Lehmer's conjecture

Lehmer's conjecture, proposed by the mathematician Edward Lehmer in 1933, pertains to the field of number theory, specifically regarding the nature of certain algebraic integers known as Salem numbers. A Salem number is a real algebraic integer greater than 1, whose conjugates (other roots of its minimal polynomial) lie within or on the unit circle in the complex plane, with at least one conjugate on the unit circle itself.