Results 101 to 110 of about 2,699,199 (290)

A physical classification of Killing magnetic fields in Thurston geometries

Mathematical Methods in the Applied Sciences, Volume 48, Issue 4, Page 5016-5023, 15 March 2025.
In recent years, numerous studies have appeared that considered Killing vectors of three‐dimensional Riemannian manifolds as magnetic fields, since these vector fields are divergenceless by definition. The existence of adivergenceless vector field modeled as a magnetic field does not imply that it is physically realizable.
Furkan Semih Dündar, Özgür Kelekçi, Gülhan Ayar   +2 more
wiley   +1 more source

Biharmonic submanifolds of pseudo-Riemannian manifolds [PDF]

arXiv, 2015
In this paper, we derived biharmonic equations for pseudo-Riemannian submanifolds of pseudo-Riemannian manifolds which includes the biharmonic equations for submanifolds of Riemannian manifolds as a special case. As applications, we proved that a pseudo-umbilical biharmonic pseudo-Riemannian submanifold of a pseudo-Riemannian manifold has constant mean
arxiv  

Geometric Machine Learning

AI Magazine, Volume 46, Issue 1, Spring 2025.
Abstract A cornerstone of machine learning is the identification and exploitation of structure in high‐dimensional data. While classical approaches assume that data lies in a high‐dimensional Euclidean space, geometric machine learning methods are designed for non‐Euclidean data, including graphs, strings, and matrices, or data characterized by ...
Melanie Weber
wiley   +1 more source

Is There a Future for Stochastic Modeling in Business and Industry in the Era of Machine Learning and Artificial Intelligence?

Applied Stochastic Models in Business and Industry, Volume 41, Issue 2, March/April 2025.
ABSTRACT The paper arises from the experience of Applied Stochastic Models in Business and Industry which has seen, over the years, more and more contributions related to Machine Learning rather than to what was intended as a stochastic model. The very notion of a stochastic model (e.g., a Gaussian process or a Dynamic Linear Model) can be subject to ...
Fabrizio Ruggeri, David Banks, William S. Cleveland, Nicholas I. Fisher, Marcos Escobar‐Anel, Paolo Giudici, Emanuela Raffinetti, Roger W. Hoerl, Dennis K. J. Lin, Ron S. Kenett, Wai Keung Li, Philip L. H. Yu, Jean‐Michel Poggi, Marco S. Reis, Gilbert Saporta, Piercesare Secchi, Rituparna Sen, Ansgar Steland, Zhanpan Zhang   +18 more
wiley   +1 more source

The Morse Index of Sacks–Uhlenbeck α-Harmonic Maps for Riemannian Manifolds

Journal of Mathematics
In this paper, first we prove a nonexistence theorem for α-harmonic mappings between Riemannian manifolds. Second, the instability of nonconstant α-harmonic maps is studied with regard to the Ricci curvature criterion of their codomain. Then, we estimate
Amir Shahnavaz, Nader Kouhestani, Seyed Mehdi Kazemi Torbaghan   +2 more
doaj   +1 more source

Hyperbolic Gradient-Bourgoignon Flow

پژوهش‌های ریاضی, 2022
Introduction ‎Ricci solitons as a generalization of Einstein manifolds introduced by Hamilton in mid 1980s‎. ‎In the last two decades‎, ‎a lot of researchers have been done on Ricci solitons‎.
Hamed Faraji, Shahroud Azami, Ghodratallah Fasihi-Ramandi   +2 more
doaj  

A nonlinear characterization of stochastic completeness of graphs

Mathematische Nachrichten, Volume 298, Issue 3, Page 925-943, March 2025.
Abstract We study nonlinear Schrödinger operators on graphs. We construct minimal nonnegative solutions to corresponding semilinear elliptic equations and use them to introduce the notion of stochastic completeness at infinity in a nonlinear setting. We provide characterizations for this property in terms of a semilinear Liouville theorem.
Marcel Schmidt, Ian Zimmermann
wiley   +1 more source

A (CHR)3-flat trans-Sasakian manifold

Pracì Mìžnarodnogo Geometričnogo Centru, 2019
In [4] M. Prvanovic considered several curvaturelike tensors defined for Hermitian manifolds. Developing her ideas in [3], we defined in an almost contact Riemannian manifold another new curvaturelike tensor field, which is called a contact ...
Koji Matsumoto
doaj   +1 more source

On a type of semi-sub-Riemannian connection on a sub-Riemannian manifold [PDF]

arXiv, 2013
The authors first in this paper define a semi-symmetric metric non-holonomic connection (called in briefly a semi-sub-Riemannian connection) on sub-Riemannian manifolds, and study the relations between sub-Riemannian connections and semi-sub-Riemannian connections. An invariant under a connection transformation $\nabla\rightarrow D$ is obtained.
arxiv  

Riemannian Shape Optimization of Thin Shells Using Isogeometric Analysis

PAMM, Volume 25, Issue 1, March 2025.
ABSTRACT In this contribution, we consider the optimal shape design of thin elastic shell structures based on a linearized shell model of Koiter's type, whose shape can be described by a surface immersed in three‐dimensional Euclidean space. We regard the set of unparametrized immersions of the surface as an infinite‐dimensional Riemannian shape space ...
Rozan Rosandi, Bernd Simeon
wiley   +1 more source