Results 21 to 30 of about 1,087 (98)

A Geometric Algorithm to construct new solitons in the O(3) Nonlinear Sigma Model [PDF]

, 2002
The O(3) nonlinear sigma model with boundary, in dimension two, is considered. An algorithm to determine all its soliton solutions that preserve a rotational symmetry in the boundary is exhibited.
Albertsson, Albertsson, Anzellotti, Anzellotti, Arroyo, Arroyo, Barros, Belavin, Biscari, Cavalcante, Concus, Do Carmo, Langer, Langer, Laughlin, Lawson, Manuel Barros, Ody, Palais, Pinkall, Purkait, Tsurumaru, Weiner   +22 more
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Pseudoinversion of degenerate metrics

International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 55, Page 3479-3501, 2003., 2003
Let (M, g) be a smooth manifold M endowed with a metric g. A large class of differential operators in differential geometry is intrinsically defined by means of the dual metric g∗ on the dual bundle TM∗ of 1‐forms on M. If the metric g is (semi)‐Riemannian, the metric g∗ is just the inverse of g. This paper studies the definition of the above‐mentioned
C. Atindogbe, J.-P. Ezin, Joël Tossa
wiley   +1 more source

Estimates for the volume of a Lorentzian manifold

, 2002
We prove new estimates for the volume of a Lorentzian manifold and show especially that cosmological spacetimes with crushing singularities have finite volume.Comment: 8 pages, a pdf version of the preprint can also be retrieved from http://www.math ...
C. Gerhardt, C. Gerhardt, C. Gerhardt, Claus Gerhardt, D. Eardley, S. W. Hawking   +5 more
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Examples of naturally reductive pseudo-Riemannian Lie groups

, 2011
We provide examples of naturally reductive pseudo-Riemannian spaces, in particular an example of a naturally reductive pseudo-Riemannian 2-step nilpotent Lie group $(N, _N)$, such that $_N$ is invariant under a left action and for which the center is ...
Ovando, Gabriela P.
core   +1 more source

Hypersurfaces in a conformally flat space with curvature collineation

International Journal of Mathematics and Mathematical Sciences, Volume 14, Issue 3, Page 595-604, 1991., 1990
We classify the shape operators of Einstein and pseudo Einstein hypersurfaces in a conformally flat space with a symmetry called curvature collineation. We solve the fundamental problem of finding all possible forms of non‐diagonalizable shape operators.
K. L. Duggal, R. Sharma
wiley   +1 more source

A note on the existence of standard splittings for conformally stationary spacetimes

, 2012
Let $(M,g)$ be a spacetime which admits a complete timelike conformal Killing vector field $K$. We prove that $(M,g)$ splits globally as a standard conformastationary spacetime with respect to $K$ if and only if $(M,g)$ is distinguishing (and, thus ...
Beem J K, Bernal A N, Caponio E Javaloyes M A, Caponio E Javaloyes M A Masiello A, Harris S G, Miguel Angel Javaloyes, Miguel Sánchez, O'Neill B, Penrose R, Sachs R K, Sanchez M, Sánchez M   +11 more
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Optimization of Soliton Structures Using Lifting Theory on Tangent Bundles of Statistical Kenmotsu Manifolds

Journal of Mathematics, Volume 2026, Issue 1, 2026.
This paper investigates the optimization of soliton structures on tangent bundles of statistical Kenmotsu manifolds through lifting theory. By constructing lifted statistical Kenmotsu structures using semisymmetric metric and nonmetric connections, we derive explicit expressions for the curvature tensor, Ricci operator, and scalar curvature. We analyze
Mohammad Nazrul Islam Khan, Lalnunenga Colney, Teg Alam, Pramita Mishra   +3 more
wiley   +1 more source

Integrable system of null curve and Betchov-Da Rios equation

Demonstratio Mathematica
This study focuses on the time evolution of a null curve using a new frame and a new transformation in Minkowski 3-space. Accordingly, Landau–Lifshitz and coupled Boussinesq-like equations for the null curve are provided in terms of the new ...
Yoon Dae Won
doaj   +1 more source

Null scrolls with prescribed curvatures in Lorentz-Minkowski 3-space

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020
In Lorentz-Minkowski 3-space, null scrolls are ruled surfaces with a null base curve and null rulings. Their mean, as well as their Gaussian curvature, depends only on a parameter of a base curve. In the present paper, we obtain the first-order nonlinear
Šipuš Željka Milin, Gajčić Ljiljana Primorac, Protrka Ivana   +2 more
doaj   +1 more source

Dependence of the Gauss-Codazzi equations and the Ricci equation of Lorentz surfaces [PDF]

, 2013
The fundamental equations of Gauss, Codazzi and Ricci provide the conditions for local isometric embeddability. In general, the three fundamental equations are independent for surfaces in Riemannian 4-manifolds. In contrast, we prove in this article that
Chen, Bang-Yen
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