Mathematics Problem Archive
Problem 12.17 — (X.-S.
v1.3 research notes(X.-S. Lin [262]) What is the homotopy type of the space L(K) of long ropes (as shown in the picture below) with the fixed kno t type K?...
Problem 12.18 — (J.
v1.3 research notes(J. Roberts) Extend Kuperberg’s work on webs....
Problem 12.19 — (J.
v1.3 research notes(J. Roberts) Extend the theory of measured laminations to higher rank groups....
Problem 12.20 — (J.
v1.3 research notes(J. Roberts) What is the generating function for q -spin net evaluations?...
Problem 12.21 — (Y.
v1.3 research notes(Y. Shinohara [364]) If n = 4 k + 1 with k > 0, is there a knot with determinant n and signature 4?...
Problem 12.22 — (T.
v1.3 research notes(T. Stanford) IsC2 solvable? Does C2 contain a free group?...
Problem 12.23 — (A.
v1.3 research notes(A. Stoimenow) Do positive links of given signature σ have bounded (below) maximal Euler characteristic χ?...
Problem 12.24 — (A.
v1.3 research notes(A. Stoimenow) If a prime knot K can be transformed into its mirror image by one crossing change, is K achiral or (algebraically?) slice?...
Problem 12.25 — (A.
v1.3 research notes(A. Stoimenow) Let n be an odd natural number, different from 1, 9, and 49, such that n is the sum of two squares. Is there a prime alternating achiral...
Conjecture 12.26 — (V.
v1.3 research notes(V. Turaev) A pair (a finitely generated abelian group H of rank 1, an element ∆( t)∈ Z[H/TorsH] = Z[t±1]) (where t is a generator of H/TorsH ) can be...
Virtual-knot problem 1 — Recognising the Kishino Knot
v1.3 research notesRecognising the Kishino Knot: There have been invented many ways to recognize the Kishino virtual knot (from the unknot): The $3$–strand Jones polynom...
Virtual-knot problem 2 — Flat Virtuals
v1.3 research notesFlat Virtuals: Flat virtual knots, also known as virtual strings , are difficult to classify. Find new combinatorial invariants of flat virtual knots....
Virtual-knot problem 3 — The Flat Hierarchy
v1.3 research notesThe Flat Hierarchy: The flat hierarchy is constructed for any ordinal $\alpha$. We label flat crossings with members of this ordinal. In a flat third ...
Virtual-knot problem 4 — Virtuals and the Theory of Doodles
v1.3 research notesVirtuals and the Theory of Doodles: Compare flat theories of virtual knots with theories of doodles. A doodle is represented by a flat diagram in the ...
Virtual-knot problem 5 — Virtual Three Manifolds
v1.3 research notesVirtual Three Manifolds: There is a theory of virtual $3$–manifolds constructed as formal equivalence classes of virtual diagrams modulo generalized K...
Virtual-knot problem 6 — Welded Knots
v1.3 research notesWelded Knots: We would like to understand welded knots . It is well known that if we admit forbidden moves to the virtual link diagrams, each virtual ...
Virtual-knot problem 7 — Long Knots and Long Flat Knots
v1.3 research notesLong Knots and Long Flat Knots: Enlarge the long knot invariant structure proposed in . Can one get new classical knot invariants from the approach in...
Virtual-knot problem 8 — Virtual Biquandle
v1.3 research notesVirtual Biquandle: Construct presentations of the virtual biquandle with the a linear (non-commutative) representation at classical crossings and some...
Virtual-knot problem 9 — Virtual braids
v1.3 research notesVirtual braids: Is there a birack such that its action on virtual braids is faithful? Is the invariant of virtual braids in , see also , faithful? T...
Virtual-knot problem 10 — The Fundamental Biquandle
v1.3 research notesThe Fundamental Biquandle: Does the fundamental biquandle, see classify virtual links up to mirror images? (We know that the biquandle has the same va...
Virtual-knot problem 11 — Virtualization and Unit Jones Polynomial
v1.3 research notesVirtualization and Unit Jones Polynomial: Suppose the knot $K$ is classical and not trivial. Suppose that ${\tilde K}$ (obtained from $K$ by virtualiz...
Virtual-knot problem 12 — Virtual Quandle Homology
v1.3 research notesVirtual Quandle Homology: Study virtual quandle homology in analogy to quandle homology ....
Virtual-knot problem 13 — Khovanov Homology
v1.3 research notesKhovanov Homology: Construct a generalization of the Khovanov complex for the case of virtual knots that will work for arbitrary virtual diagrams. Inv...
Virtual-knot problem 14 — Brauer algebra
v1.3 research notesBrauer algebra: The appropriate domain for the virtual recoupling theory is to place the Jones–Wenzl projectors in the Brauer algebra. That is, when w...
Virtual-knot problem 15 — Virtual Alternating Knots
v1.3 research notesVirtual Alternating Knots: Define and classify alternating virtual knots. Find an analogue of the Tait flyping conjecture and prove it. Compare . Cl...
Virtual-knot problem 16 — Crossing Number
v1.3 research notesCrossing Number: One of the most important problems in knot theory is the problem of finding the minimal crossing number for a given knot. It can be e...
Virtual-knot problem 17 — Crossing number problems
v1.3 research notesCrossing number problems: For each virtual link $L$, there are three crossing numbers: the minimal number $C$ of classical crossings, the minimal numb...
Virtual-knot problem 18 — Wild Virtuals
v1.3 research notesWild Virtuals: Create the category of “wild virtual knots” and establish its axiomatics. In particular, one needs a theorem that states when a wild eq...
Virtual-knot problem 19 — Vassiliev Invariants
v1.3 research notesVassiliev Invariants: Understand the connection between virtual knot polynomials and the Vassiliev knot invariants of virtual knots (in Kauffman's sen...
Virtual-knot problem 20 — Embeddings of Surfaces
v1.3 research notesEmbeddings of Surfaces: Given a non-trivial virtual knot $K$. Prove that there exists a minimal realization of $K$ in $N=S_{g}\times I$ and an unknott...
Virtual-knot problem 21 — Non-Commutativity and Long Knots
v1.3 research notesNon-Commutativity and Long Knots: It is known that any classical long knot commutes with any long knot. This is definitely not the case in the virtual...
Virtual-knot problem 22 — The Rack Space
v1.3 research notesThe Rack Space: The rack space was invented by Fenn, Rourke and Sanderson . The homology of the rack space has been considered by the above authors an...
Virtual-knot problem 23 — Find new geometric/topological interpretations for the Jones polynomial and for Khovanov homology.
v1.3 research notesFind new geometric/topological interpretations for the Jones polynomial and for Khovanov homology....
Virtual-knot problem 24 — Does it follow that $K$ and $K'$ are equivalent as classical knots?
v1.3 research notesLet $VKT/Z$ denote virtual knot theory modulo $Z$-equivalence, as defined in the section above on virtual knot theory. Recall that two virtual diagram...
Virtual-knot problem 25 — Rotational virtual knot theory introduced in is virtual knot theory without the first virtual move (thus one does not…
v1.3 research notesRotational virtual knot theory introduced in is virtual knot theory without the first virtual move (thus one does not allow the addition or deletion o...
Virtual-knot problem 26 — surface arrow invariant
v1.3 research notesThe arrow polynomial generalizes to a more powerful invariant of virtual knots by defining a version of it for knots in specific thickened surfaces. T...
Virtual-knot problem 27 — Study concordance and cobordism invariants of virtual knots.
v1.3 research notesStudy concordance and cobordism invariants of virtual knots. In particular, solve the question of virtual knots up to pass-equivalence (taking a direc...
Virtual-knot problem 28 — Biquandles
v1.3 research notesBiquandles: The first two problems are old chestnuts. Give a descriptive representation of the free biquandle. Give a topological explanation of the...
Virtual-knot problem 29 — Khovanov homology for virtual knots and links works directly with mod-$2$ coefficients.
v1.3 research notesKhovanov homology for virtual knots and links works directly with mod-$2$ coefficients. With mod-2 coefficients there are no technical difficulties as...
Virtual-knot problem 30 — In we have studied a mod-2 categorification of the arrow polynomial and discovered many baffling examples of pairs of…
v1.3 research notesIn we have studied a mod-2 categorification of the arrow polynomial and discovered many baffling examples of pairs of virtual knots that are discrimin...
Virtual-knot problem 31 — Make a systematic study of Vassiliev invariants for virtual knots and links.
v1.3 research notesMake a systematic study of Vassiliev invariants for virtual knots and links. There is ongoing work on this problem....
Virtual-knot problem 32 — Generalize virtual knot theory to virtual 2-spheres in 4-space.
v1.3 research notesGeneralize virtual knot theory to virtual 2-spheres in 4-space....
Virtual-knot problem 33 — Find a way to effectively compute the Kauffman–Radford–Hennings (KRH) invariants for three-manifolds via right integr…
v1.3 research notesFind a way to effectively compute the Kauffman–Radford–Hennings (KRH) invariants for three-manifolds via right integrals on finite dimensional Hopf al...
Virtual-knot problem 34 — Create a combinatorial homotopy theory for Khovanov homology so that the Khovanov homology of a knot or link is equiv…
v1.3 research notesCreate a combinatorial homotopy theory for Khovanov homology so that the Khovanov homology of a knot or link is equivalent to the homotopy type of an ...
Virtual-knot problem 35 — In we give a formula for the Kauffman polynomial, due to Jaeger, that expresses this invariant as a state sum over or…
v1.3 research notesIn we give a formula for the Kauffman polynomial, due to Jaeger, that expresses this invariant as a state sum over oriented, partially smoothed links ...
Virtual-knot problem 36 — electrical
v1.3 research notesIn we show how, by translating between knots and planar graphs (the checkerboard and medial constructions) one can associate a signed graph to a class...
Virtual-knot problem 37 — It has been pointed out that the chain complex for Knot Floer Homology (categorifying the Alexander–Conway polynomial…
v1.3 research notesIt has been pointed out that the chain complex for Knot Floer Homology (categorifying the Alexander–Conway polynomial) is generated by the states desc...
Virtual-knot problem 38 — The Kauffman bracket polynomial of a virtual diagram can have the leading term, i.e., the term having the highest pos…
v1.3 research notesThe Kauffman bracket polynomial of a virtual diagram can have the leading term, i.e., the term having the highest possible degree, equal to zero. Ass...
Virtual-knot problem 39 — We still do not know whether the free knot whose Gauss diagram is a heptagon (i.e.
v1.3 research notesWe still do not know whether the free knot whose Gauss diagram is a heptagon (i.e. consists of 7 chords each of which is linked with precisely two adj...
Virtual-knot problem 40 — Given a chord diagram $D$ we can construct the following formal chain complex.
v1.3 research notesGiven a chord diagram $D$ we can construct the following formal chain complex. Formally speaking, this complex will look like a simplicial complex in ...