Results 31 to 40 of about 8,028 (315)

Transmission of low-energy scalar waves through a traversable wormhole

European Physical Journal C: Particles and Fields, 2020
We study the scattering of low-energy massless and massive minimally coupled scalar fields by an asymptotically flat traversable wormhole. We provide a comprehensive treatment of this problem offering analytic expressions for the transmission and ...
Bahareh Azad, Farhang Loran, Ali Mostafazadeh   +2 more
doaj   +1 more source

Remarks on rotating shallow-water magnetohydrodynamics [PDF]

Nonlinear Processes in Geophysics, 2013
We show how the rotating shallow-water MHD model, which was proposed in the solar tachocline context, may be systematically derived by vertical averaging of the full MHD equations for the rotating magneto fluid under the influence of gravity.
V. Zeitlin
doaj   +1 more source

4D spin-2 fields from 5D Chern-Simons theory

Journal of High Energy Physics, 2018
We consider a 5-dimensional Chern-Simons gauge theory for the isometry group of Anti-de-Sitter spacetime, AdS4+1 ≃ SO(4, 2), and invoke different dimensional reduction schemes in order to relate it to 4-dimensional spin-2 theories.
N. L. González Albornoz, D. Lüst, S. Salgado, A. Schmidt-May   +3 more
doaj   +1 more source

Dynamo Generation of Galactic magnetic fields [PDF]

Symposium - International Astronomical Union, 1990
I give some results of calculations of the magnetic fields generated by dynamo processes in galaxy models consisting of a turbulent disc embedded in a low-conductivity halo. The field configuration is found to be strongly dependent on the turbulent structure of the disc.
openaire   +1 more source

Finitely generated extensions of difference fields [PDF]

Proceedings of the American Mathematical Society, 1955
Let 7, 3C, K,, be difference fields such that CaCCtK. We shall prove that if KJ is a finitely generated extension of 7, K,=7(al, a2, an)),1 then 3C is also a finitely generated extension of 7. We introduce a new notation for the ai. Let f1, * *, f3 denote a subset of the ai annulling no nonzero difference polynomial with coefficients in 3C and such ...
openaire   +2 more sources

General properties of non-commutative field theories [PDF]

Nuclear Physics B, 2003
In this paper we study general properties of noncommutative field theories obtained from the Seiberg-Witten limit of string theories in the presence of an external B-field. We analyze the extension of the Wightman axioms to this context and explore their consequences, in particular we present a proof of the CPT theorem for theories with space-space ...
Álvarez-Gaumé, Luis, Vázquez-Mozo, Miguel A.   +1 more
openaire   +3 more sources

Fractional Mathieu Equation with Two Fractional Derivatives and Some Applications

Fractal and Fractional
The importance of this research comes from the several applications of the Mathieu equation and its generalizations in many scientific fields. Two models of fractional Mathieu equations are provided using Katugampola fractional derivatives in the sense ...
Ahmed Salem, Hunida Malaikah, Naif Alsobhi   +2 more
doaj   +1 more source

Teleparallel axions and cosmology

European Physical Journal C: Particles and Fields, 2021
We consider the most general teleparallel theory of gravity whose action is a linear combination of the five scalar invariants which are quadratic in the torsion tensor.
Manuel Hohmann, Christian Pfeifer
doaj   +1 more source

General theory of quantum field mixing [PDF]

Physical Review D, 2002
We present a general theory of mixing for an arbitrary number of fields with integer or half-integer spin. The time dynamics of the interacting fields is solved and the Fock space for interacting fields is explicitly constructed. The unitary inequivalence of the Fock space of base (unmixed) eigenstates and the physical mixed eigenstates is shown by a ...
Ji, Chueng-Ryong, Mishchenko, Yuriy
openaire   +2 more sources

Revealing the structure of land plant photosystem II: the journey from negative‐stain EM to cryo‐EM

FEBS Letters, EarlyView.
Advances in cryo‐EM have revealed the detailed structure of Photosystem II, a key protein complex driving photosynthesis. This review traces the journey from early low‐resolution images to high‐resolution models, highlighting how these discoveries deepen our understanding of light harvesting and energy conversion in plants.
Roman Kouřil
wiley   +1 more source