Results 31 to 40 of about 412,587 (240)

∗-Ricci Tensor on α-Cosymplectic Manifolds

open access: yesAdvances in Mathematical Physics, 2022
In this paper, we study α-cosymplectic manifold M admitting ∗-Ricci tensor. First, it is shown that a ∗-Ricci semisymmetric manifold M is ∗-Ricci flat and a ϕ-conformally flat manifold M is an η-Einstein manifold. Furthermore, the ∗-Weyl curvature tensor
M. R. Amruthalakshmi   +3 more
doaj   +1 more source

On the Geometry of Three-dimensional Pseudo-Riemannian Homogeneous Spaces. II [PDF]

open access: yesИзвестия Саратовского университета. Новая серия: Математика. Механика. Информатика, 2020
The problem of establishing links between the curvature and the topological structure of a manifold is one of the important problems of the geometry. In general, the purpose of the research of manifolds of various types is rather complicated.
Mozhey, Natal’ya Pavlovna
doaj   +1 more source

Conjectures and Open Questions on the Structure and Regularity of Spaces with Lower Ricci Curvature Bounds [PDF]

open access: yes, 2020
In this short note we review some known results on the structure and regularity of spaces with lower Ricci curvature bounds. We present some known and new open questions about next steps.
A. Naber
semanticscholar   +1 more source

A Note on the Geometry of RW Space-Times

open access: yesMathematics, 2023
A conformally flat GRW space-time is a perfect fluid RW space-time. In this note, we investigated the influence of many differential curvature conditions, such as the existence of recurrent and semi-symmetric curvature tensors.
Sameh Shenawy   +2 more
doaj   +1 more source

On the projective Ricci curvature [PDF]

open access: yesScience China Mathematics, 2020
The notion of the Ricci curvature is defined for sprays on a manifold. With a volume form on a manifold, every spray can be deformed to a projective spray. The Ricci curvature of a projective spray is called the projective Ricci curvature. In this paper,
Z. Shen, Liling Sun
semanticscholar   +1 more source

Graph Ricci curvatures reveal atypical functional connectivity in autism spectrum disorder

open access: yesScientific Reports, 2022
While standard graph-theoretic measures have been widely used to characterize atypical resting-state functional connectivity in autism spectrum disorder (ASD), geometry-inspired network measures have not been applied. In this study, we apply Forman–Ricci
Pavithra Elumalai   +5 more
doaj   +1 more source

A Volume Comparison Estimate with Radially Symmetric Ricci Curvature Lower Bound and Its Applications

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 2010
We extend the classical Bishop-Gromov volume comparison from constant Ricci curvature lower bound to radially symmetric Ricci curvature lower bound, and apply it to investigate the volume growth, total Betti number, and finite topological type of ...
Zisheng Hu, Yadong Jin, Senlin Xu
doaj   +1 more source

On generalized complex space forms satisfying certain curvature conditions

open access: yesKarpatsʹkì Matematičnì Publìkacìï, 2016
We study Ricci soliton $(g,V,\lambda)$ of generalized complex space forms when the Riemannian, Bochner and $W_{2}$ curvature tensors satisfy certain curvature conditions like semi-symmetric, Einstein semi-symmetric, Ricci pseudo symmetric and Ricci ...
M.M. Praveena, C.S. Bagewadi
doaj   +1 more source

Estimates on the non-compact expanding gradient Ricci solitons

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2013
In this paper, we deal with the complete non-compact expanding gradient Ricci soliton (Mn,g) with positive Ricci curvature. On the condition that the Ricci curvature is positive and the scalar curvature approaches 0 towards infinity, we derive a useful ...
Gao Xiang, Xing Qiaofang, Cao Rongrong
doaj   +1 more source

Ricci Curvature, Isoperimetry and a Non-additive Entropy

open access: yesEntropy, 2015
Searching for the dynamical foundations of Havrda-Charvát/Daróczy/ Cressie-Read/Tsallis non-additive entropy, we come across a covariant quantity called, alternatively, a generalized Ricci curvature, an N-Ricci curvature or a Bakry-Émery-Ricci curvature ...
Nikos Kalogeropoulos
doaj   +1 more source

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