Scalar potential

About: Scalar potential is a research topic. Over the lifetime, 3642 publications have been published within this topic receiving 78868 citations. The topic is also known as: potential.

New constraints on classical de Sitter: flirting with the swampland

Abstract: We study the existence and stability of classical de Sitter solutions of type II supergravities with parallel Dp-branes and orientifold Op-planes. Together with the dilaton and volume scalar fields, we consider a third one that distinguishes between parallel and transverse directions to the Dp/Op. We derive the complete scalar potential for these three fields. This formalism allows us to reproduce known constraints obtained in 10d, and to derive new ones. Specifying to group manifolds with constant fluxes, we exclude a large region of parameter space, forbidding de Sitter solutions on nilmanifolds, semi-simple group manifolds, and some solvmanifolds. In the small remaining region, we identify a stability island, where the three scalars could be stabilized in any de Sitter solution. We discuss these results in the swampland context.

Magnetic materials and 3D finite element modeling

Abstract: Statics and Quasi-Statics Electromagnetics - Brief Presentation Introduction The Maxwell Equations The Maxwell Equations: Local Form The Maxwell Equations: Integral Form The Maxwell Equations in Low Frequency The Electrostatics Magnetostatic Fields Magnetic Materials Inductance and Mutual Inductance Magnetodynamic Fields Fields Defined by Potentials Final Considerations References Ferromagnetic Materials and Iron Losses Introduction Basic Concepts Losses Components Iron Losses under Alternating, Rotating and DC Biased Inductions Final Considerations References Scalar Hysteresis Modeling Introduction The Preisach's Scalar Model The Jiles-Atherton Scalar Model Final Considerations References Vector Hysteresis Modeling Introduction Vector Model Obtained with the Superposition of Scalar Models Vector Generalizations of the Jiles-Atherton Scalar Models Some Remarks Concerning the Vector Behavior of Hysteresis Final Considerations References Brief Presentation of the Finite Element Method Introduction The Galerkin Method: Basic Concepts using Real Coordinates Generalization of the FEM: Using Reference Coordinates Numerical Integration Some Finite Elements Using Edge Elements References Using Nodal Elements with Magnetic Vector Potential Introduction Main Equations Applying Galerkin Method Uniqueness of the Solution the Coulomb's Gauge Implementation Example and Comparisons Final Considerations References The Source-Field Method for 3D Magnetostatic Fields Introduction The Magnetostatic Case - Scalar Potential The Magnetostatic Case - Vector Potential Implementation Aspects and Conventions Computational Implementation Example and Results References The Source-Field Method for 3D Magnetodynamic Fields Introduction Formulation Considering Eddy Currents - Time Stepping Formulation Considering Eddy Currents - Complex Formulation Field-Circuit Coupling Computational Implementation The Differential Permeability Method Example and Results References A Matrix-Free Iterative Solution Procedure for Finite Element Problems Introduction The Classical FEM: T-Scheme The Proposed Technique: N-Scheme Implementation Convergence Implementation of N-Scheme with SOR Applying Non-Stationary Iterative Solver to the N-Scheme CG Algorithm Implementation Examples and Results Results and Discussion References

Nondecoupling of charged scalars in Higgs decay to two photons and symmetries of the scalar potential

Abstract: A large class of two- and three-Higgs-doublet models with discrete symmetries has been employed in the literature to address various aspects of flavor physics. We analyze how the precision measurement of the Higgs to diphoton signal strength would severely constrain these scenarios due to the nondecoupling behavior of the charged scalars, to the extent that in the presence of exact discrete symmetry, the number of additional noninert scalar doublets can be constrained no matter how heavy the nonstandard scalars are. We demonstrate that if the scalar potential is endowed with appropriate global continuous symmetries together with soft breaking parameters, decoupling can be achieved thanks to the unitarity constraints on the mass-square differences of the heavy scalars.

Model-Based Calibration for Magnetic Manipulation

Abstract: Model-based calibration of a magnetic workspace not only provides a smooth representation of the field and its gradient matrix, but also uses physical constraints to smooth the calibration measurements. This paper presents the first model-based technique to calibrate a magnetic manipulation system by using nonlinear least squares to solve for a scalar potential for each source. The performance of the method is verified by comparison to numerical finite element simulation and a case study calibration of a real system, where it is able to achieve an $R^{2}$ value of 0.9997. Furthermore, the analytical representations for the first three spatial derivatives of a spherical multipole expansion are provided for convenience, which correspond to the torque, force, and force-spatial-rate-of-change on a magnetic dipole in the workspace.