects
Statistics and Probability ,Conjecture ,Linking number ,Geometric Topology (math.GT) ,Omega ,Mathematics::Geometric Topology ,Combinatorics ,symbols.namesake ,Mathematics - Geometric Topology ,Knot (unit) ,57M25, 57M27 ,Braid ,symbols ,FOS: Mathematics ,Geometry and Topology ,Statistics, Probability and Uncertainty ,Twist ,Unknot ,Mathematics::Symplectic Geometry ,Analysis ,Mathematics - Abstract
Conjecturally, there are only finitely many Heegaard Floer L-space knots in $S^3$ of a given genus. We examine this conjecture for twist families of knots $\{K_n\}$ obtained by twisting a knot $K$ in $S^3$ along an unknot $c$ in terms of the linking number $\omega$ between $K$ and $c$. We establish the conjecture in case of $|\omega| \neq 1$, prove that $\{K_n\}$ contains at most three L-space knots if $\omega = 0$, and address the case where $|\omega| = 1$ under an additional hypothesis about Seifert surgeries. To that end, we characterize a twisting circle $c$ for which $\{ (K_n, r_n) \}$ contains at least ten Seifert surgeries. We also pose a few questions about the nature of twist families of L-space knots, their expressions as closures of positive (or negative) braids, and their wrapping about the twisting circle., Comment: In addition to addressing typos, V2 restructures, expands, and corrects parts of V1 and incorporates comments of referees. Accepted by Comm. Anal. Geom
- Published
- 2015
20. The slope conjecture for graph knots
- Author
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Kimihiko Motegi and Toshie Takata
- Subjects
Sequence ,Conjecture ,General Mathematics ,010102 general mathematics ,Boundary (topology) ,Geometric Topology (math.GT) ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Mathematics::Geometric Topology ,Combinatorics ,Mathematics - Geometric Topology ,57M25, 57M27 ,FOS: Mathematics ,Graph (abstract data type) ,0101 mathematics ,Mathematics - Abstract
The slope conjecture proposed by Garoufalidis asserts that the Jones slopes given by the sequence of degrees of the colored Jones polynomials are boundary slopes. We verify the slope conjecture for graph knots, i.e. knots whose Gromov volume vanish., Comment: We found a gap in the proof of Lemma 3.1 in the last version (1501.01105v2). This lemma is replaced by Proposition 3.2 in [Kalfagianni and Tran; Knot cabling and the degree of the colored Jones polynomial (1501.01574v1)]. The title of the paper is also changed
- Published
- 2015
21. Tight fibered knots and band sums
- Author
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Kimihiko Motegi and Kenneth L. Baker
- Subjects
Knot complement ,General Mathematics ,010102 general mathematics ,Skein relation ,Mathematical analysis ,Band sum ,Geometric Topology (math.GT) ,Tricolorability ,01 natural sciences ,Mathematics::Geometric Topology ,Knot theory ,Combinatorics ,Mathematics - Geometric Topology ,Prime knot ,Knot invariant ,0103 physical sciences ,57M25, 57M27 ,FOS: Mathematics ,010307 mathematical physics ,0101 mathematics ,Mathematics ,Trefoil knot - Abstract
We give a short proof that if a non-trivial band sum of two knots results in a tight fibered knot, then the band sum is a connected sum. In particular, this means that any prime knot obtained by a non-trivial band sum is not tight fibered. Since a positive L-space knot is tight fibered, a non-trivial band sum never yields an L-space knot. Consequently, any knot obtained by a non-trivial band sum cannot admit a finite surgery. For context, we exhibit two examples of non-trivial band sums of tight fibered knots producing prime knots: one is fibered but not tight, and the other is strongly quasipositive but not fibered., Comment: 8 pages, 6 figures
- Published
- 2015
- Full Text
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22. Geometric types of twisted knots
- Author
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Mohamed Aït-Nouh, Kimihiko Motegi, and Daniel Matignon
- Subjects
Knot complement ,Pure mathematics ,Algebra and Number Theory ,Applied Mathematics ,Quantum invariant ,Skein relation ,Tricolorability ,Mathematics::Geometric Topology ,Torus knot ,Combinatorics ,Knot invariant ,Geometry and Topology ,Satellite knot ,Analysis ,Trefoil knot ,Mathematics - Abstract
Let K be a knot in the 3-sphere S 3 , and a disk in S 3 meeting K transversely in the interior. For non-triviality we assume that | \ K| 2 over all isotopies of K in S 3 @ . Let K ,n( S 3 ) be a knot obtained from K by n twistings along the disk . If the original knot is unknotted in S 3 , we call K ,n a twisted knot. We describe for which pair (K,) and an integer n, the twisted knot K ,n is a torus knot, a satellite knot or a hyperbolic knot.
- Published
- 2006
23. Seifert-fibered surgeries which do not arise from primitive/Seifert-fibered constructions
- Author
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Katura Miyazaki, Thomas W. Mattman, and Kimihiko Motegi
- Subjects
Pure mathematics ,Conjecture ,Applied Mathematics ,General Mathematics ,Physics::Optics ,Fibered knot ,Mathematics::Geometric Topology ,Dehn surgery ,Knot (unit) ,Seifert surface ,Seifert fiber space ,Geometrization conjecture ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
We construct two infinite families of knots each of which admits a Seifert fibered surgery with none of these surgeries coming from Dean's primitive/Seifert-fibered construction. This disproves a conjecture that all Seifert-fibered surgeries arise from Dean's primitive/Seifert-fibered construction. The (-3, 3,5)-pretzel knot belongs to both of the infinite families.
- Published
- 2005
24. On primitive/Seifert-fibered constructions
- Author
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Katura Miyazaki and Kimihiko Motegi
- Subjects
Algebra ,Pure mathematics ,General Mathematics ,Physics::Optics ,Fibered knot ,Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology ,Mathematics - Abstract
J. Dean introduced the notion of primitive/Seifert-fibered knots and constructions to explain how Dehn surgeries on knots produce small Seifert fibered manifolds. We determine non-hyperbolic, primitive/Seifert-fibered knots, and show that for such knots any integral, small Seifert fibered surgery arises from a primitive/Seifert-fibered construction. We also show that any 2-orbifold .
- Published
- 2005
25. Obtaining graph knots by twisting unknots
- Author
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Mohamed Aı̈t Nouh, Kimihiko Motegi, and Daniel Matignon
- Subjects
Knot complement ,Quantum invariant ,Skein relation ,Gromov volume ,Tricolorability ,Mathematics::Geometric Topology ,Knot theory ,Combinatorics ,Knot invariant ,Graph knots ,Twisting ,Geometry and Topology ,Unknot ,Trefoil knot ,Mathematics - Abstract
Let K be a knot in the 3-sphere S 3 and D ad isk inS 3 meeting K transversely more than once in the interior. For nontriviality we assume that |D ∩ K| 2 over all isotopies of K in S 3 − ∂D .L et KD,n (⊂ S 3 ) be a knot obtained from K by n twisting along the disk D. We prove that if K is a trivial knot and KD,n is a graph knot, then |n| 1o rK and D form a special pair which we call an “exceptional pair”. As a corollary, if (K, D) is not an exceptional pair, then by twisting unknot K more than once (in the positive or the negative direction) along the disk D, we always obtain a knot with positive Gromov volume. We will also show that there are infinitely many graph knots each of which is obtained from a trivial knot by twisting, but its companion knot cannot be obtained in such a manner. 2004 Elsevier B.V. All rights reserved. MSC: 57M25
- Published
- 2005
- Full Text
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26. Twisted unknots
- Author
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Daniel Matignon, Mohamed Aı̈t Nouh, and Kimihiko Motegi
- Subjects
Combinatorics ,General Medicine ,Satellite knot ,Unknot ,Mathematics::Geometric Topology ,Torus knot ,Knot (mathematics) ,Mathematics - Abstract
Let K be a knot in the 3-sphere S3, and D a disk in S3 meeting K transversely in the interior. For non-triviality we assume that |D∩K|⩾2 over all isotopies of K in S3−∂D. Let KD,n(⊂S3) be the knot obtained from K by n twisting along the disk D. If the original knot is unknotted in S3, we call KD,n a twisted unknot. We describe for which pairs (K,D) and integers n, the twisted unknot KD,n is a torus knot, a satellite knot or a hyperbolic knot. To cite this article: M. Ait Nouh et al., C. R. Acad. Sci. Paris, Ser. I 337 (2003).
- Published
- 2003
27. An Experimental Study of Seifert Fibered Dehn Surgery via SnapPea
- Author
-
Kimihiko Motegi
- Subjects
SnapPea ,Pure mathematics ,Dehn surgery ,Dehn twist ,Knot (unit) ,Seifert surface ,Seifert fiber space ,Fibered knot ,Geometrization conjecture ,Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology ,Mathematics - Abstract
Jeff Weeks’ computer program SnapPea has been used widely in 3-manifold topology. This program computes hyperbolic structures after drillings and Dehn fillings on 3-manifolds, and it provides a variety of associated topological, geometric and arithmetic invariants. In our previous study about Seifert fibered Dehn surgeries on knots, we used SnapPea to investigate a relationship between closed geodesics in hyperbolic knot complements and Seifert fibers after Seifert fibered surgeries on them. We will explain how we used SnapPea in the study and propose some questions inspired by the computer experiments. These experiments were carried out in the joint work with Katura Miyazaki while we were preparing the paper [Miyazaki and Motegi, Comm. Anal. Geom., 7: 551–582].
- Published
- 2003
28. Dehn surgeries, group actions and Seifert fiber spaces
- Author
-
Kimihiko Motegi
- Subjects
Statistics and Probability ,Algebra ,Group action ,Fiber (mathematics) ,Geometry and Topology ,Statistics, Probability and Uncertainty ,Analysis ,Mathematics - Published
- 2003
29. Seifert fibering surgery on periodic knots
- Author
-
Kimihiko Motegi and Katura Miyazaki
- Subjects
Knot complement ,Pure mathematics ,Fibered manifold ,Mathematical analysis ,Fibered knot ,Mathematics::Geometric Topology ,Torus knot ,Dehn surgery ,Seifert fibered manifold ,Seifert surface ,(−2,3,7) pretzel knot ,Factor knot ,Periodic knot ,Geometry and Topology ,Geometrization conjecture ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
We show that if a periodic knot K in the 3-sphere yields a Seifert fibered manifold by Dehn surgery, then the quotient of K by the group action generated by any periodic map of K is a torus knot, except for a special case. We also consider what Seifert fibered manifolds are obtained by Dehn surgery on periodic knots. If a non-torus, periodic knot yields a Seifert fibered manifold M , then the base space of M is the 2-sphere; and some pair of exceptional fibers in M has indices coprime provided that M contains at most three exceptional fibers.
- Published
- 2002
- Full Text
- View/download PDF
30. L-space surgery and twisting operation
- Author
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Kimihiko Motegi
- Subjects
Homology (mathematics) ,01 natural sciences ,Torus knot ,Combinatorics ,Dehn surgery ,57N10 ,Mathematics - Geometric Topology ,Knot (unit) ,twisting ,L-space surgery ,seiferter ,0103 physical sciences ,57M25, 57M27 ,L-space knot ,FOS: Mathematics ,tunnel number ,0101 mathematics ,Twist ,Mathematics::Symplectic Geometry ,Mathematics ,010308 nuclear & particles physics ,010102 general mathematics ,Geometric Topology (math.GT) ,Mathematics::Geometric Topology ,Floer homology ,57M27 ,57M25 ,Berge knot ,Geometry and Topology - Abstract
A knot in the 3-sphere is called an L-space knot if it admits a nontrivial Dehn surgery yielding an L-space, i.e. a rational homology 3-sphere with the smallest possible Heegaard Floer homology. Given a knot K, take an unknotted circle c and twist K n times along c to obtain a twist family { K_n }. We give a sufficient condition for { K_n } to contain infinitely many L-space knots. As an application we show that for each torus knot and each hyperbolic Berge knot K, we can take c so that the twist family { K_n } contains infinitely many hyperbolic L-space knots. We also demonstrate that there is a twist family of hyperbolic L-space knots each member of which has tunnel number greater than one., The final version, accepted for publication by Algebr. Geom. Topol
- Published
- 2014
31. Neighbors of Seifert surgeries on a trefoil knot in the Seifert Surgery Network
- Author
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Arnaud Deruelle, Katura Miyazaki, and Kimihiko Motegi
- Subjects
medicine.medical_specialty ,General Mathematics ,Physics::Medical Physics ,Geometric Topology (math.GT) ,Mathematics::Geometric Topology ,law.invention ,Surgery ,Dehn surgery ,Mathematics - Geometric Topology ,Invertible matrix ,Knot (unit) ,law ,Seifert fiber space ,medicine ,FOS: Mathematics ,Mathematics::Symplectic Geometry ,Trefoil knot ,Mathematics ,57M25, 57M50, 57N10 - Abstract
A Seifert surgery is a pair (K, m) of a knot K in the 3-sphere and an integer m such that m-Dehn surgery on K results in a Seifert fiber space allowed to contain fibers of index zero. Twisting K along a trivial knot called a seiferter for (K, m) yields Seifert surgeries. We study Seifert surgeries obtained from those on a trefoil knot by twisting along their seiferters. Although Seifert surgeries on a trefoil knot are the most basic ones, this family is rich in variety. For any m which is not -2 it contains a successive triple of Seifert surgeries (K, m), (K, m +1), (K, m +2) on a hyperbolic knot K, e.g. 17-, 18-, 19-surgeries on the (-2, 3, 7) pretzel knot. It contains infinitely many Seifert surgeries on strongly invertible hyperbolic knots none of which arises from the primitive/Seifert-fibered construction, e.g. (-1)-surgery on the (3, -3, -3) pretzel knot., Comment: To appear in Bol. Soc. Mat. Mexicana
- Published
- 2014
- Full Text
- View/download PDF
32. Toroidal surgery on periodic knots
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Katura Miyazaki and Kimihiko Motegi
- Subjects
Toroid ,Classical mechanics ,General Mathematics ,Mathematics - Published
- 2000
33. Toroidal and annular Dehn surgeries of solid tori
- Author
-
Kimihiko Motegi and Katura Miyazaki
- Subjects
Toroidal manifold ,Toroid ,Physics::Medical Physics ,Torus ,Annular manifold ,Mathematics::Geometric Topology ,Dehn surgery ,Combinatorics ,Knot (unit) ,Physics::Plasma Physics ,Solid torus ,Geometry and Topology ,Nonlinear Sciences::Pattern Formation and Solitons ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
We obtain an infinite family of hyperbolic knots in a solid torus which admit half-integral, toroidal and annular surgeries. Among this family we find a knot with two toroidal and annular surgeries; one is integral and the other is half-integral, and their distance is 5. This example realizes the maximal distance between annular surgery slopes and toroidal ones, and that between annular surgery slopes.
- Published
- 1999
34. Seifert fibered manifolds and Dehn surgery, III
- Author
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Katura Miyazaki and Kimihiko Motegi
- Subjects
Statistics and Probability ,Pure mathematics ,Dehn surgery ,Fibered knot ,Geometry and Topology ,Statistics, Probability and Uncertainty ,Analysis ,Mathematics - Published
- 1999
35. Seifert fibered manifolds and Dehn surgery II
- Author
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Katura Miyazaki and Kimihiko Motegi
- Subjects
Dehn surgery ,Pure mathematics ,General Mathematics ,Fibered knot ,Topology ,Mathematics - Published
- 1998
36. Only single twists on unknots can produce composite knots
- Author
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Kimihiko Motegi and Chuichiro Hayashi
- Subjects
Combinatorics ,Knot (unit) ,Applied Mathematics ,General Mathematics ,Composite number ,Isotopy ,Geometry ,Mathematics - Abstract
Let K K be a knot in the 3 3 -sphere S 3 S^{3} , and D D a disc in S 3 S^{3} meeting K K transversely more than once in the interior. For non-triviality we assume that | K ∩ D | ≥ 2 \vert K \cap D \vert \ge 2 over all isotopy of K K . Let K n K_{n} ( ⊂ S 3 \subset S^{3} ) be a knot obtained from K K by cutting and n n -twisting along the disc D D (or equivalently, performing 1 / n 1/n -Dehn surgery on ∂ D \partial D ). Then we prove the following: (1) If K K is a trivial knot and K n K_{n} is a composite knot, then | n | ≤ 1 \vert n \vert \le 1 ; (2) if K K is a composite knot without locally knotted arc in S 3 − ∂ D S^{3} - \partial D and K n K_{n} is also a composite knot, then | n | ≤ 2 \vert n \vert \le 2 . We exhibit some examples which demonstrate that both results are sharp. Independently Chaim Goodman-Strauss has obtained similar results in a quite different method.
- Published
- 1997
37. Left-orderable, non-L-space surgeries on knots
- Author
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Masakazu Teragaito and Kimihiko Motegi
- Subjects
Statistics and Probability ,Fundamental group ,Conjecture ,Physics::Medical Physics ,Geometric Topology (math.GT) ,Mathematics::Geometric Topology ,Combinatorics ,Mathematics - Geometric Topology ,Primary 57M25, 57N10, 20F60, Secondary 06F15 ,Knot (unit) ,FOS: Mathematics ,Geometry and Topology ,Statistics, Probability and Uncertainty ,Mathematics::Symplectic Geometry ,Analysis ,Mathematics - Abstract
Let K be a knot in the 3--sphere. An r-surgery on K is left-orderable if the resulting 3--manifold K(r) of the surgery has left-orderable fundamental group, and an r-surgery on K is called an L-space surgery if K(r) is an L-space. A conjecture of Boyer, Gordon and Watson says that non-reducing surgeries on K can be classified into left-orderable surgeries or L-space surgeries. We introduce a way to provide knots with left-orderable, non-L-space surgeries. As an application we present infinitely many hyperbolic knots on each of which every nontrivial surgery is a hyperbolic, left-orderable, non-L-space surgery., 23 pages, substantial revisions of the previously posted paper. To appear in Comm. Anal. Geom
- Published
- 2013
38. Networking Seifert Surgeries on Knots
- Author
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Katura Miyazaki, Arnaud Deruelle, and Kimihiko Motegi
- Subjects
Combinatorics ,Knot (unit) ,Applied Mathematics ,General Mathematics ,Physics::Medical Physics ,Torus ,Annulus (mathematics) ,Twist ,Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology ,Mathematics - Abstract
How do Seifert surgeries on hyperbolic knots arise from those on torus knots? We approach this question from a networking viewpoint introduced in [9]. The Seifert surgery network is a 1‐dimensional complex whose vertices correspond to Seifert surgeries; two vertices are connected by an edge if one Seifert surgery is obtained from the other by a single twist along a trivial knot called a seiferter or along an annulus cobounded by seiferters. Successive twists along a “hyperbolic seiferter” or a “hyperbolic annular pair” produce infinitely many Seifert surgeries on hyperbolic knots. In this paper, we investigate Seifert surgeries on torus knots that have hyperbolic seiferters or hyperbolic annular pairs, and obtain results suggesting that such surgeries are restricted. 57M25; 57M50, 57N10 Dedicated to Sadayoshi Kojima on the occasion of his 60 th birthday
- Published
- 2012
39. On satellite knots
- Author
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Masaharu Kouno and Kimihiko Motegi
- Subjects
Orientation (vector space) ,Physics ,Combinatorics ,Knot (unit) ,General Mathematics ,Geometry ,Satellite ,Homeomorphism - Abstract
Throughout this paper we work in the smooth category and assume that all knots are oriented and consider two knots K1 and K2 to be equivalent if and only if there is an orientation preserving homeomorphism h:S3→S3 which carries K1 onto K2 so that their orientations match. We write K1 ≅ K2 if K1 and K2 are equivalent and – K denotes the knot obtained from K by inverting its orientation.
- Published
- 1994
40. Seifert fibered surgeries with distinct primitive/Seifert positions
- Author
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Kimihiko Motegi, Mario Eudave-Muñoz, and Katura Miyazaki
- Subjects
Pure mathematics ,Fibered knot ,Geometric Topology (math.GT) ,Surface (topology) ,57M25, 57M50 ,Dehn surgery ,Seifert fiber space ,Mathematics - Geometric Topology ,Seifert surface ,Genus (mathematics) ,FOS: Mathematics ,Geometry and Topology ,Geometrization conjecture ,Primitive/Seifert position ,Mathematics ,Knot (mathematics) - Abstract
We call a pair (K, m) of a knot K in the 3-sphere S^3 and an integer m a Seifert fibered surgery if m-surgery on K yields a Seifert fiber space. For most known Seifert fibered surgeries (K, m), K can be embedded in a genus 2 Heegaard surface of S^3 in a primitive/Seifert position, the concept introduced by Dean as a natural extension of primitive/primitive position defined by Berge. Recently Guntel has given an infinite family of Seifert fibered surgeries each of which has distinct primitive/Seifert positions. In this paper we give yet other infinite families of Seifert fibered surgeries with distinct primitive/Seifert positions from a different point of view. In particular, we can choose such Seifert surgeries (K, m) so that K is a hyperbolic knot whose complement S^3 - K has an arbitrarily large volume., Comment: 13 pages, 12 figures
- Published
- 2011
- Full Text
- View/download PDF
41. Primeness of twisted knots
- Author
-
Kimihiko Motegi
- Subjects
Combinatorics ,Knot (unit) ,Applied Mathematics ,General Mathematics ,Solid torus ,Geometry ,Mathematics - Abstract
Let V V be a standardly embedded solid torus in S 3 {S^3} with a meridian-preferred longitude pair ( μ , λ ) (\mu ,\lambda ) and K K a knot contained in V V . We assume that K K is unknotted in S 3 {S^3} . Let f n {f_n} be an orientation-preserving homeomorphism of V V which sends λ \lambda to λ + n μ \lambda + n\mu . Then we get a twisted knot K n = f n ( K ) {K_n} = {f_n}(K) in S 3 {S^3} . Primeness of twisted knots is discussed and we prove: A twisted knot K n {K_n} is prime if | n | > 5 |n| > 5 . Moreover, { K n } n ∈ Z {\{ {K_n}\} _{n \in Z}} contains at most five composite knots.
- Published
- 1993
42. Hyperbolic L-space knots and exceptional Dehn surgeries
- Author
-
Kazushige Tohki and Kimihiko Motegi
- Subjects
Algebra and Number Theory ,Physics::Medical Physics ,Fibered knot ,Geometric Topology (math.GT) ,Torus ,57M25, 57M27, 57M50 ,Mathematics::Geometric Topology ,Combinatorics ,Mathematics - Geometric Topology ,Dehn surgery ,Knot (unit) ,FOS: Mathematics ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
A knot in the 3-sphere is called an L--space knot if it admits a nontrivial Dehn surgery yielding an L--space. Like torus knots and Berge knots, many L--space knots admit also a Seifert fibered surgery. We give a concrete example of a hyperbolic, L-space knot which has no exceptional surgeries, in particular, no Seifert fibered surgeries., 13 pages. arXiv admin note: text overlap with arXiv:1202.4211
- Published
- 2014
43. Braids and Nielsen-Thurston Types of Automorphisms of Punctured Surfaces
- Author
-
Kimihiko Motegi and Kazuhiro Ichihara
- Subjects
Discrete mathematics ,Mathematics::Commutative Algebra ,37E30 ,General Mathematics ,Boundary (topology) ,Automorphism ,Surface (topology) ,57M50 ,Combinatorics ,Orientation (vector space) ,57N10 ,symbols.namesake ,Euler characteristic ,Braid ,symbols ,Diffeomorphism ,Mathematics - Abstract
Let F be a compact, orientable surface with negative Euler characteristic, and let x 1 , ··· ,x n be n fixed but arbitrarily chosen points on int F , each of which has a (small) diskal neighborhood D i ⊂ F . Denote by S n (F) a subgroup of Diff (F) consisting of “sliding” maps f each of which satisfies ( 1 )f( { x 1 , ··· ,x n } ) ={ x 1 , ··· ,x }, f(D 1 ∪···∪ D ) = D 1 ∪···∪ D n and ( 2 )f is isotopic to the identity map on F .Then by restricting such automorphismsto F ˆ = F −int (D 1 ∪···∪ D n ) ,wehave automorphisms f ˆ : Fˆ → Fˆ ,whichform a subgroup S n (F) ˆ of Diff (F) ˆ . We give a Nielsen-Thurston classification of elements of S n (F) ˆ using braids in F × I which characterize the elements of S n (F) ˆ . 1. Introduction An automorphism (i.e., orientation preserving self diffeomorphism) of a compact, ori-entable surface with possibly non-empty boundary is said to be periodic if its some power isequal to the identity map, and is said to be reducible if it leaves an essential
- Published
- 2005
44. All integral slopes can be Seifert fibered slopes for hyperbolic knots
- Author
-
Hyun-Jong Song and Kimihiko Motegi
- Subjects
Pure mathematics ,Fibered knot ,Geometric Topology (math.GT) ,57M25, 57M50 ,Mathematics::Geometric Topology ,57M50 ,Dehn surgery ,Seifert fiber space ,Mathematics - Geometric Topology ,Knot (unit) ,Integer ,hyperbolic knot ,57M25 ,FOS: Mathematics ,Geometry and Topology ,surgery slopes ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
Which slopes can or cannot appear as Seifert fibered slopes for hyperbolic knots in the 3-sphere S^3? It is conjectured that if r-surgery on a hyperbolic knot in S^3 yields a Seifert fiber space, then r is an integer. We show that for each integer n, there exists a tunnel number one, hyperbolic knot K_n in S^3 such that n-surgery on K_n produces a small Seifert fiber space., Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-16.abs.html
- Published
- 2005
45. KNOT TYPES OF SATELLITE KNOTS AND TWISTED KNOTS
- Author
-
KIMIHIKO MOTEGI
- Published
- 1997
46. A Note on Unlinking Numbers of Montesinos Links
- Author
-
Kimihiko Motegi
- Subjects
Combinatorics ,General Mathematics ,Mathematics - Published
- 1996
47. Knotting trivial knots and resulting knot types
- Author
-
Kimihiko Motegi
- Subjects
Combinatorics ,Knot (unit) ,Knot invariant ,General Mathematics ,Skein relation ,57M25 ,Fibered knot ,Tricolorability ,Topology ,Mathematics ,Pretzel link ,Trefoil knot ,Knot theory - Published
- 1993
48. Twisting and knot types
- Author
-
Tetsuo Shibuya, Kimihiko Motegi, and Masaharu Kouno
- Subjects
Pure mathematics ,General Mathematics ,57M25 ,Mathematics ,Knot (mathematics) - Published
- 1992
49. Behavior of Knots under Twisting
- Author
-
Kimihiko Motegi, Tetsuo Shibuya, and Masaharu Kouno
- Published
- 1992
50. Seifert-fibered surgeries which do not arise from primitive/Seifert-fibered constructions.
- Author
-
Thomas Mattman, Katura Miyazaki, and Kimihiko Motegi
- Published
- 2006
- Full Text
- View/download PDF
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