Disciplines / Research questions

Mathematics

247 research topics · 1651 questions

Subgraph covering problem8 questions
  1. 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 year
  2. The Dau–Milenkovic–Puleo KtK_t clique cover conjecture for t≥5t\ge 5

    Open for about 9 years
  3. Edge clique covers of graphs with independence number two: does ecc(G) ≤ n always hold?

    Open for about 26 years
  4. Is 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 year
  5. The 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 years
  6. Is the ordered biclique partition number of the complete graph O(n1/2)O(n^{1/2})? Removing the sub-polynomial term in bp1.5(Kn)=n1/2+o(1)bp_{1.5}(K_n)=n^{1/2+o(1)}

    Open for about 12 years
  7. The biclique partition number of balanced split graphs: deciding bp(G)=ω(G)−1\mathrm{bp}(G)=\omega(G)-1 versus bp(G)=ω(G)\mathrm{bp}(G)=\omega(G)

    Open for about 4 years
  8. Explicit bipartite graphs of high resistance (Jukna): construct GnG_n with ρ(Gn)≥nε\rho(G_n) \ge n^\varepsilon

    Open for about 17 years
Counting problem of self-avoiding walks6 questions
  1. Ballisticity of the self-avoiding walk on nonamenable transitive graphs: the one-ended case

    Open for about 9 years
  2. Making the lattice-point integral representation for self-avoiding walks on Zd\mathbb{Z}^d effective: rigorous main-term asymptotics and error control for cnc_n

    Open for about 1 year
  3. Universality class of the growing self-avoiding walk

    Open for about 42 years
  4. Conformal 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 years
  5. Existence and value of the closing exponent for self-avoiding walks in low dimensions

    Open for about 64 years
  6. Hammersley'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
  1. Unified Karp-Reduction Equivalence and Direct Algorithms for Inverse Mixed Integer Linear Optimization

  2. Strongly polynomial solvability of the inverse maximum-weight perfect matching problem under the l1l_1 norm

Hotspot conjecture7 questions
  1. The asymptotic convex hot spots constant: does Cd→eC_d\to\sqrt{e}? (Conjecture 1.10 of de Dios Pont, Hsu and Taylor)

    Open for about 1 year
  2. No 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 years
  3. The 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 years
  4. Unstable 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 years
  5. Necessity of connectivity for boundary Dirichlet regions in the mixed hot-spots problem

    Open for about 2 years
  6. The hot spots conjecture for simply connected planar domains (Rauch's conjecture)

    Open for about 52 years
  7. The hot spots conjecture for bounded convex planar domains

    Open for about 51 years
Computation of the polynomial of minimal differential dimension7 questions
  1. Algorithmic computation of multivariate differential dimension polynomials for nonlinear differential field extensions, and the classification of their invariants

    Open for about 6 years
  2. Effective 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 years
  3. Sharper-than-Ackermann order bounds for differential elimination and effective estimates for the minimizing coefficients of the Kolchin polynomial

    Open for about 16 years
  4. Optimality of the León Sánchez bounds for coefficients of the Kolchin differential dimension polynomial

    Open for about 9 years
  5. Effective computation of multivariate difference–differential dimension polynomials via characteristic sets with respect to several term orderings

    Open for about 14 years
  6. Bivariate Kolchin-type dimension polynomials of non-reflexive prime difference-differential ideals with several commuting translations

    Open for about 6 years
  7. Complete 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
  1. Global minimizers of Newton's problem of minimal resistance in the class of convex bodies and the infinite-height limit

    Open for about 339 years
  2. Fast rotation and constructive extremals in the Newton minimal resistance problem for rough bodies

    Open for about 17 years
  3. Singular 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 years
  4. Singular-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
  1. Computational complexity of Minimum Average Distance Triangulations with metric and Euclidean weights

    Open for about 14 years
  2. Free-boundary regularity of optimal multiphase partitions for the first Robin eigenvalue

    Open for about 8 years
  3. Asymptotic hexagonal optimality of optimal partitions for the first Dirichlet eigenvalue (the Caffarelli–Lin conjecture)

    Open for about 19 years
  4. Free-boundary regularity, general partitions, and grouping for the optimal partition problem of the principal eigenvalue of linearly coupled elliptic systems

    Open for about 7 years
  5. Acute triangulations in dimension four: existence for R4\mathbb{R}^4 and for the 16-cell, 24-cell, and 120-cell

    Open for about 17 years
  6. Optimal 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 years
  7. A polynomial-time approximation scheme for minimum weight triangulation (PTAS for MWT)

    Open for about 9 years
  8. Complexity of minimum-weight Steiner triangulation of convex polygons: NP-hard or polynomial-time?

    Open for about 32 years
ABC conjecture7 questions
  1. Status of Letendre's HH-function strengthening of the abcabc conjecture: equivalence with abcabc and truth

    Open for less than 1 year
  2. Quantitative bounds for the exceptional set in the abc conjecture

    Open for about 41 years
  3. Unconditional quantitative bounds for the four-term abcdabcd equation over Z\mathbb{Z} without size hypotheses, and the subexponential shape of the rad⁡(bc)\operatorname{rad}(bc) bound towards abcabc

    Open for about 32 years
  4. Sharp constants and second-order terms in the Robert–Stewart–Tenenbaum refinement of the abc conjecture (Conjectures A, B, C)

    Open for about 12 years
  5. Baker's explicit abc-conjecture and the unconditional resolution of its conditional Diophantine applications

    Open for about 21 years
  6. Unconditional uniform boundedness of preperiodic points for unicritical polynomials zd+cz^d+c over number fields

    Open for about 32 years
  7. Watkins'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
  1. Justification and regime of validity of the factorized-scattering criterion for (non)integrability of AdS/CFT string backgrounds

    Open for about 7 years
  2. Gap and exact finite-volume spectrum of the long-string continuum in pure-NSNS AdS3×S3×T4_3\times S^3\times T^4 strings at WZW level k≥2k\ge 2

    Open for about 5 years
  3. Completing 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 years
  4. Exactness of the Quantum Spectral Curve for planar AdS3×S3×T4AdS_3\times S^3\times T^4 strings: massless modes at finite coupling and first-principles derivation

    Open for about 5 years
  5. Completing the hexagon bootstrap for AdS3/CFT2: finite-size corrections with massless modes and the pure-NSNS long-string limit

    Open for about 5 years
  6. Rigorous foundations of the planar AdS5_5/CFT4_4 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
  1. Hodge degeneracy of simply connected Calabi–Yau manifolds in dimension greater than two

    Open for about 7 years
  2. Volume finiteness and Weil–Petersson incompleteness: the Douglas–Lu questions on projective special Kähler manifolds and Calabi–Yau moduli spaces

    Open for about 20 years
  3. Direct uniform estimates of Bott–Chern transgression forms at infinity of Calabi–Yau moduli spaces

    Open for about 17 years
  4. The AMWP curvature identity for complexified index cones of arbitrary cubic forms

    Open for about 17 years
  5. Rationality 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
  1. Hodge–Riemann relations for combinatorial intersection cohomology: arbitrary perverse sheaves on fans

    Open for about 8 years
  2. The Cheeger–Goresky–MacPherson conjecture: L2L^2-de Rham cohomology of the Fubini–Study metric and intersection cohomology of singular projective varieties

    Open for about 44 years
  3. Compatibility of the L2L^2 pure Hodge structure on intersection cohomology with Saito's pure Hodge structure (Shentu–Zhao, Conjecture 8.5)

    Open for about 5 years
  4. Complete 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 years
  5. The 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 years
  6. Cheeger–Goresky–MacPherson question: complete Kähler metrics on projective varieties whose L2L^2-cohomology computes intersection cohomology

    Open for about 44 years
  7. The Cheeger–Goresky–MacPherson conjecture for complex projective varieties with non-isolated singularities

    Open for about 44 years
  8. Compatibility of the L2L^2-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 years
  9. The Cheeger–Goresky–MacPherson conjecture for the Fubini–Study metric: does the L2L^2-cohomology of the regular part of a singular projective variety compute its intersection cohomology?

    Open for about 43 years
  10. Hodge theorem for iterated fibred cusp metrics on non-Witt stratified spaces of arbitrary depth

    Open for about 11 years
Cherlin-Zilber conjecture9 questions
  1. The positive-characteristic case of the log-CZ conjecture: linearization of absolutely simple Lie rings definable in finite-dimensional theories

  2. The uniqueness case for odd-type groups of finite Morley rank: strong embedding and quasithin classification in the tameness-free L∗L^*-theory

  3. The Cherlin–Zilber algebraicity conjecture in odd type: simple groups of finite Morley rank with normal 2-rank at most 2

  4. Algebraicity of proper Moufang sets of finite Morley rank (Borovik-Nesin Question B.17)

  5. Existence of bad groups of finite Morley rank in the generalized sense of Corredor, Borovik–Poizat, and Jaligot

  6. Removing the L-group hypothesis: bounding Alt(n)-actions and the degree of generic sharp transitivity for permutation groups of finite Morley rank

  7. Standardness of sharply 2-transitive groups of finite Morley rank (Borovik–Nesin conjecture)

  8. 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

  9. The Borovik–Burdges conjecture on strongly real elements in simple groups of finite Morley rank

A problem of Chern-Moser7 questions
  1. Convergence of Chern–Moser-type normal forms for real-analytic non-integrable almost CR structures

    Open for about 17 years
  2. CR analogue of Hamburger's theorem: at least two CR umbilical points on compact strongly convex real-analytic hypersurfaces in C2\mathbb{C}^2

    Open for about 20 years
  3. Automorphism algebras and jet determination for weighted-homogeneous polynomial models in CR geometry beyond Catlin multitype weights and holomorphic nondegeneracy

    Open for about 12 years
  4. Convergent normal forms for Levi-degenerate real hypersurfaces beyond the everywhere 2-nondegenerate case in C3\mathbb{C}^3

    Open for about 30 years
  5. A ball-like bounded strictly pseudoconvex domain in C2\mathbb C^2 without CR umbilical points (the refined Chern–Moser question)

    Open for about 10 years
  6. Global classification of obstruction-flat strictly pseudoconvex boundaries in C2\mathbb{C}^2 (the strong Ramadanov conjecture in complex dimension two)

    Open for about 8 years
  7. CR 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
  1. Characterizing embeddable deformations of compact strictly pseudoconvex CR three-manifolds

    Open for about 61 years
  2. Sharpness of the Ebenfelt–Minor two-embeddings bound: inequivalent local CR embeddings of strictly pseudoconvex hypersurfaces into spheres at critical codimension

    Open for about 14 years
  3. McLean's question: does the contact structure of the link characterize smoothness for all normal isolated singularities?

    Open for about 12 years
  4. Intrinsic characterization of local CR embeddability into spheres in degenerate curvature regimes

    Open for about 17 years
  5. The Lipman–Zariski conjecture for normal surface singularities

    Open for about 60 years
  6. Shokurov's conjecture on the maximal minimal log discrepancy of singularities

    Open for about 24 years
  7. Which 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
  1. 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 years
  2. The 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 years
  3. Construction, existence, and wall-crossing of generalized multi-monopole Seiberg–Witten invariants SWN(c1,…,cN;J)SW_N(c_1,\dots,c_N;J) at the E1E_1 point of 5d SU(2)SU(2) super Yang–Mills

    Open for less than 1 year
  4. Gluing-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 years
  5. Universality of Mochizuki's formula with Nekrasov-derived coefficients for smooth four-manifolds (Göttsche–Nakajima–Yoshioka Conjecture 4.5)

    Open for about 16 years
  6. Witten's conjecture: Donaldson invariants of four-manifolds with b1=0b_1=0 and odd b+>1b^+>1 are determined by Seiberg–Witten invariants

    Open for about 32 years
  7. Universal error formula relating Donaldson invariants and Pidstrigach-Tyurin spin invariants of smooth four-manifolds for general Dirac index

    Open for about 31 years
  8. Conjecture of Lin–Ruberman–Saveliev: equality of the Furuta–Ohta and Casson–Seiberg–Witten invariants for homology S1×S3S^1\times S^3 4-manifolds

    Open for about 17 years
The Dry Ten Martini Problem7 questions
  1. The Dry Ten Martini Problem for the critical almost Mathieu operator (remaining case: frequencies with β(α)=0\beta(\alpha)=0)

    Open for about 45 years
  2. Global transversality, complete gap labeling, and joint analyticity of the spectral dimension for Sturmian substitution Jacobi Hamiltonians

    Open for about 14 years
  3. The Dry Ten Martini Problem for the extended Harper's model: the self-dual region III and Liouvillean frequencies

    Open for about 10 years
  4. The 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 years
  5. Dry Ten Martini Problem for type-I energies of quasiperiodic Schrödinger operators with arbitrary analytic potentials

    Open for about 3 years
  6. The Dry Ten Martini Problem for C2C^2 cosine-type quasiperiodic Schrödinger operators at arbitrary irrational frequencies

    Open for about 1 year
  7. The 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
  1. Genus-1 Virasoro conjecture for Gromov–Witten invariants without semisimplicity: vanishing of the obstruction Ψ\Psi on the small phase space

    Open for about 29 years
  2. Genus-one Virasoro conjecture for Gromov-Witten invariants of arbitrary smooth projective varieties

    Open for about 29 years
  3. Virasoro conjecture for stable pairs on simply-connected 3-folds: the full descendent algebra beyond (p,p)(p,p)-cohomology and the vanishing of (p,0)(p,0)-descendants

    Open for about 6 years
  4. The λg\lambda_g conjecture with target varieties: unconditional universal Hodge-integral constraints for arbitrary smooth projective targets

    Open for about 1 year
  5. The Virasoro conjecture for Hodge integrals of arbitrary smooth projective varieties (Wang's Conjecture 1.1)

    Open for about 29 years
  6. Extending the Coates–Givental–Tseng localization formula and Virasoro reduction from toric bundles to general holomorphic torus actions

    Open for about 11 years
  7. Stationary 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 years
  8. Virasoro constraints for the Gromov–Witten theory of the Enriques surface

    Open for about 20 years
Hadwiger Conjecture7 questions
  1. Hadwiger's conjecture for graphs with independence number at most two

    Open for about 44 years
  2. The κ+\kappa^+-Hadwiger conjecture at successors of singular cardinals

    Open for about 3 years
  3. Forcing a KtK_t minor from polylogarithmically many disjoint CtCt-connected subgraphs at linear connectivity (Question 6.1 of Norin–Postle–Song)

    Open for about 6 years
  4. Six-colorability of graphs excluding the near-complete minor K7−K_7^-: the surviving level-7 instance of Seymour's H-Hadwiger conjecture

    Open for about 9 years
  5. Clique-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 years
  6. The Rolek–Song edge-density conjecture: at (t−2)n−(t−12)+1(t-2)n-\binom{t-1}{2}+1 edges every graph has a KtK_t minor or is (t−1)(t-1)-colorable

    Open for about 10 years
  7. Clustered colouring of graphs excluding a fixed minor: the Norin–Scott–Seymour–Wood conjecture χ⋆(MH)≤2 td‾(H)−2\chi_\star(\mathcal{M}_H)\le 2\,\overline{td}(H)-2

    Open for about 9 years
Kashaev-Murakami-Murakami Volume Conjecture7 questions
  1. 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 year
  2. One-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 s∼1/2s\sim 1/2)

    Open for about 8 years
  3. The Coarse Volume Conjecture: does a function of the colored Jones coefficients coarsely determine the hyperbolic volume of every hyperbolic knot?

    Open for about 15 years
  4. Rationality of the parametrized volume conjecture coefficients and the Reidemeister torsion normalization for hyperbolic knots

    Open for about 17 years
  5. The Andersen–Kashaev volume conjecture for the Teichmüller TQFT (general hyperbolic knots in closed 3-manifolds)

    Open for about 14 years
  6. Parametrization of the volume conjecture for hyperbolic knots beyond the figure-eight knot

    Open for about 16 years
  7. The Andersen–Kashaev volume conjecture for the Teichmüller TQFT: existence and volume asymptotics of the Jones function JM,KJ_{M,K} for arbitrary hyperbolic knots in closed oriented 3-manifolds

    Open for about 14 years
Koebe Problem7 questions
  1. 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 years
  2. The 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 years
  3. Koebe uniformization of infinitely connected attracting and parabolic Fatou domains of rational maps

    Open for about 2 years
  4. Does conformal removability of the boundary imply conformal rigidity? The remaining direction of the He-Schramm rigidity conjecture for circle domains

    Open for about 31 years
  5. Existence 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 years
  6. Koebe's Kreisnormierungsproblem: is every planar domain conformally equivalent to a circle domain?

    Open for about 118 years
  7. Completing 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
  1. 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 years
  2. Exact relation between R-matrix-valued linear problems with Planck constant as spectral parameter and Knizhnik–Zamolodchikov–Bernard equations

    Open for about 12 years
  3. Classical limit of the Knizhnik–Zamolodchikov–Bernard equations with surface defects and the genus-one isomonodromic tau function

    Open for about 7 years
  4. Completing 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 years
  5. Hecke transformations between topological sectors of WZW conformal blocks: intertwiners of the sector-wise elliptic KZB connections

    Open for about 14 years
  6. Modular-transformation matrices for higher-point solutions of the elliptic (q,t)(q,t)-Knizhnik–Zamolodchikov equation of the Ding–Iohara–Miki algebra

    Open for about 9 years
  7. Completing the dynamical elliptic Bethe algebra correspondence: elliptic Wronski map geometry beyond the asymptotic regime, Bethe ansatz completeness for arbitrary μ\mu, and the source-deferred extension beyond sl2\mathfrak{sl}_2

    Open for about 7 years
Lichtenbaum Conjecture8 questions
  1. Is the natural map from the modified Bloch group to indecomposable K3K_3 an isomorphism for every number field (Conjecture 3.33 of Burns–de Jeu–Gangl–Rahm–Yasaki)?

    Open for about 6 years
  2. Completing Ausoni's computation: an unconditional description of V(1)∗K(KUp)V(1)_*K(KU_p)

    Open for about 17 years
  3. The cohomological Lichtenbaum conjecture for abelian extensions of imaginary quadratic fields at the excluded primes

    Open for about 53 years
  4. Existence of Burns–de Jeu–Gangl special elements in odd-degree algebraic K-groups for general Artin characters

    Open for about 15 years
  5. Two-primary comparison of even algebraic K-groups of arithmetically equivalent number fields with real primes

    Open for less than 1 year
  6. Lichtenbaum's finiteness conjecture for integral étale motivic cohomology of arithmetic schemes

    Open for about 8 years
  7. The Generalized Quillen–Lichtenbaum Conjecture of Elmanto–Zhang: integral equivariant KK-theoretic formulas for special values of Artin LL-functions

    Open for about 2 years
  8. Finite 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
  1. 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 years
  2. The 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 years
  3. Generic coincidence of Milnor, statistical, and physical attractors beyond the continuous interval setting

    Open for about 29 years
  4. The C2C^2 Palis conjecture: eliminating zero Lyapunov exponents from the generic trichotomy for C2C^2 diffeomorphisms

    Open for about 21 years
  5. Hyperbolicity or heterodimensional cycles for general C1C^1 partially hyperbolic systems with one-dimensional center: removing the C2C^2 and nonzero-Lyapunov-exponent hypotheses

    Open for about 19 years
  6. Density of singular hyperbolicity for C1C^1 vector fields on three-dimensional manifolds

    Open for about 9 years
  7. Are all star flows multisingular hyperbolic? The full characterization of star flows beyond dimension 3

    Open for about 9 years
  8. Chain recurrence classes versus homoclinic classes away from homoclinic tangencies and heterodimensional cycles (C1C^1-generic diffeomorphisms and nonsingular flows)

    Open for about 11 years
  9. Is Axiom A dense in the C1C^1 topology among diffeomorphisms of compact surfaces? (Smale's problem, surface case)

    Open for about 59 years
Shelah's Uniqueness Conjecture10 questions
  1. Does (λ,θ)(\lambda,\theta)-weak non-forking amalgamation imply (λ,θ)(\lambda,\theta)-symmetry for independence relations in stable abstract elementary classes?

  2. Uniqueness of limit models from categoricity in abstract elementary classes without full amalgamation: deriving Assumption 1 from categoricity (the Shelah-Villaveces problem)

  3. Galois-type uniform beta-trees and the sharp spectrum of limit models in abstract elementary classes

  4. Symmetry, superlimits, and tameness from superstability-like hypotheses in abstract elementary classes with amalgamation

  5. The spectrum of limit models in the abstract elementary class (Mod⁡(T),≤pp)(\operatorname{Mod}(T),\leq_{\mathrm{pp}}) of modules with pure embeddings

  6. The spectrum of limit models in stable abstract elementary classes (Boney–VanDieren's Conjecture 1.1)

  7. Superstability versus uniqueness of limit models in abstract elementary classes with amalgamation: eliminating the no-Vaughtian-pairs hypothesis

  8. 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

  9. Uniqueness of limit models in categorical abstract elementary classes with no maximal models: removing the tower hypotheses of the Shelah-Villaveces program

  10. 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
  1. Explicit constants and convergence rates for resistances and time-scaling on generalized Sierpiński carpets

    Open for about 2 years
  2. Uniqueness of the canonical pp-energy on Sierpiński carpets and the conformal-dimension continuity threshold for generalized Sierpiński carpets

    Open for about 4 years
  3. Osada's jump conjecture: the continuity threshold for Hausdorff-measure time changes of exotic diffusions on Sierpinski carpets

    Open for about 20 years
  4. Geometric characterization of existence of standard self-similar Dirichlet forms on polygon carpets

    Open for about 4 years
  5. Diffusions with sub-Gaussian heat kernel estimates on the Sierpiński carpet for general self-similar cell weights

    Open for less than 1 year
  6. Exact value of the resistance scaling factor of the Sierpiński carpet (equivalently, its walk dimension)

    Open for about 36 years
  7. Existence of self-similar Dirichlet forms with sub-Gaussian heat kernel estimates on unconstrained Sierpiński carpets in Rd\mathbb{R}^d for d≥4d\geq 4

    Open for about 3 years
Boundedness of Sierpiński hyperbolic components9 questions
  1. Boundedness of type C (capture) hyperbolic components of bicritical rational maps

    Open for about 7 years
  2. Compactness of Sierpiński carpet hyperbolic components of rational maps (McMullen's Question 5.3)

    Open for about 38 years
  3. McMullen's conjecture: boundedness of Sierpiński carpet hyperbolic components of rational maps

    Open for about 31 years
  4. Generalized Sierpiński gasket Julia sets on the boundary of the Cantor locus for asymmetric McMullen maps fλ(z)=zm+λ/znf_\lambda(z)=z^m+\lambda/z^n with m≠nm\neq n

    Open for about 1 year
  5. The obstructed boundary at infinity of hyperbolic components of disjoint type (Dudko–Luo Conjecture 1.9)

    Open for less than 1 year
  6. Boundedness of capture (type C) hyperbolic components in the moduli space of bicritical rational maps

    Open for about 7 years
  7. Bounded 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 years
  8. Boundedness of Sierpiński carpet hyperbolic components in the moduli space of rational maps (McMullen's Question 5.3)

    Open for about 31 years
  9. Boundary at infinity of hyperbolic components of disjoint type: is ∂∞H=∂∞QH‾\partial_\infty\mathcal{H}=\overline{\partial^{\mathbb{Q}}_\infty\mathcal{H}}?

    Open for less than 1 year
Open Problems on Smashing Subcategories8 questions
  1. Silting-theoretic parametrisation of smashing subcategories of compactly generated triangulated categories beyond the dg setting

    Open for about 7 years
  2. Classifying the frame of smashing ideals of D(R) for commutative rings beyond valuation domains

    Open for about 34 years
  3. Spatiality of the frame of smashing tensor ideals of a rigidly-compactly generated tensor-triangulated category

    Open for about 9 years
  4. Open 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 year
  5. Auslander–Reiten principle for localizing subcategories of infinite-dimensional support (Ono–Yoshino, Question 2.5)

    Open for about 9 years
  6. The telescope conjecture for the derived category D(RC) of representations of a small category over a commutative noetherian ring

    Open for about 11 years
  7. The strongly dualizable generalized smashing conjecture in the BP-local category of spectra

    Open for about 13 years
  8. Bazzoni–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
  1. Canonical subgroups of p-divisible groups with OF\mathcal{O}_F-action: existence beyond the current residue-characteristic and Hasse-invariant bounds, and partial degrees without Hypothesis 0.1

    Open for about 11 years
  2. Canonicity 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 years
  3. Explicit classification of Hopf orders in group algebras over local fields of characteristic pp beyond the primitively generated case

    Open for about 10 years
  4. Full level structures on finite flat group schemes beyond rank-pp squares: the cases GnG^n with n≥3n\geq 3, stack-level naturality, and higher height

    Open for about 6 years
  5. Open questions for moderately ramified Z/pZ\mathbb{Z}/p\mathbb{Z}-actions in positive characteristic

    Open for about 7 years
  6. The structure of Ext⁡OK1(Z/pZ,μp)\operatorname{Ext}^1_{\mathcal{O}_K}(\mathbf{Z}/p\mathbf{Z},\mu_p) and KK-rational pp-torsion on elliptic curves with good reduction everywhere when the class-number and low-ramification hypotheses fail

    Open for about 17 years
  7. Splitting over the base and classification of actions for finite flat group schemes of square free order

    Open for about 9 years
  8. Tensor 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
  1. Kahn's question on reducing the Tate conjecture for divisors from characteristic zero to positive characteristic: must an ℓ\ell-adic class on a surface over Q\mathbf{Q} whose specializations are algebraic be algebraic?

    Open for about 4 years
  2. Does the Tate conjecture imply semisimplicity of Galois representations in positive characteristic?

    Open for about 8 years
  3. Torsion in Tate-twisted étale cohomology over Fˉp\bar{\mathbb{F}}_p: is Hn(X,μℓr⊗n)H^n(X,\mu_{\ell^r}^{\otimes n}) equal to N1HnN^1H^n? (Bloch–Esnault's question)

    Open for about 30 years
  4. Tate 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 years
  5. Vanishing of the Galois-invariant birational cohomology of projective space over finite fields

    Open for about 60 years
  6. Unconditional and integral Brauer–Tate–Shafarevich comparison over global function fields: finiteness of coker⁡ρd\operatorname{coker}\rho_d, pp-primary control, and Kato homology vanishing beyond degree 3

    Open for about 8 years
  7. The Tate conjecture for divisors on surfaces over a finite field in Kahn's affine-open reformulation

    Open for about 61 years
  8. The Tate conjecture for divisors over finite fields, reduced to the case of surfaces with H1(X,OX)=0H^1(X,\mathcal{O}_X)=0

    Open for about 61 years
  9. The Tate conjecture for divisors on irreducible holomorphic symplectic varieties over finite fields without restrictions on the characteristic

    Open for about 14 years
  10. Crystalline Variational Tate Conjecture beyond divisors: higher-codimension cycles and non-projective smooth proper families

    Open for about 12 years
Veech Conjecture8 questions
  1. Veech's conjecture on Möbius averages for bounded sequences with zero-entropy shift orbit closure

    Open for about 16 years
  2. Fine 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 years
  3. Strong Möbius and Liouville MOMO property for the unipotent automorphism of the two-torus

    Open for about 5 years
  4. Eigenvalue multiplicity and continuity dichotomy for minimal non-weak-mixing directions on non-arithmetic Veech surfaces (Avila–Delecroix conjecture)

    Open for about 13 years
  5. Non-parabolic directions of vanishing SAF invariant on Veech surfaces of cubic and higher trace field (the Arnoux-Schmidt presumption)

    Open for about 17 years
  6. Finiteness of quotient saddle-connection graphs as a characterization of Veech surfaces (Pan's Question 1)

    Open for about 7 years
  7. Veech'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 years
  8. Veech's question: density of pure point induced transformations of an irrational rotation

    Open for about 54 years
Virtual Haken Conjecture5 questions
  1. Which compact 3-manifold groups are RFRS: the strict (non-virtual) clause remaining from Agol's 2008 RFRS question

    Open for about 19 years
  2. Acylindrical arc choices and connected covering spaces in Charitos's new proof of the virtual Haken theorem

    Open for less than 1 year
  3. Effective bounds for hierarchies and the Malnormal Special Quotient Theorem for relatively hyperbolic virtually special groups

    Open for about 7 years
  4. Is Hakenness a profinite property of 3-manifolds?

    Open for less than 1 year
  5. Absolute profinite rigidity of finite-volume hyperbolic 3-manifold groups (Bridson–Reid conjecture, manifold case)

    Open for about 11 years

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