Results 41 to 50 of about 42,669 (197)

Generalization of instanton-induced inflation and dynamical compactification

Journal of High Energy Physics, 2023
It was shown that Yang-Mills instantons on an internal space can trigger the expansion of our four-dimensional universe as well as the dynamical compactification of the internal space.
Jeongwon Ho, Kyung Kiu Kim, Seoktae Koh, Hyun Seok Yang   +3 more
doaj   +1 more source

η-Ricci soliton on η-Einstein-like LP-Sasakian manifolds

Annals of the West University of Timisoara: Mathematics and Computer Science, 2022
The object of the present article is to study the notion of η-Einstein-like LP-Sasakian manifolds admitting η-Ricci soliton. Furthermore, we study the η-Ricci soliton on LP-Sasakian manifolds when the potential vector field V is point-wise collinear.
Das Susanta, Biswas Ashis, Baishya Kanak Kanti   +2 more
doaj   +1 more source

Conformally Einstein Products and Nearly K\"ahler Manifolds

, 2008
In the first part of this note we study compact Riemannian manifolds (M,g) whose Riemannian product with R is conformally Einstein. We then consider compact 6--dimensional almost Hermitian manifolds of type W_1+W_4 in the Gray--Hervella classification ...
A. Besse, A. Gray, A. Gray, A. Gray, Andrei Moroianu, C. Bär, H.W. Brinkmann, H.W. Brinkmann, J.-B. Butruille, L. Ornea, Liviu Ornea, M. Listing, M. Listing, M. Matsumoto, M. Obata, Nagy, R. Gover, R. Grünewald, T. Friedrich   +18 more
core   +5 more sources

On $K$-contact Einstein manifolds

Novi Sad Journal of Mathematics, 2016
In this paper, we investigate K-contact Einstein manifolds satisfying the conditions RC = Q(S,C), where C is the conformal curvature tensor and R the Riemannian curvature tensor. Next we consider K-contact Einstein manifolds satisfying the curvature condition C.S = 0, where S is the Ricci tensor.
De, U. C., Mandal, Krishanu
openaire   +2 more sources

Sasaki–Einstein Manifolds and Volume Minimisation [PDF]

Communications in Mathematical Physics, 2008
We study a variational problem whose critical point determines the Reeb vector field for a Sasaki-Einstein manifold. This extends our previous work on Sasakian geometry by lifting the condition that the manifolds are toric. We show that the Einstein-Hilbert action, restricted to a space of Sasakian metrics on a link L in a Calabi-Yau cone X, is the ...
Martelli D., Sparks J., Yau S. -T.
openaire   +4 more sources

$m$-quasi-$*$-Einstein contact metric manifolds

Karpatsʹkì Matematičnì Publìkacìï, 2022
The goal of this article is to introduce and study the characterstics of $m$-quasi-$*$-Einstein metric on contact Riemannian manifolds. First, we prove that if a Sasakian manifold admits a gradient $m$-quasi-$*$-Einstein metric, then $M$ is $\eta ...
H.A. Kumara, V. Venkatesha, D.M. Naik
doaj   +1 more source

Compact Einstein Spaces based on Quaternionic K\"ahler Manifolds

, 2003
We investigate the Einstein equation with a positive cosmological constant for $4n+4$-dimensional metrics on bundles over Quaternionic K\"ahler base manifolds whose fibers are 4-dimensional Bianchi IX manifolds.
Atiyah M F, Bogoyavlenskii O I, Bryant R, Bérard-Bergery L, Cvetic M, Cvetic M, Cvetic M, Cvetic M, Cvetic M, Galicki K, Gibbons G W, Gibbons G W, Hideki Ishihara, Hitchin N, Hitchin N J, Hitchin N J, Ishihara S, Kanno H, Mitsuo Hiragane, Page D N, Page D N, Slamon S, Wang M, Yukinori Yasui   +23 more
core   +1 more source

Molecular Dynamics Studies of Shape Memory Polymers: From Bead–Spring Models to Atomistic Simulations

Advanced Engineering Materials, EarlyView.
Coarse‐grained (left) and atomistic (right) models of the shape memory polymer ESTANE ETE 75DT3 are shown schematically. The two representations bridge molecular detail and mesoscopic description. Both models capture shape memory behavior, linking segmental mobility and conformational relaxation of anisotropic chains to macroscopic recovery, and ...
Fathollah Varnik
wiley   +1 more source

Deformations of Killing spinors on Sasakian and 3-Sasakian manifolds [PDF]

, 2015
We consider some natural infinitesimal Einstein deformations on Sasakian and 3-Sasakian manifolds. Some of these are infinitesimal deformations of Killing spinors and further some integrate to actual Killing spinor deformations.
van Coevering, Craig
core  

On Conformally Compact Einstein Manifolds [PDF]

Mathematical Research Letters, 2001
During the last couple of years conformally compact Einstein manifolds have appeared in string theory as the mathematical framework for the Ads/CFT correspondence which gives a close connection between conformal field theory and supergravity. Inspired by these facts the author establishes several results which support an expectation that there should ...
openaire   +1 more source