• Title/Summary/Keyword: Curvature.

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SELF-DUAL EINSTEIN MANIFOLDS OF POSITIVE SECTIONAL CURVATURE

  • Ko, Kwanseok
    • Korean Journal of Mathematics
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    • v.13 no.1
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    • pp.51-59
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    • 2005
  • Let (M, $g$) be a compact oriented self-dual 4-dimensional Einstein manifold with positive sectional curvature. Then we show that, up to rescaling and isometry, (M, $g$) is $S^4$ or $\mathbb{C}\mathbb{P}_2$, with their cannonical metrics.

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ON A GENERALIZATION OF FENCHEL`S THEOREM

  • Chai, Y.D.;Kim, Moon-Jeong
    • Communications of the Korean Mathematical Society
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    • v.15 no.1
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    • pp.103-109
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    • 2000
  • In this paper, we present the proof of generalized Fenchel's theorem by estimating the Gauss-Kronecker curvature of the tube of a nondegenerate closed curve in R$^{n}$ .

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MANIFOLDS WITH NONNEGATIVE RICCI CURVATURE ALMOST EVERYWHERE

  • Paeng, Seong-Hun
    • Journal of the Korean Mathematical Society
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    • v.36 no.1
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    • pp.125-137
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    • 1999
  • Under the condition of RicM $\geq$ -(n-1), injM $\geq$ I0, we prove the existence of an $\varepsilon$>0 such that on the region of volume $\varepsilon$>0 the curvature condition of splitting theorem can be weakened.

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A NOTE ON CONTACT CONFORMAL CURVATURE TENSOR

  • Pak, Jin-Suk;Shin, Yang-Jae
    • Communications of the Korean Mathematical Society
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    • v.13 no.2
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    • pp.337-343
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    • 1998
  • In this paper we show that every contact metric manifold with vanishing contact conformal curvature tensor is a Sasakian space form.

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