Menasco W., Thistlethwaite M. (Eds.) Handbook of Knot Theory
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Hyperbolic Structures from Link Diagrams
Hyperbolic Structures from Link Diagrams Anastasiia Tsvietkova, joint work with Morwen Thistlethwaite Louisiana State University/University of Tennessee Anastasiia Tsvietkova, joint work with MorwenHyperbolic Thistlethwaite Structures (UTK) from Link Diagrams 1/23 Every knot can be uniquely decomposed as a knot sum of prime knots (H. Schubert). It also true for non-split links (i.e. if there is no a 2–sphere in the complement separating the link). Of the 14 prime knots up to 7 crossings, 3 are non-hyperbolic. Of the 1,701,935 prime knots up to 16 crossings, 32 are non-hyperbolic. Of the 8,053,378 prime knots with 17 crossings, 30 are non-hyperbolic. Motivation: knots Anastasiia Tsvietkova, joint work with MorwenHyperbolic Thistlethwaite Structures (UTK) from Link Diagrams 2/23 Of the 14 prime knots up to 7 crossings, 3 are non-hyperbolic. Of the 1,701,935 prime knots up to 16 crossings, 32 are non-hyperbolic. Of the 8,053,378 prime knots with 17 crossings, 30 are non-hyperbolic. Motivation: knots Every knot can be uniquely decomposed as a knot sum of prime knots (H. Schubert). It also true for non-split links (i.e. if there is no a 2–sphere in the complement separating the link). Anastasiia Tsvietkova, joint work with MorwenHyperbolic Thistlethwaite Structures (UTK) from Link Diagrams 2/23 Of the 1,701,935 prime knots up to 16 crossings, 32 are non-hyperbolic. Of the 8,053,378 prime knots with 17 crossings, 30 are non-hyperbolic. Motivation: knots Every knot can be uniquely decomposed as a knot sum of prime knots (H. -
A Knot-Vice's Guide to Untangling Knot Theory, Undergraduate
A Knot-vice’s Guide to Untangling Knot Theory Rebecca Hardenbrook Department of Mathematics University of Utah Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 1 / 26 What is Not a Knot? Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 2 / 26 What is a Knot? 2 A knot is an embedding of the circle in the Euclidean plane (R ). 3 Also defined as a closed, non-self-intersecting curve in R . 2 Represented by knot projections in R . Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 3 / 26 Why Knots? Late nineteenth century chemists and physicists believed that a substance known as aether existed throughout all of space. Could knots represent the elements? Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 4 / 26 Why Knots? Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 5 / 26 Why Knots? Unfortunately, no. Nevertheless, mathematicians continued to study knots! Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 6 / 26 Current Applications Natural knotting in DNA molecules (1980s). Credit: K. Kimura et al. (1999) Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 7 / 26 Current Applications Chemical synthesis of knotted molecules – Dietrich-Buchecker and Sauvage (1988). Credit: J. Guo et al. (2010) Rebecca Hardenbrook A Knot-vice’s Guide to Untangling Knot Theory 8 / 26 Current Applications Use of lattice models, e.g. the Ising model (1925), and planar projection of knots to find a knot invariant via statistical mechanics. Credit: D. Chicherin, V.P. -
Knots: a Handout for Mathcircles
Knots: a handout for mathcircles Mladen Bestvina February 2003 1 Knots Informally, a knot is a knotted loop of string. You can create one easily enough in one of the following ways: • Take an extension cord, tie a knot in it, and then plug one end into the other. • Let your cat play with a ball of yarn for a while. Then find the two ends (good luck!) and tie them together. This is usually a very complicated knot. • Draw a diagram such as those pictured below. Such a diagram is a called a knot diagram or a knot projection. Trefoil and the figure 8 knot 1 The above two knots are the world's simplest knots. At the end of the handout you can see many more pictures of knots (from Robert Scharein's web site). The same picture contains many links as well. A link consists of several loops of string. Some links are so famous that they have names. For 2 2 3 example, 21 is the Hopf link, 51 is the Whitehead link, and 62 are the Bor- romean rings. They have the feature that individual strings (or components in mathematical parlance) are untangled (or unknotted) but you can't pull the strings apart without cutting. A bit of terminology: A crossing is a place where the knot crosses itself. The first number in knot's \name" is the number of crossings. Can you figure out the meaning of the other number(s)? 2 Reidemeister moves There are many knot diagrams representing the same knot. For example, both diagrams below represent the unknot. -
Hyperbolic Structures from Link Diagrams
University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2012 Hyperbolic Structures from Link Diagrams Anastasiia Tsvietkova [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Geometry and Topology Commons Recommended Citation Tsvietkova, Anastasiia, "Hyperbolic Structures from Link Diagrams. " PhD diss., University of Tennessee, 2012. https://trace.tennessee.edu/utk_graddiss/1361 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Anastasiia Tsvietkova entitled "Hyperbolic Structures from Link Diagrams." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Mathematics. Morwen B. Thistlethwaite, Major Professor We have read this dissertation and recommend its acceptance: Conrad P. Plaut, James Conant, Michael Berry Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Hyperbolic Structures from Link Diagrams A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Anastasiia Tsvietkova May 2012 Copyright ©2012 by Anastasiia Tsvietkova. All rights reserved. ii Acknowledgements I am deeply thankful to Morwen Thistlethwaite, whose thoughtful guidance and generous advice made this research possible. -
An Odd Analog of Plamenevskaya's Invariant of Transverse
AN ODD ANALOG OF PLAMENEVSKAYA'S INVARIANT OF TRANSVERSE KNOTS by GABRIEL MONTES DE OCA A DISSERTATION Presented to the Department of Mathematics and the Graduate School of the University of Oregon in partial fulfillment of the requirements for the degree of Doctor of Philosophy September 2020 DISSERTATION APPROVAL PAGE Student: Gabriel Montes de Oca Title: An Odd Analog of Plamenevskaya's Invariant of Transverse Knots This dissertation has been accepted and approved in partial fulfillment of the requirements for the Doctor of Philosophy degree in the Department of Mathematics by: Robert Lipshitz Chair Daniel Dugger Core Member Nicholas Proudfoot Core Member Micah Warren Core Member James Brau Institutional Representative and Kate Mondloch Interim Vice Provost and Dean of the Graduate School Original approval signatures are on file with the University of Oregon Graduate School. Degree awarded September 2020 ii c 2020 Gabriel Montes de Oca iii DISSERTATION ABSTRACT Gabriel Montes de Oca Doctor of Philosophy Department of Mathematics September 2020 Title: An Odd Analog of Plamenevskaya's Invariant of Transverse Knots Plamenevskaya defined an invariant of transverse links as a distinguished class in the even Khovanov homology of a link. We define an analog of Plamenevskaya's invariant in the odd Khovanov homology of Ozsv´ath,Rasmussen, and Szab´o. We show that the analog is also an invariant of transverse links and has similar properties to Plamenevskaya's invariant. We also show that the analog invariant can be identified with an equivalent invariant in the reduced odd Khovanov homology. We demonstrate computations of the invariant on various transverse knot pairs with the same topological knot type and self-linking number. -
Performance of the Uniform Closure Method for Open Knotting As a Bayes-Type Classifier
Performance of the Uniform Closure Method for open knotting as a Bayes-type classifier Emily Tibor1, Elizabeth M. Annoni2, Erin Brine-Doyle2, Nicole Kumerow2, Madeline Shogren2, Jason Cantarella3, Clayton Shonkwiler4, and Eric J. Rawdon2 1Department of Mathematics, University of Minnesota, Minneapolis, MN 55455, USA 2University of St. Thomas, St. Paul, MN 55105, USA 3Department of Mathematics, University of Georgia, Athens, GA 30602, USA 4Department of Mathematics, Colorado State University, Fort Collins, CO 80523, USA November 19, 2020 Abstract The discovery of knotting in proteins and other macromolecular chains has moti- vated researchers to more carefully consider how to identify and classify knots in open arcs. Most definitions classify knotting in open arcs by constructing an ensemble of closures and measuring the probability of different knot types among these closures. In this paper, we think of assigning knot types to open curves as a classification problem and compare the performance of the Bayes MAP classifier to the standard Uniform Closure Method. Surprisingly, we find that both methods are essentially equivalent as classifiers, having comparable accuracy and positive predictive value across a wide range of input arc lengths and knot types. Keywords: Open knot, polygonal knot, Uniform Closure Method 1 Introduction Many physical systems contain long, open chain-like objects with two free ends, e.g. DNA, RNA, and other proteins. Anyone who has ever packed away a string of lights, a garden 1 hose, or headphone cables knows that these sorts of objects tend to be entangled. However, it is not clear how to measure this entanglement mathematically. Several techniques have been proposed [5, 14]. -
The Three-Variable Bracket Polynomial for Reduced, Alternating Links
Rose-Hulman Undergraduate Mathematics Journal Volume 14 Issue 2 Article 7 The Three-Variable Bracket Polynomial for Reduced, Alternating Links Kelsey Lafferty Wheaton College, Wheaton, IL, [email protected] Follow this and additional works at: https://scholar.rose-hulman.edu/rhumj Recommended Citation Lafferty, Kelsey (2013) "The Three-Variable Bracket Polynomial for Reduced, Alternating Links," Rose- Hulman Undergraduate Mathematics Journal: Vol. 14 : Iss. 2 , Article 7. Available at: https://scholar.rose-hulman.edu/rhumj/vol14/iss2/7 Rose- Hulman Undergraduate Mathematics Journal The Three-Variable Bracket Polynomial for Reduced, Alternating Links Kelsey Lafferty a Volume 14, no. 2, Fall 2013 Sponsored by Rose-Hulman Institute of Technology Department of Mathematics Terre Haute, IN 47803 Email: [email protected] a http://www.rose-hulman.edu/mathjournal Wheaton College, Wheaton, IL Rose-Hulman Undergraduate Mathematics Journal Volume 14, no. 2, Fall 2013 The Three-Variable Bracket Polynomial for Reduced, Alternating Links Kelsey Lafferty Abstract.We first show that the three-variable bracket polynomial is an invariant for reduced, alternating links. We then try to find what the polynomial reveals about knots. We find that the polynomial gives the crossing number, a test for chirality, and in some cases, the twist number of a knot. The extreme degrees of d are also studied. Acknowledgements: I would like to thank Dr. Rollie Trapp for advising me on this project, providing suggestions for what to investigate, and helping to complete several proofs. I would also like to thank Dr. Corey Dunn for his advice. This research was jointly funded by NSF grant DMS-1156608, and by California State University, San Bernardino. -
On the Additivity of Crossing Numbers
ON THE ADDITIVITY OF CROSSING NUMBERS A Thesis Presented to the Faculty of California State Polytechnic University, Pomona In Partial Fulfillment Of the Requirements for the Degree Master of Science In Mathematics By Alicia Arrua 2015 SIGNATURE PAGE THESIS: ON THE ADDITIVITY OF CROSSING NUMBERS AUTHOR: Alicia Arrua DATE SUBMITTED: Spring 2015 Mathematics and Statistics Department Dr. Robin Wilson Thesis Committee Chair Mathematics & Statistics Dr. Greisy Winicki-Landman Mathematics & Statistics Dr. Berit Givens Mathematics & Statistics ii ACKNOWLEDGMENTS This thesis would not have been possible without the invaluable knowledge and guidance from Dr. Robin Wilson. His support throughout this entire experience has been amazing and incredibly helpful. I’d also like to thank Dr. Greisy Winicki- Landman and Dr. Berit Givens for being a part of my thesis committee and offering their support. I’d also like to thank my family for putting up with my late nights of work and motivating me when I needed it. Lastly, thank you to the wonderful friends I’ve made during my time at Cal Poly Pomona, their humor and encouragement aided me more than they know. iii ABSTRACT The additivity of crossing numbers over a composition of links has been an open problem for over one hundred years. It has been proved that the crossing number over alternating links is additive independently in 1987 by Louis Kauffman, Kunio Murasugi, and Morwen Thistlethwaite. Further, Yuanan Diao and Hermann Gru ber independently proved that the crossing number is additive over a composition of torus links. In order to investigate the additivity of crossing numbers over a composition of a different class of links, we introduce a tool called the deficiency of a link. -
1 Introduction
Gap between the alternation number and the dealternating number Mar´ıa de los Angeles Guevara Hernandez´ Abstract In this paper we show a family of infinitely many knots whose alternation and dealternating numbers are distinct and arbitrary. Furthermore, the difference between both invariants is arbitrary large. 1 Introduction Links can be divided into alternating and non-alternating depending on if they possess an alternating diagram or not. Furthermore, after the proof of the Tait flype conjecture on alternating links given by Menasco and Thistlethwaite in [17], it became an important question to ask how a non-alternating link is “close to” alternating links [9]. For example, Adams et al. in [3] introduced the dealternating number. The dealternating number of a link diagram D is the minimum number of crossing changes necessary to transform D into an alternating diagram. The dealternating number of a link L, denoted dalt(L), is the min- imum dealternating number of any diagram of L. A link L with dealternating number k is also called k-almost alternating and we say that a link is almost alternating if it is 1-almost alternating. Likewise, Kawauchi in [9] introduced the concept of alternation number. The alternation number of a link diagram D is the minimum number of crossing changes nec- essary to transform D into some (possibly non-alternating) diagram of an alternating link. The alternation number of a link L, denoted alt(L), is the minimum alternation number of any diagram of L. He constructed infinitely many hyperbolic links with Gordian distance far from the set of (possibly, splittable) alternating links in the concordance class of every link. -
A Characterisation of Alternating Knot Exteriors Arxiv:1511.04945V1 [Math
A characterisation of alternating knot exteriors Joshua Howie Abstract We give a topological characterisation of alternating knot exteriors based on the presence of special spanning surfaces. This shows that alternating is a topological property of the knot exterior and not just a property of diagrams, answering an old question of Fox. We also give a characterisation of alternating link exteriors which have marked meridians. We then describe a normal surface algorithm which can decide if a knot is prime and alternating given a triangulation of its exterior as input. 1 Introduction Let L be a link in S3, and let N(L) be a regular open neighbourhood. Then the link exterior X ∼= S3 nN(L) is a compact 3-manifold with torus boundary components. A planar link diagram π(L) is a projection π : S2 × I ! S2; where L has been isotoped to lie in some S2 × I ⊂ S3, together with crossing information. A diagram π(L) is alternating if the crossings alternate between over- and under-crossings as we traverse the projection of the link. A non- trivial link is alternating if it admits an alternating diagram. We take the arXiv:1511.04945v1 [math.GT] 16 Nov 2015 convention that the unknot is not alternating. A simple Euler characteristic argument shows that if π(L) is a planar diagram with n crossings and checkerboard surfaces Σ and Σ0, then χ(Σ) + χ(Σ0) + n = 2: Furthermore, if π(L) is reduced, non-split and alternating, then Σ and Σ0 are both π1-essential in X and 2n is the difference between the aggregate slopes 1 of Σ and Σ0. -
5 the Jones' Polynomial
5 The Jones' polynomial In the early 90's a mathematician at UC Berkeley named Vaughn Jones (a native of New Zealand) discovered a new way to tell knots apart. For this work he received the Fields Medal, the highest award in mathematics (equivalent to the Nobel Prize). He assigns a polynomial to every knot. If the polynomials are different, the knots are also different. It is possible for different knots to have the same Jones' polynomial, but it happens rarely. This polynomial is a remarkably good method of distinguishing knots. We will go through the construction of this polynomial that is due to Louis Kauffman. The first step is to assign a bracket < K > to every knot (or link) diagram K. This is going to be a polynomial, initially in variables A; B; C, and it will satisfy the following rules. Rule 1: < >=1 Rule 2: < >=A< >+B< > < >=A< >+B< > Rule 3: <L >=C<L> Bracket rules Now we want to make sure that things don't change when we perform a Reidemeister move. 17. Using Rules 1-3 express < > in terms of < > and < >. Deduce: To ensure that the bracket does not change under the Reidemeister move of type II we need the following relations between A; B; C: A2 + ABC + B2 = 0; BA = 1 We will now put B = A−1 and C = −A2 −A−2 and our Rules 1-3 become: 9 Rule 1: < >=1 −1 Rule 2: < >=A< >+A < > < >=A< >+A −1 < > Rule 3: <L >=(−A2 −A−2 )<L> Bracket rules 18. Check that the bracket does not change after a Type III Reidemeister move. -
Knots: a Handout for Summer Math Program
Knots: a handout for Summer Math Program Mladen Bestvina June 2007 1 Knots Informally, a knot is a knotted loop of string. You can create one easily enough in one of the following ways: • Take an extension cord, tie a knot in it, and then plug one end into the other. • Let your cat play with a ball of yarn for a while. Then find the two ends (good luck!) and tie them together. This is usually a very complicated knot. • Draw a diagram such as those pictured below. Such a diagram is a called a knot diagram or a knot projection. Trefoil and the figure 8 knot 1 The above two knots are the world’s simplest knots. At the end of the handout you can see many more pictures of knots (from Robert Scharein’s web site). The same picture contains many links as well. A link consists of several loops of string. Some links are so famous that they have names. For 2 2 3 example, 21 is the Hopf link, 51 is the Whitehead link, and 62 are the Bor- romean rings. They have the feature that individual strings (or components in mathematical parlance) are untangled (or unknotted) but you can’t pull the strings apart without cutting. A bit of terminology: A crossing is a place where the knot crosses itself. The first number in knot’s “name” is the number of crossings. Can you figure out the meaning of the other number(s)? 2 Reidemeister moves There are many knot diagrams representing the same knot.