Vector Potential Continuity
Vector Potential Continuity - Related Videos
01:15
Magnetic Vector Potential
0 Views •
2023
In electrostatics, the electric field can be written as the negative gradient of the potential. In magnetostatics, the zero divergence of the magnetic field ensures that the magnetic field can be expressed as the curl of a vector potential. This potential is known as the magnetic vector potential. Consider an ideal solenoid with n turns per unit length and radius R. If I is the current through the solenoid, the magnetic field inside the solenoid is expressed as the product of vacuum...
10:42
A Protocol for the Production of Integrase-deficient Lentiviral Vectors for CRISPR/Cas9-mediated Gene Knockout in Dividing Cells
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Cited by 21 •
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09:20
Vectors in Multiple Directions
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2023
Source: Nicholas Timmons, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA This experiment demonstrates how vectors add and subtract in multiple directions. The goal will be to analytically calculate the addition or subtraction of multiple vectors and then to experimentally confirm the calculations. A vector is an object with both magnitude and direction. The magnitude of a vector is simply denoted as the length,...
09:40
Batch and Continuous Bioreactors
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2023
Bioreactors are used to grow organisms in large volumes, thereby enabling the production of mass quantities of the target product. These reactors can be batch reactors, which contain all of the components needed for cell growth, or continuous reactors, which have inlet and outlet ports allowing for the addition of fresh growth media and the removal of cell waste. This video presents batch and continuous reactors and demonstrates the use of bioreactors to grow bacteria in the laboratory.
01:21
The Resting Membrane Potential
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2019
Overview The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane. The Inside of a Neuron Is More Negative The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular...
FAQs
Gauge choice affects whether the same vector potential appears continuous, because different gauges can produce different forms of A while preserving the represented electromagnetic fields. Consequently, continuity is imposed within a compatible gauge rather than treated as an absolute physical law. The selected gauge must work with the boundary conditions so that the resulting magnetic and electric fields remain consistent with Maxwell’s equations.
The components of A and, when required, its derivatives are matched according to the boundary conditions and the chosen gauge. The goal is not to impose identical conditions on every component automatically, but to preserve the correct curl and field behavior on both sides. This selective matching supports solutions in which the magnetic and electric fields satisfy Maxwell’s equations at the interface.
Surface currents or charges can modify the boundary conditions that determine how A and its derivatives are matched. These sources may require a discontinuity or altered relation in the relevant quantities rather than simple smooth matching everywhere. Accounting for them prevents the potential-based solution from producing electromagnetic fields that conflict with Maxwell’s equations at the interface.
Continuity of A depends on gauge, whereas the magnetic field obtained from its curl and the electric field derived within the formulation represent the physically relevant quantities. A may therefore change under a gauge transformation without changing the fields. Boundary analysis must consequently distinguish a convenient potential matching condition from requirements imposed on observable electromagnetic behavior.
A typical workflow selects a gauge, writes the vector-potential solution in each region, and identifies the boundary conditions that connect the regions. The relevant components of A and any needed derivatives are then matched, with surface sources included when present. Finally, the resulting fields are checked against Maxwell’s equations, providing a consistent analytical boundary-value solution.
In electromagnetic simulations, compatible gauges and boundary conditions allow the potential to be matched across regions without creating inconsistent field representations. The numerical formulation can then calculate fields from the potential while respecting interfaces, sources, and Maxwell’s equations. This approach supports stable simulations, particularly when the computational domain contains multiple regions requiring coordinated boundary treatment.
A successful treatment shows that the regional potential descriptions work together to produce magnetic and electric fields satisfying the required equations and interface conditions. It also indicates that gauge choices, derivatives, and any surface sources were handled consistently. In physics research, this validation helps distinguish a mathematically convenient potential representation from an electromagnetic solution that is physically acceptable.