Browsing by Author "YE, YUN-GANG"

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    EXTREMAL RAYS AND NULL GEODESICS ON A COMPLEX CONFORMAL MANIFOLD
    (International Journal of Mathematics, 1994-02) YE, YUN-GANG
    A holomorphic conformal structure on a complex manifold X is an everywhere non-degenerate section [Formula: see text] for some line bundle N. In this paper, we show that if X is a projective complex n-dimensional manifold with non-numerically effective Kx and admits a holomorphic conformal structure, then X ≅ ℚn. This in particular answers affirmatively a question of Kobayashi and Ochiai. They asked if the same holds assuming c1 (X) > 0. As a consequence, we also show that any projective conformal manifold with an immersed rational null geodesic is necessarily a smooth hyperquadric ℚn.
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    ON FANO MANIFOLDS WITH NORMAL PROJECTIVE CONNECTIONS
    (International Journal of Mathematics, 1994-04) YE, YUN-GANG
    In this paper, we show that a Fano manifold with a normal projective connection is necessarily a projective space. This answers a question raised by Kobayashi and Ochiai.