Mathematics Problem Archive

Showing 851-900 of 963 problems (Page 18 of 20)

AMR-105-0007
Partially Solved

Virtual-knot problem 7 — Long Knots and Long Flat Knots

v1.3 research notes

Long Knots and Long Flat Knots: Enlarge the long knot invariant structure proposed in . Can one get new classical knot invariants from the approach in...

L3
Topology
AMR-105-0009
Partially Solved

Virtual-knot problem 9 — Virtual braids

v1.3 research notes

Virtual 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...

L3
Topology
AMR-105-0013
Partially Solved

Virtual-knot problem 13 — Khovanov Homology

v1.3 research notes

Khovanov Homology: Construct a generalization of the Khovanov complex for the case of virtual knots that will work for arbitrary virtual diagrams. Inv...

L3
Topology
AMR-105-0014
Partially Solved

Virtual-knot problem 14 — Brauer algebra

v1.3 research notes

Brauer algebra: The appropriate domain for the virtual recoupling theory is to place the Jones–Wenzl projectors in the Brauer algebra. That is, when w...

L3
Topology
AMR-105-0015
Partially Solved

Virtual-knot problem 15 — Virtual Alternating Knots

v1.3 research notes

Virtual Alternating Knots: Define and classify alternating virtual knots. Find an analogue of the Tait flyping conjecture and prove it. Compare . Cl...

L3
Topology
AMR-105-0016
Partially Solved

Virtual-knot problem 16 — Crossing Number

v1.3 research notes

Crossing 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...

L3
Topology
AMR-105-0017
Partially Solved

Virtual-knot problem 17 — Crossing number problems

v1.3 research notes

Crossing number problems: For each virtual link $L$, there are three crossing numbers: the minimal number $C$ of classical crossings, the minimal numb...

L3
Topology
AMR-105-0019
Partially Solved

Virtual-knot problem 19 — Vassiliev Invariants

v1.3 research notes

Vassiliev Invariants: Understand the connection between virtual knot polynomials and the Vassiliev knot invariants of virtual knots (in Kauffman's sen...

L3
Topology
AMR-105-0022
Partially Solved

Virtual-knot problem 22 — The Rack Space

v1.3 research notes

The 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...

L3
Topology
AMR-105-0025
Partially Solved

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 notes

Rotational virtual knot theory introduced in is virtual knot theory without the first virtual move (thus one does not allow the addition or deletion o...

L3
Topology
AMR-105-0026
Partially Solved

Virtual-knot problem 26 — surface arrow invariant

v1.3 research notes

The arrow polynomial generalizes to a more powerful invariant of virtual knots by defining a version of it for knots in specific thickened surfaces. T...

L3
Topology
AMR-105-0027
Partially Solved

Virtual-knot problem 27 — Study concordance and cobordism invariants of virtual knots.

v1.3 research notes

Study concordance and cobordism invariants of virtual knots. In particular, solve the question of virtual knots up to pass-equivalence (taking a direc...

L3
Topology
AMR-105-0029
Partially Solved

Virtual-knot problem 29 — Khovanov homology for virtual knots and links works directly with mod-$2$ coefficients.

v1.3 research notes

Khovanov homology for virtual knots and links works directly with mod-$2$ coefficients. With mod-2 coefficients there are no technical difficulties as...

L3
Topology
AMR-105-0030
Partially Solved

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 notes

In we have studied a mod-2 categorification of the arrow polynomial and discovered many baffling examples of pairs of virtual knots that are discrimin...

L3
Topology
AMR-105-0031
Partially Solved

Virtual-knot problem 31 — Make a systematic study of Vassiliev invariants for virtual knots and links.

v1.3 research notes

Make a systematic study of Vassiliev invariants for virtual knots and links. There is ongoing work on this problem....

L3
Topology
AMR-105-0032
Partially Solved

Virtual-knot problem 32 — Generalize virtual knot theory to virtual 2-spheres in 4-space.

v1.3 research notes

Generalize virtual knot theory to virtual 2-spheres in 4-space....

L3
Topology
AMR-105-0033
Partially Solved

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 notes

Find a way to effectively compute the Kauffman–Radford–Hennings (KRH) invariants for three-manifolds via right integrals on finite dimensional Hopf al...

L3
Topology
AMR-105-0034
Partially Solved

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 notes

Create 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 ...

L3
Topology
AMR-105-0035
Partially Solved

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 notes

In we give a formula for the Kauffman polynomial, due to Jaeger, that expresses this invariant as a state sum over oriented, partially smoothed links ...

L3
Topology
AMR-105-0037
Partially Solved

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 notes

It has been pointed out that the chain complex for Knot Floer Homology (categorifying the Alexander–Conway polynomial) is generated by the states desc...

L3
Topology
AMR-105-0041
Partially Solved

Virtual-knot problem 41 — Which quantum invariants extend to virtual knots themselves without restrictions?

v1.3 research notes

Which quantum invariants extend to virtual knots themselves without restrictions? Certainly, there are such ones, e.g., the Kauffman bracket and the J...

L3
Topology
AMR-105-0043
Partially Solved

Virtual-knot problem 43 — In his wonderful paper , which firstly had the title “Knot Floer Homotopy”, Sarkar constructs a cell complex.

v1.3 research notes

In his wonderful paper , which firstly had the title “Knot Floer Homotopy”, Sarkar constructs a cell complex. The homology of this complex coincides w...

L3
Topology
AMR-105-0046
Partially Solved

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 notes

In 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...

L3
Topology
AMR-105-0047
Partially Solved

Virtual-knot problem 47 — It is well known that flat virtual knots are easily algorithmically recognizable, see .

v1.3 research notes

It is well known that flat virtual knots are easily algorithmically recognizable, see . The absence of a geometric approach to the definition of free ...

L3
Topology
AMR-105-0048
Partially Solved

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 notes

The 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...

L3
Topology
AMR-105-0053
Partially Solved

Virtual-knot problem 53 — Is there any algorithm for recognition whether two graph-links are equivalent or not?

v1.3 research notes

Is there any algorithm for recognition whether two graph-links are equivalent or not? Our conjecture is “no”. The idea behind that is that graph-links...

L4
Topology
AMR-105-0060
Partially Solved

Virtual-knot problem 60 — Problems on Free Knot Cobordism

v1.3 research notes

Problems on Free Knot Cobordism: The methods used for proving the fact that the invariant $L$ gives an obstruction to the sliceness are not immediatel...

L3
Topology
AMR-106-0001
Partially Solved

String topology and smooth structures on 4-manifolds

v1.3 research notes

Is string topology sensitive to smooth structures on 4-manifolds?...

L3
Topology
AMR-107-0005
Partially Solved

Problem 1E — What are the obstructions to the realization of these chains of formal changes by paths in the paramet…

v1.3 research notes

What are the obstructions to the realization of these chains of formal changes by paths in the parameter space ${\mathbb{R}}^{k}$?...

L3
Topology
AMR-107-0010
Partially Solved

Problem 4 — Are these geometric obstructions sufficient to solve the above problem?

v1.3 research notes

Are these geometric obstructions sufficient to solve the above problem?...

L3
Topology
AMR-107-0011
Partially Solved

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 notes

Is 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...

L3
Topology
AMR-107-0014
Partially Solved

Problem 5D — Do non-singular real plane projective curves of an odd degree consisting of a single connected compone…

v1.3 research notes

Do non-singular real plane projective curves of an odd degree consisting of a single connected component form a connected set (i.e., are they rigid is...

L2
Topology
AMR-107-0017
Partially Solved

Problem 6C — Is it true that any component of the complement of the discriminant variety of a versal deformation co…

v1.3 research notes

Is it true that any component of the complement of the discriminant variety of a versal deformation contains a Morsification, whose all $\mu(f)$ criti...

L2
Topology
AMR-108-0004
Partially Solved

1.4 (Danciger) — Convex projective structures on glued figure-eight complements

v1.3 research notes

Let $N$ be the closed $3$-manifold obtained by gluing two copies of the figure-eight knot complement along their torus boundaries by a homeomorphism. ...

L3
Geometry
AMR-108-0005
Partially Solved

1.5 (Danciger) — Convex projective structures and hyperbolic JSJ pieces

v1.3 research notes

Let $N$ be a closed $3$-manifold whose JSJ decomposition contains only hyperbolic pieces. Does $N$ admit a convex projective structure?...

L3
Geometry
AMR-108-0006
Partially Solved

2.1 (Leitner) — Limits between Thurston geometries

v1.3 research notes

Geometric transitions are continuous paths of geometries that abruptly change type in the limit. Understand all transitions between the eight Thurston...

L3
Geometry
AMR-108-0013
Partially Solved

3.5 (Agol) — Quasi-Fuchsian surfaces cubulating away from cusps

v1.3 research notes

Do cusped finite-volume hyperbolic $3$-manifolds have closed quasi-Fuchsian surfaces that cubulate except for the cusps? Equivalently in the stated ge...

L3
Topology
AMR-108-0015
Partially Solved

3.7 (Agol) — Kleinian groups with closed quasi-Fuchsian surface subgroups

v1.3 research notes

Which Kleinian groups admit closed quasi-Fuchsian surface subgroups?...

L3
Group Theory
AMR-108-0016
Partially Solved

3.8 (Agol) — Twisted homology products after cutting along a surface

v1.3 research notes

Let $M$ be a $3$-manifold, let $\phi:\pi_1M\to\mathbb{Z}$ be dual to $(\Sigma,\partial\Sigma)\subset(M,\partial M)$, and let $N$ be obtained by cuttin...

L3
Topology
AMR-108-0018
Partially Solved

3.10 (Futer, Schleimer) — A practical 3-manifold homeomorphism algorithm

v1.3 research notes

Is there a practical algorithm to test whether a pair of $3$-manifolds are homeomorphic?...

L3
Computer Science
AMR-108-0019
Partially Solved

3.11 (Walsh) — Unbounded CAT(0) cubical dimension

v1.3 research notes

The CAT(0) cubical dimension of a group $G$ is the least dimension of a CAT(0) cubical space on which $G$ acts geometrically. Is there a sequence of c...

L3
Group Theory
AMR-108-0023
Partially Solved

4.4 (Kassel, Mann) — Proper affine actions on $\mathbb{R}^5$

v1.3 research notes

Let $\Gamma$ be a discrete group acting properly discontinuously by affine transformations on $\mathbb{R}^5$. Is $\Gamma$ virtually an extension of a ...

L3
Group Theory
AMR-108-0024
Partially Solved

4.5 (Kassel, Mann) — Proper affine surface-group actions on $\mathbb{R}^6$

v1.3 research notes

Classify all properly discontinuous affine actions of a given closed surface group on $\mathbb{R}^6$....

L3
Group Theory
AMR-108-0025
Partially Solved

4.6 (Kassel, Mann) — Minimal dimension of a proper affine Coxeter-group action

v1.3 research notes

For a given right-angled Coxeter group, what is the least $n$ for which it admits a proper affine action on $\mathbb{R}^n$?...

L3
Group Theory
AMR-108-0028
Partially Solved

5.3 (Agol) — Thurston norm polytopes

v1.3 research notes

Characterize the Thurston norm polytopes of finite-volume hyperbolic $3$-manifolds....

L3
Topology
AMR-108-0032
Partially Solved

5.7 (Agol) — Renormalized volume as a metric

v1.3 research notes

The renormalized volume of quasi-Fuchsian groups gives a function $\rho:\mathcal{T}(S)\times\mathcal{T}(S)\to\mathbb{R}$. Is $\rho$ a metric on the Te...

L3
Geometry
AMR-108-0036
Partially Solved

5.11 (Futer) — A combinatorial model with explicit bilipschitz constants

v1.3 research notes

Build a combinatorial model for hyperbolic $3$-manifolds with explicit bilipschitz constants....

L3
Topology
AMR-108-0037
Partially Solved

5.12 (Reid) — Finite quotients of finite-covolume Kleinian groups

v1.3 research notes

Let $\Gamma$ be a Kleinian group of finite covolume, and let $\mathcal{C}(\Gamma)$ be the set of isomorphism classes of its finite quotient groups. Do...

L3
Group Theory
AMR-108-0038
Partially Solved

5.13 (Reid) — Finite quotients of free groups

v1.3 research notes

For $\Gamma=F_r$ with $r\geq2$, does $\mathcal{C}(F_r)$ determine $F_r$ up to isomorphism?...

L3
Group Theory
AMR-108-0039
Partially Solved

5.14 (Reid) — Finite-quotient rigidity among 3-manifold groups

v1.3 research notes

Let $\Gamma$ be a Kleinian group of finite covolume. Does its set $\mathcal{C}(\Gamma)$ of finite quotient isomorphism classes determine $\Gamma$ amon...

L3
Group Theory