On holomorphic invariants of logarithmic spirals (Q1293600)

The authors compute certain holomorphic invariants defined by \textit{A. V. Loboda} [Mat. Zametki 59, No. 2, 211-223 (1996; Zbl 0884.32015)] for tubular hypersurfaces in \(\mathbb{C}^2\), using the Moser normal form, for the case of the logarithmic spiral, given in polar coordinates by \(r=e^{a\varphi}\). To avoid difficulties that arise in making computations directly, the authors use the fact that the angle between the radius vector of a point of such a curve and the tangent at this point is constant.