Isotopy classes of crossing arcs in hyperbolic alternating links
|
|
- Katherine Collins
- 5 years ago
- Views:
Transcription
1 Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 1 altern / 21 Isotopy classes of crossing arcs in hyperbolic alternating links Anastasiia Tsvietkova Rutgers University, Newark
2 Geometry and topology of 3-manifolds: global picture Geometrization (Thurston 1976, Perelman 2006 completing Hamilton s program) prompted the study of topological objects, manifolds, using geometry. Thurston demonstrated that many 3-manifolds have hyperbolic metric or can be decomposed into pieces with such a metric. Mostow-Prasad rigidity assures that for a manifold with finite volume, the metric is unique as long as it is complete. W. Thurston demonstrated that every link in a 3-sphere is either a torus link, a satellite link, or a hyperbolic link, and these three categories are mutually exclusive. Every alternating link is either a composite link, or a hyperbolic link, or a (2, n)-torus link, and this can be seen from a link diagram (Menasco 1984). Anastasiia Tsvietkova (RutgersIsotopy University, Newark) classes of crossing arcs in hyperbolic 2altern / 21
3 Geometry and topology of 3-manifolds: local picture We still know little about the relations between intrinsic topology and intrinsic geometry of hyperbolic 3-manifolds. E.g., given an arc in a 3-manifold with a topological description, what geometric properties does it have? Some arcs with a topological description: 1) An unknotting tunnel (alternatively, a tunnel arc). A manifold that admits a single unknotting tunnel (and is not a solid torus) is called a tunnel number 1 manifold. A tunnel arc in a tunnel number 1 manifold is always homotopic to a geodesic. But when is it isotopic to a geodesic (Adams, 1995)? Conjecture (Sakuma-Weeks, 1995). Any unknotting tunnel of a hyperbolic knot is isotopic to a geodesic. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 3 altern / 21
4 Geometry of arcs with a topological description Some arcs that have topological description (continued): 2) A crossing arc runs from an underpass to an overpass at a crossing of a link diagram. For alternating links, the reduced alternating diagram is unique up to flypes (Tait flyping conjecture, Menasco-Thistlethwaite). Thus, being a crossing arc is a topological property: it does not depend on a diagram. Conjecture (Sakuma-Weeks, 1995). All crossing arcs in a reduced alternating diagram of a hyperbolic alternating link are isotopic to geodesics. Note: for link complements in S 3, tunnel arcs are often a subset of crossing arcs. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 4 altern / 21
5 What has been proved? 1) Tunnel arcs Is a tunnel arc in a tunnel number 1 manifold always isotopic to a geodesic? In a hyperbolic knot? Both questions are open. Partial progress Adams-Reid: some tunnel arcs in 2-bridge links are isotopic to geodesics. Cooper-Futer-Purcell: all tunnel arcs in certain one-cusped manifolds are isotopic to geodesics. The manifolds are all manifolds obtained by Dehn filling on one cusp of a two-cusped hyperbolic manifold, with meridian and longtitude for the filling both sufficiently large (i.e. finitely many slopes are avoided) Generalization: take a collection of arcs in a manifold such that the complement is a collection of handlebodies (and arcs can be isotoped fixing endpoints to be disjoint). Burton-Purcell: some evidence that collections of n such arcs may not be isotopic to geodesics in tunnel number n manifolds. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 5 altern / 21
6 What has been proved? 2) Crossings arcs Conjecture (Sakuma-Weeks, 1995). All crossing arcs in a reduced alternating diagram of a hyperbolic alternating links are isotopic to geodesics. Proved for: 2-bridge links (Gueritad-Futer, 2006, as well as an unpublished proof by Akiyoshi-Sakuma-Wada) Three infinite families of links with highly symmetric diagrams (Sakuma and Weeks, 1995): 3-braids (σ 1 σ 1 2 )n for n > 1; n-component chains for n > 2; and links C (n) on the right for n even and n > 3. Several more links by Aitchison-Reeves and Hatcher. Overall, 4 infinite families, and few more (up to 20) links outside these families. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 6 altern / 21
7 Hyperbolic 2-bridge links (Gueritad); hyperbolic 1-punctured torus bundles (Lackenby); three symmetric families of links (mentioned above, Salkuma-Weeks). No other classes of 3-manifolds for which the CCD is even conjecturally understood. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 7 altern / 21 Related questions and significance Canonical cell decomposition (CCD) Epstein-Penner, 1988: every hyperbolic 3-manifold has a decomposition into hyperbolic convex polyhedra. This decomposition is a complete topological invariant of hyperbolic 3-manifolds. Arcs of a canonical cell decomposition are isotopic to geodesics.
8 Related questions and significance (continued) Ideal geodesic triangulation - a triangulation that agrees with the complete hyperbolic structure of the 3-manifold M. Ideal means that vertices are on the torus boundary of M. Edges of an ideal geodesic triangulation are isotopic to geodesics. There is no algorithm known that constructs such a triangulation for an arbitrary hyperbolic 3-manifold with torus boundary. Even for hyperbolic links, this is an open question (solved by Gueritad and Futer for 2-bridge links). Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 8 altern / 21
9 Related questions and significance (continued) Length of arcs. For a hyperbolic geodesic, one can measure its hyperbolic length. Empirically, for certain classes of manifolds there are upper and lower bounds for the length, and for the related cusp area. Conjecture (Thistlethwaite). Crossing arcs of alternating links are short. In particular, if the meridian of a link fixed to be 1, the hyperbolic intercusp length is at most log 8. Lackenby and Purcell recently offered another fact supporting the conjecture. The conjecture however is still open. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic 9 altern / 21
10 (A.T.) Sufficient conditions for crossings arcs in alternating links to be isotopic to geodesics. The conditions are numerical (a set of simple inequalities for parameters that can be computed from a link diagram). As a result: a) New examples of links, including infinite families, with crossings arcs isotopic to geodesics. E.g., the family of closed braids with the braid word (σ 1 σ 3 σ2 1 )n, k > 0, n > 1. One can use similar argument for any of the infinitely many families (σ 1 σ 3...σ 2k±1 σ2 1 σ σ 1 2k )n, k > 0, n > 1. One of Sakuma-Weeks three families, braids (σ 1 σ2 1 )n, is a subset. b) Many triangulations are ideal geodesic triangulations. The links are then hyperbolic without a reference to Geometrization. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic10 altern / 21
11 Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic11 altern / 21 Proof: main ingridients I. (Thislethwaite-T.) An alternative method for computing hyperbolic structure of links: assigns labels with geometric meaning to a link diagram.
12 Proof: main ingridients I. (Thislethwaite-T.) An alternative method for computing hyperbolic structure of links: assigns labels with geometric meaning to a link diagram. In the upper half-space model of H 3, a ball tangent to the boundary of H 3 is a horoball, bounded by a horosphere. In H 3, the preimage of a boundary torus for a hyperbolic link is a set of horospheres. A meridian is a simple closed curve traveling once around the torus. Its preimage is on a horosphere. Parameterize Euclidean translations on each horosphere by complex numbers so that the meridional translation corresponds to 1. If one of the horospheres is the plane z = 1, the horoballs have disjoint interiors (follows from Adams results). nastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic11 altern / 21
13 A crossing label contains the information about the distance and angle between the strands of the link. In particular, the red (geodesic) arc has γ as the preimage in H 3, joining the centers of the corresponding horospheres. The modulus of the label determines the hyperbolic (cusp-to-cusp) distance along the arc, and its argument is the angle between the meridional translations on horospheres. An edge label contains information about a preimage of an arc traveling on the boundary torus between two crossings. In H 3, it is a complex number determining the Euclidean translation along β. The arc β travels between the points where the preimages of crossings arcs pierce the horosphere. Its orientation agrees with the orientation of the link. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic12 altern / 21
14 Proof: main ingridients Using isometries rotating the regions of the diagram, one obtains a system of polynomial equations in edge and crossing labels. One of the solutions describes the complete hyperbolic structure. For our proof: rather than starting with a hyperbolic link, take an arbitrary alternating link diagram and assign labels (possibly, with no geometric meaning). Want to obtain the conditions on the labels that guarantee the existence of a complete hyperbolic structure. Compare with completeness and consistency conditions on a triangulation by W. Thurston. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic13 altern / 21
15 Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic14 altern / 21 Proof: main ingridients II. Thurston-Menasco s decomposition: 2 polyhedra, above and below a link diagram, mirror images of each other. Correspond to the combinatorics of the diagram closely. To construct one, place an ideal vertex on every edge of the diagram (i.e. on a segment from a crossing to the subsequent crossing). For every crossing of the diagram, place 4 polyhedral edges around it, 2 for the polyhedron above, and 2 for the one below (these will be identified later into just one edge). Identify two edges of every bigon of the diagram so that there are no more bigons.
16 Proof: main ingridients II. Thurston-Menasco s decomposition: 2 polyhedra, above and below a link diagram, mirror images of each other. Correspond to the combinatorics of the diagram closely. To construct one, place an ideal vertex on every edge of the diagram (i.e. on a segment from a crossing to the subsequent crossing). For every crossing of the diagram, place 4 polyhedral edges around it, 2 for the polyhedron above, and 2 for the one below (these will be identified later into just one edge). Identify two edges of every bigon of the diagram so that there are no more bigons. After identifications, every n-sided region of the diagram that is not a bigon yields an n-sided face of a polyhedron. The edges of the polyhedra are crossing arcs. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic14 altern / 21
17 Proof: main idgridients II. Thurston-Menasco s polyhedra are polyhedra only in topological sense: the faces might not be planar. Every ideal vertex corresponds to a triangular or rectangular cross-section. if the link is hyperbolic, the cross-sections are Euclidean polygons. For our proof: decompose the link complement into two (possibly non-geometric) polyhedra. Using the labels, track what happens with cross-sections of the polyhedra. Angles of the cross-sections are captured by ratios of two corresponding edge labels, e.g. Im u v + 1. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic15 altern / 21
18 Proof: main ingridiients III. (Petronio-Weeks + Thurston) A topological triangulation is an ideal geodesic triangulation if and only if 1) Every simplex is a hyperbolic tetrahedron (three pairs of opposite edges correspond to the arguments of z, 1 1/z, 1/(1 z) for a complex number z, called a tetrahedral shape or parameter). 2) At every edge of a triangulation, after faces of n tetrahedra are identified in pairs and glued at that edge to obtain the manifold, the corresponding shapes satisfy z 1 z 2...z n = 1. 3) All tetrahedra have non-negative volume, and not all have 0-volume. 4) The metric is complete, i.e. the cross-sectional triangles are glued together to give a closed Euclidean surface. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic16 altern / 21
19 For our proof: triangulate the polyhedra. There are many ways to do this, and crossing arcs are always some of the edges. Keep track of what happens with the cross-sections using edge and crossing labels. Use the above criterion to obtain the conditions on the labels that are sufficient for the existence of a complete hyperbolic structure. Additionally, the crossing arcs are the arcs of an ideal geodesic triangulation, and are therefore isotopic to geodesics. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic17 altern / 21
20 Geometric interpretation of the sufficient conditions Suppose P is an ideal cell in H 3, and every vertex has valency 3 or 4. Call P cross-sectionally convex if at every vertex, a Euclidean cross-section is a convex polygon. The conditions we obtained force Menasco-Thurston polyhedra to be cross-sectionally convex and not to have cusp-to-cusp edges of length 0. We prove that once faces of such a complex are triangulated, the resulting polyhedron is properly embedded in H 3. Equivalently, the Menasco-Thurston decomposition of a link complement, with faces triangulated, can be realized by ideal hyperbolic polyhedra. Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic18 altern / 21
21 Anastasiia Tsvietkova (Rutgers Isotopy University, Newark) classes of crossing arcs in hyperbolic19 altern / 21 Conjecture. For a hyperbolic alternating link, the preimage of every Menasco-Thurston polyhedron is cross-sectionally convex. The polyhedra can then be subdivided into partially flat ideal geodesic triangulation. Question. For which links, in addition, the faces of these polyhedra are planar (i.e. lie in one hyperbolic plane)? If the polyhedra are cross-sectionally convex, and faces are planar, the resulting decomposition is the canonical cell decomposition. This happens, for example, for the link (σ 1 σ 3 σ 1 2 )4.
22 Infinite families of closed braids To check that sufficient conditions hold for the closed braids 1 n (σ1 σ3...σ2k+1 σ2 1 σ4 1...σ2k ), use symmetry of the diagram. The central region corresponds to a regular ideal polygon. Labels are obtained by a computation performed for an infinite family at once. Since a triangulation might be partially flat, check that edges are simple geodesics. Anastasiia Tsvietkova (RutgersIsotopy University, Newark) classes of crossing arcs in hyperbolic 20altern / 21
23 Infinite families of closed braids To check that sufficient conditions hold for the closed braids 1 n (σ1 σ3...σ2k+1 σ2 1 σ4 1...σ2k ), use symmetry of the diagram. The central region corresponds to a regular ideal polygon. Labels are obtained by a computation performed for an infinite family at once. Since a triangulation might be partially flat, check that edges are simple geodesics. Acknowledgments: the work was motivated by discussions with Marc Lackenby. Anastasiia Tsvietkova (RutgersIsotopy University, Newark) classes of crossing arcs in hyperbolic 20altern / 21
24 Okinawa Institute of Science and Technology (OIST), Japan, is currently inviting applications in topology and geometry of manifolds for postdoctoral positions and positions for senior researchers willing to spend at least 6 months in residence (no teaching duties): Anastasiia Tsvietkova (RutgersIsotopy University, Newark) classes of crossing arcs in hyperbolic 21altern / 21
Exact Volume of Hyperbolic 2-bridge Links
Exact Volume of Hyperbolic 2-bridge Links Anastasiia Tsvietkova Louisiana State University Parts of this work are joint with M. Thislethwaite, O. Dasbach Anastasiia Tsvietkova (Louisiana State University
More informationTwist knots and augmented links
CHAPTER 7 Twist knots and augmented links In this chapter, we study a class of hyperbolic knots that have some of the simplest geometry, namely twist knots. This class includes the figure-8 knot, the 5
More informationHyperbolic Structures from Ideal Triangulations
Hyperbolic Structures from Ideal Triangulations Craig Hodgson University of Melbourne Geometric structures on 3-manifolds Thurston s idea: We would like to find geometric structures (or metrics) on 3-manifolds
More informationAngle Structures and Hyperbolic Structures
Angle Structures and Hyperbolic Structures Craig Hodgson University of Melbourne Throughout this talk: M = compact, orientable 3-manifold with M = incompressible tori, M. Theorem (Thurston): M irreducible,
More informationGeometrically maximal knots
Geometrically maximal knots Abhijit Champanerkar Department of Mathematics, College of Staten Island & The Graduate Center, CUNY Discussion Meeting on Knot theory and its Applications IISER Mohali, India
More informationCHAPTER 8. Essential surfaces
CHAPTER 8 Essential surfaces We have already encountered hyperbolic surfaces embedded in hyperbolic 3-manifolds, for example the 3-punctured spheres that bound shaded surfaces in fully augmented links.
More informationCHAPTER 8. Essential surfaces
CHAPTER 8 Essential surfaces We have already encountered hyperbolic surfaces embedded in hyperbolic 3-manifolds, for example the 3-punctured spheres that bound shaded surfaces in fully augmented links.
More informationHyperbolic structures and triangulations
CHAPTER Hyperbolic structures and triangulations In chapter 3, we learned that hyperbolic structures lead to developing maps and holonomy, and that the developing map is a covering map if and only if the
More informationSlope lengths and generalized augmented links
communications in analysis and geometry Volume 16, Number 4, 883 905, 2008 Slope lengths and generalized augmented links Jessica S. Purcell In this paper, we determine geometric information on slope lengths
More informationSLOPE LENGTHS AND GENERALIZED AUGMENTED LINKS
SLOPE LENGTHS AND GENERALIZED AUGMENTED LINKS JESSICA S PURCELL Abstract In this paper, we determine geometric information on slope lengths of a large class of knots in the 3 sphere, based only on diagrammatical
More informationTriangulations of hyperbolic 3-manifolds admitting strict angle structures
Triangulations of hyperbolic 3-manifolds admitting strict angle structures Craig D. Hodgson, J. Hyam Rubinstein and Henry Segerman segerman@unimelb.edu.au University of Melbourne January 4 th 2012 Ideal
More informationAN INTRODUCTION TO FULLY AUGMENTED LINKS
AN INTRODUCTION TO FULLY AUGMENTED LINKS JESSICA S. PURCELL Abstract. In this article we summarize information on the class of fully augmented links. These links are geometrically explicit, and therefore
More informationpα i + q, where (n, m, p and q depend on i). 6. GROMOV S INVARIANT AND THE VOLUME OF A HYPERBOLIC MANIFOLD
6. GROMOV S INVARIANT AND THE VOLUME OF A HYPERBOLIC MANIFOLD of π 1 (M 2 )onπ 1 (M 4 ) by conjugation. π 1 (M 4 ) has a trivial center, so in other words the action of π 1 (M 4 ) on itself is effective.
More informationThe geometry of embedded surfaces
CHAPTER 12 The geometry of embedded surfaces In this chapter, we discuss the geometry of essential surfaces embedded in hyperbolic 3-manifolds. In the first section, we show that specific surfaces embedded
More informationCombinatorial constructions of hyperbolic and Einstein four-manifolds
Combinatorial constructions of hyperbolic and Einstein four-manifolds Bruno Martelli (joint with Alexander Kolpakov) February 28, 2014 Bruno Martelli Constructions of hyperbolic four-manifolds February
More informationDecomposition of the figure-8 knot
CHAPTER 1 Decomposition of the figure-8 knot This book is an introduction to knots, links, and their geometry. Before we begin, we need to define carefully exactly what we mean by knots and links, and
More informationGeometric structures on manifolds
CHAPTER 3 Geometric structures on manifolds In this chapter, we give our first examples of hyperbolic manifolds, combining ideas from the previous two chapters. 3.1. Geometric structures 3.1.1. Introductory
More informationGeometric structures on manifolds
CHAPTER 3 Geometric structures on manifolds In this chapter, we give our first examples of hyperbolic manifolds, combining ideas from the previous two chapters. 3.1. Geometric structures 3.1.1. Introductory
More informationGEOMETRY OF PLANAR SURFACES AND EXCEPTIONAL FILLINGS
GEOMETRY OF PLANAR SURFACES AND EXCEPTIONAL FILLINGS NEIL R. HOFFMAN AND JESSICA S. PURCELL Abstract. If a hyperbolic 3 manifold admits an exceptional Dehn filling, then the length of the slope of that
More informationHyperbolic Invariants and Computing hyperbolic structures on 3-Orbifolds. Craig Hodgson. University of Melbourne
Hyperbolic Invariants and Computing hyperbolic structures on 3-Orbifolds Craig Hodgson University of Melbourne Some References W. Thurston, Geometry and topology of 3-manifolds, Lecture Notes, Princeton
More informationGEOMETRY OF PLANAR SURFACES AND EXCEPTIONAL FILLINGS
GEOMETRY OF PLANAR SURFACES AND EXCEPTIONAL FILLINGS NEIL R. HOFFMAN AND JESSICA S. PURCELL Abstract. If a hyperbolic 3 manifold admits an exceptional Dehn filling, then the length of the slope of that
More informationPart 2. Tools, techniques, and families of examples
Part 2 Tools, techniques, and families of examples CHAPTER 7 Twist knots and augmented links In this chapter, we study a class of hyperbolic knots that have some of the simplest geometry, namely twist
More informationTwo-bridge knots and links
CHAPTER 0 Two-bridge knots and links In this chapter we will study in detail a class of knots and links that has particularly nice geometry, namely the class of 2-bridge knots and links. The key property
More informationAngled decompositions of arborescent link complements
Proceedings of the London Mathematical Society Advance Access published July 18, 2008 Proc. London Math. Soc. Page 1 of 40 C 2008 London Mathematical Society doi:10.1112/plms/pdn033 Angled decompositions
More informationNESTED AND FULLY AUGMENTED LINKS
NESTED AND FULLY AUGMENTED LINKS HAYLEY OLSON Abstract. This paper focuses on two subclasses of hyperbolic generalized fully augmented links: fully augmented links and nested links. The link complements
More informationTHE CANONICAL DECOMPOSITION OF ONCE-PUNCTURED TORUS BUNDLES
THE CANONICAL DECOMPOSITION OF ONCE-PUNCTURED TORUS BUNDLES MARC LACKENBY 1. Introduction Epstein and Penner proved that any complete, non-compact, finite volume hyperbolic manifold admits a canonical
More informationto hyperbolic 3-manifolds. Dehn Surgery Approach to The Figure-Eight Knot Complement
Hyperbolic 3-Manifolds Dehn Surgery Approach to The Figure-Eight Knot Complement Sarah Dubicki, 11 Math 490: Senior Independent Study Advisor Dr. Barbara Nimershiem May 5, 2011 Abstract This project provides
More informationINTRODUCTION TO 3-MANIFOLDS
INTRODUCTION TO 3-MANIFOLDS NIK AKSAMIT As we know, a topological n-manifold X is a Hausdorff space such that every point contained in it has a neighborhood (is contained in an open set) homeomorphic to
More informationHyperbolic Geometry on the Figure-Eight Knot Complement
Hyperbolic Geometry on the Figure-Eight Knot Complement Alex Gutierrez Arizona State University December 10, 2012 Hyperbolic Space Hyperbolic Space Hyperbolic space H n is the unique complete simply-connected
More informationHeegaard splittings and virtual fibers
Heegaard splittings and virtual fibers Joseph Maher maher@math.okstate.edu Oklahoma State University May 2008 Theorem: Let M be a closed hyperbolic 3-manifold, with a sequence of finite covers of bounded
More informationGuts of surfaces and colored Jones knot polynomials
Guts of surfaces and colored Jones knot polynomials David Futer, Efstratia Kalfagianni, and Jessica S. Purcell Knots in Poland III: Conference on Knot Theory and its Ramifications, Stefan Banach International
More informationAngled decompositions of arborescent link complements
Submitted exclusively to the London Mathematical Society doi:10.1112/0000/000000 Angled decompositions of arborescent link complements David Futer and François Guéritaud Abstract This paper describes a
More informationThe geometry of state surfaces and the colored Jones polynomials
The geometry of state surfaces and the colored Jones polynomials joint with D. Futer and J. Purcell December 8, 2012 David Futer, Effie Kalfagianni, and Jessica S. Purcell () December 8, 2012 1 / 15 Given:
More informationVOLUME BOUNDS FOR GENERALIZED TWISTED TORUS LINKS
VOLUME BOUNDS FOR GENERALIZED TWISTED TORUS LINKS ABHIJIT CHAMPANERKAR, DAVID FUTER, ILYA KOFMAN, WALTER NEUMANN, AND JESSICA S. PURCELL Abstract. Twisted torus knots and links are given by twisting adjacent
More informationarxiv: v1 [math.gt] 28 Nov 2014
GEOMETRICALLY AND DIAGRAMMATICALLY MAXIMAL KNOTS ABHIJIT CHAMPANERKAR, ILYA KOFMAN, AND JESSICA S. PURCELL arxiv:1411.7915v1 [math.gt] 8 Nov 014 Abstract. The ratio of volume to crossing number of a hyperbolic
More informationVOLUME BOUNDS FOR WEAVING KNOTS
VOLUME BOUNDS FOR WEVING KNOTS BHIJIT CHMPNERKR, ILY KOFMN, ND JESSIC S. PURCELL bstract. Weaving knots are alternating knots with the same projection as torus knots, and were conjectured by X.-S. Lin
More informationON MULTIPLY TWISTED KNOTS THAT ARE SEIFERT FIBERED OR TOROIDAL
ON MULTIPLY TWISTED KNOTS THAT ARE SEIFERT FIBERED OR TOROIDAL JESSICA S PURCELL Abstract We consider knots whose diagrams have a high amount of twisting of multiple strands By encircling twists on multiple
More informationPolyhedra inscribed in a hyperboloid & AdS geometry. anti-de Sitter geometry.
Polyhedra inscribed in a hyperboloid and anti-de Sitter geometry. Jeffrey Danciger 1 Sara Maloni 2 Jean-Marc Schlenker 3 1 University of Texas at Austin 2 Brown University 3 University of Luxembourg AMS
More informationVeering triangulations admit strict angle structures
Veering triangulations admit strict angle structures Craig Hodgson University of Melbourne Joint work with Hyam Rubinstein, Henry Segerman and Stephan Tillmann. Geometric Triangulations We want to understand
More information0 efficient triangulations of Haken three-manifolds
The University of Melbourne Doctoral Thesis 0 efficient triangulations of Haken three-manifolds Shanil Ramanayake A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy
More informationAn alternative method for computing the canonical cell decomposition of a hyperbolic link complement. Preliminary version (no figures yet)
An alternative method for computing the canonical cell decomposition of a hyperbolic link complement Preliminary version (no figures yet) Phillip Andreae, Laura Mansfield, Kristen Mazur, Morwen Thistlethwaite,
More informationWilliam P. Thurston. The Geometry and Topology of Three-Manifolds
William P. Thurston The Geometry and Topology of Three-Manifolds Electronic version 1.1 - March 2002 http://www.msri.org/publications/books/gt3m/ This is an electronic edition of the 1980 notes distributed
More informationRatcliffe, Foundations of hyperbolic manifolds, Springer (elementary)
1 Introduction About this lecture P SL(2, C) and hyperbolic 3-spaces. Subgroups of P SL(2, C) Hyperbolic manifolds and orbifolds Examples 3-manifold topology and Dehn surgery Rigidity Volumes and ideal
More informationVOLUME AND GEOMETRY OF HOMOGENEOUSLY ADEQUATE KNOTS
VOLUME AND GEOMETRY OF HOMOGENEOUSLY ADEQUATE KNOTS PAIGE BARTHOLOMEW, SHANE MCQUARRIE, JESSICA S. PURCELL, AND KAI WESER arxiv:1406.0195v2 [math.gt] 17 Jun 2014 Abstract. We bound the hyperbolic volumes
More informationGEOMETRICALLY AND DIAGRAMMATICALLY MAXIMAL KNOTS
GEOMETRICALLY AND DIAGRAMMATICALLY MAXIMAL KNOTS ABHIJIT CHAMPANERKAR, ILYA KOFMAN, AND JESSICA S. PURCELL Abstract. The ratio of volume to crossing number of a hyperbolic knot is known to be bounded above
More informationANGLED TRIANGULATIONS OF LINK COMPLEMENTS
ANGLED TRIANGULATIONS OF LINK COMPLEMENTS a dissertation submitted to the department of mathematics and the committee on graduate studies of stanford university in partial fulfillment of the requirements
More informationAN ALGORITHM TO DETERMINE THE HEEGAARD GENUS OF SIMPLE 3-MANIFOLDS WITH NON-EMPTY BOUNDARY
AN ALGORITHM TO DETERMINE THE HEEGAARD GENUS OF SIMPLE 3-MANIFOLDS WITH NON-EMPTY BOUNDARY MARC LACKENBY 1. Introduction The Heegaard genus of a compact orientable 3-manifold is an important invariant.
More information6.3 Poincare's Theorem
Figure 6.5: The second cut. for some g 0. 6.3 Poincare's Theorem Theorem 6.3.1 (Poincare). Let D be a polygon diagram drawn in the hyperbolic plane such that the lengths of its edges and the interior angles
More information274 Curves on Surfaces, Lecture 5
274 Curves on Surfaces, Lecture 5 Dylan Thurston Notes by Qiaochu Yuan Fall 2012 5 Ideal polygons Previously we discussed three models of the hyperbolic plane: the Poincaré disk, the upper half-plane,
More informationHYPERBOLIC STRUCTURE OF KNOT COMPLEMENTS
HYPERBOLIC STRUCTURE OF KNOT COMPLEMENTS MIHAIL HURMUZOV Abstract. In this survey we demonstrate the construction of a hyperbolic structure on several knot/link complements. We mainly follow a manuscript
More informationVeering structures of the canonical decompositions of hyperbolic fibered two-bridge links
Veering structures of the canonical decompositions of hyperbolic fibered two-bridge links Naoki Sakata Hiroshima University 8th Mar 2016 Branched Coverings, Degenerations, and Related Topics 2016 Main
More informationHYPERBOLIC GRAPHS OF SMALL COMPLEXITY
HYPERBOLIC GRAPHS OF SMALL COMPLEXITY DAMIAN HEARD, CRAIG HODGSON, BRUNO MARTELLI, AND CARLO PETRONIO Abstract. In this paper we enumerate and classify the simplest pairs (M, G) where M is a closed orientable
More informationarxiv:math/ v1 [math.gt] 27 Nov 2002
arxiv:math/0211425v1 [math.gt] 27 Nov 2002 Small hyperbolic 3-manifolds with geodesic boundary Roberto Frigerio Bruno Martelli Carlo Petronio January 5, 2014 Abstract We classify the orientable finite-volume
More informationThe Construction of a Hyperbolic 4-Manifold with a Single Cusp, Following Kolpakov and Martelli. Christopher Abram
The Construction of a Hyperbolic 4-Manifold with a Single Cusp, Following Kolpakov and Martelli by Christopher Abram A Thesis Presented in Partial Fulfillment of the Requirement for the Degree Master of
More informationTopological Issues in Hexahedral Meshing
Topological Issues in Hexahedral Meshing David Eppstein Univ. of California, Irvine Dept. of Information and Computer Science Outline I. What is meshing? Problem statement Types of mesh Quality issues
More informationBELTED SUM DECOMPOSITION OF FULLY AUGMENTED LINKS
BELTED SUM DECOMPOSITION OF FULLY AUGMENTED LINKS PORTER MORGAN, DEAN SPYROPOULOS, ROLLIE TRAPP, AND CAMERON ZIEGLER Abstract. Purcell and Adams have introduced notions of nerves and belted sums for fully
More informationThe geometry and combinatorics of closed geodesics on hyperbolic surfaces
The geometry and combinatorics of closed geodesics on hyperbolic surfaces CUNY Graduate Center September 8th, 2015 Motivating Question: How are the algebraic/combinatoric properties of closed geodesics
More informationWilliam P. Thurston. The Geometry and Topology of Three-Manifolds
William P. Thurston The Geometry and Topology of Three-Manifolds Electronic version 1.1 - March 2002 http://www.msri.org/publications/books/gt3m/ This is an electronic edition of the 1980 notes distributed
More informationProving the absence of certain totally geodesic surfaces
Proving the absence of certain totally geodesic surfaces Warren Shull August 24, 2012 Abstract We have proven the absence of totally geodesic surfaces bounded or punctured by either the figure-eight knot
More informationUNKNOTTING GENUS ONE KNOTS
UNKNOTTING GENUS ONE KNOTS ALEXANDER COWARD AND MARC LACKENBY 1. Introduction There is no known algorithm for determining whether a knot has unknotting number one, practical or otherwise. Indeed, there
More informationTHE CROSSING NUMBER OF SATELLITE KNOTS
THE CROSSING NUMBER OF SATELLITE KNOTS MARC LACKENBY 1. Introduction One of the most basic invariants of a knot K is its crossing number c(k), which is the minimal number of crossings in any of its diagrams.
More informationGeometric structures on 2-orbifolds
Geometric structures on 2-orbifolds Section 1: Manifolds and differentiable structures S. Choi Department of Mathematical Science KAIST, Daejeon, South Korea 2010 Fall, Lectures at KAIST S. Choi (KAIST)
More informationTopological Data Analysis - I. Afra Zomorodian Department of Computer Science Dartmouth College
Topological Data Analysis - I Afra Zomorodian Department of Computer Science Dartmouth College September 3, 2007 1 Acquisition Vision: Images (2D) GIS: Terrains (3D) Graphics: Surfaces (3D) Medicine: MRI
More informationGeneralized Cell Decompositions of Nested Lorenz Links
Generalized Cell Decompositions of Nested Lorenz Links illiam Coenen August 20, 2018 Abstract This paper focuses on generalizing the cell decompositions of various nested Lorenz links to determine types
More informationEVERY KNOT HAS CHARACTERISING SLOPES
EVERY KNOT HAS CHARACTERISING SLOPES MARC LACKENBY 1. Introduction Any closed orientable 3-manifold is obtained by Dehn surgery on a link in the 3-sphere [19, 32]. This surgery description of the manifold
More informationAll tunnels of all tunnel number 1 knots
All tunnels of all tunnel number 1 knots Darryl McCullough University of Oklahoma Geometric Topology Conference Beijing University June 22, 27 1 (joint work with Sangbum Cho, in The tree of knot tunnels,
More informationarxiv: v1 [math.gt] 24 May 2012
A CLASSIFICATION OF SPANNING SURFACES FOR ALTERNATING LINKS COLIN ADAMS AND THOMAS KINDRED arxiv:1205.5520v1 [math.gt] 24 May 2012 Abstract. A classification of spanning surfaces for alternating links
More informationalso can be decomposed into generalized triangles,
13. ORBIFOLDS The orbifold D 2 (;m 1,...,m l ) also can be decomposed into generalized triangles, for instance in the pattern above. One immediately sees that the orbifold has hyperbolic structures (provided
More informationON THE MAXIMAL VOLUME OF THREE-DIMENSIONAL HYPERBOLIC COMPLETE ORTHOSCHEMES
Proceedings of the Institute of Natural Sciences, Nihon University No.49 04 pp.63 77 ON THE MAXIMAL VOLUME OF THREE-DIMENSIONAL HYPERBOLIC COMPLETE ORTHOSCHEMES Kazuhiro ICHIHARA and Akira USHIJIMA Accepted
More informationPacific Journal of Mathematics
Pacific Journal of Mathematics SIMPLIFYING TRIANGULATIONS OF S 3 Aleksandar Mijatović Volume 208 No. 2 February 2003 PACIFIC JOURNAL OF MATHEMATICS Vol. 208, No. 2, 2003 SIMPLIFYING TRIANGULATIONS OF S
More informationTopic: Orientation, Surfaces, and Euler characteristic
Topic: Orientation, Surfaces, and Euler characteristic The material in these notes is motivated by Chapter 2 of Cromwell. A source I used for smooth manifolds is do Carmo s Riemannian Geometry. Ideas of
More informationTHREE-MANIFOLD CONSTRUCTIONS AND CONTACT STRUCTURES HUAN VO
THREE-MANIFOLD CONSTRUCTIONS AND CONTACT STRUCTURES HUAN VO 1. Introduction Recently, there s been an interest in open book decompositions of 3-manifolds, partly because of a fundamental theorem by Giroux,
More informationThe Classification Problem for 3-Manifolds
The Classification Problem for 3-Manifolds Program from ca. 1980: 1. Canonical decomposition into simpler pieces. 2. Explicit classification of special types of pieces. 3. Generic pieces are hyperbolic
More informationPunctured Torus Groups
Punctured Torus Groups Talk by Yair Minsky August, 7 One of the simplest classes of examples of Kleinian surface groups is given by punctured torus groups. We define a punctured torus group to be a discrete
More informationSimplicial Hyperbolic Surfaces
Simplicial Hyperbolic Surfaces Talk by Ken Bromberg August 21, 2007 1-Lipschitz Surfaces- In this lecture we will discuss geometrically meaningful ways of mapping a surface S into a hyperbolic manifold
More information6.2 Classification of Closed Surfaces
Table 6.1: A polygon diagram 6.1.2 Second Proof: Compactifying Teichmuller Space 6.2 Classification of Closed Surfaces We saw that each surface has a triangulation. Compact surfaces have finite triangulations.
More informationCAT(0) BOUNDARIES OF TRUNCATED HYPERBOLIC SPACE
CAT(0) BOUNDARIES OF TRUNCATED HYPERBOLIC SPACE KIM RUANE Abstract. We prove that the CAT(0) boundary of a truncated hyperbolic space is homeomorphic to a sphere with disks removed. In dimension three,
More informationGeometric Modeling Mortenson Chapter 11. Complex Model Construction
Geometric Modeling 91.580.201 Mortenson Chapter 11 Complex Model Construction Topics Topology of Models Connectivity and other intrinsic properties Graph-Based Models Emphasize topological structure Boolean
More informationJONES POLYNOMIALS, VOLUME AND ESSENTIAL KNOT SURFACES: A SURVEY
JONES POLYNOMIALS, VOLUME AND ESSENTIAL KNOT SURFACES: A SURVEY DAVID FUTER, EFSTRATIA KALFAGIANNI, AND JESSICA S. PURCELL Abstract. This paper is a brief overview of recent results by the authors relating
More informationNew York Journal of Mathematics. Boundary-twisted normal form and the number of elementary moves to unknot
New York Journal of Mathematics New York J. Math. 18 (2012) 389 408. Boundary-twisted normal form and the number of elementary moves to unknot Chan-Ho Suh Abstract. Suppose K is an unknot lying in the
More informationNormal Surfaces and 3-Manifold Algorithms
Colby College Digital Commons @ Colby Honors Theses Student Research 2017 Normal Surfaces and 3-Manifold Algorithms Josh D. Hews Colby College Follow this and additional works at: http://digitalcommons.colby.edu/honorstheses
More informationToroidal Dehn fillings on hyperbolic 3-manifolds. Cameron McA. Gordon Ying-Qing Wu
Toroidal Dehn fillings on hyperbolic 3-manifolds Cameron McA. Gordon Ying-Qing Wu Author address: Department of Mathematics, The University of Texas at Austin, University Station C00, Austin, TX 787-057
More informationFrom angled triangulations to hyperbolic structures
Contemporary Mathematics From angled triangulations to hyperbolic structures David Futer and François Guéritaud Abstract. This survey paper contains an elementary exposition of Casson and Rivin s technique
More informationBranched coverings and three manifolds Third lecture
J.M.Montesinos (Institute) Branched coverings Hiroshima, March 2009 1 / 97 Branched coverings and three manifolds Third lecture José María Montesinos-Amilibia Universidad Complutense Hiroshima, March 2009
More informationThe Cyclic Cycle Complex of a Surface
The Cyclic Cycle Complex of a Surface Allen Hatcher A recent paper [BBM] by Bestvina, Bux, and Margalit contains a construction of a cell complex that gives a combinatorial model for the collection of
More informationKnot complements, hidden symmetries and reflection orbifolds
Knot complements, hidden symmetries and reflection orbifolds M. Boileau,S.Boyer,R.Cebanu &G.S.Walsh March 15, 2015 Abstract In this article we examine the conjecture of Neumann and Reid that the only hyperbolic
More informationEuler s Theorem. Brett Chenoweth. February 26, 2013
Euler s Theorem Brett Chenoweth February 26, 2013 1 Introduction This summer I have spent six weeks of my holidays working on a research project funded by the AMSI. The title of my project was Euler s
More informationMath 210 Manifold III, Spring 2018 Euler Characteristics of Surfaces Hirotaka Tamanoi
Math 210 Manifold III, Spring 2018 Euler Characteristics of Surfaces Hirotaka Tamanoi 1. Euler Characteristic of Surfaces Leonhard Euler noticed that the number v of vertices, the number e of edges and
More informationJ. W. Cannon and W. J. Floyd and W. R. ParryCannon, Floyd, and Parry A SURVEY OF TWISTED FACE-PAIRING 3-MANIFOLDS
J. W. Cannon and W. J. Floyd and W. R. ParryCannon, Floyd, and Parry A SURVEY OF TWISTED FACE-PAIRING 3-MANIFOLDS J. W. CANNON, W. J. FLOYD, AND W. R. PARRY Abstract. The twisted face-pairing construction
More informationCourse Number: Course Title: Geometry
Course Number: 1206310 Course Title: Geometry RELATED GLOSSARY TERM DEFINITIONS (89) Altitude The perpendicular distance from the top of a geometric figure to its opposite side. Angle Two rays or two line
More informationA Preliminary Study of Klein Knots
A Preliminary Study of Klein Knots Louisa Catalano, David Freund, Rutendo Ruzvidzo, Jennifer Bowen, and John Ramsay The College of Wooster Department of Mathematics Wooster, OH 44691 LCatalano11@wooster.edu,
More informationGeometric Structures on Manifolds
Geometric Structures on Manifolds Sam Ballas (joint with J. Danciger and G.-S. Lee) Mathematics Colloquium Florida State University January 15, 2016 1. Background 1.1 What is Geometry? 1.2 Examples 1.3
More informationGlossary of dictionary terms in the AP geometry units
Glossary of dictionary terms in the AP geometry units affine linear equation: an equation in which both sides are sums of terms that are either a number times y or a number times x or just a number [SlL2-D5]
More informationarxiv:math/ v3 [math.gt] 12 Jun 2007
arxiv:math/0406271v3 [math.gt] 12 Jun 2007 Normal surfaces in topologically finite 3 manifolds Stephan Tillmann Abstract The concept of a normal surface in a triangulated, compact 3 manifold was generalised
More informationOn the Heegaard splittings of amalgamated 3 manifolds
On the Heegaard splittings of amalgamated 3 manifolds TAO LI We give a combinatorial proof of a theorem first proved by Souto which says the following. Let M 1 and M 2 be simple 3 manifolds with connected
More informationWe have set up our axioms to deal with the geometry of space but have not yet developed these ideas much. Let s redress that imbalance.
Solid geometry We have set up our axioms to deal with the geometry of space but have not yet developed these ideas much. Let s redress that imbalance. First, note that everything we have proven for the
More informationCAT(0)-spaces. Münster, June 22, 2004
CAT(0)-spaces Münster, June 22, 2004 CAT(0)-space is a term invented by Gromov. Also, called Hadamard space. Roughly, a space which is nonpositively curved and simply connected. C = Comparison or Cartan
More informationIdeal triangulations of 3 manifolds I: spun normal surface theory
ISSN 6-8997 (on line) 6-8989 (printed) 5 Geometry & Topology Monographs Volume 7: Proceedings of the asson Fest Pages 5 65 Ideal triangulations of manifolds I: spun normal surface theory Ensil Kang J Hyam
More informationWilliam P. Thurston. The Geometry and Topology of Three-Manifolds
William P. Thurston The Geometry and Topology of Three-Manifolds Electronic version 1.1 - March 2002 http://www.msri.org/publications/books/gt3m/ This is an electronic edition of the 1980 notes distributed
More informationOn a Triply Periodic Polyhedral Surface Whose Vertices are Weierstrass Points
Arnold Math J. DOI 10.1007/s40598-017-0067-9 RESEARCH CONTRIBUTION On a Triply Periodic Polyhedral Surface Whose Vertices are Weierstrass Points Dami Lee 1 Received: 3 May 2016 / Revised: 12 March 2017
More information