Mathematics Problem Archive
Curvature-Type Tensors of Statistical Manifolds
v1.3 research notesLet $K(X,Y,Z,W)=h(R(X,Y)Z,W)$ be the curvature $(0,4)$-tensor of a statistical manifold. Investigate the structure of all $(0,4)$-tensors satisfying $...
Integrable Radial Distributions and One-Conformal Flatness
v1.3 research notesOn a statistical manifold, let $D$ be the rank-$(n-1)$ distribution orthogonal to the velocity of the $\nabla$-geodesic from a fixed point. If every s...
Inflection Points of Projectively Flat Curves
v1.3 research notesEstimate the minimum number of inflection points of a closed curve on a Riemann surface with a projectively flat connection....
Affine Vertices and Inflection Points
v1.3 research notesFor a closed curve on a Riemann surface with projectively flat connection, estimate the number of affine vertices and, assuming isolated inflection po...
Global Affine Curve Flow
v1.3 research notesProve existence of a time-global solution to the affine-plane curve evolution equation $\partial x/\partial u=(1+kp)x''$, where $u$ is time, $x''$ is ...
Stein Tangent Bundles of Complete Hessian Manifolds
v1.3 research notesIf $(M,g)$ is a complete Hessian manifold, is its tangent bundle with the natural complex structure a Stein manifold? In particular, if a convex domai...
Stability of Hessian Metrics
v1.3 research notesLet $M$ be a compact Hessian manifold and deform its affine structure. Does every sufficiently small deformation admit a Hessian metric?...
Nonproduct Compact Hessian Manifolds
v1.3 research notesConstruct compact Hessian manifolds other than direct products of hyperbolic and flat compact Hessian manifolds; in particular, construct one with no ...
Boundaries of Groups and Kleinian Groups — Problem 1
v1.3 research notesWhat spaces can arise as boundaries of hyperbolic groups? As a sub-problem: For which k do k-dimensional stable Menger spaces appear as boundaries?...
Boundaries of Groups and Kleinian Groups — Problem 3
v1.3 research notesWhat 2-dimensional spaces arise as boundaries of hyperbolic groups?...
Boundaries of Groups and Kleinian Groups — Problem 13
v1.3 research notesFind further universality phenomena: classes of groups or spaces of different nature whose ideal boundaries are nevertheless all homeomorphic, beyond ...
Boundaries of Groups and Kleinian Groups — Problem 28
v1.3 research notesExtend the known necessary conditions for a compact metrizable space $X$ to be the boundary of a proper cocompact CAT(0) space, or give a complete cla...
Boundaries of Groups and Kleinian Groups — Problem 29
v1.3 research notesDoes every CAT(0) group have finite asymptotic dimension?...
Boundaries of Groups and Kleinian Groups — Problem 40
v1.3 research notesDevelop a theory for analysis on the ideal boundaries of relatively hyperbolic groups, as it is done for hyperbolic groups....
Boundaries of Groups and Kleinian Groups — Problem 41
v1.3 research notesIn what generality does quasiconformal imply quasisymmetric?...
Boundaries of Groups and Kleinian Groups — Problem 51
v1.3 research notesAre all quasi-isometric embeddings between higher-rank symmetric spaces either isometries or algebraic in this way?...
Boundaries of Groups and Kleinian Groups — Problem 64
v1.3 research notes[Cannon–Thurston] Is this action conjugate to a conformal action?...
Boundaries of Groups and Kleinian Groups — Problem 67
v1.3 research notesLet H ⊂ G be a hyperbolic subgroup of a hyperbolic group (we do not assume that H is quasiconvex). Is it true that there exists an equivariant continu...
Boundaries of Groups and Kleinian Groups — Problem 68
v1.3 research notesWhat is the Poisson boundary of the free group with an arbitrary measure?...
Boundaries of Groups and Kleinian Groups — Problem 72
v1.3 research notesCharacterize the hitting measure ν on PMF obtained from the random walk by mapping classes on Teichm¨ uller space. Is it absolutely continuous with re...
Boundaries of Groups and Kleinian Groups — Problem 73
v1.3 research notesWhat is the Poisson boundary of Outer space?...
Boundaries of Groups and Kleinian Groups — Problem 74
v1.3 research notesIs there are meaningful structure theory for lacunary hyperbolic groups? Can one define a useful boundary for such groups? Is it true that either Out(G...
Boundaries of Groups and Kleinian Groups — Problem 75
v1.3 research notesEvery relatively hyperbolic group has cut points in all of its asymptotic cones. To what extent does the converse hold? Characterize the finitely gene...
Boundaries of Groups and Kleinian Groups — Problem 77
v1.3 research notesFor the fundamental group G of a closed hyperbolic n-manifold consider a short exact sequence 1 →Zp → Γ → G → 1. Is the group Γ residually finite? In o...
Boundaries of Groups and Kleinian Groups — Problem 79
v1.3 research notesLet G be a Gromov-hyperbolic Coxeter group. Does G admit a discrete embedding in Isom(Hn) for large n?...
Boundaries of Groups and Kleinian Groups — Problem 81
v1.3 research notesLet G ⊂ Isom(Hn) be a discrete torsion-free finitelygenerated subgroup without abelian subgroups of rank ≥ 2. Is it true that (a) cdZ(G) ≤ Hdim(Λc(G)) ...
Boundaries of Groups and Kleinian Groups — Problem 90
v1.3 research notesGeneralize Bestvina-Feighn combination theorem from graphs of groups to complexes of groups....
Boundaries of Groups and Kleinian Groups — Problem 92
v1.3 research notesThere is a theory of quasi-convex groups acting on Gromov hyperbolic spaces, generalizing the theory of convex-compact groups of isometries of the rea...
Boundaries of Groups and Kleinian Groups — Problem 93
v1.3 research notesExtend this relation of Anosov structure and dynamics on the limit set to representations of other hyperbolic groups....
Boundaries of Groups and Kleinian Groups — Problem 95
v1.3 research notesObtain new rigidity results for embeddings of realhyperbolic lattices into higher-rank semisimple Lie groups in terms of the boundary maps....
Boundaries of Groups and Kleinian Groups — Problem 99
v1.3 research notesConsider Teichm¨ uller spaceT (S) with Teichm¨ uller metric. Does it have quadratic isoperimetric inequality?...
Boundaries of Groups and Kleinian Groups — Problem 105
v1.3 research notesCompute cogrowth for notable subgroups $H\subset G$, where cogrowth is the growth of the Schreier graph $\Gamma_{G/H}$. In particular: prove that the ...
Distinguishing Fintushel-Stern Manifolds
v1.3 research notesIf knots $K$ and $K'$ have the same Alexander polynomial, are the corresponding Fintushel--Stern four-manifolds $X_K$ and $X_{K'}$ diffeomorphic?...
Classification at Symplectic Kodaira Invariant Zero
v1.3 research notesExtend Liu's classification of compact symplectic four-manifolds with positive numerical invariant $\kappa$ to the borderline case $\kappa=0$; determi...
Uniqueness of Symplectic Structures on Four-Manifolds
v1.3 research notesIs a symplectic structure $\omega$ on a four-manifold unique up to diffeomorphism when the elementary topological invariants $[\omega]$ and $c_1(M)$ a...
Complex Jörgens-Calabi-Pogorelov Theorem
v1.3 research notesProve an appropriate complex analogue of the Jörgens--Calabi--Pogorelov theorem: classify global solutions on $\mathbb{C}^n$ of the complex Monge--Amp...
Topology of Compact Manifolds with Holonomy G2
v1.3 research notesWhich compact seven-manifolds admit a Riemannian metric with holonomy $G_2$?...
Global Moduli of G2 Metrics
v1.3 research notesFor a compact seven-manifold $M$ admitting holonomy-$G_2$ metrics, describe their moduli space modulo diffeomorphisms isotopic to the identity. If $\p...
Compactness for Calibrated Submanifolds
v1.3 research notesDevelop compactness and singularity theories for special Lagrangian, associative, and co-associative calibrated submanifolds that are strong enough to...
Closed Curves with a Nondegenerate Frenet Frame
v1.3 research notesLet $\mu(n)$ be the least $m$ such that a convex plane curve traversed $m$ times has a regular small perturbation in $\mathbb{R}^n$. Determine $\mu(n)...
Scalar Curvature Question [?1]: ○What arepossible topologiesof manifolds whichadmit Riemannin metrics with scalar curvaturesSc > 0
v1.3 research notes○What arepossible topologiesof manifolds whichadmit Riemannin metrics with scalar curvaturesSc > 0?...
Scalar Curvature Question [?2]: ○What are topologies ofspaces of metricsg with Sc(g)>0
v1.3 research notes○What are topologies ofspaces of metricsg with Sc(g)>0?...
Scalar Curvature Question [?3]: ○What are geometries ofindividual manifoldswith Sc > σ
v1.3 research notes○What are geometries ofindividual manifoldswith Sc > σ?...
Scalar Curvature Question [?4]: ○What are effect of lower boundsSc ≥σ on the topology and geometry of maps between manifolds
v1.3 research notes○What are effect of lower boundsSc ≥σ on the topology and geometry of maps between manifolds?...
Scalar Curvature Question [?6]: that the surface-tangent-bundle condition in Llarull's scalar-curvature rigidity theorem is redundant
v1.3 research notesConjecture that the surface-tangent-bundle condition in Llarull's scalar-curvature rigidity theorem is redundant. Specifically, let $X$ be a closed or...
Scalar Curvature Question [?8]: Find a useful local geometric definition of a scalar-curvature lower bound $\operatorname{Sc}\geq\sigma$ that
v1.3 research notesFind a useful local geometric definition of a scalar-curvature lower bound $\operatorname{Sc}\geq\sigma$ that supports global theorems and extends to ...
Scalar Curvature Question [?10]: Extend the concept ofSc > 0 to singular Fano Varieties
v1.3 research notesProblem Extend the concept ofSc > 0 to singular Fano Varieties. For example, work out a definition ofSc(X) along the lines suggested in Question 1 of t...
Scalar Curvature Question [?12]: Q-Non-Essentiality of Manifolds with Sc > 0
v1.3 research notesConjecture: Q-Non-Essentiality of Manifolds with Sc > 0. No rational homology class14 in the classifying spaceBΓ of a discrete groupΓ can be realised ...
Scalar Curvature Question [?16]: Singularities are Unstable
v1.3 research notesConjecture. Singularities are Unstable. Brian White told me about 30 years ago that he believed that Volume minimising hypersurfaces in generic Rieman...
Scalar Curvature Question [?17]: 6
v1.3 research notesConjecture 6. ISC: Singularities are Irrelevant. Schoen and Yau announced 35 years ago [110], [114] that their descent metod extends to singular minim...