We consider a 3-dimensional Riemannian manifold with an additional circulant structure, whose third power is the identity. This structure is compatible with the metric such that an isometry is induced in any tangent space of the manifold. Further, we consider an associated metric with the Riemannian metric, which is necessary indefinite. We find equations of a sphere and of a circle, which are given in terms of the associated metric, with respect to the Riemannian metric.
@article{7233, title = {Spheres and circles with respect to an indefinite metric on a Riemannian manifold with a circulant structure}, journal = {Novi Sad Journal of Mathematics}, volume = {48}, year = {2018}, language = {EN}, url = {http://dml.mathdoc.fr/item/7233} }
Dzhelepov, Georgi Dimitrov. Spheres and circles with respect to an indefinite metric on a Riemannian manifold with a circulant structure. Novi Sad Journal of Mathematics, Tome 48 (2018) . http://gdmltest.u-ga.fr/item/7233/