Results 61 to 70 of about 519,784 (286)

A Note on the Geometry of RW Space-Times

Mathematics, 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, Uday Chand De, Nasser Bin Turki   +2 more
doaj   +1 more source

Neutral perfect fluids of Majumdar-type in general relativity

, 2005
We consider the extension of the Majumdar-type class of static solutions for the Einstein-Maxwell equations, proposed by Ida to include charged perfect fluid sources. We impose the equation of state $\rho+3p=0$ and discuss spherically symmetric solutions
A.P. Lightman, B.S. Guilfoyle, D. Ida, D. Vogt, H. Weyl, J. Ponce de León, J. Ponce de León, J.M. Cohen, J.R. Gott, M. Gürses, N. Dadhich, P.S. Wesson, R.M. Wald, V. Varela, Victor Varela, Y. Cho, Ø. Grøn   +16 more
core   +1 more source

Ellipsoidal shapes in general relativity: general definitions and an application [PDF]

, 2003
A generalization of the notion of ellipsoids to curved Riemannian spaces is given and the possibility to use it in describing the shapes of rotating bodies in general relativity is examined.
Bradley M, Chandrasekhar S, Dyer C C, Ferwagner R, Gergely L Á, Geroch R, Geroch R, Herlt E, J zsef Zsigrai, Kramer D, Krasinski A, Lukács B, Maison D, Marklund M, Misner C, Musgrave P, Neugebauer G, Neugebauer G, Neugebauer G, Perjés Z, Rácz I, Rácz I, Rácz I, Rácz I, Stewart J M, Vacaru S I, Vacaru S I, Vacaru S I, Vacaru S I, Vacaru S I, Vacaru S I, Zsigrai J, Zsigrai J   +32 more
core   +3 more sources

A Workflow to Accelerate Microstructure‐Sensitive Fatigue Life Predictions

Advanced Engineering Materials, EarlyView.
This study introduces a workflow to accelerate predictions of microstructure‐sensitive fatigue life. Results from frameworks with varying levels of simplification are benchmarked against published reference results. The analysis reveals a trade‐off between accuracy and model complexity, offering researchers a practical guide for selecting the optimal ...
Luca Loiodice, Krzysztof S. Stopka, Michael D. Sangid   +2 more
wiley   +1 more source

Anisotropic Cosmological Model in a Modified Theory of Gravitation

East European Journal of Physics
In this research, spatially homogeneous and anisotropic LRS Bianchi type-I cosmological model in f(R, T) theory is discussed by choosing the specific form as f(R, T) = R + μe-γR + λT, here R is the Ricci scalar, T is the trace of the energy-momentum ...
G. Satyanarayana, T. Vinutha, Y. Sobhanbabu, B. Srinivasu, P. Jnana Prasuna, M. Pruthvi Raju   +5 more
doaj   +1 more source

Matter ouside a Static Higher-dimensional Black Hole

, 2012
We considered matter fields composed of a perfect fluid in the static higher-dimensional spherically symmetric asymptotically flat black hole spacetime.
Rogatko, Marek
core   +1 more source

Investigation of Oxygen‐Free Wetting Behavior of Aluminum on Copper via Molecular Dynamics Simulations and Experiments

Advanced Engineering Materials, EarlyView.
The wettability of aluminum droplets (Al) on different copper substrates (Cu), where liquid Al spreads on solid Cu surfaces to form a liquid–solid interface, is studied numerically and experimentally. The experimental and numerical results show good agreement in the fast‐spreading regime.
Shan Lyu, Timon Steinhoff, Finn‐Lennard Janthur, Sarah Seffer, Jörg Hermsdorf, Christian Klose, Ludger Overmeyer, Hans‐Jürgen Maier, Nina Merkert   +8 more
wiley   +1 more source

Semiconformal curvature tensor and perfect fluid spacetimes in general relativity

Journal of Taibah University for Science, 2020
The semiconformal curvature tensor and its divergence have been studied for perfect fluid spacetimes. It is seen, apart from other results, that the perfect fluid spacetimes with divergence-free semiconformal curvature tensor either satisfy the vacuum ...
Musavvir Ali, Naeem Ahmad Pundeer, Akram Ali   +2 more
doaj   +1 more source

Static and stationary dark fluid universes: a gravitoelectromagnetic perspective

Scientific Reports, 2022
The usual characterization of exact solutions of Einstein field equations, including cosmological solutions, is based on the symmetry properties of their corresponding metrics which is obviously mathematically involved.
M. Nouri-Zonoz, A. Nourizonoz
doaj   +1 more source

Dynamics of locally rotationally symmetric Bianchi type VIII cosmologies with anisotropic matter

, 2012
This paper is a study of the effects of anisotropic matter sources on the qualitative evolution of spatially homogenous cosmologies of Bianchi type VIII.
Heißel, Gernot
core   +1 more source