Wu () is a Chinese term translating to "shaman" or "sorcerer", originally the practitioners of Chinese shamanism or "Wuism" (巫教 wū jiào). The glyph ancestral to modern is first recorded in bronze script, where it could refer to shamans or sorcerers of either sex. Modern Mandarin wu (Cantonese mouh) continues a Middle Chinese mju or mjo. The Old Chinese reconstruction is uncertain, given as *mywo or as *myag, the presence of a final velar -g or -ɣ in Old Chinese being uncertain.
In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak disturbance to the system. If the disturbance is not too large, the various physical quantities associated with the perturbed system (e.g.
In mathematics, a conjecture is a conclusion or a proposition that is proffered on a tentative basis without proof. Some conjectures, such as the Riemann hypothesis (still a conjecture) or Fermat's Last Theorem (a conjecture until proven in 1995 by Andrew Wiles), have shaped much of mathematical history as new areas of mathematics are developed in order to prove them. Formal mathematics is based on provable truth.