harmonic
61Harmonic function — In mathematics, mathematical physics and the theory of stochastic processes, a harmonic function is a twice continuously differentiable function f : U rarr; R (where U is an open subset of R n ) which satisfies Laplace s equation,… …
62Harmonic series (mathematics) — In mathematics, the harmonic series is the divergent infinite series: Its name derives from the concept of overtones, or harmonics in music: the wavelengths of the overtones of a vibrating string are 1/2, 1/3, 1/4, etc., of the string s… …
63Harmonic divisor number — This article is about harmonic divisor numbers. For meanings of harmonic number, see harmonic number (disambiguation). In mathematics, a harmonic divisor number, or Ore number (named after Øystein Ore who defined it in 1948), is a positive… …
64Harmonic mean — In mathematics, the harmonic mean (formerly sometimes called the subcontrary mean) is one of several kinds of average. Typically, it is appropriate for situations when the average of rates is desired.The harmonic mean H of the positive real… …
65Harmonic map — A (smooth) map φ: M → N between Riemannian manifolds M and N is called harmonic if it is a critical point of the energy functional E (φ).This functional E will be defined precisely below mdash;one way of understanding it is to imagine that M is… …
66Harmonic number — The term harmonic number has multiple meanings. For other meanings, see harmonic number (disambiguation) .In mathematics, the n th harmonic number is the sum of the reciprocals of the first n natural numbers::H n=… …
67Harmonic conjugate — For geometric conjugate points, see Projective harmonic conjugates. In mathematics, a function defined on some open domain is said to have as a conjugate a function if and only if they are respectively real and imaginary part of a holomorphic… …
68Harmonic generation — Perturbative Harmonic Generation Perturbative Harmonic Generation is a process where by laser lightof frequency ω and photon energy ħω can be usedto generate new frequencies of light. The newly generatedfrequencies are integer multiples of the… …
69Harmonic measure — In mathematics, harmonic measure is a concept that arises in the theory of harmonic functions, where it can be used to estimate the modulus of an analytic function inside a domain D given bounds on the modulus on the boundary of the domain. In a… …
70Harmonic drive — A harmonic drive is an input/output gearing mechanism. It is typically used for gearing reduction, but may also be used to increase rotational speed or for differential gearing. Very high gear reduction ratios are possible in a small volume… …
