Cauchy-Riemann Equations

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Cauchy-Riemann equations

[kō·shē ′rē‚män i′kwā·zhənz]
A pair of partial differential equations that is satisfied by the real and imaginary parts of a complex function ƒ(z) if and only if the function is analytic: ∂ u /∂ x = ∂ v /∂ y and ∂ u /∂ y = - ∂ v /∂ x, where ƒ(z) = u + iv and z = x + iy.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Cauchy-Riemann Equations


in the theory of analytic functions, partial differential equations of the first order connecting the real and imaginary parts of an analytic function w = u + iv of the complex variable z = x + iy:

∂u/∂x = ∂v/∂y ∂u/∂y = −∂v/∂x

These equations are of fundamental importance in the theory of analytic functions and in its applications to mechanics and physics. They were first examined by J. d'Alembert and L. Euler long before the works of A. Cauchy and B. Riemann.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
In [Q.sub.1] = {z [member of] C : 0 < Re z, 0 < Im z}, the following result for the Dirichlet boundary value problem is given for the inhomogeneous Cauchy-Riemann equation in [23].
They have considered the boundary value problems for inhomo-geneous Cauchy-Riemann equation and Poisson equation in concentric ring domains.
Along the process one discovers many interesting facts: for instance, that the choice of the Cauchy-Riemann equation is not at all a matter of taste, but it is driven by the chirality context.
Then one looks for other type of decompositions, where the Cauchy-Riemann equations nevertheless express the vanishing of some particular term.
To find this ratio, Seidl and Klose [15] converted the Cauchy-Riemann equations into a set of two Laplace equations and proposed an iterative procedure with a finite difference solution.
Leonhard Euler's identity, the Pythagorean identity and the Cauchy-Riemann equations were the formula most consistently rated as beautiful.
The formulae most consistently rated as beautiful (both before and during the scans) were Leonhard Euler's identity, the Pythagorean identity and the Cauchy-Riemann equations. Leonhard Euler's identity links five fundamental mathematical constants with three basic arithmetic operations each occurring once and the beauty of this equation has been likened to that of the soliloquy in Hamlet.
This is well defined using the Cauchy-Riemann equations for the coordinate interchanges.
In other words, the Cauchy-Riemann equations need not to be satisfied, so the functions need not to be analytic (Duren, 2004).
He starts with Cauchy-Riemann equations in the introduction, then proceeds to power series, results on holomorphic functions, logarithms, winding numbers, Couchy's theorem, counting zeros and the open mapping theorem, Eulers formula for sin(z), inverses of holomorphic maps, conformal mappings, normal families and the Riemann mapping theorem, harmonic functions, simply connected open sets, Runge's theorem and the Mittag-Leffler theorem, the Weierstrass factorization theorem, Caratheodory's theorem, analytic continuation, orientation, the modular function, and the promised Picard theorems.
the generalized Cauchy-Riemann equations contain 2-spinor and C-gauge structures, and their integrability conditions take the form of Maxwell and Yang-Mills equations.
For instance, the Cauchy-Riemann equations, which specify the regularity conditions for a complex-valued function to be analytic (expressible as a power series), generalize to the Lanczos equations in Minkowski spacetime, and then generalize further to the Nijenhuis tensor equations for holomorphic functions in n-dimensional space.