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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402 views

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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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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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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Do semiclassical GR and charge quantisation imply magnetic monopoles?

Assuming charge quantisation and semiclassical gravity, would the absence of magnetically charged black holes lead to a violation of locality, or some other inconsistency? If so, how? (I am not ...
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205 views

Question about Monopole Operator

I've been studying IR-dualities in 2+1 dimensions. I encountered monopole operators in the following paper: Time-Reversal Symmetry, Anomalies, and Dualities in (2+1)d On page 10, starting from $...
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Why does Witten say that his work only makes sense if magnetic monopoles exist?

Witten emphasises (in the Q&A session after his talk on introductory knot theory) that he works on theories which admit magnetic monopoles. But how would the theories break down if magnetic ...
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333 views

Fields with SO(3) diagonal subgroup symmetry

I read about a Higgs field $\vec{\phi}=\frac{1}{2}a\hat{r}\cdot \vec{\sigma}$ (in the context of 't Hooft-Polyakov monopole) with SO(3) diagonal subgroup symmetry consisting of simultaneous and equal ...
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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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136 views

Quantizing fermion zero modes in topological phases

I don't understand how the fermionic zero modes which become monopole operators are being quantized in Witten and Seiberg's paper on gapped boundary phases of TI's via weak coupling: https://arxiv.org/...
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103 views

Are there any models that explain the cause of the dual symmetry-breaking of the in electrodynamics?

Source-free Maxwell eqautions a dual symmetry between electric and magnetic fields is obvious. But in the presence of electric charge, such symmetry is broken. Recover it possible by an introduction ...
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109 views

Divergence calculation of a lie algebra valued quantity having spinor indices

I am reading this paper by E. Weinberg - Fundamental monopoles and multimonopole solutions for arbitrary simple gauge groups. I am having a problem with a calculation. I don't have much experience ...
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302 views

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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33 views

Monopoles from hypothetical Weinberg-Salam model with massless Z boson

We know that no monopoles exist in the Weinberg-Salam model (a good explanation is provided in the answer to this previous question). Now let us assume that the initial $SU(2)\times U(1)$ gauge ...
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62 views

No global monopoles in QCD

If a global symmetry gets both spontaneously and explicitly broken, the explicit symmetry breaking pattern is crucial for understanding the formation of topological defects. For example, in the axion ...
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67 views

Magnetic monopole's behavior in a magnetic field

I have seen the statement in a physics forum: "Imagine a magnetic monopole and a very thin magnet so that the monopole is able to just shoot through the magnet. It then goes around in circles, ...
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130 views

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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Classical/ Quantum mechanical view of magnetic monopoles

Is there any classical/ quantum mechanical proof for the non-existence of magnetic monopoles? Or is it just lack of experimental evidence that has led us to the conclusion that monopoles do not exist, ...
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45 views

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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86 views

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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66 views

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 ...
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19 views

Linking phase of flux lines and excitation energy of monopole

I am reading this paper and on the left-hand side of pp.10 it states the following relation between linking phase and excitation energy of monopole: Now the $\theta = \pi$ term in the bulk implies ...
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Can we have $\nabla\cdot B \neq 0$ and still no magnetic work?

I had an argument with a friend who says that it's possible to have a force that does no work on monopoles with $\nabla \cdot B \neq 0$. I believe this is not possible, as if we imagine approaching ...
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Why won't this magnetic levitation system work?

According to Earnshaw's theorem, a system of static magnets cannot be stable. I have a though experiment and I'm wondering what would happen in real life. If one were to take a ball and cover it with ...
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84 views

If they were freely available, what would be potential applications of the magnetic monopole?

viz., if the magnetic monopole (the hypothetical fundamental particle, not the fauxmonopole behavior in BECs) was discovered, and then found to be abundant or easily produced, what could they be used ...
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Why does Monopole in $D=3+1$ not drive a compact $U(1)$ gauge theory into a Confined Phase?

In compact $U(1)$ gauge theory, it has confined/deconfined phase. For $D=2+1$, monopole (2$\pi$-flux) event can always drive a system into a confined phase, as shown by duality mapping to a Sine-...
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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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73 views

Showing the force on magnetic dipole

We're given a situation where the circuit can move under the influence of a magnetic force. Now I need to show that the force on the magnetic dipole is $$\vec{F} = (\vec{m} \nabla) \vec{B} $$ Could ...
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120 views

What would happen if you put a superconductor shell around a magnetic monopole?

According to Meissner effect, there would be no magnetic field outside. But according to Gauss's law, the total magnetic flux must be non zero.
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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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93 views

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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1answer
90 views

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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81 views

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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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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131 views

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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23 views

quasiparticles resembling monopole energy generator

Is it possible using quasiparticles that superficially resemble monopoles to make a generator providing a sustainable source of power
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183 views

Magnetic monopole

I've been watching a lot of videos claiming to make monopoles either by dropping the temperature to 5k (-268° C) and splitting the magnet or by pouring molten metal through an induction system and was ...
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395 views

Explanation for the physics behind magnetic monopoles?

Ok so I am looking for a simple explanation of how the process is done from the information I could access and the knowledge I was allowed I have the idea that it is a matter of quantum physics and ...
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70 views

What is Higgs transition?

In recent publications there is a frequent mentioning of the so-called "Higgs transition" in connection with magnetic monoples. Can anybody please describe the phenomenon in simple terms? For example,...
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1answer
448 views

Need of vector potential in quantum mechanics

I need your opinions. Why is the vector potential of a magnetic field important (or even necessary) to quantum mechanics? Why it has to be defined everywhere? Is there any fundamental reason you can ...
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Pauli equation with magnetic monopoles

Magnetic monopoles are thought to exist in some Grand Unified theories. The Pauli Equation uses the magnetic potential A. The curl of A is the magnetic field B. But the divergence of the curl is ...
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27 views

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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13 views

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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2answers
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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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23 views

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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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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45 views

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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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?