Results 31 to 40 of about 1,253 (179)

RICCI and Matter Collineations of SOM-ROY Chaudhary Symmetric Space Time

Mehran University Research Journal of Engineering and Technology, 2018
gThis paper is devoted to explore the RICCI and MCs (Matter Collineations of the Som-Ray Chaudhary spacetime. The spacetime under consideration is one of the spatially homogeneous and rotating spacetimes.
Muhammad Ramzan, Yaqoob Ahmad, Muhammad Rafiq Mufti   +2 more
doaj   +1 more source

Scalar–tensor gravitation and the Bakry–Émery–Ricci tensor [PDF]

Classical and Quantum Gravity, 2013
The Bakry-Emery generalized Ricci tensor arises in scalar-tensor gravitation theories in the conformal gauge known as the Jordan frame. Recent results from the mathematics literature show that standard singularity and splitting theorems that hold when an energy condition is applied in general relativity also hold when that energy condition is applied ...
openaire   +2 more sources

Ricci Curvature, Isoperimetry and a Non-additive Entropy

Entropy, 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

η-Ricci Solitons on Quasi-Sasakian Manifolds

Annals of the West University of Timisoara: Mathematics and Computer Science, 2018
The object of the present paper is to study η-Ricci solitons in a 3-dimensional non-cosymplectic quasi-Sasakian manifolds. We study a particular type of second order parallel tensor in this manifold.
Ghosh Sujit
doaj   +1 more source

The Long-Time Behavior of the Ricci Tensor under the Ricci Flow [PDF]

Geometry, 2013
We show that, given an immortal solution to the Ricci flow on a closed manifold with uniformly bounded curvature and diameter, the Ricci tensor goes to zero as . We also show that if there exists an immortal solution on a closed 3-dimensional manifold such that the product of the curvature and the square of the diameter is uniformly bounded, then this ...
openaire   +2 more sources

Ricci Solitons in β-Kenmotsu Manifolds

Annals of the West University of Timisoara: Mathematics and Computer Science, 2018
The object of the present paper is to study Ricci soliton in β-Kenmotsu manifolds. Here it is proved that a symmetric parallel second order covariant tensor in a β-Kenmotsu manifold is a constant multiple of the metric tensor.
Kumar Rajesh
doaj   +1 more source

Weyl structures with positive Ricci tensor

Differential Geometry and its Applications, 2003
We prove the vanishing of the first Betti number on compact manifolds admitting a Weyl structure whose Ricci tensor satisfies certain positivity conditions, thus obtaining a Bochner-type vanishing theorem in Weyl geometry. We also study compact Hermitian-Weyl manifolds with non-negative symmetric part of the Ricci tensor of the canonical Weyl ...
Alexandrov, B, Ivanov, S
openaire   +3 more sources

Kropina Metrics with Isotropic Scalar Curvature

Axioms, 2023
In this paper, we study Kropina metrics with isotropic scalar curvature. First, we obtain the expressions of Ricci curvature tensor and scalar curvature. Then, we characterize the Kropina metrics with isotropic scalar curvature on by tensor analysis.
Liulin Liu, Xiaoling Zhang, Lili Zhao
doaj   +1 more source

Compact Manifolds With Unbounded Nilpotent Fundamental Groups and Positive Ricci Curvature

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT It follows from the work of Kapovitch and Wilking that a closed manifold with nonnegative Ricci curvature has a uniformly almost nilpotent fundamental group. Leftover questions and conjectures, have asked if in this context the fundamental group is actually uniformly almost abelian. The main goal of this work is to construct examples (Mk9,gk)$(
Elia Bruè, Aaron Naber, Daniele Semola
wiley   +1 more source

When Digitalization Meets Sustainability: A Bibliometric and Systematic Literature Review of Its Impact on Firm Performance

Corporate Social Responsibility and Environmental Management, EarlyView.
ABSTRACT Research on digitalization, sustainability, and firm performance has grown rapidly in recent years, yet the literature remains fragmented across disciplines, concepts, and empirical settings. This study addresses the fragmentation by providing a combined bibliometric and systematic literature review (B‐SLR) of research at the intersection of ...
Muhammad Haseeb, Stefania Migliori, Maria Figueroa   +2 more
wiley   +1 more source