Results 51 to 60 of about 375,845 (279)
Can dark matter induce cosmological evolution of the fundamental constants of Nature?
, 2015 We demonstrate that massive fields, such as dark matter, can directly produce a cosmological evolution of the fundamental constants of Nature. We show that a scalar or pseudoscalar (axion-like) dark matter field $\phi$, which forms a coherently ...
Flambaum, V. V., Stadnik, Y. V.
core +1 more source
Nilpotent Center in a Continuous Piecewise Quadratic Polynomial Hamiltonian Vector Field
International Journal of Bifurcation and Chaos, 2022 In this paper, we study the global dynamics of continuous piecewise quadratic Hamiltonian systems separated by the straight line [Formula: see text], where these kinds of systems have a nilpotent center at [Formula: see text], which comes from the combination of two cusps of both Hamiltonian systems.
Chen, Ting, Llibre, Jaume
openaire +2 more sources
Predicting Atomic Charges in MOFs by Topological Charge Equilibration
Advanced Functional Materials, EarlyView.An atomic charge prediction method is presented that is able to accurately reproduce ab‐initio‐derived reference charges for a large number of metal–organic frameworks. Based on a topological charge equilibration scheme, static charges that fulfill overall neutrality are quickly generated.
Babak Farhadi Jahromi +2 more
wiley +1 more source
Speed Controller of Three Phase Induction Motor Using Sliding Mode Controller
Journal of Engineering, 2019 In this paper, an adaptive integral Sliding Mode Control (SMC) is employed to control the speed of Three-Phase Induction Motor. The strategy used is the field oriented control as ac drive system. The SMC is used to estimate the frequency that required to
Farazdaq R. Yasien, Wala’a H. Nasser
doaj +1 more source
Notes on a surface defect in the O(N) model
Journal of High Energy Physics, 2023 We study a surface defect in the free and critical O(N) vector models, defined by adding a quadratic perturbation localized on a two-dimensional subspace of the d-dimensional CFT.
Simone Giombi, Bowei Liu
doaj +1 more source
Imaging of Biphoton States: Fundamentals and Applications
Advanced Functional Materials, EarlyView.Quantum states of two photons exhibit a rich polarization and spatial structure, which provides a fundamental resource of strongly correlated and entangled states. This review analyzes the physics of these intriguing properties and explores the various techniques and technologies available to measure them, including the state of the art of their ...
Alessio D'Errico, Ebrahim Karimi
wiley +1 more source
3-dimensional piecewise linear and quadratic vector fields with invariant spheres
Electronic Journal of Qualitative Theory of Differential EquationsWe consider the class $\mathcal{X}$ of $3$-dimensional piecewise smooth vector fields that admit a first integral which leaves invariant any sphere centered at the origin.
Claudio Buzzi +2 more
doaj +1 more source
A Correction to the Paper “Quadratic Hamiltonian Vector Fields”
Journal of Differential Equations, 1996 The authors present a corrected version of Theorem 5.2 from their paper [ibid. 107, No. 1, 80-95 (1994; Zbl 0791.34048)].
Artés, Joan C., Llibre, Jaume
openaire +1 more source
2D Magnetic and Topological Quantum Materials and Devices for Ultralow Power Spintronics
Advanced Functional Materials, EarlyView.2D magnets and topological quantum materials enable ultralow‐power spintronics by combining robust magnetic order with symmetry‐protected, Berry‐curvature‐driven transport. Fundamentals of 2D anisotropy and spin‐orbit‐coupling induced band inversion are linked to scalable growth and vdW stacking.
Brahmdutta Dixit +5 more
wiley +1 more source
Quadratic Killing tensors on symmetric spaces which are not generated by Killing vector fields
Comptes Rendus. MathématiqueEvery Killing tensor field on the space of constant curvature and on the complex projective space can be decomposed into the sum of symmetric tensor products of Killing vector fields (equivalently, every polynomial in velocities integral of the geodesic ...
Matveev, Vladimir S., Nikolayevsky, Yuri
doaj +1 more source