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Richmond Surface
In differential geometry, a Richmond surface is a minimal surface first described by Herbert William Richmond in 1904. It is a family of surfaces with one planar end and one Enneper surface-like self-intersecting end. It has Weierstrass–Enneper parameterization f(z)=1/z^2, g(z)=z^m. This allows a parametrization based on a complex parameter as :\begin X(z) &= \Re -1/2z) - z^/(4m+2)\ Y(z) &= \Re -i/2z) + i z^/(4m+2)\ Z(z) &= \Re ^m / m\end The associate family In differential geometry, the associate family (or Bonnet family) of a minimal surface is a one-parameter family of minimal surfaces which share the same Weierstrass data. That is, if the surface has the representation :x_k(\zeta) = \Re \left\ + ... of the surface is just the surface rotated around the z-axis. Taking ''m'' = 2 a real parametric expression becomes:John Oprea, The Mathematics of Soap Films: Explorations With Maple, American Mathematical Soc., 2000 :\begin X(u,v) &= (1/3)u^3 - uv^2 + \fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richmond Surface
In differential geometry, a Richmond surface is a minimal surface first described by Herbert William Richmond in 1904. It is a family of surfaces with one planar end and one Enneper surface-like self-intersecting end. It has Weierstrass–Enneper parameterization f(z)=1/z^2, g(z)=z^m. This allows a parametrization based on a complex parameter as :\begin X(z) &= \Re -1/2z) - z^/(4m+2)\ Y(z) &= \Re -i/2z) + i z^/(4m+2)\ Z(z) &= \Re ^m / m\end The associate family In differential geometry, the associate family (or Bonnet family) of a minimal surface is a one-parameter family of minimal surfaces which share the same Weierstrass data. That is, if the surface has the representation :x_k(\zeta) = \Re \left\ + ... of the surface is just the surface rotated around the z-axis. Taking ''m'' = 2 a real parametric expression becomes:John Oprea, The Mathematics of Soap Films: Explorations With Maple, American Mathematical Soc., 2000 :\begin X(u,v) &= (1/3)u^3 - uv^2 + \fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Geometry
Differential geometry is a mathematical discipline that studies the geometry of smooth shapes and smooth spaces, otherwise known as smooth manifolds. It uses the techniques of differential calculus, integral calculus, linear algebra and multilinear algebra. The field has its origins in the study of spherical geometry as far back as antiquity. It also relates to astronomy, the geodesy of the Earth, and later the study of hyperbolic geometry by Lobachevsky. The simplest examples of smooth spaces are the plane and space curves and surfaces in the three-dimensional Euclidean space, and the study of these shapes formed the basis for development of modern differential geometry during the 18th and 19th centuries. Since the late 19th century, differential geometry has grown into a field concerned more generally with geometric structures on differentiable manifolds. A geometric structure is one which defines some notion of size, distance, shape, volume, or other rigidifying structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimal Surface
In mathematics, a minimal surface is a surface that locally minimizes its area. This is equivalent to having zero mean curvature (see definitions below). The term "minimal surface" is used because these surfaces originally arose as surfaces that minimized total surface area subject to some constraint. Physical models of area-minimizing minimal surfaces can be made by dipping a wire frame into a soap solution, forming a soap film, which is a minimal surface whose boundary is the wire frame. However, the term is used for more general surfaces that may self-intersect or do not have constraints. For a given constraint there may also exist several minimal surfaces with different areas (for example, see minimal surface of revolution): the standard definitions only relate to a local optimum, not a global optimum. Definitions Minimal surfaces can be defined in several equivalent ways in R3. The fact that they are equivalent serves to demonstrate how minimal surface theory lies at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbert William Richmond
Herbert William Richmond (born on the 17 July 1863 in Tottenham, England) was a mathematician who studied the Cremona–Richmond configuration. One of his most popular works is an exact construction of the regular heptadecagon in 1893 (which was calculated before by Carl Friedrich Gauss). Herbert was elected as a Fellow of the Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ... in 1911. On the 22 April 1948, Herbert died in Cambridge, England. The Richmond surface is named after him. References * * {{DEFAULTSORT:Richmond, Herbert William English mathematicians 1863 births 1948 deaths People from Tottenham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jesse Douglas
Jesse Douglas (3 July 1897 – 7 September 1965) was an American mathematician and Fields Medalist known for his general solution to Plateau's problem. Life and career He was born to a Jewish family in New York City, the son of Sarah (née Kommel) and Louis Douglas. He attended City College of New York as an undergraduate, graduating with honors in Mathematics in 1916. He then moved to Columbia University as a graduate student, obtaining a PhD in mathematics in 1920. Douglas was one of two winners of the first Fields Medals, awarded in 1936. He was honored for solving, in 1930, the problem of Plateau, which asks whether a minimal surface exists for a given boundary. The problem, open since 1760 when Lagrange raised it, is part of the calculus of variations and is also known as the ''soap bubble problem''. Douglas also made significant contributions to the inverse problem of the calculus of variations. The American Mathematical Society awarded him the Bôcher Memorial Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
End (topology)
In topology, a branch of mathematics, the ends of a topological space are, roughly speaking, the connected components of the "ideal boundary" of the space. That is, each end represents a topologically distinct way to move to infinity within the space. Adding a point at each end yields a compactification of the original space, known as the end compactification. The notion of an end of a topological space was introduced by . Definition Let ''X'' be a topological space, and suppose that :K_1 \subseteq K_2 \subseteq K_3 \subseteq \cdots is an ascending sequence of compact subsets of ''X'' whose interiors cover ''X''. Then ''X'' has one end for every sequence :U_1 \supseteq U_2 \supseteq U_3 \supseteq \cdots, where each ''U''''n'' is a connected component of ''X'' \ ''K''''n''. The number of ends does not depend on the specific sequence of compact sets; there is a natural bijection between the sets of ends associated with any two such sequences. Using this definiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enneper Surface
In differential geometry and algebraic geometry, the Enneper surface is a self-intersecting surface that can be described parametrically by: \begin x &= \tfrac u \left(1 - \tfracu^2 + v^2\right), \\ y &= \tfrac v \left(1 - \tfracv^2 + u^2\right), \\ z & = \tfrac \left(u^2 - v^2\right). \end It was introduced by Alfred Enneper in 1864 in connection with minimal surface theory.Ulrich Dierkes, Stefan Hildebrandt, Friedrich Sauvigny (2010). Minimal Surfaces. Berlin Heidelberg: Springer. . The Weierstrass–Enneper parameterization is very simple, f(z)=1, g(z)=z, and the real parametric form can easily be calculated from it. The surface is conjugate to itself. Implicitization methods of algebraic geometry can be used to find out that the points in the Enneper surface given above satisfy the degree-9 polynomial equation \begin & 64 z^9 - 128 z^7 + 64 z^5 - 702 x^2 y^2 z^3 - 18 x^2 y^2 z + 144 (y^2 z^6 - x^2 z^6)\\ & + 162 (y^4 z^2 - x^4 z^2) + 27 (y^6 - x^6) + 9 (x^4 z + y^4 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weierstrass–Enneper Parameterization
In mathematics, the Weierstrass–Enneper parameterization of minimal surfaces is a classical piece of differential geometry. Alfred Enneper and Karl Weierstrass studied minimal surfaces as far back as 1863. Let f and g be functions on either the entire complex plane or the unit disk, where g is meromorphic and f is analytic, such that wherever g has a pole of order m, f has a zero of order 2m (or equivalently, such that the product f g^2 is holomorphic), and let c_1,c_2,c_3 be constants. Then the surface with coordinates (x_1, x_2, x_3) is minimal, where the x_k are defined using the real part of a complex integral, as follows: \begin x_k(\zeta) &= \Re \left\ + c_k , \qquad k=1,2,3 \\ \varphi_1 &= f(1-g^2)/2 \\ \varphi_2 &= \mathbf f(1+g^2)/2 \\ \varphi_3 &= fg \end The converse is also true: every nonplanar minimal surface defined over a simply connected domain can be given a parametrization of this type. For example, Enneper's surface has , . Parametric surface of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Associate Family
In differential geometry, the associate family (or Bonnet family) of a minimal surface is a one-parameter family of minimal surfaces which share the same Weierstrass data. That is, if the surface has the representation :x_k(\zeta) = \Re \left\ + c_k , \qquad k=1,2,3 the family is described by :x_k(\zeta,\theta) = \Re \left\ + c_k , \qquad \theta \in ,2\pi where \Re indicates the real part of a complex number. For ''θ'' = ''π''/2 the surface is called the conjugate of the ''θ'' = 0 surface. The transformation can be viewed as locally rotating the principal curvature directions. The surface normals of a point with a fixed ''ζ'' remains unchanged as ''θ'' changes; the point itself moves along an ellipse. Some examples of associate surface families are: the catenoid and helicoid family, the Schwarz P, Schwarz D and gyroid family, and the Scherk's first and second surface family. The Enneper surface In differential geometry and algebraic geometry, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
