Results 151 to 160 of about 250,111 (340)

Conharmonically flat and conharmonically symmetric warped product manifolds

AIP Advances
This article presents characterizations of warped product manifolds based on the flatness and symmetry of the conharmonic curvature tensor. It is proved that when a warped product manifold is conharmonically flat, both the base and fiber manifolds ...
Abdallah Abdelhameed Syied, Uday Chand De, Nasser Bin Turki   +2 more
doaj   +1 more source

RC-positivity and rigidity of harmonic maps into Riemannian manifolds [PDF]

arXiv, 2018
In this paper, we show that every harmonic map from a compact K\"ahler manifold with uniformly RC-positive curvature to a Riemannian manifold with non-positive complex sectional curvature is constant. In particular, there is no non-constant harmonic map from a compact K\"ahler manifold with positive holomorphic sectional curvature to a Riemannian ...
arxiv  

On the Isometric Immersions in Euclidean Space of Manifolds with Nonnegative Sectional Curvatures. II [PDF]

, 1970
Philip Hartman
openalex   +1 more source

KCS1 and VIP1, the genes encoding yeast phosphoinositol pyrophosphate synthases, are required for Ca2+‐mediated response to dimethylsulfoxide (DMSO)

FEBS Open Bio, EarlyView.
Ca2+‐mediated response to DMSO was investigated in Saccharomyces cerevisiae cells expressing Ca2+‐dependent aequorin. Cell exposure to DMSO induced a cytosolic Ca2+ wave dependent on the integrity of the Cch1/Mid1 channel. Deletion of KCS1 or VIP1 genes encoding the phosphoinositol pyrophosphate (PP‐IP) synthases suppressed the DMSO‐induced Ca2 ...
Larisa Ioana Gogianu, Lavinia Liliana Ruta, Claudia Valentina Popa, Simona Ghenea, Ileana Cornelia Farcasanu   +4 more
wiley   +1 more source

Algebraic Properties of Curvature Operators in Lorentzian Manifolds with Large Isometry Groups

Symmetry, Integrability and Geometry: Methods and Applications, 2010
Together with spaces of constant sectional curvature and products of a real line with a manifold of constant curvature, the socalled Egorov spaces and ε-spaces exhaust the class of n-dimensional Lorentzian manifolds admitting a group of isometries of ...
Giovanni Calvaruso, Eduardo García-Río
doaj   +1 more source

Fundamental groups of 2-complexes with nonpositive planar sectional curvature [PDF]

arXiv
We show that the finite simply connected 2-complexes of nonpositive planar sectional curvature are collapsible. Moreover, we show that each finite connected 2-complex with negative planar sectional curvature and fundamental group $\mathbb{Z}$ can be collapsed to a 1-dimensional cycle.
arxiv  

Curvature tensors whose Jacobi or Szabo operator is nilpotent on null vectors [PDF]

arXiv, 2002
We show that any $k$ Osserman Lorentzian algebraic curvature tensor has constant sectional curvature and give an elementary proof that any local 2 point homogeneous Lorentzian manifold has constant sectional curvature. We also show that a Szab\'o Lorentzian covariant derivative algebraic curvature tensor vanishes.
arxiv  

Notes on a $K$-space of constant holomorphic sectional curvature [PDF]

, 1975
Sumio Sawaki, Yoshiyuki Watanabe, Takuji Sato   +2 more
openalex   +1 more source

Homogeneous convex domains of negative sectional curvature [PDF]

, 1977
Hirohiko Shima
openalex   +1 more source

On Riemannian manifolds with Sasakian $3$-structure of constant horizontal sectional curvature [PDF]

, 1976
Mariko Konishi, Shōichi Funabashi
openalex   +1 more source