Questions in Geometric Group Theory — Q 1.5
v1.3 research notes(Davis) If $G$ is word-hyperbolic, does the Rips complex $P_d(G)$ have an equivariant negatively curved metric for $d$ sufficiently large?...
Questions in Geometric Group Theory — Q 1.10
v1.3 research notes(Canary) Let $G$ be word-hyperbolic and $H$ a finitely presented subgroup of $G$. Suppose that for every $g\in G$ there is $n>0$ such that $g^n\in H$....
Questions in Geometric Group Theory — Q 1.21
v1.3 research notes(Thurston) Is every closed hyperbolic 3-manifold finitely covered by one that fibers over the circle?...
Questions in Geometric Group Theory — Q 2.3
v1.3 research notes(Eilenberg-Ganea) Is there a group G of cohomological dimension 2 and geometric dimension 3?...
Questions in Geometric Group Theory — Q 2.9
v1.3 research notesDoes every Artin group have a finite $K(G,1)$?...
Questions in Geometric Group Theory — Q 8.8
v1.3 research notesCompute the asymptotic dimension of CAT(0) groups, Out(Fn), mapping class groups, nonuniform lattices, Thompson’s group. Is there a group of finite ty...
Questions in Geometric Group Theory — Q 9.2
v1.3 research notes(Andrews-Curtis) If K and L are simple homotopy equivalent finite 2-complexes, can one transform K to L by a sequence of elementary collapses and expa...
Questions in Geometric Group Theory — Q 10.2
v1.3 research notes(Belegredek) Is there a 3-complex X (not necessarily aspherical) which is not homotopy equivalent to a 2-complex but H³(X; {G}) = 0 for all local coef...
Questions in Geometric Group Theory — Q 11.1
v1.3 research notesStudy the quasi-isometry group QI(Rn). How big is it?...
Questions in Geometric Group Theory — Q 11.5
v1.3 research notes(Bridson) Classify the mapping tori of automorphisms $\mathbb{Z}^n\to\mathbb{Z}^n$ up to quasi-isometry....
Questions in Geometric Group Theory — Q 11.6
v1.3 research notes(Bridson) Is G×Z quasi-isometric to G for G =Thompson’s group? Any f.g. group?...
Questions in Geometric Group Theory — Q 12.2
v1.3 research notes(Lubotzky) Does Out(Fn) have the congruence subgroup property?...
Questions in Geometric Group Theory — Q 12.80
v1.3 research notes(Yves de Cornulier) Let G be residually torsion-free nilpotent. Is G Haagerup (= a-(T)-menable)?...
Questions in Geometric Group Theory — Q 13.3
v1.3 research notes(Henry Glover) Does for every finite graph G the following 1−2−∞- conjecture hold: G is planar, a double cover of G is planar, or no finite cover is p...
Questions in Geometric Group Theory — Q 13.7
v1.3 research notesLet $L$ be a flag triangulation of $S^{2k-1}$, let $f_i$ be the number of $i$-simplices of $L$, and define $$\chi=1-\sum_{i=0}^{2k-1}(-1)^i\frac{f_i}{...
Questions in Geometric Group Theory — Q 13.8
v1.3 research notesDo there exist groups G with balanced presentation (same number of generators and relations), with H1(G) = 0 and with unsolvable word problem?...
Questions in Geometric Group Theory — Q 13.9
v1.3 research notesIs there a sequence of (perfect, of course) groups with balanced presentations among which one cannot recognize trivial groups?...
Some Questions — Question 3
v1.3 research notesLet $G$ be a closed transitive subgroup of the automorphism group of a rooted tree. Must every level stabilizer of $G$ contain an element acting witho...
Some Questions — Question 40
v1.3 research notesIf $A$ and $B$ are countably infinite groups, does $A\times B$ have fixed price $1$?...
Some Questions — Question 41
v1.3 research notesDoes every countable group have fixed price; that is, do all its free probability-measure-preserving actions have the same cost?...
Algebraic Stories — Hilbert functions of fat points.
v1.3 research notesGiven a scheme of generic fat points $X \subset \mathbb{P}^{n_1-1}\times\ldots\times \mathbb{P}^{n_t-1}$, what is the multi-graded Hilbert function $\...
Green's conjecture
v1.3 research notesFor a non-hyperelliptic algebraic curve, is its Clifford index determined by the extent to which its canonical embedding has linear syzygies?...
Grothendieck–Katz p-curvature conjecture
v1.3 research notesProve the conjectured local-to-global principle for linear ordinary differential equations known as the Grothendieck–Katz $p$-curvature conjecture....
Zariski–Lipman conjecture
v1.3 research notesLet $V$ be a complex algebraic variety with coordinate ring $R$. If the module of derivations of $R$ is free over $R$, must $V$ be smooth?...
Geometry of Continued Fractions — Further open questions
v1.3 research notesStudy geometric properties of Markov spectrum....
Some Open Problems in Elasticity — Regularity of minimizers
v1.3 research notesDetermine when the minimizer $y^*$ in Theorem 2.1 of the source is smooth....
Some Open Problems in Elasticity — Lavrentiev phenomena
v1.3 research notesCan the Lavrentiev phenomenon occur for elastostatics under growth conditions ensuring that all finite-energy deformations are continuous?...
Some Open Problems in Elasticity — Global dynamics
v1.3 research notesProve global existence and uniqueness for suitable initial-boundary-value problems in dynamic nonlinear elasticity....
Research Problems in Function Theory — Problem 2.22
v1.3 research notesWith the terminology of Problem 2.20, denote by $\mathcal{F}(f)$ the set of points where the sequence $\{f_n(z)\}$ is not normal. Fatou asks if there ...
Research Problems in Function Theory — Problem 2.78
v1.3 research notes(Fatou's conjecture) Show that the subset $U$ of functions $g$ in $R_d$, such that all the critical points of $g$ are in the basins of attraction of p...
Research Problems in Function Theory — Problem 2.88
v1.3 research notesLet $B$ denote the boundary of the Mandelbrot set (or, equivalently, the topological bifurcation set of the family $z\mapsto z^2+c$, $c\in\mathbb{C}$....
Research Problems in Function Theory — Problem 5.26
v1.3 research notesLet $B$ be the Bergman space of square integrable functions in $\mathbb{D}$, that is, those functions $f(z) = \sum^\infty_{n=0} a_nz^n$ for which $\su...
Research Problems in Function Theory — Problem 6.1
v1.3 research notesThe Bieberbach conjecture Is it true that $|a_n|\leq n$ for $f$ in $S$ with equality only for $f(z)\equiv f_\theta(z)$? The result is known to be true...
Research Problems in Function Theory — Problem 6.94
v1.3 research notesLet $\Omega$ be a simply-connected domain in $\mathbb{C}$ with at least two boundary points, and let the function $\phi$ map $\Omega$ analytically and...
Research Problems in Function Theory — Problem 6.96
v1.3 research notesFor $-\infty<p<+\infty$ let \[B(p):=\sup\{\beta_f(p):f\text{ conformal map of }\mathbb{D}\text{ into }\mathbb{D}\}\] where \[\beta_f(p)=\limsup_{r\to1...
Research Problems in Function Theory — Problem 7.74
v1.3 research notesIn their famous Acta paper , Hardy and Littlewood introduced the celebrated Hardy-Littlewood maximal function in connection with complex function theo...
Fuglede's conjecture in dimensions one and two
v1.3 research notesFor nonconvex subsets of $\mathbb{R}$ and $\mathbb{R}^2$, is a set spectral if and only if it tiles by translations?...
Kung–Traub conjecture
v1.3 research notesFor an iteration without memory that uses $n$ evaluations of a function or its derivatives per step, is its convergence order always at most $2^{n-1}$...
Mean value problem for polynomial critical points
v1.3 research notesGiven a complex polynomial $f$ of degree $d\geq2$ and $z\in\mathbb{C}$, must there be a critical point $c$ of $f$ such that $|f(z)-f(c)|\leq |f'(z)|\,...
Pompeiu problem
v1.3 research notesCharacterize the domains for which there exists a nonzero function whose integral vanishes over every congruent copy of the domain....
Vlasov–Maxwell regularity
v1.3 research notesEstablish global regularity, or exhibit breakdown, for solutions of the Vlasov–Maxwell equations from appropriate smooth initial data....
Finite-dimensional dynamics for two-dimensional Navier–Stokes
v1.3 research notesIs the global attractor of the periodically forced two-dimensional Navier–Stokes equations conjugate to a smooth finite-dimensional dynamical system? ...
Five Open Problems — Global Cauchy theory for one-dimensional Euler–Fourier flow
v1.3 research notesDevelop a global-in-time theory of the Cauchy problem for the one-dimensional Euler–Fourier system for initial data constrained only by finite energy ...
Five Open Problems — Compensated compactness for symmetric matrices
v1.3 research notesDevelop a compensated-compactness calculus for symmetric matrices when compensated compactness yields only inequalities. As a first application, prove...
Five Open Problems — Compressible Navier–Stokes near vacuum
v1.3 research notesFor compressible Navier–Stokes equations with constant viscosities near vacuum, does the unphysical one-dimensional consequence identified by Hoff and...
Five Open Problems — Eternal finite-energy compressible Euler flow
v1.3 research notesDoes the compressible Euler system in odd spatial dimension admit a nontrivial smooth eternal solution having finite nonzero mass and energy?...
Five Open Problems — Regular reflection without irrotationality
v1.3 research notesProve existence of a regular reflection for compressible flow against a wedge without assuming that the flow is irrotational....
10 Lectures and 42 Open Problems — Open Problem 3.3
v1.3 research notesLet ${G=(V,E,W)}$ be a graph and ${k}$ a positive integer, is the following true? $\rho_G(k) \leq \mathrm{polylog}(k) \sqrt{\lambda_k}. \ \ \ \ \ (2)$...
10 Lectures and 42 Open Problems — Deterministic Restricted Isometry Property matrices
v1.3 research notesConstruct deterministic matrices $A\in\mathbb{C}^{M\times N}$ (or $A\in\mathbb{R}^{M\times N}$ ) satisfying the $(s,\frac13)$ -RIP for $s\approx\frac{...
10 Lectures and 42 Open Problems — Mutually Unbiased Bases
v1.3 research notesHow many mutually unbiased bases are there in 6 dimensions?...