Problems

A question, for example a value to find or a classification to make.

Ideas 151–256 of 256.

Name	Kind	Subject
P versus NP problem	Problem	Computer science
Danzer set	Problem	Convex and discrete geometry
Group isomorphism problem	Problem	Group theory and generalizations
Busemann–Petty problem	Problem	Convex and discrete geometry
Congruent number problem	Problem	Number theory
Inhomogeneous Cauchy–Riemann equations	Problem	Several complex variables and analytic spaces
Inverse heat conduction problem	Problem	Classical thermodynamics, heat transfer
Minkowski problem	Problem	Convex and discrete geometry
Bernstein's problem	Problem	Differential geometry
Hilbert's fifth problem	Problem	Topological groups, Lie groups
Lambert's problem	Problem	Mechanics of particles and systems
Abraham–Minkowski controversy	Problem	Optics, electromagnetic theory
Hilbert's program	Problem	Mathematical logic and foundations
Word problem for groups	Problem	Group theory and generalizations
Two-body problem in general relativity	Problem	Relativity and gravitational theory
Molodensky's problem	Problem	Geophysics
Kepler problem in general relativity	Problem	Relativity and gravitational theory
Happy ending problem	Problem	Convex and discrete geometry
Gelfand–Bratu problem	Problem	Partial differential equations
dbar-Neumann problem	Problem	Several complex variables and analytic spaces
Kuratowski's closure-complement problem	Problem	General topology
Signorini problem	Problem	Mechanics of deformable solids
Problem of time	Problem	Relativity and gravitational theory
Boussinesq problem	Problem	Mechanics of deformable solids
Steiner tree problem	Problem	Operations research, mathematical programming
Hilbert's nineteenth problem	Problem	Partial differential equations
Gravity inversion	Problem	Geophysics
Poincaré problem	Problem	Several complex variables and analytic spaces
Calderón problem	Problem	Partial differential equations
Tarski's high school algebra problem	Problem	General algebraic systems
Dedekind's problem	Problem	Order, lattices, ordered algebraic structures
Newsvendor model	Problem	Operations research, mathematical programming
Riemann–Hilbert problem	Problem	Functions of a complex variable
Hilbert's eighteenth problem	Problem	Convex and discrete geometry
Multiple comparisons problem	Problem	Statistics
Sommerfeld's half-plane diffraction problem	Problem	Optics, electromagnetic theory
Milloux problem	Problem	Potential theory
Congruence subgroup problem	Problem	K-theory
Secretary problem	Problem	Probability theory and stochastic processes
Hilbert's sixth problem and the hydrodynamic limit	Problem	Statistical mechanics, structure of matter
Steklov eigenvalue problem	Problem	Partial differential equations
Lebesgue's universal covering problem	Problem	Convex and discrete geometry
Filtering problem	Problem	Probability theory and stochastic processes
Maximum cut	Problem	Operations research, mathematical programming
Loschmidt's paradox	Problem	Statistical mechanics, structure of matter
Learning with errors	Problem	Information and communication theory, circuits
Hamburger moment problem	Problem	Integral transforms, operational calculus
Newton's minimal resistance problem	Problem	Calculus of variations and optimal control; optimization
Bell's spaceship paradox	Problem	Relativity and gravitational theory
Flow-shop scheduling	Problem	Operations research, mathematical programming
No-three-in-line problem	Problem	Convex and discrete geometry
Measure problem of Lebesgue	Problem	Measure and integration
Complex structure on the six-sphere	Problem	Several complex variables and analytic spaces
Sitnikov problem	Problem	Mechanics of particles and systems
Orchard-planting problem	Problem	Convex and discrete geometry
Smale's fourteenth problem	Problem	Dynamical systems and ergodic theory
Ericksen's problem of universal deformations	Problem	Mechanics of deformable solids
Yang–Mills existence and mass gap	Problem	Quantum theory
Unknotting problem	Problem	Manifolds and cell complexes
Graetz problem	Problem	Classical thermodynamics, heat transfer
Finite lattice representation problem	Problem	Order, lattices, ordered algebraic structures
Shortest path problem	Problem	Operations research, mathematical programming
Lüroth problem	Problem	Algebraic geometry
Congruence lattice problem	Problem	Order, lattices, ordered algebraic structures
Hilbert's thirteenth problem	Problem	Real functions
Hilbert's fifteenth problem	Problem	Algebraic geometry
True quantified Boolean formula	Problem	Computer science
Shape optimization	Problem	Calculus of variations and optimal control; optimization
Euler's thirty-six officers problem	Problem	Combinatorics
Logic optimization	Problem	Information and communication theory, circuits
Kakeya needle problem	Problem	Measure and integration
Matrix multiplication exponent	Problem	Computer science
Vehicle routing problem	Problem	Operations research, mathematical programming
Stable marriage problem	Problem	Game theory, economics, finance, and other social and behavioral sciences
Eshelby's inclusion problem	Problem	Mechanics of deformable solids
Hearing the shape of a drum	Problem	Global analysis, analysis on manifolds
Hilbert's fourth problem	Problem	Geometry
Sub-Riemannian geodesic problem	Problem	Differential geometry
Chapman–Ferraro problem	Problem	Geophysics
Travelling salesman problem	Problem	Operations research, mathematical programming
Equilibrium problem with an external field	Problem	Potential theory
Heilbronn triangle problem	Problem	Convex and discrete geometry
Burnside problem	Problem	Group theory and generalizations
Set cover problem	Problem	Operations research, mathematical programming
Expenditure minimization problem	Problem	Game theory, economics, finance, and other social and behavioral sciences
Circular restricted three-body problem	Problem	Mechanics of particles and systems
Stieltjes moment problem	Problem	Integral transforms, operational calculus
Hilbert's twenty-third problem	Problem	Calculus of variations and optimal control; optimization
Olbers' paradox	Problem	Astronomy and astrophysics
Trigonometric moment problem	Problem	Harmonic analysis on Euclidean spaces
Inverse Galois problem	Problem	Field theory and polynomials
Discrete Dirichlet problem	Problem	Potential theory
Integer factorization	Problem	Number theory
Free boundary problem	Problem	Partial differential equations
Time-optimal control	Problem	Calculus of variations and optimal control; optimization
Hadwiger–Nelson problem	Problem	Combinatorics
Connes embedding problem	Problem	Functional analysis
Change detection	Problem	Statistics
Absolute stability problem of Lur'e	Problem	Systems theory; control
Normal Moore space problem	Problem	General topology
Riemann problem for gas dynamics	Problem	Fluid mechanics
Kervaire invariant problem	Problem	Algebraic topology
Ramsey problem of optimal taxation	Problem	Game theory, economics, finance, and other social and behavioral sciences
Cauchy's functional equation	Problem	Difference and functional equations
Multi-commodity flow problem	Problem	Operations research, mathematical programming
Brachistochrone problem	Problem	Calculus of variations and optimal control; optimization