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There are two questions.. 1. What is the concept of magnetic monopole here? 2. Why Maxwell's eqns remain unmodified? They are not elementary particles as anticipated by P.M.Dirac. But the concept comes from the non-zero divergence of magnetization field. In electrostatics when you have $\nabla\cdot \mathbf{P}$ (polarization vector) not equal to zero, you ...


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No, a magnetic monopole a la the Dirac string does not "violate" gauge symmetry. Rather, the statement "we have a magnetic monopole" means only that we are forced to consider the gauge theory not on the whole spacetime, but on the spacetime with the location of the magnetic monopole removed. Why? Because, at the location of the magnetic monopole, the curl of ...


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I have demagnetized materials to try to eliminate magnetic fields from experiments. I took a coil of wire and passed AC mains through it to create an oscillating magnetic field - The AC was connected through an AC transformer like the one in the picture. slowly over time the voltage was reduced so a smaller and smaller magnetic field was used. To ...


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You should take an electromagnet that operates on some frequency (tens of Hertz) and creates enough large magnetic field to magnetise your permanent magnet. Then you switch on your electromagnet in the vicinity of the permanent magnet and go slowly back from the permanent magnet at the distance of several meters. After this the permanent magnet should be ...


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In the absence of magnetic monopoles, Maxwell's equations are $$\text d F = 0,$$ $$\star\text d\star F = J_e,$$ where $J$ is the 4- current 1-form due to electric charges. For cohomological reasons, from the first equation one can asserts that there exists a 1-form $A$ such that $F = \text d A$, and $A$ is the interpreted as the 4-potential $(\phi,\mathbf ...



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