Commutator (electric) — This article is about the electrical component. For mathematical concept, see Commutator . A tiny 5 segment commutator less than 2 mm in diameter, on a direct current motor in a toy radio control ZipZaps car. A commutator is a rotary electri … Wikipedia
Fitting length — In mathematics, especially in the area of algebra known as group theory, the Fitting length (or nilpotent length) measures how far a solvable group is from being nilpotent. The concept is named after Hans Fitting, due to his investigations of… … Wikipedia
Danny Calegari — Danny Matthew Cornelius Calegari (* 24. Mai 1972 in Australien) ist ein australisch amerikanischer Mathematiker. Calegari studierte an der University of Melbourne (Bachelor Abschluss 1994), war dann dort Forschungsassistent, 1996/97 am MSRI und… … Deutsch Wikipedia
electric motor — motor (def. 4). [1885 90] * * * Introduction any of a class of devices that convert electrical energy to mechanical energy, usually by employing electromagnetic phenomena. Most electric motors develop their mechanical torque by the… … Universalium
Electric motor — For other kinds of motors, see motor (disambiguation). For a railroad electric engine, see electric locomotive. Various electric motors. A 9 volt PP3 transistor battery is in the center foreground for size comparison. An electric motor converts… … Wikipedia
electric generator — ▪ instrument Introduction also called dynamo, any machine that converts mechanical energy to electricity for transmission and distribution over power lines to domestic, commercial, and industrial customers. Generators also produce the… … Universalium
Lie algebra — In mathematics, a Lie algebra is an algebraic structure whose main use is in studying geometric objects such as Lie groups and differentiable manifolds. Lie algebras were introduced to study the concept of infinitesimal transformations. The term… … Wikipedia
Central series — In mathematics, especially in the fields of group theory and Lie theory, a central series is a kind of normal series of subgroups or Lie subalgebras, expressing the idea that the commutator is nearly trivial. For groups, this is an explicit… … Wikipedia
Matrix mechanics — Quantum mechanics Uncertainty principle … Wikipedia
Trace (linear algebra) — In linear algebra, the trace of an n by n square matrix A is defined to be the sum of the elements on the main diagonal (the diagonal from the upper left to the lower right) of A, i.e., where aii represents the entry on the ith row and ith column … Wikipedia