For every real numbers a⩾1, b⩾1 with $(a,b) \neq
(1,1),thecurveparametrizedby\theta \in RvaluedinC^2 \cong R^4$ γ:θ⟼(x(θ)+−1y(θ),u(θ)+−1v(θ)) with components: x(θ):=a(ab−1)a−1cosθ,y(θ):=ab−1b(a−1)sinθ,u(θ):=b(ab−1)b−1sinθ,v(θ):=−ab−1a(b−1)cosθ, has
image contained in the CR-umbilical locus: γ(R)⊂UmbCR(Ea,b)⊂Ea,b of the
ellipsoid Ea,b⊂C2 of equation
ax2+y2+bu2+y2=1.