Results 21 to 30 of about 122,594 (207)

Shear free solutions in General Relativity Theory

, 2011
The Goldberg-Sachs theorem is an exact result on shear-free null geodesics in a vacuum spacetime. It is compared and contrasted with an exact result for pressure-free matter: shear-free flows cannot both expand and rotate.
B.J. Carr, C.B. Collins, C.B. Collins, C.G. Tsagas, E. Newman, E. Schücking, G.F.R. Ellis, G.F.R. Ellis, G.F.R. Ellis, George F. R. Ellis, H. Balasin, H. Bondi, H. Bondi, H. Elst van, H. Elst van, I. Robinson, J. Carminati, J.M.M. Senovilla, J.V. Narlikar, L. Wylleman, M. Bruni, N. Van den Bergh, N. Van den Bergh, P.K.S. Dunsby, R. D’Inverno, R. Maartens, R. Penrose, R. Penrose, R. Penrose, R.K. Sachs, S. Dain, S. Matarrese, S.W. Hawking, S.W. Hawking, W. Israel   +34 more
core   +1 more source

Conformal scattering on the Schwarzschild metric [PDF]

, 2015
We show that existing decay results for scalar fields on the Schwarzschild metric are sufficient to obtain a conformal scattering theory. Then we re-interpret this as an analytic scattering theory defined in terms of wave operators, with an explicit ...
Nicolas, Jean-Philippe
core   +3 more sources

Development of a Prediction Model for Progression Risk in High‐Grade Gliomas Based on Habitat Radiomics and Pathomics

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective To investigate the value of constructing models based on habitat radiomics and pathomics for predicting the risk of progression in high‐grade gliomas. Methods This study conducted a retrospective analysis of preoperative magnetic resonance (MR) images and pathological sections from 72 patients diagnosed with high‐grade gliomas (52 ...
Yuchen Zhu, Yuxi Gong, Weilin Xu, Xingjian Sun, Gefei Jiang, Lei Qiu, Kexin Shi, Mengxing Wu, Yinjiao Fei, Jinling Yuan, Jinyan Luo, Yurong Li, Yuandong Cao, Minhong Pan, Shu Zhou   +14 more
wiley   +1 more source

Astrophysical Accretion as an Analogue Gravity Phenomena [PDF]

, 2006
In recent years, strong analogies have been established between the physics of acoustic perturbations in an inhomogeneous dynamical fluid system, and some kinematic features of space-time in general relativity.
Das, Tapas Kumar
core   +1 more source

High‐Resolution MRI Revealed Different Etiology‐Specific Associations With Cerebral Infarction in Adult Moyamoya Vasculopathy

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective High‐resolution MRI enables detailed assessment of intracranial vessel wall pathology in moyamoya vasculopathy. We aimed to classify adult moyamoya vasculopathy etiologies using high‐resolution MRI and to examine subtype‐specific associations between high‐resolution MRI features and ischemic infarction.
Guangsong Han, Jiachun Pan, Yuehui Hong, Xiaoyuan Fan, Ming Yao, Lixin Zhou, Yicheng Zhu, Feng Feng, Jun Ni   +8 more
wiley   +1 more source

Particle production from marginally trapped surfaces of general spacetimes [PDF]

, 2015
We provide a general formalism that allows to analyze the phenomenon of tunneling in arbitrary spacetimes. We show that a flux of particles produced by tunneling through general marginally trapped surfaces may be perceived by some privileged observers ...
Senovilla, José M. M., Torres, Ramón
core   +4 more sources

Reconstruction and interpretation of ionization asymmetry in magnetic confinement via synthetic diagnostics

Nuclear Fusion
Strong poloidal refueling asymmetry in the DIII-D tokamak is inferred from line radiation measurements. Synthetic diagnostics in neutral transport modeling coupled to gyrokinetic simulations illuminate implications for the plasma flow profile in the ...
G.J. Wilkie, F. Laggner, R. Hager, A. Rosenthal, S.-H. Ku, R.M. Churchill, L. Horvath, C.S. Chang, A. Bortolon   +8 more
doaj   +1 more source

Prediction of Surface Topography Parameters in Direct Laser Interference Patterning of Stainless Steel Using Infrared Monitoring and Convolutional Neural Networks

Advanced Engineering Materials, EarlyView.
This study presents an infrared monitoring approach for direct laser interference patterning (DLIP) combined with a convolutional neural network (CNN). Thermal emission data captured during structuring are used to predict surface topography parameters.
Lukas Olawsky, Marcelo Sallese, Leander Kläber, Clemens Kuhn, Keming Du, Andrés Fabián Lasagni   +5 more
wiley   +1 more source

Black holes and Hawking radiation in spacetime and its analogues

, 2012
These notes introduce the fundamentals of black hole geometry, the thermality of the vacuum, and the Hawking effect, in spacetime and its analogues. Stimulated emission of Hawking radiation, the trans-Planckian question, short wavelength dispersion, and ...
A. Coutant, B.Z. Foster, C. Barcelo, C. Barrabès, C. Mayoral, D. Mattingly, D.M. Eardley, J. Collins, J. Macher, J. Macher, L.C.B. Crispino, R. Brout, R. Penrose, R. Penrose, R.M. Wald, R.M. Wald, S. Corley, S. Corley, S. Finazzi, S. Weinfurtner, T. Jacobson, T. Jacobson, T. Jacobson, T. Jacobson, T.A. Jacobson, W.G. Unruh   +25 more
core   +1 more source

Investigation of Laser Ablation and Brush Pre‐Treatments for AlCu Cold Roll Bonding in Oxygen‐Free Conditions

Advanced Engineering Materials, EarlyView.
It is shown that laser ablation pretreatment under oxygen‐free conditions enables copper–aluminium bonding at significantly lower deformation degrees and improved properties compared to mechanical brushing. Laser ablation further increases interface contact area and induces favourable residual stress states and microstructural compatibility ...
Khemais Barienti, Finn‐Lennard Janthur, Selina Raumel, Sascha Jan Zimmermann, Sarah Seffer, René Gustus, Sebastian Herbst, Marc C. Wurz, Ludger Overmeyer, Wolfgang Maus‐Friedrichs, Hans Jürgen Maier, Florian Nürnberger   +11 more
wiley   +1 more source