Mathematics Problem Archive
Kirby Problem 2.25
Consider surface bundles over surfaces where both fiber $F$ and base $B$ have genus $\geq 2$ and where $\pi_{1}(B)$ injects in the mapping class group...
Kirby Problem 2.26
(Kontsevich–Zorich conjecture). Understand the homotopy types of strata of abelian differentials. Which stratum-components are $K(\pi, 1)$ spaces? Wha...
Kirby Problem 2.27
For $n \geq 4$, does the braid group $B_{n}$ admit a finite-index sub- group that embeds in a right-angled Artin group?...
Kirby Problem 2.28
Let $\Gamma$ be a graph that is not a nontrivial join, and let $A(\Gamma)$ be the associated right-angled Artin group. Does there exist an injective m...
Kirby Problem 2.29
Determine the Artin groups that can be embedded into a map- ping class group....
Kirby Problem 2.30
Which right-angled Artin groups contain closed hyperbolic sur- face groups? Is there an algorithmic or graph-theoretic criterion to decide this?...
Kirby Problem 2.31
Let $S$ be a closed surface of genus at least 2. Show that the stable commutator length is rational on the commutator subgroup of $\pi_{1}(S)$....
Kirby Problem 2.32
Does every surface bundle over a surface admit a flat connec- tion? What about surface bundles over 3-manifolds?...
Kirby Problem 2.33
Let $S$ be a closed compact surface (without boundary). Is there a finitely generated, torsion-free group $G$ such that $G$ cannot act faithfully by h...
Kirby Problem 2.34
Let $S$ be a compact surface. For $0 \leq r < s$, does there exist a nontrivial finitely generated subgroup $G_{r} \leq \operatorname{Diff}^{r}_{0}(S)...
Kirby Problem 2.35
Is the first-order theory of the mapping class group of a surface decidable?...
Kirby Problem 2.36
Are systems of equations over mapping class groups and braid groups decidable?...
Kirby Problem 2.37
Give a Nielsen–Thurston-type classification for the mapping class groups of infinite-type surfaces. In particular, which homeomorphisms are the approp...
Kirby Problem 2.38
Give an appropriate analogue of the curve graph for infinite- type surfaces, and characterize the surfaces for which no such graph exists....
Kirby Problem 2.39
(a) Does the mapping class group of an infinite-genus surface with no planar ends contain every countable group? (b) Does the mapping class group of t...
Kirby Problem 2.40
(a) Let $S$ be an infinite-type surface and $\varphi$ a mapping class for which there is a (marked) conformal structure $\Sigma$ on $S$ with respect t...
Kirby Problem 2.41
Give a finite list of practically computable invariants of the mapping class group or pure mapping class group of an infinite-type surface $S$ that de...
Kirby Problem 2.42
Is the geodesic flow in almost every direction on the Chamanara surface ergodic? What about on the translation surface considered by Bruin and Lukina,...
Kirby Problem 2.43
Let $X$ be a compact, totally disconnected subset of $\mathbb{R}^{2}$ with $|X| \geq 2$, and let $\Gamma_{X}$ denote the mapping class group of $\math...
Kirby Problem 2.44
Given an infinite-type surface $S$, which homeomorphisms $f: S \to$ $S$ give rise to mapping tori $M_{f}$ that admit a hyperbolic structure? For those...
Kirby Problem 2.45
Compute the end-periodic cobordism group $\Delta^{e}_{2}$ of end-periodic automorphisms (diffeomorphisms or homeomorphisms) of surfaces....
Kirby Problem 2.46
(a) Which coarsely boundedly generated mapping class groups of infinite-type surfaces are hyperbolic? (b) Consider the class of surfaces with $n \geq ...
Kirby Problem 2.47
(a) Given a mapping class $\psi$ of a based surface $S$, there is an induced endo- morphism of the symmetric product $\operatorname{Sym}^{i}(S)$ and h...
Kirby Problem 2.48
The mapping class group of a closed, orientable, genus $g$ sur- face $S$ acts by symplectomorphisms on the symmetric product $\operatorname{Sym}^{g}(S...
Kirby Problem 2.49
(AMU conjecture). Let $S$ be a surface with negative Euler char- acteristic. If $\varphi \in \operatorname{Mod}(S)$ acts by a pseudo-Anosov on some su...
Kirby Problem 2.50
(Volume conjecture for surface diffeomorphisms). Let $S$ be a closed oriented surface, let $q=e^{2\pi i/n}$ be a root of unity, and let $\mathcal{K}^{...
Kirby Problem 3.1
Classify the smallest volume hyperbolic 3-manifolds of various types. In particular: (a) Determine the nonorientable closed hyperbolic 3-manifolds of...
Kirby Problem 3.2
Show that the volumes of hyperbolic 3-manifolds are not all rationally related....
Kirby Problem 3.3
Does every cusped hyperbolic 3-manifold have a geometric ideal triangulation?...
Kirby Problem 3.4
(Chen--Yang Volume Conjecture). (a) Prove that, for any hyperbolic 3-manifold $M$, $$ \lim_{\substack{r\to\infty\\ r\ \mathrm{odd}}}\frac{1}{r}\log\b...
Kirby Problem 3.5
(a) Do there exist closed non-Haken hyperbolic 3-manifolds with arbitrarily large injectivity radius? (b) Does there exist a cofinal tower of regular...
Kirby Problem 3.6
Given a cofinal tower of covers M $\leftarrow$ $M_1$ $\leftarrow$ $M_2$ $\leftarrow$ $\cdots$, is it true that the torsion subgroups $\operatorname{To...
Kirby Problem 3.7
Does every finite-volume hyperbolic 3-manifold admit a finitesheeted cover fibering over the circle with orientable pseudo-Anosov monodromy?...
Kirby Problem 3.8
If $M_1$ and $M_2$ are finite-volume hyperbolic 3-manifolds whose fundamental groups have isomorphic profinite completions, must $M_1$ and $M_2$ be is...
Kirby Problem 3.9
Is being Haken a profinite invariant amongst 3-manifolds? That is, if $M_1$ and $M_2$ are 3-manifolds so that $\pi_1(M_{1})$ and $\pi_1(M_{2})$ have i...
Kirby Problem 3.10
(a) Are there infinitely many commensurability classes of arithmetic rational homology 3-spheres? (b) Are there infinitely many arithmetic integral h...
Kirby Problem 3.11
Does every hyperbolic knot in the 3-sphere have meridian length at most 4?...
Kirby Problem 3.12
(a) Considering all closed, orientable, $\pi_1$-injective surfaces (possibly non-embedded) in all closed hyperbolic 3-manifolds, what is the infimum o...
Kirby Problem 3.13
Does every closed hyperbolic 3-manifold admit an immersed $\pi_1$-injective surface with only double points? More precisely, if M is a closed, connect...
Kirby Problem 3.14
Can a hyperbolic knot complement in the 3-sphere contain a closed, embedded totally geodesic surface?...
Kirby Problem 3.15
Let $M$ be a closed hyperbolic 3-manifold with positive first Betti number. (a) Which elements of $H^{2}(M;\mathbb{R})$ are realized as the Euler cla...
Kirby Problem 3.16
Does every finite-volume hyperbolic 3-manifold contain infinitely many simple closed geodesics?...
Kirby Problem 3.17
Let $M_1$ and $M_2$ be finite-volume hyperbolic n--manifolds. If the length spectra of $M_1$ and $M_2$ coincide, must the two manifolds be commensurab...
Kirby Problem 3.18
Is there a closed hyperbolic 3-manifold that is foliated with minimal leaves?...
Kirby Problem 3.19
(a) Does every closed hyperbolic 3-manifold have a nowhere zero vector field whose lift to the universal cover has proper flow lines? (b) Can one ens...
Kirby Problem 3.20
Let $M$ be a closed hyperbolic 3-manifold with a faithful homomorphism $\rho:\pi_1(M)\to \operatorname{Homeo}^{+}(\mathbb{R})$. Prove that $M$ support...
Kirby Problem 3.21
In this problem, all 3-manifolds are orientable, while all flows are considered up to orbit equivalence and are assumed to be transitive. (a) Are the...
Kirby Problem 3.22
Let $G=\pi_1(M)$ be the fundamental group of a finite-volume hyperbolic 3-manifold $M$. What is the regularity of the smoothest (virtual) action of $G...
Kirby Problem 3.23
What is the Margulis constant in dimension 3? Is it realized uniquely by the Weeks manifold W, where $\mu(W)$ = 0.77442...?...
Kirby Problem 3.24
(a) (Cannon Conjecture) If G is a finitely presented, Gromov hyperbolic group with space at infinity equal to the 2-sphere, must G be a cocompact Klei...