Results 21 to 30 of about 190,445 (136)
Approximate Lie Symmetry Conditions of Autoparallels and Geodesics
Abstract and Applied Analysis, Volume 2020, Issue 1, 2020., 2020 This paper is devoted to the study of approximate Lie point symmetries of general autoparallel systems. The significance of such systems is that they characterize the equations of motion of a Riemannian space under an affine parametrization. In particular, we formulate the first‐order symmetry determining equations based on geometric requirements and ...
Sameerah Jamal, Shi Liang Wu
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Homotheties of a Class of Spherically Symmetric Space‐Time Admitting G3 as Maximal Isometry Group
Advances in Mathematical Physics, Volume 2018, Issue 1, 2018., 2018 The homotheties of spherically symmetric space‐time admitting G4, G6, and G10 as maximal isometry groups are already known, whereas, for the space‐time admitting G3 as isometry groups, the solution in the form of differential constraints on metric coefficients requires further classification. For a class of spherically symmetric space‐time admitting G3
Daud Ahmad +2 more
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Advances in Mathematical Physics, Volume 2017, Issue 1, 2017., 2017 The aim of this paper is to give the geometrical/physical interpretation of the conserved quantities corresponding to each Noether symmetry of the geodetic Lagrangian of plane symmetric space‐times. For this purpose, we present a complete list of plane symmetric nonstatic space‐times along with the generators of all Noether symmetries of the geodetic ...
Bismah Jamil +3 more
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Features from a Single Vector Pressure Stroke
Mathematical Problems in Engineering, Volume 2017, Issue 1, 2017., 2017 Freehand sketching in a real‐time 3D styling system presents a different way to create a 3D model from the traditional CAD system. Strokes are the most common and useful objects in the expression of a stylist’s intention by using the gesture commands and in the construction of geometries.
Qiang Li +6 more
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Relativistic Localizing Processes Bespeak an Inevitable Projective Geometry of Spacetime
Advances in High Energy Physics, Volume 2017, Issue 1, 2017., 2017 Surprisingly, the issue of events localization in spacetime is poorly understood and a fortiori realized even in the context of Einstein’s relativity. Accordingly, a comparison between observational data and theoretical expectations might then be strongly compromised. In the present paper, we give the principles of relativistic localizing systems so as
Jacques L. Rubin, Ralf Hofmann
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Journal of Mathematics, Volume 2026, Issue 1, 2026.This article explores the necessary and sufficient conditions for a vector field on the cotangent bundle of a Riemannian manifold to qualify as an m− modified conformal vector field or a Ricci bi‐conformal vector field. The analysis employs an adapted frame and concerns the Riemannian extension metric.
Lokman Bilen +3 more
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Non‐Perfect‐Fluid Space‐Times in Thermodynamic Equilibrium and Generalized Friedmann Equations
Journal of Gravity, Volume 2016, Issue 1, 2016., 2016 We determine the energy‐momentum tensor of nonperfect fluids in thermodynamic equilibrium and, respectively, near to it. To this end, we derive the constitutive equations for energy density and isotropic and anisotropic pressure as well as for heat‐flux from the corresponding propagation equations and by drawing on Einstein’s equations.
Konrad Schatz +3 more
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Multistable Soft Robots Assembled from Bistable Auxetic Building Blocks
Advanced Intelligent Systems, Volume 7, Issue 4, April 2025.Bistable and multistable structures offer solutions for enhancing shape retention and load capacity in soft robots. This study presents a multistable soft robot design using bistable auxetic building blocks. Illustrated through a manipulator with 216 discrete stable states and a tube‐crawling robot, the design demonstrates significant versatility and ...
Bojian Zhang +6 more
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Ricci solitons and curvature inheritance on Robinson-Trautman spacetimes
, 2023 The purpose of the article is to investigate the existence of Ricci solitons and the nature of curvature inheritance as well as collineations on the Robinson-Trautman (briefly, RT) spacetime.
Shaikh, Absos Ali, Datta, Biswa Ranjan
core
The spinor representation of constant mean curvature one surfaces in the Hyperbolic space [PDF]
, 1970 We review and comment on some aspects of the spinor representation for constant mean curvature one surfaces in hyperbolic space developed by Bobenko-Pavlyukevich-Springborn in [1].
Nicolodi, Lorenzo +4 more
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