Unsolved Problems

Showing 1-50 of 242 problems (Page 1 of 5)

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NT-002
Open

Collatz Conjecture

Starting with any positive integer $n$, repeatedly apply the function: if $n$ is even, divide by 2; if $n$ is odd, multiply by 3 and add 1. Does this ...

L4
Number Theory
892
67
NT-003
Open

Twin Prime Conjecture

Are there infinitely many twin primes? Twin primes are pairs of primes that differ by 2, such as (3, 5), (5, 7), (11, 13), (17, 19), (29, 31)....

L4
Number Theory
1234
89
NT-004
Open

Goldbach's Conjecture

Every even integer greater than 2 can be expressed as the sum of two primes....

L4
Number Theory
1567
112
GT-001
Open

Hadwiger Conjecture

Every graph with chromatic number $k$ has a $K_k$ minor (where $K_k$ is the complete graph on $k$ vertices)....

L4
Graph Theory
654
38
COMB-002
Solved

Erdős-Faber-Lovász Conjecture

If a graph is the union of $n$ cliques of size $n$, no two of which share more than one vertex, then the chromatic number is $n$....

L4
Combinatorics
345
19
GEO-001
Solved

Kepler Conjecture

No packing of congruent spheres in three dimensions has density greater than $\frac{\pi}{\sqrt{18}} \approx 0.74048$....

L4
Geometry
567
31
GEO-002
Open

Sphere Packing in Higher Dimensions

What is the densest packing of congruent spheres in $n$ dimensions for $n \geq 4$?...

L4
Geometry
456
27
ALG-001
Open

Inverse Galois Problem

Is every finite group the Galois group of some Galois extension of the rational numbers $\mathbb{Q}$?...

L4
Algebra
543
29
ALG-002
Open

Kaplansky's Conjectures

A set of conjectures about group rings: (1) Zero divisor conjecture: If $G$ is a torsion-free group and $K$ is a field, then $K[G]$ has no zero diviso...

L4
Algebra
321
18
ANA-001
Open

Invariant Subspace Problem

Does every bounded linear operator on a separable Hilbert space over the complex numbers have a non-trivial invariant subspace?...

L4
Analysis
432
23
ANA-002
Open

Schanuel's Conjecture

Given $n$ complex numbers $z_1, \ldots, z_n$ that are linearly independent over the rationals, the transcendence degree of $\mathbb{Q}(z_1, \ldots, z_...

L4
Analysis
345
19
NT-007
Open

Are there infinitely many Mersenne primes?

Are there infinitely many prime numbers of the form $M_p = 2^p - 1$ where $p$ is prime?...

L4
Number Theory
654
38
GEO-003
Open

The Kakeya Conjecture

A Kakeya set (containing a unit line segment in every direction) in $\mathbb{R}^n$ must have Hausdorff dimension $n$....

L4
Geometry
432
24
TOP-002
Open

The Volume Conjecture

For a hyperbolic knot $K$, the limit of normalized colored Jones polynomials equals the hyperbolic volume of the knot complement....

L4
Topology
298
17
TOP-003
Solved

The Triangulation Conjecture

Every topological manifold can be triangulated....

L4
Topology
345
19
AG-002
Open

The Abundance Conjecture

For a minimal model $X$ of non-negative Kodaira dimension, the canonical divisor $K_X$ is semi-ample....

L4
Algebraic Geometry
298
16
PDE-001
Open

The Regularity Problem for Euler Equations

Do solutions to the 3D Euler equations for incompressible fluid flow remain smooth for all time, given smooth initial data?...

L4
Partial Differential Equations
456
26
SET-002
Open

Singular Cardinals Hypothesis

If $\kappa$ is a singular strong limit cardinal, then $2^\kappa = \kappa^+$....

L4
Set Theory
287
15
SET-003
Open

Whitehead Problem

Is every abelian group $A$ such that $\text{Ext}^1(A, \mathbb{Z}) = 0$ a free abelian group?...

L4
Set Theory
198
11
CS-001
Open

The Unique Games Conjecture

For certain constraint satisfaction problems (unique games), it is NP-hard to approximate the maximum fraction of satisfiable constraints beyond a cer...

L4
Computer Science
543
32
LAN-004
Open

Landau's Fourth Problem: Primes of the Form n² + 1

Are there infinitely many primes of the form $n^2 + 1$?...

L4
Number Theory
398
22
SMA-004
Open

Smale's 4th Problem: Integer Zeros of Polynomials

Find efficient algorithms for deciding whether a polynomial with integer coefficients has an integer root....

L4
Computer Science
287
16
SMA-005
Open

Smale's 5th Problem: Height Bounds for Diophantine Curves

Find effective uniform bounds for the heights of rational points on algebraic curves....

L4
Algebraic Geometry
234
13
SMA-006
Open

Smale's 6th Problem: Finiteness of Central Configurations

For the Newtonian $n$-body problem with positive masses, are there only finitely many central configurations (relative equilibria) for each $n$?...

L4
Geometry
198
11
SMA-009
Open

Smale's 9th Problem: Linear Programming in Polynomial Time

Find a strongly polynomial algorithm for linear programming....

L4
Computer Science
312
18
SMA-010
Open

Smale's 10th Problem: The Pugh Closing Lemma

Is the $C^r$ closing lemma true for dynamical systems?...

L4
Geometry
176
9
SMA-016
Open

The Jacobian Conjecture

If $F: \mathbb{C}^n \to \mathbb{C}^n$ is a polynomial map with constant non-zero Jacobian determinant, then $F$ is invertible....

L4
Algebra
298
17
GEO-005
Open

Inscribed Square Problem (Toeplitz Conjecture)

Does every simple closed curve in the plane contain all four vertices of some square?...

L4
Geometry
432
24
NT-011
Solved

Catalan's Conjecture (Mihăilescu's Theorem)

The only solution to $x^p - y^q = 1$ in natural numbers x, y > 0 and p, q > 1 is $3^2 - 2^3 = 1$....

L4
Number Theory
287
16
GT-004
Open

The Cycle Double Cover Conjecture

Every bridgeless graph has a cycle double cover: a collection of cycles that covers each edge exactly twice....

L4
Graph Theory
298
17
HIL-013
Open

Hilbert's 13th Problem: Seventh Degree Equations

Prove that the general equation of the seventh degree cannot be solved using functions of only two variables....

L4
Algebra
287
16
SMA-011
Open

Smale's 11th Problem: One-Dimensional Dynamics

Is one-dimensional dynamics generally hyperbolic?...

L4
Analysis
198
11
SMA-012
Open

Smale's 12th Problem: Centralizers of Diffeomorphisms

Determine the structure of centralizers of generic diffeomorphisms....

L4
Geometry
176
9
DARPA-002
Open

The Dynamics of Networks

Develop high-dimensional mathematics to model and predict behavior in large-scale distributed networks....

L4
Graph Theory
389
21
DARPA-003
Open

Capture and Harness Stochasticity in Nature

Develop methods that capture persistence in stochastic environments, addressing Mumford's call for new mathematics....

L4
Analysis
298
17
DARPA-004
Open

21st Century Fluids

Extend classical fluid dynamics to handle complex substances like foams, suspensions, gels, and liquid crystals....

L4
Partial Differential Equations
345
19
DARPA-008
Open

Beyond Convex Optimization

Determine whether algebraic geometry can systematically replace linear algebra in optimization....

L4
Computer Science
312
18
DARPA-013
Open

Game Theory at Scale

Create scalable mathematics for differential games, replacing traditional PDE approaches....

L4
Computer Science
289
16
DARPA-014
Open

Information Theory for Virus Evolution

Apply Shannon's information theory to biological evolution....

L4
Analysis
234
13
DARPA-020
Open

Computation at Scale

Develop asymptotics for systems with massive degrees of freedom....

L4
Computer Science
276
15
DARPA-006
Open

Computational Duality

Use mathematical duality and geometry as foundations for developing novel computational algorithms....

L4
Computer Science
198
11
DARPA-007
Open

Occam's Razor in Many Dimensions

Find lower bounds for sensing complexity as data collection grows, addressing entropy maximization....

L4
Computer Science
234
13
DARPA-009
Open

Physical Consequences of Perelman's Proof

Apply Perelman's proof of the Poincaré conjecture to materials fabrication across scales....

L4
Topology
267
15
DARPA-010
Open

Algorithmic Origami and Biology

Strengthen mathematical theory for isometric and rigid embedding relevant to protein folding....

L4
Geometry
298
17
DARPA-011
Open

Optimal Nanostructures

Develop mathematics for creating optimal symmetric structures through nanoscale self-assembly....

L4
Geometry
223
12
DARPA-015
Open

The Geometry of Genome Space

Establish appropriate distance metrics on genome space incorporating biological utility....

L4
Geometry
245
14
HIL-007
Open

Hilbert's 7th Problem: Transcendence of Certain Numbers

If $\alpha$ is algebraic and irrational, and $\beta$ is algebraic and irrational, is $\alpha^\beta$ transcendental?...

L4
Number Theory
321
18
HIL-011
Open

Hilbert's 11th Problem: Quadratic Forms over Algebraic Number Fields

Extend the theory of quadratic forms with algebraic numerical coefficients....

L4
Number Theory
198
11
HIL-014
Open

Hilbert's 14th Problem: Finite Generation of Rings

Is the ring of invariants of a linear algebraic group acting on a polynomial ring always finitely generated?...

L4
Algebra
176
9
HIL-015
Open

Hilbert's 15th Problem: Schubert's Enumerative Calculus

Rigorously justify Schubert's enumerative geometry....

L4
Algebraic Geometry
267
15
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