Results 21 to 30 of about 172 (147)
Stability of Doubly Warped Product Spacetimes [PDF]
Nonlinear stability for a class of doubly warped spacetimes is proved. The background spacetimes have negative Einstein factors. It shown that for dimension D≥11 there is a full parameter family of solutions to the vacuum Einstein equations which has Kasner-like singularity and Friedmann like asympotics in the future.
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Exploring the links between Large Igneous Provinces and dramatic environmental impact
An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Jessica H. Whiteside +3 more
wiley +1 more source
Gradient Ricci-harmonic solitons on doubly warped product manifolds
We give necessary and sufficient conditions for doubly warped product manifolds to be gradient Ricci-harmonic solitons. We also give a physical application for this kind of solitons.
Karaca, Fatma, Ozgur, Cihan
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ON RICCI-PSEUDOSYMMETRIC DOUBLY WARPED PRODUCTS
In this paper doubly warped product manifolds that satisfy a curvature condition known as Ricci-pseudosymmetry are studied. Necessary and sufficient conditions for a doubly warped product to be Ricci-pseudosymmetric are stated. In the special case that the two factor manifolds of the doubly warped product are both Einstein manifolds, the author states ...
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We investigate Ricci–Bourguignon solitons on mixed doubly sequential warped product manifolds. Necessary and sufficient conditions for the existence of such solitons are established, and their implications for Einstein manifolds are analyzed.
Ayman Elsharkawy +3 more
doaj +1 more source
Wood‐Derived Nanocellulose‐Biocarbon Fresnel‐Zone Plate Lenses for Sub‐THz Frequency Applications
Wood‐derived nanocellulose and lignin‐based biocarbon were combined to fabricate fully bio‐based Fresnel zone plate (FZP) lenses for sub‐terahertz frequencies. These sustainable FZP lenses exhibit low dielectric loss and high directivity, achieving performance comparable to that of metallic references, and remain functional under environmental stress ...
Riikka Haataja +9 more
wiley +1 more source
Visual teach‐and‐repeat (VTR) navigation allows robots to learn and follow routes without building a full metric map. We show that navigation accuracy for VTR can be improved by integrating a topological map with error‐drift correction based on stereo vision.
Fuhai Ling, Ze Huang, Tony J. Prescott
wiley +1 more source
Muscle Control of an Extra Robotic Digit
This study compares muscle‐ and movement‐based control for operating a supernumerary robotic thumb. While movement control performs better in the proposed tasks, muscle‐based (EMG) control promotes broader motor learning. The results highlight the promise and challenges of using biosignals for human augmentation, offering new insights into intuitive ...
Julien Russ +7 more
wiley +1 more source
This paper introduces a description of a doubly warped product manifold, taking into account certain conditions related to the projective curvature tensor.
Abdallah Abdelhameed Syied +3 more
doaj +1 more source
In NIID, expanded NOTCH2NLC repeats give rise to nuclear polyG inclusions. Tracer‐guided in situ cryo‐electron tomography enables cross‐scale structural analysis from mouse brain to native neuronal nuclei, revealing dense‐core/peripheral‐halo inclusions built from compact polyG ribbons.
Hui Dong +13 more
wiley +1 more source

