# Tagged Questions

A magnetic monopole is a hypothetical particle with only one magnetic pole. Their magnetic fields would not be divergence-less. Predicted by certain modern theories, including string theory, supergravity, and various popular grand unified theories.

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### Theoretical magnetic Monopole

I'm trying to solve question B2 on the 2012 USAPHO semifinal exam (last page). The solutions are here on the last three pages. I don't understand the following line: The flux through the loop ...
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### How to demagnetize a magnet temporarily?

How to demagnetize a magnet temporarily? Is it possible making a permanent magnet demagnetize for a short span of time? Or at least long time but temporarily!
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### Plane-wave wave function in 3D with vector potential

I was looking into a monopole scattering problem in 3D with magnetic potential. What would be the most general incident plane wave solution ? The way I see this is that I need to ensure that current ...
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### Permanent Magnet Lines & Currents:

A permanent magnet produces lines of magnet flux that we call a "magnetic field". Those lines come from inside the magnet, come out of the N pole, loop outside the magnet, & return back into the ...
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### Question from Terning's book

In Chapter 7 of Terning's book (Modern Supersymmetry), the first example considered is that of an SO(3) gauge theory, a complex scalar in the triplet representation of SO(3) and a potential term: ...
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### Is it possible to make an electromagnet with two like ends?

Is it possible to create an electromagnet with one continuous wire with 2 like poles (i.e. both ends either north or south)?. Visualising it with the right hand screw rule for current carrying ...
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### Purpose of magnetic charge and current density

I am aware that introducing a magnetic charge density and a magnetic current density makes Maxwell's equations much more symmetric. But in what situations/problems is this beneficial? Could someone ...
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### How to make a monopole magnet?

I want to create a monopole magnet. Is this practically / theoretically possible?
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### Can the poles of a magnet have varying intensity?

In re-reading Is it possible to separate the poles of a magnet? (amongst others) the question mentioned in the title here just occurred to me. It may not be possible, at our current levels of ...
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### Dirac monopole of Berry curvature?

We know that there is an effective "magnetic field" in terms of Berry curvature, which leads to Luttinger's anomalous velocity, etc; and similarly there is also a "magnetic flux", which appears in ...
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### Magnetic monopole using differential forms

I'm trying to understand the different variations of the Maxwell's equations using differential forms. The Maxwell's equations are $$dF=0\\ *d*F=J$$ where $F$ is the electromagnetic tensor ($F=dA$) ...
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### Search for unpublished note on Magnetic Monopole Detection

Design of an electromagnetic detector for Dirac monopoles by Luis Alvarez This is an unpublished 1963 note from Lawrence Radiation Laboratory (Physics Note 470), and is heavily cited in all papers on ...
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### How we can detect a magnetic monopole? [duplicate]

How we can detect magnet monopole? How we can distinguish it from electric monopole? If we change E to B and B to -E in Maxwell's equations we get proper equations for charge and current density which ...
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### How would I go about detecting monopoles?

A question needed for a "solid" sci-fi author: How to detect a strong magnetic monopole? (yes, I know no such thing is to be found on Earth). Think of basic construction details, principles of ...
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### $S^2$ and monopole [closed]

In mathematics, to describe a sphere $S^2$ we need two coordinate patches which we call the North semi-sphere and South semi-sphere. Between them there is a map which mathematicians called the ...
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### Magnetic monopole bound state

Magnetic monopole (mm) bound states Background: I'm an experimentalist, simple equations are appreciated. (Complicated equations are fine, as long as I can ask questions.) This is one of many ...
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### Total angular momentum of electron in a magnetic field

In this question: Electron in the proximity of a magnetic monopole It is stated that for an electron in the magnetic field of a monopole, $\vec{B}(\vec{r}) = \frac{g}{r^3}\vec{r}$ , that the ...
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### What consequences could discovery of Magnetic Monopoles have? [closed]

What will happen if fundamental (as opposed to synthetic) magnetic monopoles are somehow discovered? Will it contrbute to the generation of electricity? This thought has been haunting me ever since I ...
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### Dyon condensation and generalized Meissner effect

In section 2.B of Metlitski and Vishwanath's paper: "Generally condensation of a dyon with charges $(q,m)$ gives rise to an analogue of a Meissner effect for the gauge field combination ...
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### Distinction of Dirac monopole and Polyakov-'t Hooft monopole

Can anybody explain the physical difference between Dirac monopole and Polyakov monopole? First, let me write down what I know briefly. Dirac monopole It comes from the symmetry of Maxwell ...
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### What is the difference between Reissner-Nordstrom (RN) black hole and dyonic black hole?

A RN black hole is a black hole with electric charge, and a dyonic black hole with both electric charge and magnetic charge. My Questions: Is the above statement correct? Is the charges the unique ...
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### Why do physicists believe that there exist magnetic monopoles?

One thing I've heard stated many times is that "most" or "many" physicists believe that, despite the fact that they have not been observed, there are such things as magnetic monopoles. However, I've ...
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### Coupling an electric charge to a gauge field. How is it done in this setup?

In page 9 of Tachikawa's N=2 susy dynamics for pedestrians it says that an electric particle with charge $n$ in the first quantised setup (in what sense first quantised?), Wick rotated to Euclidean ...
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### Instantons and Fivebranes

What is the general relationship between instantons and fivebranes? In the paper Magnetic Monopoles in String Theory'' by Gauntlett, Harvey and Liu, the authors state the fivebrane ansatz of ...
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### Quantising the magnetic monopoles the make Maxwell symmetric

I don't believe this has already been asked, but I might be wrong; sorry. One can add a magnetic charge density/magnetic monopoles to Maxwell's equations to make the theory symmetric between the ...
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### The magnetic field of a magnetic monopole

Let us define the magnetic field $$\vec{B} = g\frac{\vec{r}}{r^3}$$ for some constant $g$. How can we show that the divergence of this field correspond to the charge distribution of a single magnetic ...
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### Would magnetic charge (i.e., magnetic monopoles) be Lorentz invariant if it existed?

Would magnetic charge (i.e., magnetic monopoles) be Lorentz invariant if it existed? It is clear that Maxwell's equations in themselves permit magnetic charges but what would their relativistic ...
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### Poincaré' lemma and EM potential $A^{\mu}$

My lecturer said that given the sourceless Maxwell's equations $$\partial_{\mu}\, ^ *F^{\mu\nu} = 0$$, we can find a solution $$F^{\mu\nu} = \partial_{\mu}A_{\nu} - \partial_{\nu}A_{\mu},$$ that ...
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### Experiments looking for monopoles

Background: (skip it if you know it) In the easiest formulation of classical electromagnetism magnetic monopoles do not exist. In fact, the Maxwell's equation $\nabla \cdot \vec{B}=0$ implies (using ...
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### Experiments or phenomenon to falsify the existence of monopoles?

This is a related, but opposite question to this one I have heard about a lot of things regarding elementary and GUT magnetic monopoles, as well the quasiparticle monopoles in spin ice Since there's ...
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### What is the assurance that a magnetic monopole (if created) can be detected through the MoEDAL Experiment?

Please refer to this paper (http://web.mit.edu/ellisk/www/monopoles.pdf). It says in the Section B, ... One search technique relies upon the fact that, just as an electric current produces a ...
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### Is it possible to separate the poles of a magnet?

It might seem common sense that when we split a magnet we get 2 magnets with their own N-S poles. But somehow, I find it hard to accept this fact.(Which I now know is stated by Gauss's Law) I have ...
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### What will be the motion of an electron kept at rest in the vicinity of a magnetic monopole?

Consider that both an electron and a magnetic monopole are kept at rest close to each other. Will this result any motion of the electron? If yes, please give a derivation of the equation of motion.
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### How are the Lorentz force, Maxwell's third law and Faraday's law of induction clasically related?

Faraday's law of induction can be used in any situation where the magnetic flux is changing through a closed conducting loop. While giving the correct answer, it seems to me that for the following ...
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### Magnetic monopoles and special relativity

I was thinking about magnetism as a product of special relativity and the result of this approach to the magnetic monopoles. So if magnetism is a product of electricity(like electricity from another ...
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### Quantum mechanical monopole [duplicate]

Recently in physics news, scientists have experimentally discovered the so-called quantum mechanical monopole. It seems that a quantum mechanical monopole is different from a magnetic monopole. So my ...
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### Is this a possible monopole setup, or will it cancel out? [duplicate]

Suppose you have a ball that is covered in magnets, in which the North Pole of every magnet faces outward. Is this a monopole? Or at least "functions" as a monopole? And what will happen if you placed ...
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### Electric fields and magnetic fields [closed]

I would love to know if this is roughly correct with regards magnetic fields. I recently heard someone say that there are people still looking for monopoles. I said I don't think that can be true as ...
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### What do we mean with magnetic monopole and dipole?

What do we mean with magnetic monopole and dipole? I can not find a way to relate magnetic monopoles and dipoles with electric ones. I do not understand their outcomes. Also,what is their role in ...
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### Dirac quantization condition for magnetic monopoles how is obtained? [duplicate]

assuming we have a magnetic monopole charge on the origin with magnetic field given by $$D= \frac{q.dr}{r^{2}}$$ how is the quantization of the charge for a monopole obtained in this case ?? i ...
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### conducting hollow sphere in magnetic monopole

if a hollow copper sphere(or any conducting hollow sphere) is connected to dc at points diametrical and a magnetic monopole is right at the center of the sphere then will there be any movement of the ...
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### Can you put a magnetic ball into a hollow magnetic sphere?

if all magnets have to have two poles(one north one south), is it possible to construct a hollow sphere where the inside face of the sphere was one pole, and the outside face another pole? is it also ...
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### Is the Lorentz force expression valid for magnetic field created by a magnetic monopole?

Will the Lorentz force expression be valid for a magnetic field created by a magnetic monopole? I haven't seen any derivation of Lorentz force expression yet and I don't know whether it was derived ...
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### Are the recently observed Dirac monopoles separable?

I just went through Observation of Dirac monopoles in a synthetic magnetic field. What exactly has been observed? More importantly, are these monopoles localized inside the apparatus (no stray ...
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### Why magnetic monopole found in spin ice don't modify the Maxwell's Equations?

Magnetic monopole predicted by Dirac nearly a century ago was found in spin ice as quasi-particle(2). My question is Why magnetic monopole found in spin ice don't modify the Maxwell's Equations? (I ...
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### Does magnetic monopole violate $U(1)$ gauge symmetry?

Does a magnetic monopole violate $U(1)$ gauge symmetry? In what sense and why? Insofar as I know, there are at least two types of magnetic monopoles. One is the Dirac monopole while the other is the ...
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### How will SR EM Lagrangian change if we find a magnetic charge?

When we introduce electromagnetic field in Special Relativity, we add a term of $$-\frac e c A_idx^i$$ into Lagrangian. When we then derive equations of motion, we get the magnetic field that is ...
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### Is there a relation between (non-) existence of magnetic monopoles and thermodynamics?

This question follows on previous work on connections between (other) areas of physics and thermodynamics as in here, here and even here. P. Dirac (an electrical engineer initially) was one of the ...