• 제목/요약/키워드: Scalar curvature

검색결과 189건 처리시간 0.021초

ON THE CONFORMAL DEFORMATION OVER WARPED PRODUCT MANIFOLDS

  • YOON-TAE JUNG;CHEOL GUEN SHIN
    • 한국수학교육학회지시리즈B:순수및응용수학
    • /
    • 제4권1호
    • /
    • pp.27-33
    • /
    • 1997
  • Let (M = B$\times$f F, g) be an ($n \geq3$ )-dimensional differential manifold with Riemannian metric g. We solve the following elliptic nonlinear partial differential equation (equation omitted). where $\Delta_{g}$ is the Laplacian in the $\Delta$g-metric and ($h(\chi)$) is the scalar curvature of g and ($H(\chi)$) is a function on M.

  • PDF

ON QUASI RICCI SYMMETRIC MANIFOLDS

  • Kim, Jaeman
    • Korean Journal of Mathematics
    • /
    • 제27권1호
    • /
    • pp.9-15
    • /
    • 2019
  • In this paper, we study a type of Riemannian manifold, namely quasi Ricci symmetric manifold. Among others, we show that the scalar curvature of a quasi Ricci symmetric manifold is constant. In addition if the manifold is Einstein, then its Ricci tensor is zero. Also we prove that if the associated vector field of a quasi Ricci symmetric manifold is either recurrent or concurrent, then its Ricci tensor is zero.

CURVATURES ON THE ABBENA-THURSTON MANIFOLD

  • Han, Ju-Wan;Kim, Hyun Woong;Pyo, Yong-Soo
    • 호남수학학술지
    • /
    • 제38권2호
    • /
    • pp.359-366
    • /
    • 2016
  • Let H be the 3-dimensional Heisenberg group, ($G=H{\times}S^1$, g) a product Riemannian manifold of Riemannian manifolds H and S with arbitrarily given left invariant Riemannian metrics respectively, and ${\Gamma}$ the discrete subgroup of G with integer entries. Then, on the Riemannian manifold ($M:=G/{\Gamma}$, ${\Pi}^*g=\bar{g}$), ${\Pi}:G{\rightarrow}G/{\Gamma}$, we evaluate the scalar curvature and the Ricci curvature.

SOME RIGIDITY CHARACTERIZATIONS OF EINSTEIN METRICS AS CRITICAL POINTS FOR QUADRATIC CURVATURE FUNCTIONALS

  • Huang, Guangyue;Ma, Bingqing;Yang, Jie
    • 대한수학회보
    • /
    • 제57권6호
    • /
    • pp.1367-1382
    • /
    • 2020
  • We study rigidity results for the Einstein metrics as the critical points of a family of known quadratic curvature functionals involving the scalar curvature, the Ricci curvature and the Riemannian curvature tensor, characterized by some pointwise inequalities involving the Weyl curvature and the traceless Ricci curvature. Moreover, we also provide a few rigidity results for locally conformally flat critical metrics.

RIGIDITY OF COMPLETE RIEMANNIAN MANIFOLDS WITH VANISHING BACH TENSOR

  • Huang, Guangyue;Ma, Bingqing
    • 대한수학회보
    • /
    • 제56권5호
    • /
    • pp.1341-1353
    • /
    • 2019
  • For complete Riemannian manifolds with vanishing Bach tensor and positive constant scalar curvature, we provide a rigidity theorem characterized by some pointwise inequalities. Furthermore, we prove some rigidity results under an inequality involving $L^{\frac{n}{2}}$-norm of the Weyl curvature, the traceless Ricci curvature and the Sobolev constant.

ON THE SECOND APPROXIMATE MATSUMOTO METRIC

  • Tayebi, Akbar;Tabatabaeifar, Tayebeh;Peyghan, Esmaeil
    • 대한수학회보
    • /
    • 제51권1호
    • /
    • pp.115-128
    • /
    • 2014
  • In this paper, we study the second approximate Matsumoto metric F = ${\alpha}+{\beta}+{\beta}^2/{\alpha}+{\beta}^3/{\alpha}^2$ on a manifold M. We prove that F is of scalar flag curvature and isotropic S-curvature if and only if it is isotropic Berwald metric with almost isotropic flag curvature.

CERTAIN STUDY OF GENERALIZED B CURVATURE TENSOR WITHIN THE FRAMEWORK OF KENMOTSU MANIFOLD

  • Rahuthanahalli Thimmegowda Naveen Kumar;Basavaraju Phalaksha Murthy;Puttasiddappa Somashekhara;Venkatesha Venkatesha
    • 대한수학회논문집
    • /
    • 제38권3호
    • /
    • pp.893-900
    • /
    • 2023
  • In the present study, we consider some curvature properties of generalized B-curvature tensor on Kenmotsu manifold. Here first we describe certain vanishing properties of generalized B curvature tensor on Kenmostu manifold. Later we formulate generalized B pseudo-symmetric condition on Kenmotsu manifold. Moreover, we also characterize generalized B ϕ-recurrent Kenmotsu manifold.

화염 곡률과 스칼라 소산율에 따른 층류부상화염의 화염전파속도에 관한 연구 (A Study on The Flame Propagation Velocity of Laminar Lifted Flame with Flame Curvatur e and Scalar Dissipation Rate)

  • 김경호;김태권;박정;하지수
    • 한국가스학회지
    • /
    • 제15권2호
    • /
    • pp.47-56
    • /
    • 2011
  • 삼지화염의 화염안정화 메커니즘 중 중요한 한 가지는 화염전파속도이다. 화염전파속도의 정량적인 규명을 위해 Bilger는 층류 유동이론에 근거하여 혼합분율 기울기에 비선형적으로 연관된 삼지화염전파속도를 제시하였다. 그러나 지금까지의 연구에서는 화염의 곡률 반경과 스칼라소산율 및 삼지화염의 화염전파속도에 관한 직접적인 관계에 관하여 제시된 바가 없었다. 본 논문은 실험과 수치해석에 따른 수치해석 결과를 검증하고, 수치해석을 통해 스칼라소산율에 따른 화염전파속도를 확인하였다. 그리고 화염스트레치 분석을 통하여 화염전파속도의 곡률반경 및 스칼라소산율에 따른 의존도를 명확히 하였다.