(mathematics) A type of measure of central tendency calculated as the reciprocal of the mean of the reciprocals, ie, H=n/1/x_1+1/x_2+⋯+1/x_n

(mathematics) A function of two, three or n variables which is a solution to any of Laplace's equations

(mathematics) The solutions to Laplace's equation using spherical coordinates

(mathematical analysis) A study of the representation of functions or signals as the superposition of basic waves, involving the notions of harmonic functions, trigonometric series, Fourier series, Fourier transforms, almost periodic functions, and others.

(classical mechanics) A system which, when displaced from its equilibrium position, experiences a restoring force F proportional to the displacement x according to Hooke's law: F=-kx,, where k is a positive constant.

(geology) A rhythmic shaking of the ground detectable by a seismograph, and associated with volcanic activity. Often a symptomatic warning of an eruption.

(number theory) Any of a series of numbers formed from the sum of the reciprocals of consecutive natural numbers

(linguistics, Optimality Theory) A situation where one input-to-output mapping pair receives a set of constraint violations that is a proper subset of the set of constraint violations received by a different input-output pair.

(transitive, linguistics, Optimality Theory) Of an input-output pair, to incur a proper subset of constraint violations of a different input-output pair.

plural of harmonic oscillator