Disciplines / Research questions
Mathematics
247 research topics · 1651 questions
Subgraph covering problem8 questions
Exact values of the cover numbers by perfect, generalized split, co-unipolar and unipolar graphs, and which functions are cover-number functions
Open for about 1 yearThe Dau–Milenkovic–Puleo clique cover conjecture for
Open for about 9 yearsEdge clique covers of graphs with independence number two: does ecc(G) ≤ n always hold?
Open for about 26 yearsIs the local bipartite covering number bounded by a function of the fractional chromatic number? (Question 6.1 of Goetze–Schwebler)
Open for less than 1 yearThe de Caen–Gregory–Pritikin conjecture on k-fold biclique partitions of the complete graph, and the extremal constant for clique partitions of complementary graphs
Open for about 40 yearsIs the ordered biclique partition number of the complete graph ? Removing the sub-polynomial term in
Open for about 12 yearsThe biclique partition number of balanced split graphs: deciding versus
Open for about 4 yearsExplicit bipartite graphs of high resistance (Jukna): construct with
Open for about 17 years
Counting problem of self-avoiding walks6 questions
Ballisticity of the self-avoiding walk on nonamenable transitive graphs: the one-ended case
Open for about 9 yearsMaking the lattice-point integral representation for self-avoiding walks on effective: rigorous main-term asymptotics and error control for
Open for about 1 yearUniversality class of the growing self-avoiding walk
Open for about 42 yearsConformal invariance of the critical self-avoiding walk on the hexagonal lattice: convergence to chordal SLE(8/3) and the predicted critical exponents
Open for about 24 yearsExistence and value of the closing exponent for self-avoiding walks in low dimensions
Open for about 64 yearsHammersley's program for the existence of critical exponents of two-dimensional self-avoiding walks: worm super-multiplicativity, two-layer slab asymptotics, and ratio-of-ratios decay
Open for about 64 years
Computational complexity of combinatorial optimization inverse problems2 questions
Hotspot conjecture7 questions
The asymptotic convex hot spots constant: does ? (Conjecture 1.10 of de Dios Pont, Hsu and Taylor)
Open for about 1 yearNo interior extrema for first mixed Dirichlet–Neumann eigenfunctions with a single-segment Dirichlet set (Hatcher's Conjecture 1.8), and the L-shaped eigenvalue inequalities of Remark 6.2
Open for about 2 yearsThe strong hot spots conjecture in higher dimensions beyond lip and symmetric domains, and the spectrum of the associated vector-valued Laplacian
Open for about 51 yearsUnstable nonvertex critical points of second Neumann eigenfunctions on convex quadrilaterals: unconditional existence and consequences for the deformation approach to the hot spots conjecture
Open for about 5 yearsNecessity of connectivity for boundary Dirichlet regions in the mixed hot-spots problem
Open for about 2 yearsThe hot spots conjecture for simply connected planar domains (Rauch's conjecture)
Open for about 52 yearsThe hot spots conjecture for bounded convex planar domains
Open for about 51 years
Computation of the polynomial of minimal differential dimension7 questions
Algorithmic computation of multivariate differential dimension polynomials for nonlinear differential field extensions, and the classification of their invariants
Open for about 6 yearsEffective computation of the minimal differential dimension polynomial of a differential field extension and classification of Macaulay-constant boundedness under changes of generators
Open for about 4 yearsSharper-than-Ackermann order bounds for differential elimination and effective estimates for the minimizing coefficients of the Kolchin polynomial
Open for about 16 yearsOptimality of the León Sánchez bounds for coefficients of the Kolchin differential dimension polynomial
Open for about 9 yearsEffective computation of multivariate difference–differential dimension polynomials via characteristic sets with respect to several term orderings
Open for about 14 yearsBivariate Kolchin-type dimension polynomials of non-reflexive prime difference-differential ideals with several commuting translations
Open for about 6 yearsComplete invariant theory for multivariable dimension polynomials of finitely generated filtered modules over Ore polynomial rings
Open for about 19 years
Minimal resistance convex body problem4 questions
Global minimizers of Newton's problem of minimal resistance in the class of convex bodies and the infinite-height limit
Open for about 339 yearsFast rotation and constructive extremals in the Newton minimal resistance problem for rough bodies
Open for about 17 yearsSingular set of optimal bodies in Newton's least resistance problem: Plakhov's ridge-symmetry conjecture, conical singular points, and non-disk base domains
Open for about 4 yearsSingular-set structure and classification of minimizers in Newton's problem of minimal resistance
Open for about 6 years
Relevant theory and computational problems of optimal triangulations8 questions
Computational complexity of Minimum Average Distance Triangulations with metric and Euclidean weights
Open for about 14 yearsFree-boundary regularity of optimal multiphase partitions for the first Robin eigenvalue
Open for about 8 yearsAsymptotic hexagonal optimality of optimal partitions for the first Dirichlet eigenvalue (the Caffarelli–Lin conjecture)
Open for about 19 yearsFree-boundary regularity, general partitions, and grouping for the optimal partition problem of the principal eigenvalue of linearly coupled elliptic systems
Open for about 7 yearsAcute triangulations in dimension four: existence for and for the 16-cell, 24-cell, and 120-cell
Open for about 17 yearsOptimal spectral partitions for the sum and the maximum of the first Dirichlet eigenvalues on the square, the disk, and the equilateral triangle
Open for about 9 yearsA polynomial-time approximation scheme for minimum weight triangulation (PTAS for MWT)
Open for about 9 yearsComplexity of minimum-weight Steiner triangulation of convex polygons: NP-hard or polynomial-time?
Open for about 32 years
ABC conjecture7 questions
Status of Letendre's -function strengthening of the conjecture: equivalence with and truth
Open for less than 1 yearQuantitative bounds for the exceptional set in the abc conjecture
Open for about 41 yearsUnconditional quantitative bounds for the four-term equation over without size hypotheses, and the subexponential shape of the bound towards
Open for about 32 yearsSharp constants and second-order terms in the Robert–Stewart–Tenenbaum refinement of the abc conjecture (Conjectures A, B, C)
Open for about 12 yearsBaker's explicit abc-conjecture and the unconditional resolution of its conditional Diophantine applications
Open for about 21 yearsUnconditional uniform boundedness of preperiodic points for unicritical polynomials over number fields
Open for about 32 yearsWatkins's conjecture: divisibility of the modular degree of an elliptic curve by the power of two attached to its Mordell–Weil rank
Open for about 24 years
Integrability in AdS/CFT correspondence6 questions
Justification and regime of validity of the factorized-scattering criterion for (non)integrability of AdS/CFT string backgrounds
Open for about 7 yearsGap and exact finite-volume spectrum of the long-string continuum in pure-NSNS AdS strings at WZW level
Open for about 5 yearsCompleting the hexagon-with-handles formalism: double-trace mixing, multi-mirror integrands, and the strong-coupling genus expansion for nonplanar N=4 supersymmetric Yang-Mills theory
Open for about 8 yearsExactness of the Quantum Spectral Curve for planar strings: massless modes at finite coupling and first-principles derivation
Open for about 5 yearsCompleting the hexagon bootstrap for AdS3/CFT2: finite-size corrections with massless modes and the pure-NSNS long-string limit
Open for about 5 yearsRigorous foundations of the planar AdS/CFT quantum spectral curve: pole-freeness for arbitrary operators, a first-principles derivation beyond the TBA, and exact state-universal equivalence with the Y-system/TBA
Open for about 12 years
Chern-number inequalities on Calabi–Yau moduli spaces5 questions
Hodge degeneracy of simply connected Calabi–Yau manifolds in dimension greater than two
Open for about 7 yearsVolume finiteness and Weil–Petersson incompleteness: the Douglas–Lu questions on projective special Kähler manifolds and Calabi–Yau moduli spaces
Open for about 20 yearsDirect uniform estimates of Bott–Chern transgression forms at infinity of Calabi–Yau moduli spaces
Open for about 17 yearsThe AMWP curvature identity for complexified index cones of arbitrary cubic forms
Open for about 17 yearsRationality of the Weil–Petersson Chern numbers of Weil–Petersson subvarieties of Calabi–Yau moduli (Lu–Sun conjecture)
Open for about 20 years
Cheeger-Goresky-MacPherson conjecture10 questions
Hodge–Riemann relations for combinatorial intersection cohomology: arbitrary perverse sheaves on fans
Open for about 8 yearsThe Cheeger–Goresky–MacPherson conjecture: -de Rham cohomology of the Fubini–Study metric and intersection cohomology of singular projective varieties
Open for about 44 yearsCompatibility of the pure Hodge structure on intersection cohomology with Saito's pure Hodge structure (Shentu–Zhao, Conjecture 8.5)
Open for about 5 yearsComplete Kähler metric on a singular projective variety whose full-degree L2-cohomology is the intersection cohomology (Cheeger–Goresky–MacPherson question, complete-metric variant)
Open for about 43 yearsThe Cheeger–Goresky–MacPherson conjecture: L²-cohomology of the smooth part of a complex projective variety in the Fubini–Study metric versus intersection cohomology
Open for about 44 yearsCheeger–Goresky–MacPherson question: complete Kähler metrics on projective varieties whose -cohomology computes intersection cohomology
Open for about 44 yearsThe Cheeger–Goresky–MacPherson conjecture for complex projective varieties with non-isolated singularities
Open for about 44 yearsCompatibility of the -Hodge structure with Saito's pure Hodge structure on the intersection cohomology of a singular Kähler space (Shentu–Zhao, Conjecture 8.5)
Open for about 5 yearsThe Cheeger–Goresky–MacPherson conjecture for the Fubini–Study metric: does the -cohomology of the regular part of a singular projective variety compute its intersection cohomology?
Open for about 43 yearsHodge theorem for iterated fibred cusp metrics on non-Witt stratified spaces of arbitrary depth
Open for about 11 years
Cherlin-Zilber conjecture9 questions
The positive-characteristic case of the log-CZ conjecture: linearization of absolutely simple Lie rings definable in finite-dimensional theories
The uniqueness case for odd-type groups of finite Morley rank: strong embedding and quasithin classification in the tameness-free -theory
The Cherlin–Zilber algebraicity conjecture in odd type: simple groups of finite Morley rank with normal 2-rank at most 2
Algebraicity of proper Moufang sets of finite Morley rank (Borovik-Nesin Question B.17)
Existence of bad groups of finite Morley rank in the generalized sense of Corredor, Borovik–Poizat, and Jaligot
Removing the L-group hypothesis: bounding Alt(n)-actions and the degree of generic sharp transitivity for permutation groups of finite Morley rank
Standardness of sharply 2-transitive groups of finite Morley rank (Borovik–Nesin conjecture)
The characteristic-3 case of the classification of Lie rings of finite Morley rank: Rosengarten's Fact 1 as an obstruction, and simple Lie rings of Morley rank 4 in characteristic 3
The Borovik–Burdges conjecture on strongly real elements in simple groups of finite Morley rank
A problem of Chern-Moser7 questions
Convergence of Chern–Moser-type normal forms for real-analytic non-integrable almost CR structures
Open for about 17 yearsCR analogue of Hamburger's theorem: at least two CR umbilical points on compact strongly convex real-analytic hypersurfaces in
Open for about 20 yearsAutomorphism algebras and jet determination for weighted-homogeneous polynomial models in CR geometry beyond Catlin multitype weights and holomorphic nondegeneracy
Open for about 12 yearsConvergent normal forms for Levi-degenerate real hypersurfaces beyond the everywhere 2-nondegenerate case in
Open for about 30 yearsA ball-like bounded strictly pseudoconvex domain in without CR umbilical points (the refined Chern–Moser question)
Open for about 10 yearsGlobal classification of obstruction-flat strictly pseudoconvex boundaries in (the strong Ramadanov conjecture in complex dimension two)
Open for about 8 yearsCR umbilical points on unit circle bundles over Riemann surfaces: the torus case and Loewner-type index bounds
Bonnet rigidity problem of CR type and Siu's superrigidity problem of isolated complex normal singularities7 questions
Characterizing embeddable deformations of compact strictly pseudoconvex CR three-manifolds
Open for about 61 yearsSharpness of the Ebenfelt–Minor two-embeddings bound: inequivalent local CR embeddings of strictly pseudoconvex hypersurfaces into spheres at critical codimension
Open for about 14 yearsMcLean's question: does the contact structure of the link characterize smoothness for all normal isolated singularities?
Open for about 12 yearsIntrinsic characterization of local CR embeddability into spheres in degenerate curvature regimes
Open for about 17 yearsThe Lipman–Zariski conjecture for normal surface singularities
Open for about 60 yearsShokurov's conjecture on the maximal minimal log discrepancy of singularities
Open for about 24 yearsWhich closed contact manifolds are links of isolated complex singularities, and how much of the singularity does the contact link determine?
Open for about 12 years
The Relationship between Donaldson Invariants and Seiberg-Witten Invariants8 questions
Local gluing-map properties for SO(3) monopoles: Hypothesis 2.5 of Feehan–Leness and the unconditional SO(3)-monopole cobordism formula
Open for about 27 yearsThe Moore–Mariño–Witten relation for higher-rank Donaldson invariants: U(N)-simple type (N ≥ 3) and the Seiberg–Witten formula for the U(3)-series
Open for about 28 yearsConstruction, existence, and wall-crossing of generalized multi-monopole Seiberg–Witten invariants at the point of 5d super Yang–Mills
Open for less than 1 yearGluing-map properties for SO(3) monopoles: the missing analytic step toward an unconditional SO(3)-monopole cobordism formula and Witten's conjecture for four-manifolds of simple type
Open for about 27 yearsUniversality of Mochizuki's formula with Nekrasov-derived coefficients for smooth four-manifolds (Göttsche–Nakajima–Yoshioka Conjecture 4.5)
Open for about 16 yearsWitten's conjecture: Donaldson invariants of four-manifolds with and odd are determined by Seiberg–Witten invariants
Open for about 32 yearsUniversal error formula relating Donaldson invariants and Pidstrigach-Tyurin spin invariants of smooth four-manifolds for general Dirac index
Open for about 31 yearsConjecture of Lin–Ruberman–Saveliev: equality of the Furuta–Ohta and Casson–Seiberg–Witten invariants for homology 4-manifolds
Open for about 17 years
The Dry Ten Martini Problem7 questions
The Dry Ten Martini Problem for the critical almost Mathieu operator (remaining case: frequencies with )
Open for about 45 yearsGlobal transversality, complete gap labeling, and joint analyticity of the spectral dimension for Sturmian substitution Jacobi Hamiltonians
Open for about 14 yearsThe Dry Ten Martini Problem for the extended Harper's model: the self-dual region III and Liouvillean frequencies
Open for about 10 yearsThe arithmetic spectral program for the unitary almost Mathieu operator: dry Ten Martini problem, sharp arithmetic spectral transitions, eigenfunction hierarchy, and spectral regularity
Open for about 4 yearsDry Ten Martini Problem for type-I energies of quasiperiodic Schrödinger operators with arbitrary analytic potentials
Open for about 3 yearsThe Dry Ten Martini Problem for cosine-type quasiperiodic Schrödinger operators at arbitrary irrational frequencies
Open for about 1 yearThe Dry Ten Martini Problem for the Unitary Almost Mathieu Operator: Critical Coupling and Non-Diophantine Frequencies
Open for about 1 year
The Virasoro Conjecture for Gromov-Witten Invariants8 questions
Genus-1 Virasoro conjecture for Gromov–Witten invariants without semisimplicity: vanishing of the obstruction on the small phase space
Open for about 29 yearsGenus-one Virasoro conjecture for Gromov-Witten invariants of arbitrary smooth projective varieties
Open for about 29 yearsVirasoro conjecture for stable pairs on simply-connected 3-folds: the full descendent algebra beyond -cohomology and the vanishing of -descendants
Open for about 6 yearsThe conjecture with target varieties: unconditional universal Hodge-integral constraints for arbitrary smooth projective targets
Open for about 1 yearThe Virasoro conjecture for Hodge integrals of arbitrary smooth projective varieties (Wang's Conjecture 1.1)
Open for about 29 yearsExtending the Coates–Givental–Tseng localization formula and Virasoro reduction from toric bundles to general holomorphic torus actions
Open for about 11 yearsStationary closed formula for the reduced descendent Gromov-Witten theory of a K3 surface and its polynomiality structure (Oberdieck's Conjectures 0.2, 0.4 and 3.10)
Open for about 3 yearsVirasoro constraints for the Gromov–Witten theory of the Enriques surface
Open for about 20 years
Hadwiger Conjecture7 questions
Hadwiger's conjecture for graphs with independence number at most two
Open for about 44 yearsThe -Hadwiger conjecture at successors of singular cardinals
Open for about 3 yearsForcing a minor from polylogarithmically many disjoint -connected subgraphs at linear connectivity (Question 6.1 of Norin–Postle–Song)
Open for about 6 yearsSix-colorability of graphs excluding the near-complete minor : the surviving level-7 instance of Seymour's H-Hadwiger conjecture
Open for about 9 yearsClique-minor constants left open by the disproof of the odd Hadwiger conjecture: the Duchet–Meyniel constant at independence number two and the 3/2 odd-minor separation ratio in general graphs
Open for about 44 yearsThe Rolek–Song edge-density conjecture: at edges every graph has a minor or is -colorable
Open for about 10 yearsClustered colouring of graphs excluding a fixed minor: the Norin–Scott–Seymour–Wood conjecture
Open for about 9 years
Kashaev-Murakami-Murakami Volume Conjecture7 questions
Universality of the generalized FAMED condition for ideal triangulations of hyperbolic knot complements (Conjectures 1.2 and 1.8 of Wong, 2025)
Open for less than 1 yearOne-parameter-family asymptotic expansions of colored Jones polynomials and Turaev–Viro invariants for general hyperbolic knots (Wong–Au Conjectures 3–5, and the figure-eight regime )
Open for about 8 yearsThe Coarse Volume Conjecture: does a function of the colored Jones coefficients coarsely determine the hyperbolic volume of every hyperbolic knot?
Open for about 15 yearsRationality of the parametrized volume conjecture coefficients and the Reidemeister torsion normalization for hyperbolic knots
Open for about 17 yearsThe Andersen–Kashaev volume conjecture for the Teichmüller TQFT (general hyperbolic knots in closed 3-manifolds)
Open for about 14 yearsParametrization of the volume conjecture for hyperbolic knots beyond the figure-eight knot
Open for about 16 yearsThe Andersen–Kashaev volume conjecture for the Teichmüller TQFT: existence and volume asymptotics of the Jones function for arbitrary hyperbolic knots in closed oriented 3-manifolds
Open for about 14 years
Koebe Problem7 questions
Koebe's circle domain conjecture (Kreisnormierungsproblem) and the equivalent Weyl-type realization of genus-zero hyperbolic surfaces as convex hull boundaries in hyperbolic 3-space
Open for about 118 yearsThe Weyl problem for convex surfaces in hyperbolic 3-space beyond countably many ends: existence and uniqueness of circle-type convex realizations (Luo–Wu conjecture and its equivalence with the Koebe circle domain conjecture)
Open for about 6 yearsKoebe uniformization of infinitely connected attracting and parabolic Fatou domains of rational maps
Open for about 2 yearsDoes conformal removability of the boundary imply conformal rigidity? The remaining direction of the He-Schramm rigidity conjecture for circle domains
Open for about 31 yearsExistence and uniqueness of dual circle configurations for arbitrary cellular decompositions of the plane (the infinite Koebe–Andreev–Thurston conjecture of Rehwinkel–Whitehead–Yang–Yang)
Open for about 3 yearsKoebe's Kreisnormierungsproblem: is every planar domain conformally equivalent to a circle domain?
Open for about 118 yearsCompleting the extremal theory of uniformization by square domains: the maximizer of Bonk's functional and an independent variational existence proof
Open for about 10 years
KZB Equations7 questions
Explicit algebraic KZB-type connections and the maximal metabelian de Rham period map for punctured curves of genus at least two
Open for about 3 yearsExact relation between R-matrix-valued linear problems with Planck constant as spectral parameter and Knizhnik–Zamolodchikov–Bernard equations
Open for about 12 yearsClassical limit of the Knizhnik–Zamolodchikov–Bernard equations with surface defects and the genus-one isomonodromic tau function
Open for about 7 yearsCompleting the classification of twisted elliptic classical dynamical r-matrices for finite-order automorphisms of simple Lie algebras with all admissible characteristic classes, together with the spinless Calogero–Moser reductions and twisted Gaudin/KZB extensions of the same framework
Open for about 11 yearsHecke transformations between topological sectors of WZW conformal blocks: intertwiners of the sector-wise elliptic KZB connections
Open for about 14 yearsModular-transformation matrices for higher-point solutions of the elliptic -Knizhnik–Zamolodchikov equation of the Ding–Iohara–Miki algebra
Open for about 9 yearsCompleting the dynamical elliptic Bethe algebra correspondence: elliptic Wronski map geometry beyond the asymptotic regime, Bethe ansatz completeness for arbitrary , and the source-deferred extension beyond
Open for about 7 years
Lichtenbaum Conjecture8 questions
Is the natural map from the modified Bloch group to indecomposable an isomorphism for every number field (Conjecture 3.33 of Burns–de Jeu–Gangl–Rahm–Yasaki)?
Open for about 6 yearsCompleting Ausoni's computation: an unconditional description of
Open for about 17 yearsThe cohomological Lichtenbaum conjecture for abelian extensions of imaginary quadratic fields at the excluded primes
Open for about 53 yearsExistence of Burns–de Jeu–Gangl special elements in odd-degree algebraic K-groups for general Artin characters
Open for about 15 yearsTwo-primary comparison of even algebraic K-groups of arithmetically equivalent number fields with real primes
Open for less than 1 yearLichtenbaum's finiteness conjecture for integral étale motivic cohomology of arithmetic schemes
Open for about 8 yearsThe Generalized Quillen–Lichtenbaum Conjecture of Elmanto–Zhang: integral equivariant -theoretic formulas for special values of Artin -functions
Open for about 2 yearsFinite generation of motivic, Frobenius, Kato, and Weil-étale (co)homology of schemes over finite fields (Geisser's Conjecture 2.5 / Lichtenbaum's finiteness)
Open for about 15 years
Palis Conjecture9 questions
Completing the lower-spectral-radius characterization of interval presence in the algebraic difference of two M-adic random Cantor sets: the asymmetric case and the critical regime
Open for about 16 yearsThe linear case of the Palis–Takens conjecture and the existence of positive-measure self-similar sets with empty interior on the line
Open for about 39 yearsGeneric coincidence of Milnor, statistical, and physical attractors beyond the continuous interval setting
Open for about 29 yearsThe Palis conjecture: eliminating zero Lyapunov exponents from the generic trichotomy for diffeomorphisms
Open for about 21 yearsHyperbolicity or heterodimensional cycles for general partially hyperbolic systems with one-dimensional center: removing the and nonzero-Lyapunov-exponent hypotheses
Open for about 19 yearsDensity of singular hyperbolicity for vector fields on three-dimensional manifolds
Open for about 9 yearsAre all star flows multisingular hyperbolic? The full characterization of star flows beyond dimension 3
Open for about 9 yearsChain recurrence classes versus homoclinic classes away from homoclinic tangencies and heterodimensional cycles (-generic diffeomorphisms and nonsingular flows)
Open for about 11 yearsIs Axiom A dense in the topology among diffeomorphisms of compact surfaces? (Smale's problem, surface case)
Open for about 59 years
Shelah's Uniqueness Conjecture10 questions
Does -weak non-forking amalgamation imply -symmetry for independence relations in stable abstract elementary classes?
Uniqueness of limit models from categoricity in abstract elementary classes without full amalgamation: deriving Assumption 1 from categoricity (the Shelah-Villaveces problem)
Galois-type uniform beta-trees and the sharp spectrum of limit models in abstract elementary classes
Symmetry, superlimits, and tameness from superstability-like hypotheses in abstract elementary classes with amalgamation
The spectrum of limit models in the abstract elementary class of modules with pure embeddings
The spectrum of limit models in stable abstract elementary classes (Boney–VanDieren's Conjecture 1.1)
Superstability versus uniqueness of limit models in abstract elementary classes with amalgamation: eliminating the no-Vaughtian-pairs hypothesis
Symmetry for non-μ-splitting over limit models from μ-superstability alone, and the equivalence of uniqueness of limit models with superstability in abstract elementary classes
Uniqueness of limit models in categorical abstract elementary classes with no maximal models: removing the tower hypotheses of the Shelah-Villaveces program
Does uniqueness of limit models imply mu-symmetry or mu^+-symmetry in superstable abstract elementary classes?
Construction of Dirichlet forms on the Sierpiński carpet7 questions
Explicit constants and convergence rates for resistances and time-scaling on generalized Sierpiński carpets
Open for about 2 yearsUniqueness of the canonical -energy on Sierpiński carpets and the conformal-dimension continuity threshold for generalized Sierpiński carpets
Open for about 4 yearsOsada's jump conjecture: the continuity threshold for Hausdorff-measure time changes of exotic diffusions on Sierpinski carpets
Open for about 20 yearsGeometric characterization of existence of standard self-similar Dirichlet forms on polygon carpets
Open for about 4 yearsDiffusions with sub-Gaussian heat kernel estimates on the Sierpiński carpet for general self-similar cell weights
Open for less than 1 yearExact value of the resistance scaling factor of the Sierpiński carpet (equivalently, its walk dimension)
Open for about 36 yearsExistence of self-similar Dirichlet forms with sub-Gaussian heat kernel estimates on unconstrained Sierpiński carpets in for
Open for about 3 years
Boundedness of Sierpiński hyperbolic components9 questions
Boundedness of type C (capture) hyperbolic components of bicritical rational maps
Open for about 7 yearsCompactness of Sierpiński carpet hyperbolic components of rational maps (McMullen's Question 5.3)
Open for about 38 yearsMcMullen's conjecture: boundedness of Sierpiński carpet hyperbolic components of rational maps
Open for about 31 yearsGeneralized Sierpiński gasket Julia sets on the boundary of the Cantor locus for asymmetric McMullen maps with
Open for about 1 yearThe obstructed boundary at infinity of hyperbolic components of disjoint type (Dudko–Luo Conjecture 1.9)
Open for less than 1 yearBoundedness of capture (type C) hyperbolic components in the moduli space of bicritical rational maps
Open for about 7 yearsBounded escape as a component property: bounded multipliers and the uniform extremal-annulus modulus in nested hyperbolic components of rational maps (Luo, Questions 11.14–11.15)
Open for about 7 yearsBoundedness of Sierpiński carpet hyperbolic components in the moduli space of rational maps (McMullen's Question 5.3)
Open for about 31 yearsBoundary at infinity of hyperbolic components of disjoint type: is ?
Open for less than 1 year
Open Problems on Smashing Subcategories8 questions
Silting-theoretic parametrisation of smashing subcategories of compactly generated triangulated categories beyond the dg setting
Open for about 7 yearsClassifying the frame of smashing ideals of D(R) for commutative rings beyond valuation domains
Open for about 34 yearsSpatiality of the frame of smashing tensor ideals of a rigidly-compactly generated tensor-triangulated category
Open for about 9 yearsOpen questions in Aambø's classification of localizing subcategories along t-structures: coherent subsets of noetherian schemes and derived lifts of abelian localizations
Open for about 1 yearAuslander–Reiten principle for localizing subcategories of infinite-dimensional support (Ono–Yoshino, Question 2.5)
Open for about 9 yearsThe telescope conjecture for the derived category D(RC) of representations of a small category over a commutative noetherian ring
Open for about 11 yearsThe strongly dualizable generalized smashing conjecture in the BP-local category of spectra
Open for about 13 yearsBazzoni–Šťovíček's support-equality question: are the compactly generated localizations of D(R) exactly the support-closed classes for arbitrary commutative rings?
Open for about 12 years
Tate-Oort Problem8 questions
Canonical subgroups of p-divisible groups with -action: existence beyond the current residue-characteristic and Hasse-invariant bounds, and partial degrees without Hypothesis 0.1
Open for about 11 yearsCanonicity and completion of Abrashkin's explicit classification of finite flat group schemes of period p: dependence on the p-power lift, functorial reconstruction ideals, and the p = 2 case
Open for about 18 yearsExplicit classification of Hopf orders in group algebras over local fields of characteristic beyond the primitively generated case
Open for about 10 yearsFull level structures on finite flat group schemes beyond rank- squares: the cases with , stack-level naturality, and higher height
Open for about 6 yearsOpen questions for moderately ramified -actions in positive characteristic
Open for about 7 yearsThe structure of and -rational -torsion on elliptic curves with good reduction everywhere when the class-number and low-ramification hypotheses fail
Open for about 17 yearsSplitting over the base and classification of actions for finite flat group schemes of square free order
Open for about 9 yearsTensor operations on finite flat commutative group schemes over general bases: preservation of flatness and finiteness, and minimal hypotheses for the multilinear theory
Open for about 15 years
Tate Conjecture10 questions
Kahn's question on reducing the Tate conjecture for divisors from characteristic zero to positive characteristic: must an -adic class on a surface over whose specializations are algebraic be algebraic?
Open for about 4 yearsDoes the Tate conjecture imply semisimplicity of Galois representations in positive characteristic?
Open for about 8 yearsTorsion in Tate-twisted étale cohomology over : is equal to ? (Bloch–Esnault's question)
Open for about 30 yearsTate conjecture for abelian varieties over finite fields: algebraicity of Tate classes in codimension at least 2, and the rationality of the field of motivated cycles
Open for about 61 yearsVanishing of the Galois-invariant birational cohomology of projective space over finite fields
Open for about 60 yearsUnconditional and integral Brauer–Tate–Shafarevich comparison over global function fields: finiteness of , -primary control, and Kato homology vanishing beyond degree 3
Open for about 8 yearsThe Tate conjecture for divisors on surfaces over a finite field in Kahn's affine-open reformulation
Open for about 61 yearsThe Tate conjecture for divisors over finite fields, reduced to the case of surfaces with
Open for about 61 yearsThe Tate conjecture for divisors on irreducible holomorphic symplectic varieties over finite fields without restrictions on the characteristic
Open for about 14 yearsCrystalline Variational Tate Conjecture beyond divisors: higher-codimension cycles and non-projective smooth proper families
Open for about 12 years
Veech Conjecture8 questions
Veech's conjecture on Möbius averages for bounded sequences with zero-entropy shift orbit closure
Open for about 16 yearsFine structure of the Lyapunov spectrum of the Kontsevich-Zorich cocycle: individual exponents, zero exponents, and the rank filtration of the second fundamental form (open core of Forni's 2006 Handbook problem list)
Open for about 20 yearsStrong Möbius and Liouville MOMO property for the unipotent automorphism of the two-torus
Open for about 5 yearsEigenvalue multiplicity and continuity dichotomy for minimal non-weak-mixing directions on non-arithmetic Veech surfaces (Avila–Delecroix conjecture)
Open for about 13 yearsNon-parabolic directions of vanishing SAF invariant on Veech surfaces of cubic and higher trace field (the Arnoux-Schmidt presumption)
Open for about 17 yearsFiniteness of quotient saddle-connection graphs as a characterization of Veech surfaces (Pan's Question 1)
Open for about 7 yearsVeech's conjecture for the Möbius flow: uniform orthogonality of the coordinate projection to the Pinsker σ-algebra of every quasi-generic measure
Open for about 10 yearsVeech's question: density of pure point induced transformations of an irrational rotation
Open for about 54 years
Virtual Haken Conjecture5 questions
Which compact 3-manifold groups are RFRS: the strict (non-virtual) clause remaining from Agol's 2008 RFRS question
Open for about 19 yearsAcylindrical arc choices and connected covering spaces in Charitos's new proof of the virtual Haken theorem
Open for less than 1 yearEffective bounds for hierarchies and the Malnormal Special Quotient Theorem for relatively hyperbolic virtually special groups
Open for about 7 yearsIs Hakenness a profinite property of 3-manifolds?
Open for less than 1 yearAbsolute profinite rigidity of finite-volume hyperbolic 3-manifold groups (Bridson–Reid conjecture, manifold case)
Open for about 11 years