Results 21 to 30 of about 1,695 (179)

Emmy Noether and Her Theorems

open access: yesAnnalen der Physik, 2023
AbstractToday Noether's principal theorem occupies a prominent place in theoretical physics, though for a long time its significance was largely overlooked. Even now, relatively few physicists realize that Emmy Noether's original paper from 1918 contains two fundamental theorems.
openaire   +3 more sources

Electric–magnetic symmetry and Noether's theorem

open access: yesNew Journal of Physics, 2012
In the absence of charges, Maxwell's equations are highly symmetrical. In particular, they place the electric and magnetic fields on equal footing.
Robert P Cameron, Stephen M Barnett
doaj   +1 more source

About Lie algebra classification, conservation laws, and invariant solutions for the relativistic fluid sphere equation

open access: yesRevista Integración, 2023
The optimal generating operators for the relativistic fluid sphere equation have been derived. We have characterized all invariant solutions of this equation using these operators.
Yeisson Alexis Acevedo Agudelo   +3 more
doaj   +1 more source

Noether's theorem and gauge transformations. Application to the bosonic string and CP(2,n-1) model [PDF]

open access: yes, 1989
New results on the theory of constrained systems are applied to characterize the generators of Noethers symmetry transformations. As a byproduct, an algorithm to construct gauge transformations in Hamiltonian formalism is derived.
C. Batlle   +4 more
core   +1 more source

On the structure of conservation laws of (3+1)-dimensional wave equation

open access: yesArab Journal of Mathematical Sciences, 2018
In this paper, a (3+1)-dimensional wave equation is studied from the point of view of Lie’s theory in partial differential equations including conservation laws.
S. Reza Hejazi, Elham Lashkarian
doaj   +1 more source

Extensions of Noether's Second Theorem: from continuous to discrete systems [PDF]

open access: yes, 2011
A simple local proof of Noether's Second Theorem is given. This proof immediately leads to a generalization of the theorem, yielding conservation laws and/or explicit relationships between the Euler--Lagrange equations of any variational problem whose ...
Dorodnitsyn V.   +2 more
core   +2 more sources

Noether theorem for μ-symmetries [PDF]

open access: yesJournal of Physics A: Mathematical and Theoretical, 2007
We give a version of Noether theorem adapted to the framework of mu-symmetries; this extends to such case recent work by Muriel, Romero and Olver in the framework of lambda-symmetries, and connects mu-symmetries of a Lagrangian to a suitably modified conservation law. In some cases this "mu-conservation law'' actually reduces to a standard one; we also
G. Cicogna, G. Gaeta
openaire   +3 more sources

Linear Time-Dependent Invariants for Scalar Fields and Noether's Theorem [PDF]

open access: yes, 1994
The infinite number of time-dependent linear in field and conjugated momenta invariants is derived for the scalar field using the Noether's theorem procedure.Comment: LaTeX, 6 pages, preprint of Instituto de Ciencias Nucleares, UNAM, Departamento de F ...
Castaños, O.   +2 more
core   +2 more sources

Fractional derivative generalization of Noether’s theorem

open access: yesOpen Mathematics, 2015
The symmetry of the Bagley–Torvik equation is investigated by using the Lie group analysis method. The Bagley–Torvik equation in the sense of the Riemann–Liouville derivatives is considered.
Khorshidi Maryam   +2 more
doaj   +1 more source

Calculation of the angular momentum of an electromagnetic field inside a waveguide with absolutely conducting walls: ab initio [PDF]

open access: yesКомпьютерная оптика, 2018
In this paper, explicit expressions for the momentum and angular momentum from the Noether's theorem (ab initio) are obtained. These expressions contain squared modules of the coefficients of a guided mode expansion, weighted by the phase singularity ...
Sergey Kharitonov   +2 more
doaj   +1 more source

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