Unsolved Problems

Showing 501-548 of 548 problems (Page 11 of 11)

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-001
Open

Brennan Conjecture

For conformal maps f into the unit disk, when is $\int |f'(z)|^p dA < \infty$ for $p > 0$?...

L4
Analysis
134
10
ANA-002
Open

Fuglede's Conjecture

Is a measurable set spectral if and only if it tiles $\mathbb{R}^d$ by translation?...

L4
Analysis
198
15
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
ANA-004
Open

Lehmer's Conjecture

Is there a constant c > 1 such that all non-cyclotomic polynomials have Mahler measure ≥ c?...

L4
Analysis
187
14
ANA-005
Open

Mean Value Problem

For any polynomial f of degree d≥2 and complex z, does there exist a critical point c with $|f(z)-f(c)| \leq |f'(z)||z-c|$?...

L4
Analysis
156
12
ANA-006
Open

Pompeiu Problem

Characterize domains where nonzero functions have vanishing integrals over every congruent copy....

L4
Analysis
143
11
ANA-007
Open

Sendov's Conjecture

If all roots of a polynomial lie in the unit disk, is each root within distance 1 from some critical point?...

L4
Analysis
176
14
ANA-008
Open

Bloch's Constant

What is the exact value of Bloch's constant (the largest radius for which every holomorphic function contains a univalent disk)?...

L4
Analysis
165
13
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-002
Open

Berge Conjecture

Are Berge knots the only knots in S³ admitting lens space surgeries?...

L4
Topology
167
13
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-006
Open

Unknotting Problem

Can unknots be recognized in polynomial time?...

L4
Topology
256
20
TOP-007
Open

Volume Conjecture

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

L5
Topology
201
16
TOP-008
Open

Whitehead Conjecture

Is every connected subcomplex of a 2-dimensional aspherical CW complex also aspherical?...

L4
Topology
143
11
TOP-009
Open

Zeeman Conjecture

Is $K \times [0,1]$ collapsible for every finite contractible 2-dimensional CW complex K?...

L4
Topology
134
10
COMB-001
Open

1/3-2/3 Conjecture

Does every non-total finite poset have two elements x,y with P(x before y in random linear extension) ∈ [1/3, 2/3]?...

L3
Combinatorics
124
9
COMB-002
Open

Lonely Runner Conjecture

If k runners with distinct speeds run on a unit circle, will each runner be "lonely" (≥1/k away from others) at some time?...

L4
Combinatorics
156
12
COMB-003
Open

Sunflower Conjecture

Can the minimum size for sunflowers be bounded by an exponential (not super-exponential) function of k?...

L4
Combinatorics
178
14
COMB-004
Open

Union-Closed Sets Conjecture

For any finite union-closed family of sets, does some element appear in at least half the sets?...

L4
Combinatorics
189
15
COMB-005
Open

Ramsey Number R(5,5)

What is the exact value of the Ramsey number R(5,5)?...

L4
Combinatorics
267
21
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-001
Open

Singmaster's Conjecture

Is there a finite upper bound on multiplicities of entries >1 in Pascal's triangle?...

L4
Number Theory
178
14
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-004
Open

Quasiperfect Numbers

Do quasiperfect numbers exist?...

L4
Number Theory
167
13
NUM-005
Open

Lychrel Numbers

Do Lychrel numbers exist in base 10?...

L3
Number Theory
234
18
NUM-006
Open

Odd Weird Numbers

Do odd weird numbers exist?...

L4
Number Theory
189
15
NUM-007
Open

Infinitude of Amicable Pairs

Are there infinitely many pairs of amicable numbers?...

L4
Number Theory
212
17
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-010
Open

Gilbreath's Conjecture

Does iterating unsigned differences on prime sequence always yield 1 as first element?...

L4
Number Theory
156
12
NUM-011
Open

Lander-Parkin-Selfridge Conjecture

If Σᵢ aᵢᵏ = Σⱼ bⱼᵏ with m terms on left, n on right, is m+n ≥ k?...

L4
Number Theory
178
14
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