scholarly journals Formation and Evolution of Wakes in the Spacetime Generated by a Cosmic String in <i>f</i>(<i>R</i>) Theory of Gravity

2022 ◽  
Vol 08 (01) ◽  
pp. 85-96
Author(s):  
Gabriela Coutinho de Carvalho ◽  
Maria Emília Xavier Guimarães ◽  
Pablo Oliveira Mesquita ◽  
Joaquim Lopes Neto
Keyword(s):  
Cosmic String ◽  
Formation And Evolution ◽  
Theory Of Gravity

scholarly journals SPINNING COSMIC STRINGS: A GENERAL CLASS OF SOLUTIONS

2005 ◽  
Vol 20 (13) ◽  
pp. 2821-2832 ◽  
Author(s):  
N. ÖZDEMİR
Keyword(s):  
Exact Solution ◽  
Cosmic String ◽  
General Class ◽  
Symmetry Axis ◽  
Cosmic Strings ◽  
Space Time ◽  
Closed Timelike Curves ◽  
Interior Space ◽  
Theory Of Gravity ◽  
Spin Fluid

In this work, we give a general class of solutions of the spinning cosmic string in Einstein's theory of gravity. After treating same problem in Einstein–Cartan (EC) theory of gravity, the exact solution satisfying both exterior and interior space–times representing a spin fluid moving along the symmetry axis is presented in the EC theory. The existence of closed timelike curves in this space–time are also examined.

AFM study of the dynamics of α-alumina surface faceting during high-temperature processing

1995 ◽  
Vol 53 ◽  
pp. 334-335 ◽  
Author(s):  
Michael W. Bench ◽  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
High Temperature ◽  
Thin Foil ◽  
Sem Analysis ◽  
Conductive Coatings ◽  
Force Microscopy ◽  
Minimal Sample ◽  
Atomic Force ◽  
Formation And Evolution ◽  
High Temperature Processing ◽  
Nominal Surface

To gain a better understanding of the surface faceting that occurs in α-alumina during high temperature processing, atomic force microscopy (AFM) studies have been performed to follow the formation and evolution of the facets. AFM was chosen because it allows for analysis of topographical details down to the atomic level with minimal sample preparation. This is in contrast to SEM analysis, which typically requires the application of conductive coatings that can alter the surface between subsequent heat treatments. Similar experiments have been performed in the TEM; however, due to thin foil and hole edge effects the results may not be representative of the behavior of bulk surfaces.The AFM studies were performed on a Digital Instruments Nanoscope III using microfabricated Si3N4 cantilevers. All images were recorded in air with a nominal applied force of 10-15 nN. The alumina samples were prepared from pre-polished single crystals with (0001), , and nominal surface orientations.

The First Galaxies in the Universe

2013 ◽  
Author(s):  
Abraham Loeb ◽  
Steven R. Furlanetto
Keyword(s):  
Galaxy Evolution ◽  
Big Bang ◽  
First Stars ◽  
Distant Galaxies ◽  
Formation And Evolution ◽  
Early Galaxies ◽  
First Galaxies ◽  
Large Telescopes ◽  
New Generation ◽  
The Big Bang

This book provides a comprehensive, self-contained introduction to one of the most exciting frontiers in astrophysics today: the quest to understand how the oldest and most distant galaxies in our universe first formed. Until now, most research on this question has been theoretical, but the next few years will bring about a new generation of large telescopes that promise to supply a flood of data about the infant universe during its first billion years after the big bang. This book bridges the gap between theory and observation. It is an invaluable reference for students and researchers on early galaxies. The book starts from basic physical principles before moving on to more advanced material. Topics include the gravitational growth of structure, the intergalactic medium, the formation and evolution of the first stars and black holes, feedback and galaxy evolution, reionization, 21-cm cosmology, and more.

SILICA KINETICS AND THE FORMATION AND EVOLUTION OF ASPERITIES ALONG THE SUBDUCTION INTERFACE

2019 ◽  
Author(s):  
Donald M. Fisher ◽  
◽  
Andrew J. Smye ◽  
John N. Hooker ◽  
Chris Marone
Keyword(s):  
Formation And Evolution
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