P versus NP Problem
v1.5 literature triageDoes $P = NP$? More formally: if the solution to a problem can be quickly verified (in polynomial time), can the solution also be quickly found (in po...
The Riemann Hypothesis
v1.5 literature triageDo all non-trivial zeros of the Riemann zeta function $\zeta(s)$ have real part equal to $\frac{1}{2}$?...
Yang–Mills Existence and Mass Gap
v1.5 literature triageProve that Yang–Mills theory exists and has a mass gap on $\mathbb{R}^4$, meaning the quantum particles have positive masses....
Navier–Stokes Existence and Smoothness
v1.5 literature triageProve or give a counterexample: Do solutions to the Navier–Stokes equations in three dimensions always exist and remain smooth for all time?...
Birch and Swinnerton-Dyer Conjecture
v1.5 literature triageThe conjecture relates the rank of the abelian group of rational points of an elliptic curve to the order of zero of the associated L-function at $s=1...
Hodge Conjecture
v1.5 literature triageOn a projective non-singular algebraic variety over $\mathbb{C}$, any Hodge class is a rational linear combination of classes of algebraic cycles....
Odd Perfect Numbers
v1.5 literature triageDoes there exist an odd perfect number? A perfect number is a positive integer that is equal to the sum of its proper divisors (excluding itself). For...
Collatz Conjecture
v1.5 literature triageStarting 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 ...
Twin Prime Conjecture
v1.5 literature triageAre 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)....
Goldbach's Conjecture
v1.5 literature triageEvery even integer greater than 2 can be expressed as the sum of two primes....
ABC Conjecture
v1.5 literature triageFor any $\epsilon > 0$, there exist only finitely many triples $(a, b, c)$ of coprime positive integers with $a + b = c$ such that $c > \text{rad}(abc...
The Hadwiger-Nelson Problem
v1.5 literature triageWhat is the minimum number of colors needed to color the points of the plane such that no two points at distance 1 have the same color?...
Hadwiger Conjecture
v1.5 literature triageEvery graph with chromatic number $k$ has a $K_k$ minor (where $K_k$ is the complete graph on $k$ vertices)....
Reconstruction Conjecture
v1.5 literature triageEvery finite simple graph on at least 3 vertices is uniquely determined by its vertex-deleted subgraphs....
Smooth 4-Dimensional Poincaré Conjecture
v1.5 literature triageIs every smooth homotopy 4-sphere diffeomorphic to the standard 4-sphere $S^4$?...
Sphere Packing in Higher Dimensions
v1.5 literature triageWhat is the densest packing of congruent spheres in $n$ dimensions for $n \geq 4$?...
Inverse Galois Problem
v1.5 literature triageIs every finite group the Galois group of some Galois extension of the rational numbers $\mathbb{Q}$?...
Kaplansky's Conjectures
v1.5 literature triageA 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...
Continuum Hypothesis
v1.5 literature triageThere is no set whose cardinality is strictly between that of the integers and the real numbers....
Legendre's Conjecture
v1.5 literature triageFor every positive integer $n$, there exists a prime number between $n^2$ and $(n+1)^2$....
Are there infinitely many Mersenne primes?
v1.5 literature triageAre there infinitely many prime numbers of the form $M_p = 2^p - 1$ where $p$ is prime?...
Are there infinitely many perfect powers in the Fibonacci sequence?
v1.5 literature triageBesides 1, 8, and 144, are there any other perfect powers (numbers of the form $a^b$ where $a, b > 1$) in the Fibonacci sequence?...
Gilbreath's Conjecture
v1.5 literature triageStarting with the sequence of primes and repeatedly taking absolute differences of consecutive terms, the first term of each row is always 1....
Ramsey Number R(5,5)
v1.5 literature triageWhat is the exact value of $R(5,5)$, the smallest number $n$ such that any 2-coloring of the edges of $K_n$ contains a monochromatic $K_5$?...
The Lonely Runner Conjecture
v1.5 literature triageFor any $n$ runners on a circular track with distinct constant speeds, each runner is "lonely" (distance at least $1/n$ from all others) at some time....
The Graceful Tree Conjecture
v1.5 literature triageEvery tree can be gracefully labeled: vertices can be assigned distinct labels from $\{0, 1, \ldots, |E|\}$ such that edge labels (absolute difference...
The Kakeya Conjecture
v1.5 literature triageA Kakeya set (containing a unit line segment in every direction) in $\mathbb{R}^n$ must have Hausdorff dimension $n$....
The Moving Sofa Problem
v1.5 literature triageWhat is the largest area of a shape that can be maneuvered through an L-shaped corridor of unit width?...
The Volume Conjecture
v1.5 literature triageFor a hyperbolic knot $K$, the limit of normalized colored Jones polynomials equals the hyperbolic volume of the knot complement....
The Standard Conjectures on Algebraic Cycles
v1.5 literature triageA collection of conjectures about algebraic cycles on smooth projective varieties, including Lefschetz standard conjecture and Künneth standard conjec...
The Abundance Conjecture
v1.5 literature triageFor a minimal model $X$ of non-negative Kodaira dimension, the canonical divisor $K_X$ is semi-ample....
The Köthe Conjecture
v1.5 literature triageA ring has no non-zero nil ideal (an ideal all of whose elements are nilpotent) if and only if it has no non-zero nil one-sided ideal....
The Regularity Problem for Euler Equations
v1.5 literature triageDo solutions to the 3D Euler equations for incompressible fluid flow remain smooth for all time, given smooth initial data?...
Singular Cardinals Hypothesis
v1.5 literature triageIf $\kappa$ is a singular strong limit cardinal, then $2^\kappa = \kappa^+$....
Whitehead Problem
v1.5 literature triageIs every abelian group $A$ such that $\text{Ext}^1(A, \mathbb{Z}) = 0$ a free abelian group?...
The Unique Games Conjecture
v1.5 literature triageFor certain constraint satisfaction problems (unique games), it is NP-hard to approximate the maximum fraction of satisfiable constraints beyond a cer...
The Polynomial Hirsch Conjecture
v1.5 literature triageThe diameter of the graph of a $d$-dimensional polytope with $n$ facets is bounded by a polynomial in $d$ and $n$....
Hilbert's 12th Problem: Extension of Kronecker-Weber Theorem
v1.5 literature triageExtend the Kronecker-Weber theorem on abelian extensions of the rationals to any base number field....
Hilbert's 16th Problem: Topology of Algebraic Curves and Limit Cycles
v1.5 literature triageDetermine the maximum number and relative positions of limit cycles for polynomial vector fields of degree $n$, and investigate the topology of real a...
Landau's Fourth Problem: Primes of the Form n² + 1
v1.5 literature triageAre there infinitely many primes of the form $n^2 + 1$?...
Smale's 4th Problem: Integer Zeros of Polynomials
v1.5 literature triageFind efficient algorithms for deciding whether a polynomial with integer coefficients has an integer root....
Smale's 5th Problem: Height Bounds for Diophantine Curves
v1.5 literature triageFind effective uniform bounds for the heights of rational points on algebraic curves....
Smale's 6th Problem: Finiteness of Central Configurations
v1.5 literature triageFor the Newtonian $n$-body problem with positive masses, are there only finitely many central configurations (relative equilibria) for each $n$?...
Smale's 7th Problem: Distribution of Points on the 2-Sphere
v1.5 literature triageWhat is the optimal arrangement of $n$ points on the 2-sphere to minimize energy for various potential functions?...
Smale's 9th Problem: Linear Programming in Polynomial Time
v1.5 literature triageFind a strongly polynomial algorithm for linear programming....
Smale's 10th Problem: The Pugh Closing Lemma
v1.5 literature triageIs the $C^r$ closing lemma true for dynamical systems?...
The Jacobian Conjecture
v1.5 literature triageIf $F: \mathbb{C}^n \to \mathbb{C}^n$ is a polynomial map with constant non-zero Jacobian determinant, then $F$ is invertible....
Frankl's Union-Closed Sets Conjecture
v1.5 literature triageFor every finite union-closed family of sets (other than the empty family), there exists an element that belongs to at least half of the sets....
Inscribed Square Problem (Toeplitz Conjecture)
v1.5 literature triageDoes every simple closed curve in the plane contain all four vertices of some square?...
Brocard's Problem
v1.5 literature triageFind all integer solutions to $n! + 1 = m^2$....