Mathematics Problem Archive
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 ...
Virtual-knot problem 41 — Which quantum invariants extend to virtual knots themselves without restrictions?
v1.3 research notesWhich quantum invariants extend to virtual knots themselves without restrictions? Certainly, there are such ones, e.g., the Kauffman bracket and the J...
Virtual-knot problem 42 — One can consider braids with even numbers of strands.
v1.3 research notesOne can consider braids with even numbers of strands. Markov's moves change the parity of the number of strands. Can one reformulate Markov's theorem ...
Virtual-knot problem 43 — In his wonderful paper , which firstly had the title “Knot Floer Homotopy”, Sarkar constructs a cell complex.
v1.3 research notesIn his wonderful paper , which firstly had the title “Knot Floer Homotopy”, Sarkar constructs a cell complex. The homology of this complex coincides w...
Virtual-knot problem 44 — A complete invariant is used for proving that one theory is a part of another theory.
v1.3 research notesA complete invariant is used for proving that one theory is a part of another theory. For example, the fact that the set of classical knots is a part ...
Virtual-knot problem 45 — To prove that the invariant $\mathcal{F}$ constructed by V.
v1.3 research notesTo prove that the invariant $\mathcal{F}$ constructed by V. O. Manturov for virtual braids, is complete for virtual braids with more than two strands....
Virtual-knot problem 46 — In it was showed how one could determine non-invertibility of long virtual knots and non-commutativity of long virtua…
v1.3 research notesIn it was showed how one could determine non-invertibility of long virtual knots and non-commutativity of long virtual knots. This method used two typ...
Virtual-knot problem 47 — It is well known that flat virtual knots are easily algorithmically recognizable, see .
v1.3 research notesIt is well known that flat virtual knots are easily algorithmically recognizable, see . The absence of a geometric approach to the definition of free ...
Virtual-knot problem 48 — The functorial mapping was constructed, by means of it we constructed the map from the set of virtual knots to the se…
v1.3 research notesThe functorial mapping was constructed, by means of it we constructed the map from the set of virtual knots to the set of virtual knots with orientabl...
Virtual-knot problem 49 — Turaev constructed the map from the set of long flat knots to the set of long virtual knots.
v1.3 research notesTuraev constructed the map from the set of long flat knots to the set of long virtual knots. Can one construct any map from the set of long free knots...
Virtual-knot problem 50 — The problem about cobordisms in sections: Let us have a free knot and its cobordism.
v1.3 research notesThe problem about cobordisms in sections: Let us have a free knot and its cobordism. Construct a parity on the given free knot, which is defined by us...
Virtual-knot problem 51 — Prove or disprove the conjecture about the non-uniqueness of minimal representative of a free link, i.e.
v1.3 research notesProve or disprove the conjecture about the non-uniqueness of minimal representative of a free link, i.e. there exists a free link having several minim...
Virtual-knot problem 52 — If $X$ is the free rack, is $\Gamma X$ a cat(0) space?
v1.3 research notesIf $X$ is the free rack, is $\Gamma X$ a cat(0) space? A positive answer would imply that all its higher homotopy groups are trivial....
Virtual-knot problem 54 — Can one construct a projection from the set of graph-links to the set of realizable graph-links?
v1.3 research notesCan one construct a projection from the set of graph-links to the set of realizable graph-links?...
Virtual-knot problem 55 — Construct a parity on graph-links by using Bouchet's criterion about the realizability of a graph.
v1.3 research notesConstruct a parity on graph-links by using Bouchet's criterion about the realizability of a graph. Try to find a parity which is responsible for the c...
Virtual-knot problem 56 — Construct generalizations of the Frobenius extension and the Rasmussen for “rigid” graph-links with orientable atoms.
v1.3 research notesConstruct generalizations of the Frobenius extension and the Rasmussen for “rigid” graph-links with orientable atoms....
Virtual-knot problem 57 — Is it true that two equivalent realizable graph-links are equivalent in the class of realizable graph-links?
v1.3 research notesIs it true that two equivalent realizable graph-links are equivalent in the class of realizable graph-links? If it is not true, then construct an exam...
Virtual-knot problem 58 — Construct a group for graph-links which is analogous to the group from .
v1.3 research notesConstruct a group for graph-links which is analogous to the group from ....
Virtual-knot problem 59 — Construct “graph-braids”.
v1.3 research notesConstruct “graph-braids”....
Virtual-knot problem 60 — Problems on Free Knot Cobordism
v1.3 research notesProblems on Free Knot Cobordism: The methods used for proving the fact that the invariant $L$ gives an obstruction to the sliceness are not immediatel...
String topology and smooth structures on 4-manifolds
v1.3 research notesIs string topology sensitive to smooth structures on 4-manifolds?...
Problem 1A — Present explicit obstructions to the Lyashko–Looijenga covering in terms of braid groups.
v1.3 research notesPresent explicit obstructions to the Lyashko–Looijenga covering in terms of braid groups. Which braids cannot be lifted to the space ${\mathbb{C}}^{\m...
Problem 1B — Let a non-simple singularity $f$ be given and the Dynkin diagram of it be defined by an easily disting…
v1.3 research notesLet a non-simple singularity $f$ be given and the Dynkin diagram of it be defined by an easily distinguished system of paths connecting 0 with critica...
Problem 1C — Are there more refined restrictions to the collision of critical values?
v1.3 research notesAre there more refined restrictions to the collision of critical values? Is it true that for any two vanishing cycles, whose intersection number is eq...
Problem 1D — Give more general lower bounds of the dimension of $\mu=const$ strata in terms of intersection forms o…
v1.3 research notesGive more general lower bounds of the dimension of $\mu=const$ strata in terms of intersection forms of vanishing cycles....
Problem 1E — What are the obstructions to the realization of these chains of formal changes by paths in the paramet…
v1.3 research notesWhat are the obstructions to the realization of these chains of formal changes by paths in the parameter space ${\mathbb{R}}^{k}$?...
Problem 1F — Is there any convenient topological characteristic of the function $f_{-\varepsilon}$ which allows to…
v1.3 research notesIs there any convenient topological characteristic of the function $f_{-\varepsilon}$ which allows to predict these indices?...
Problem 2A — What is the minimal number of open sets $U_{i}$ covering ${\mathbb{R}}^{6}$ such that for any $U_{i}$…
v1.3 research notesWhat is the minimal number of open sets $U_{i}$ covering ${\mathbb{R}}^{6}$ such that for any $U_{i}$ there is a continuous map $\varphi_{i}:U_{i}\to{...
Problem 2B — The same questions concerning the approximate solutions.
v1.3 research notesThe same questions concerning the approximate solutions. That is, for any $i$ and any $(a,b)\in U_{i}$, the value $\varphi_{i}(a,b)$ should be not nec...
Problem 3 — Is the complement of the essential ramification set in ${\mathbb{R}}^{d}$ a $K(\pi,1)$-space?
v1.3 research notesIs the complement of the essential ramification set in ${\mathbb{R}}^{d}$ a $K(\pi,1)$-space?...
Problem 4 — Are these geometric obstructions sufficient to solve the above problem?
v1.3 research notesAre these geometric obstructions sufficient to solve the above problem?...
Problem 5A — Is it true that any hypersurface from the space $P(d;N)$ can be connected with a trivial one by a gene…
v1.3 research notesIs it true that any hypersurface from the space $P(d;N)$ can be connected with a trivial one by a generic path in this space in such a way that it exp...
Problem 5B — A version of the previous problem, in which the complexity measure is not purely topological: namely,…
v1.3 research notesA version of the previous problem, in which the complexity measure is not purely topological: namely, it is the lowest number of critical points of Mo...
Problem 5C — Give an upper bound for the function $T\mapsto F$.
v1.3 research notesGive an upper bound for the function $T\mapsto F$....