A representation formula for curves in C3 with preset infinitesimal arc length

Abstract

We consider an algebraic representation formula for meromorphic curves in C 3 with preset infinitesimal arc length, i. e., a differential operator M assigning to triples (f, h, d) of meromorphic functions meromorphic curves Φ = (ϕ1, ϕ2, ϕ3) such that d is the infinitesimal arclength of Φ, in this way obtaining the complete solution of the differential equation ϕ Computer algebra systems are an excellent tool to handle formulas of this type. We give simple Mathematica code and apply it to work out some examples, graphics as well as algebraic expressions of complex curves with special properties. For the case d = 0 of null curves, we give some graphical examples of minimal surfaces constructed in this way, showing deformations and symmetries. We give an expression for the curvature κ of Φ in terms of the Schwarzian derivative of f and for the case d = 1 a simple differential relation for f and h equivalent to the condition κ = 1

Null-curves in R^{2,n} as flat dynamical systems

“…1 This problem was considered in [8], where with the help of quite cumbersome differential-geometric constructions it was shown that system (7) is 3-flat. Our construction, being elementary, allows us to lower the order of the flat control by one.…”

“…By changing the signature of the quadratic form in Eq. (8), it is possible to obtain a parametrization of the null-curves in pseudo-Euclidean spaces R p,q with min(p, q) > 2. The possible velocity vectors of these curves will cover, however, only some open region in the light cone.…”