Intrinsic Equations for a Relaxed Elastic Line of Second Kind in Minkowski 3-Space

Abstract

Let alpha be an arc on a connected oriented surface S in Minkowski 3-space, parameterized by arc length s, with torsion tau and length l. The total square torsion H of alpha is defined by H = integral(1)(0)tau(2)ds. The arc alpha is called a relaxed elastic line of second kind if it is an extremal for the variational problem of minimizing the value of H within the family of all arcs of length l on S having the same initial point and initial direction as alpha. In this study, we obtain the differential equation and boundary conditions for a relaxed elastic line of second kind on an oriented surface in Minkowski 3-space. This formulation should give a more direct and more geometric approach to questions concerning relaxed elastic lines of second kind on a surface.