Unsolved Problems

Showing 101-146 of 146 problems (Page 3 of 3)

ST-007
Open

Woodin's Ω-Conjecture

If there is a proper class of Woodin cardinals, does Ω-logic satisfy an analogue of Gödel's completeness theorem?...

L5
Set Theory
145
11
ST-008
Open

Strongly Compact vs Supercompact Cardinals

Does the consistency of a strongly compact cardinal imply the consistent existence of a supercompact cardinal?...

L5
Set Theory
167
13
ST-011
Open

Reinhardt Cardinals without Choice

Without assuming the axiom of choice, can a nontrivial elementary embedding V→V exist?...

L5
Set Theory
189
15
GEOM-017
Open

Hopf Conjectures

What are the relationships between curvature and Euler characteristic for higher-dimensional Riemannian manifolds?...

L5
Geometry
234
18
GEOM-018
Open

Yau's Conjecture on First Eigenvalue

Is the first eigenvalue of the Laplace-Beltrami operator on an embedded minimal hypersurface of $S^{n+1}$ equal to $n$?...

L5
Geometry
178
14
GRAPH-017
Open

GNRS Conjecture

Do minor-closed graph families have $\ell_1$ embeddings with bounded distortion?...

L5
Graph Theory
145
11
GRAPH-026
Open

Moore Graph Existence

Does a Moore graph with girth 5 and degree 57 exist?...

L5
Graph Theory
223
18
GRAPH-031
Open

Erdős-Hajnal Conjecture

Does every graph family defined by a forbidden induced subgraph have polynomial-sized cliques or independent sets?...

L5
Graph Theory
234
19
GRAPH-056
Open

Tutte's 5-Flow Conjecture

Does every bridgeless graph have a nowhere-zero 5-flow?...

L5
Graph Theory
267
21
GRAPH-057
Open

Tutte's 4-Flow Conjecture for Petersen-Minor-Free Graphs

Does every Petersen-minor-free bridgeless graph have a nowhere-zero 4-flow?...

L5
Graph Theory
198
16
ALG-001
Open

Birch-Tate Conjecture

Relate the order of the center of the Steinberg group of the ring of integers to the Dedekind zeta function....

L5
Algebra
187
14
ALG-003
Open

Connes Embedding Problem

Can every finite von Neumann algebra be embedded into an ultrapower of the hyperfinite II₁ factor?...

L5
Algebra
289
22
ALG-007
Open

Farrell-Jones Conjecture

Are the assembly maps in algebraic K-theory and L-theory isomorphisms?...

L5
Algebra
165
13
MOD-001
Open

Cherlin-Zilber Conjecture

Is every simple group with a stable first-order theory an algebraic group over an algebraically closed field?...

L5
Algebra
176
14
MOD-003
Open

Hilbert's Tenth Problem for Number Fields

For which number fields is there an algorithm to determine if a Diophantine equation has solutions?...

L5
Algebra
234
18
MOD-004
Open

Vaught Conjecture

Does every complete first-order theory in a countable language have countably many, $\aleph_0$, or $2^{\aleph_0}$ countable models?...

L5
Algebra
198
16
MOD-005
Open

Tarski's Exponential Function Problem

Is the theory of the real numbers with addition, multiplication, and exponentiation decidable?...

L5
Algebra
256
20
MOD-006
Open

Stable Field Conjecture

Is every infinite field with a stable first-order theory separably closed?...

L5
Algebra
167
13
MOD-008
Open

O-Minimal Theory with Trans-Exponential Growth

Does there exist an o-minimal first-order theory with a trans-exponential (rapid growth) function?...

L5
Algebra
145
11
MOD-010
Open

Keisler's Order

Determine the structure of Keisler's order on first-order theories....

L5
Algebra
156
12
ALG-013
Open

Serre's Conjecture II

For simply connected semisimple algebraic groups over fields of cohomological dimension ≤2, is $H^1(F,G) = 0$?...

L5
Algebra
178
14
ALG-014
Open

Serre's Positivity Conjecture

If R is a regular local ring and P,Q are prime ideals with $\dim(R/P) + \dim(R/Q) = \dim(R)$, is $\chi(R/P, R/Q) > 0$?...

L5
Algebra
145
11
ALG-015
Open

Uniform Boundedness Conjecture for Rational Points

Is there a bound N(g,d) such that all curves of genus g≥2 over degree d number fields have at most N(g,d) rational points?...

L5
Algebra
213
17
ANA-003
Open

Invariant Subspace Problem

Does every bounded operator on an infinite-dimensional complex Banach space have a nontrivial closed invariant subspace?...

L5
Analysis
289
22
TOP-001
Open

Baum-Connes Conjecture

Is the assembly map in K-theory an isomorphism for all locally compact groups?...

L5
Topology
198
15
TOP-003
Open

Borel Conjecture

Are aspherical closed manifolds determined up to homeomorphism by their fundamental groups?...

L5
Topology
189
15
TOP-004
Open

Hilbert-Smith Conjecture

If a locally compact group acts faithfully and continuously on a manifold, must it be a Lie group?...

L5
Topology
212
17
TOP-005
Open

Novikov Conjecture

Are certain polynomials in Pontryagin classes homotopy invariants?...

L5
Topology
234
18
TOP-007
Open

Volume Conjecture

Do quantum invariants of knots determine their hyperbolic volume?...

L5
Topology
201
16
DYN-001
Open

Mandelbrot Set Local Connectivity

Is the Mandelbrot set locally connected?...

L5
Analysis
298
23
DYN-002
Open

Weinstein Conjecture

Does every regular compact contact-type level set of a Hamiltonian carry a periodic orbit?...

L5
Analysis
187
15
NUM-002
Open

Odd Perfect Numbers

Do any odd perfect numbers exist?...

L5
Number Theory
412
32
NUM-003
Open

Infinitude of Perfect Numbers

Are there infinitely many perfect numbers?...

L5
Number Theory
345
27
NUM-008
Open

Pi Normality

Is π a normal number (all digits equally frequent in all bases)?...

L5
Number Theory
389
30
NUM-009
Open

Algebraic Number Normality

Are all irrational algebraic numbers normal?...

L5
Number Theory
201
16
NUM-012
Open

Class Number Problem

Are there infinitely many real quadratic fields with class number 1 (unique factorization)?...

L5
Number Theory
198
16
NUM-013
Open

Hilbert's 12th Problem

Extend Kronecker-Weber theorem to abelian extensions of arbitrary number fields....

L5
Number Theory
187
15
NUM-014
Open

Leopoldt's Conjecture

Does the p-adic regulator of an algebraic number field never vanish?...

L5
Number Theory
156
12
NUM-015
Open

Siegel Zeros

Do Siegel zeros (real zeros of Dirichlet L-functions near s=1) exist?...

L5
Number Theory
234
18
NUM-016
Open

Schanuel's Conjecture

For e and π: are they algebraically independent? Is e+π, eπ, π^e, etc. transcendental?...

L5
Number Theory
287
22
NUM-017
Open

Euler-Mascheroni Constant Irrationality

Is the Euler-Mascheroni constant γ irrational? Transcendental?...

L5
Number Theory
323
25
NUM-018
Open

Littlewood Conjecture

For any α,β ∈ ℝ, is lim inf_{n→∞} n·||nα||·||nβ|| = 0?...

L5
Number Theory
189
15
NUM-019
Open

Four Exponentials Conjecture

If x₁,x₂ and y₁,y₂ are linearly independent over ℚ, is at least one of e^(xᵢyⱼ) transcendental?...

L5
Number Theory
167
13
NUM-020
Open

Integer Factorization Polynomial Time

Can integer factorization be done in polynomial time?...

L5
Number Theory
456
35
PDE-001
Open

Navier-Stokes Existence and Smoothness

Do smooth solutions to Navier-Stokes equations exist globally in 3D? Or do finite-time singularities occur?...

L5
Partial Differential Equations
512
39
GEOM-001
Open

Sphere Packing Problem Higher Dimensions

What is the optimal sphere packing density in dimensions >3?...

L5
Geometry
298
23