Abstract
We present a variational study of finding null relaxed elastic lines which are extremals of a
geometric energy functional, subject to suitable constraints and boundary conditions on a timelike
surface in Minkowski 3-space. We derive an Euler-Lagrange equation for a null relaxed elastic
line with regard to geodesic curvature, geodesic torsion and normal curvature of the curve on the
timelike surface. Finally, we give some examples for null relaxed elastic lines on the pseudo-sphere
and pseudo-cylinder.