(quantum mechanics) A no-go theorem that places certain constraints on the permissible types of hidden-variable theories that try to explain the apparent randomness of quantum mechanics as a deterministic model featuring hidden states. It demonstrates the impossibility of quantum-mechanical observables representing "elements of physical reality".

Synonym of Kochen-Specker theorem

An interpretation of electrodynamics derived from the assumption that the solutions of the electromagnetic field equations must be invariant under time-reversal transformation, as are the field equations themselves.

One who studies chaos theory.

(topology) A theorem which (in one of its simplest forms) states that a continuous function from an n-dimensional unit cube (in ℝⁿ) to itself has a fixed point.

(mathematics) A theorem stating that, if S, is an IP set and S=C_1∪C_2∪...∪C_n, then at least one C_i, contains an IP set.

(graph theory) A theorem stating that, among the n-vertex simple graphs with no (r + 1)-cliques, T(n, r) has the maximum number of edges.

(number theory) The theorem that the Diophantine equation aⁿ+bⁿ=cⁿ has no solutions for positive integers a,b,c,n, where n>2.

(number theory) The theorem that, for any prime number p and integer a, aᵖ-a is an integer multiple of p.

(topology) A theorem which states that for any open covering of some given set in Euclidean n-space there is an open subcovering (of that same set) which is countable.