Results 101 to 110 of about 2,411,333 (204)

Evolution of Axially Symmetric Anisotropic Sources in $f(R,T)$ Gravity

, 2015
We discuss the dynamical analysis in $f(R,T)$ gravity (where $R$ is Ricci scalar and $T$ is trace of energy momentum tensor) for gravitating sources carrying axial symmetry.
Noureen, Ifra, Zubair, M.
core   +1 more source

The General Linear Cartan Khronon

Universe, 2019
A Cartan geometry of the General Linear symmetry is formulated by dividing out the displacements from the group. The resulting action is quadratic in curvature, polynomial in all the (minimal) variables, and describes an observer space that—in the ...
Tomi Koivisto, Manuel Hohmann, Tom Złośnik   +2 more
doaj   +1 more source

Tetrakis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidin-9-ido-κ2N1,N9)niobium(V) hexafluoridophosphate

Acta Crystallographica Section E, 2008
The title complex, [Nb(C7H12N3)4]PF6, features chelating hpp anions (hpp is 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) that define a distorted dodecahedral coordination geometry based on an N8 donor set.
Edward R. T. Tiekink, Nattamai Bhuvanesh, Pavel V. Poplaukhin, Carlos A. Murillo, F. Albert Cotton   +4 more
doaj   +1 more source

Approximate symmetries of geodesic equations on 2-spheres [PDF]

Il Nuovo Cimento B Vol 125 (2010) 297, 2010
Approximate symmetries of geodesic equations on 2-spheres are studied. These are the symmetries of the perturbed geodesic equations which represent approximate path of a particle rather than exact path. After giving the exact symmetries of the geodesic equations, two different approaches to study the approximate symmetries of the approximate geodesic ...
arxiv  

EXPLAINING THE GEOMETRY OF SIMPLE MOLECULES USING MOLECULAR ORBITAL ENERGY-LEVEL DIAGRAMS BUILT BY USING SYMMETRY PRINCIPLES

Química Nova
The built of qualitative energy-level molecular diagrams for different geometries of simple molecules allow to explain the preferred geometry. The diagrams are built using simple symmetry principles and explain, on basis of the number of nonbonding ...
Sérgio P. Machado, Roberto B. Faria
doaj   +1 more source

Higher symmetries of symplectic Dirac operator [PDF]

arXiv, 2018
We construct in projective differential geometry of the real dimension $2$ higher symmetry algebra of the symplectic Dirac operator ${D}\kern-0.5em\raise0.22ex\hbox{/}_s$ acting on symplectic spinors. The higher symmetry differential operators correspond to the solution space of a class of projectively invariant overdetermined operators of arbitrarily ...
arxiv  

Bis(1,10-phenanthroline-κ2N,N′)(sulfato-κ2O,O′)zinc(II) propane-1,3-diol solvate

Acta Crystallographica Section E, 2010
In the title compound, [Zn(SO4)(C12H8N2)2]·C3H8O2, the Zn2+ ion (site symmetry 2) is coordinated by two chelating 1,10-phenanthroline ligands and an O,O′-bidentate sulfate ion (S site symmetry 2), resulting in a distorted cis-ZnO2N4 ...
Jiang-Dong Cui, Kai-Long Zhong, Yan-Yun Liu   +2 more
doaj   +1 more source

Geometry-symmetry-free and material-symmetry-guaranteed polariton-induced transparency

iScience
Summary: Plasmon-induced transparency is a classical analogue of electromagnetically induced transparency (EIT). However, its realization and control primarily rely on geometry engineering rather than tuning plasmon polaritons (PPs) themselves, due to ...
Xingyu Tang, Huaping Wang, Zhenyang Cui, Sihao Xia, Zhiwei He, Song Han, Hongsheng Chen, Yingjie Wu   +7 more
doaj  

Nonlocal Lagrangian fields and the second Noether theorem. Non-commutative U(1) gauge theory

Journal of High Energy Physics
This article focuses on three main contributions. Firstly, we provide an in-depth overview of the nonlocal Lagrangian formalism. Secondly, we introduce an extended version of the second Noether’s theorem tailored for nonlocal Lagrangians.
Carlos Heredia, Josep Llosa
doaj   +1 more source

Internal symmetry in Poincarè gauge gravity

Nuclear Physics B
We find a large internal symmetry within 4-dimensional Poincarè gauge theory.In the Riemann-Cartan geometry of Poincaré gauge theory the field equation and geodesics are invariant under projective transformation, just as in affine geometry.
James T. Wheeler
doaj