• 제목/요약/키워드: $\varphi$-holomorphic sectional curvature

검색결과 2건 처리시간 0.015초

C12-SPACE FORMS

  • Gherici Beldjilali;Nour Oubbiche
    • 대한수학회논문집
    • /
    • 제38권2호
    • /
    • pp.629-641
    • /
    • 2023
  • The aim of this paper is two-fold. First, we study the Chinea-Gonzalez class C12 of almost contact metric manifolds and we discuss some fundamental properties. We show there is a one-to-one correspondence between C12 and Kählerian structures. Secondly, we give some basic results for Riemannian curvature tensor of C12-manifolds and then establish equivalent relations among 𝜑-sectional curvature. Concrete examples are given.

GEOMETRY OF CONTACT STRONGLY PSEUDO-CONVEX CR-MANIFOLDS

  • Cho, Jong-Taek
    • 대한수학회지
    • /
    • 제43권5호
    • /
    • pp.1019-1045
    • /
    • 2006
  • As a natural generalization of a Sasakian space form, we define a contact strongly pseudo-convex CR-space form (of constant pseudo-holomorphic sectional curvature) by using the Tanaka-Webster connection, which is a canonical affine connection on a contact strongly pseudo-convex CR-manifold. In particular, we classify a contact strongly pseudo-convex CR-space form $(M,\;\eta,\;\varphi)$ with the pseudo-parallel structure operator $h(=1/2L\xi\varphi)$, and then we obtain the nice form of their curvature tensors in proving Schurtype theorem, where $L\xi$ denote the Lie derivative in the characteristic direction $\xi$.