Abstract:
We determine the complete conjugate locus along all geodesics parallel or perpendicular
to the center (Theorem 2.3). When the center is one-dimensional we obtain formulas in all cases
(Theorem 2.5), and when a certain operator is also diagonalizable these formulas become completely
explicit (Corollary 2.7). These yield some new information about the smoothness of the pseudoriemannian
conjugate locus. We also obtain the multiplicities of all conjugate points.
