Questions tagged [magnetic-monopoles]

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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In which representation are monopoles of grand unifying theories classified?

In the context of grand unification theories A.Zee's book states that $SU(5)$ (or $SO(10)$ if $SU(5)$ is considered as outdated as GUT candidate) as GUT and as spontaneously broken non-abelian gauge ...
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Field-strength tensor after symmetry breaking of $SU(2)$

I am currently trying to understand the paper https://iopscience.iop.org/article/10.1088/0034-4885/41/9/001 and I am stuck on eq. (4.29). Basically what I understand is that, you have your field ...
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An improved magnetic monopole detection setup?

A "common" way to try to detect magnetic monopoles is to look for otherwise inexplicable changes in the current carried in a superconducting loop. The idea there is that the radial field surrounding ...
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How magnetic monopole modifies faraday's law

I have encountered a statement that upon existence of magnetic monopoles, the equation $$\nabla \times \textbf{E} = -\partial_t \textbf{B}$$ must be modified. I only see that the last equation $$\...
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Magnetic Dipole Moments and Dipole Contributions

I'm currently in Physics 2 (calc-based) at my University. On the last exam we had questions over magnetic dipole moments and dipole contributions. I'm still unable to solve these problems. Would ...
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Why did David Tong say that the global topological $U(1)$ symmetry is unbroken in Higgs phase?

In the paper A Duality Web in 2+1 Dimensions and Condensed Matter Physics by Seiberg, Senthil, Wang, and Witten, they studied the particle-vortex dualities in $2+1$ dimensions. On page 20, section 3....
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Gravity, particle properties and magnetic monopoles

Generally, magnetic monopoles searches assume it has a mass. And that introduces gravity into the game. But, my question rough is: Why should a magnetic monopole have a mass or any other ...
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Halbach Array and Levitation

Full disclosure: I am a total novice when it comes to physics apart from being very curious and basic physics classes at school level. (Long long ago). Using 16mm diameter disc magnets. I am ...
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What do magnetic field lines represent?

When magnetic field lines of permanent magnet were put, they supposed a north monopole magnet, so if you put a monopole north magnet it will follow the magnetic field lines. But what about the ...
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Non-relativistic vector first integral

In this paper the author discusses the Poincaré vector $\vec D$, and he wrote the Lorentz equation when magnetic charge is present. Do you have any suggested reading for this and how he derived the ...
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Magnetic fields and closed loop

It is well known that there don't appear to be magnetic poles. In Maxwell's equations this has the implication $$ \nabla \cdot \mathbf{B} = 0 $$ and results in the statement "the magnetic field forms ...
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Moving charge to define magnetic field

1-why charged particle has to be in motion to define magnetic field? 2-will magnetic force exert any force on a static charge?(as in the static test charge in electric field) 3-A line from my book ...
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Do magnetic field lines indicate how a mangetic field will act on an “idealized” test magnetic north monopole?

We imagine an electric field and a magnetic field as vector fields. When we are introduced to a static electric field, we usually picture it as an infinite number of vectors (magnitude,direction) in ...
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If a magnetic monopole travels through a wire loop, which way does the current flow in the circuit?

I am confused about the sign convention for the electric field as described in the wikipedia article "Magnetic_monopole" and I would appreciate some help clarifying the topic. Take a positive (north) ...
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Some questions on a certain Lagrangian related to $n$ dyons

I am trying to understand Gibbons and Manton's article. I am trying to understand the Lagrangian that they wrote down, from a physical point of view. Let me paraphrase from that article. "Consider $...
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Monopole Spherical Harmonics

I was following Yakov Shnir his book about magnetic monopoles, there they derive the monopole spherical harmonics. I will sketch the derivation briefly, The starting equation is the eigenvalue ...
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Wave function constrained to a fixed trajectory? Really?

this is probably a very stupid question. First of all, I'm a mathematician so please try to use coordinate-free notations. It's often used in quantum mechanics a wave function depending on a fixed ...
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Is Brandt-Neri-Coleman stability analysis valid?

My question is related to the problem of stability of magnetic monopoles in Yang-Mills-Higgs theories. I have read "The Magnetic Monopole 50 years later" from Coleman and, in section 3.5, he discusses ...
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Singularity of $B$-field in a Dirac String

I was assigned this question related to Dirac strings: Given a vector potential $\vec{A}= \frac{1-\cos(\theta)}{r\sin(\theta)}\hat{\phi}$, show that there is a singularity in the B field ...
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Dirac's Theory of magnetic monopoles

Can someone give a breif summary of Dirac's theory of magnetic monopoles a rather simple way? Please also tell what methods he used and key ideas presented in his paper. I am asking this because it is ...
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Vector potential of magnetic monopole

I am following the step on this introduction to magnetic monopole. I understand that the vector potential produced by semi-infinite solenoid is exactly the vector potential of magnetic monopole. But ...
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Classical Yang-Mills equation of motion with both electric and magnetic sources?

We know the classical Maxwell equation of motion (eom) with both electric and magnetic source can be written as: (1) Explicit form or more schematically as: (2) Differential form $$ d * F = * J_e $$...
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Basic question on magnetism regarding north and south pole

I am currently busy with some magnetism and quite shockingly (to me at least) I haven't yet read anything about the difference between the north pole and the south pole of a magnet. Before I started ...
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Why separate magnetic poles do not exist? [duplicate]

We are always taught that it is not possible to have separate magnetic poles .Even kn cutting a magnet in half a new magnet are constructed . What is the reason for this unique behaviour ?
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Do magnetic dipoles align with $\mathbf B$ or $\mathbf H$, and why are the two field so closely associated?

As the title says, do magnetic dipoles align with $\mathbf B$ or $\mathbf H$? If one and not the other, why is that? In addition, what force is responsible for causing the magnetic dipoles to align ...
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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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Can the Dirac quantization condition be derived within Lev Vaidman's formalism without gauge fields?

Textbooks often claim that phenomena like the Aharonov-Bohm effect require that any local formulation of quantum gauge theory use gauge potential fields. (It's also sometimes claimed that the A-B ...
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Does a rotating magnetic monopole have electric and magnetic moment in classical view?

Would a rotating sphere of magnetic monopole charge have electric moment ? In a duality transformation $E\rightarrow B\cdot c$ etc. how is the magnetic moment translated $m = I\cdot S $ ? $M_{el} = \...
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Conservation of magnetic charge

It is well known that the electric charge of a system can be thought of as the Noether charge associated with isotropic large gauge transformations. That is, given Einstein-Maxwell theory $$S=\frac{1}...
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Where did the idea that there *might* be magnetic monopoles come from? [duplicate]

I know that we declare that there exist no magnetic monopoles. I see it all the time in my E&M class. $$\vec{\nabla}\cdot\vec{B}=0$$ So there exists no point for $\vec{B}$ to originate from and no ...
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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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What will be the difference in the behaviour between electric charges and between magnetic charges?

It’s often asked in PSE about the existence of particles with magnetic monopoles. What’s the difference in interaction between magnetic monopoles and electric monopoles in such a theoretical case? ...
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how much magnetic field is experienced at the centre of bar-magent?

What is the magnitude of magnetic field at the centre of bar magnet? What's its mathematical expression?
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Can Maxwell's equations be derived from Coulomb's Law and Special Relativity?

As an exercise I sat down and derived the magnetic field produced by moving charges for a few contrived situations. I started out with Coulomb's Law and Special Relativity. For example, I derived the ...
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How should I think of monopoles in a 3+1D lattice $U(1)$ gauge theory?

The Hamiltonian for 3+1D compact $U(1)$ gauge theory on a cubic lattice is of the form \begin{equation} H = J\sum_{\text{links}\ l}E^2_{l}+ g \sum_{\text{plaquettes}\ P}\cos(\Phi_P), \end{equation} ...
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Dirac magnetic monopoles and quark fractional electric charge quantization

When applying the Dirac quantization rule for electric and magnetic charge, I assume one is considering unit electric charges such as electrons. How does the Dirac quantization rule apply for the ...
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Can the field of an earth magnet be changed using electricity this way?

Is there any way to coil a wire around a permanent magnetic and apply an electrical current in which a permanent magnet field can be neutralized, increased or reversed? Just like making a simple ...
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What is the formula for electromagnetic force on magnetic charge in condensed matter?

It is known that if we take into account the magnetic charges, Maxwell's equations acquire a symmetrical form (Jackson, 3rd edition, eq. 6.150): \begin{align} \begin{aligned} -\nabla \times \...
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Question about Charge and Gauge Transformation

Does gauge invariance imply charge neutrality? I understand that all physical observables must be gauge invariant. Does this mean that physical observables must be neutral? If a quark is in red, a ...
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If monopoles are excised points in a $U(1)$ bundle, how are they affected by other charges?

We currently understand electromagnetism as a U(1) gauge theory. If you take a point out the space manifold (base space) you can create magnetic monopoles with integral charges by making non-trivial ...
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Why can't a particle that carries magnetic charge exist? [duplicate]

Electron is the source of electric field and changing electric field produce magnetic force, what about particle that can do vice versa? My concern is how come universe favors particles that carry ...
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Runaway Monopole Catalyzed Baryon Decay

I am a layman in the subject, but I have recently learned that magnetic monopoles could be used to induce baryon decay (Callan-Rubakov mechanism), according to some GUTs. I have also learned that ...
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How to show monopole term in magnetic vector potential is 0?

Assume we are in a magnetostatic and electrostatic situation. In the multipole expansion of the magnetic vector potential, we end up with $\vec{A}(\vec{r})=\sum_{n=0}^\infty \vec{A}_n(\vec{r})$ ...
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Explanation for magnetic declination [closed]

A compass in New York points about 15 degrees west of true north; in California, it points about 15 degrees east of true north. Magnetic declination also varies with time. What are some possible ...
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Dirac equation and Hamiltonian for a collection of magnetic monopoles

I am trying to understand a mathematical comment by Eugene Wigner in some old lecture$,^{[1]}$ "The Hamiltonian of the Dirac equation for two oppositely charged monopoles is not self-adjoint." What ...
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Maxwell theory : How to justify the potential gauge fields if there are magnetic monopoles?

Without magnetic monopoles, the Maxwell equations are these (I'm dropping vector notations and all constants, for simplicity): \begin{align} \nabla \cdot E &= \rho_{elec}, \tag{1} \\[12pt] \nabla \...
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Magnetic Shielding

Imagine a substance in an electric field. You don't want the electric field to interact with the object you have put in its way. What should be the type of material this magnet should be made of to ...
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Does the electrodynamics-like PDE $\epsilon^{ijk}\partial_j B_{kl}(x) = \delta^i_l\delta^{(3)}(x)$ have solutions?

Consider the following PDE in 3 dimensions $$ \epsilon^{ijk}\partial_j B_{kl}(x) = \delta^i_l\delta^{(3)}(x)$$ Does $B_{kl}(x)$ have a solution? (It can have any kind of singularity, e.g. it can have ...