All Questions
Tagged with duality lagrangian-formalism
11
questions
5
votes
0
answers
78
views
How many Lagrangians can a QFT have?
I just stumbled across a presentation by Tachikawa about "What is Quantum Field Theory". He has an interesting perspective that we should think of (at least a subset of) quantum field ...
- 1,014
0
votes
0
answers
136
views
Action in AdS/CFT correspondence
I am a beginner trying to study AdS/CFT correspondence.
Could someone please explain, can we connect action in the gravity side to the field theory side by this correspondence? Can we write the ...
- 186
0
votes
1
answer
100
views
What is $\mu_5$ in string theory?
I have come across the quantity $\mu_5$ in string theory quite a lot but I have not found it explicitly defined anywhere.
The bosonic worldvolume action reads [1]
\begin{equation}
S = \frac{\mu_5}{g_s}...
- 119
6
votes
1
answer
287
views
Why is the electromagnetic duality an S-duality?
One of the examples that Wikipedia gives of S-duality is the EM duality. Namely that
$$
\begin{align}
\mathbf{E} &\rightarrow\mathbf{B} \\
\mathbf{B} &\rightarrow -\frac{1}{c^2}\mathbf{E} \...
- 1,544
2
votes
1
answer
735
views
Legendre transformation in QFT
I know that given the Hamiltonian of a theory, there can be many different associated Lagrangians, or even none at all, but why is that so? In classical mechanics the Hamiltonian and Lagrangian ...
- 431
1
vote
1
answer
108
views
Showing that the $\mathcal{N=2}$ SUSY Effective Action is Duality-Invariant
The effective action of the $\mathcal{N}=2$ supersymmetric $SU(2)$ gauge theory contains the following term;
$$Im\int d^{4}xd^{2}\theta d^{2}\bar{\theta}\Phi^{\dagger}\mathcal{F}'(\Phi)$$
Where $\Phi$ ...
- 577
5
votes
2
answers
620
views
Duality transformations, such as between a massless scalar field and the Kalb-Ramond field
There is a kind of duality transformations between antisymmetric tensor fields which I learnt from a series of lectures by Gia Dvali on quantum field theory. I have not been able to locate a source ...
- 2,568
2
votes
0
answers
105
views
New-minimal vs old-minimal supergravity
New-minimal set of supergravity auxiliary fields includes a two-form field, whereas the old-minimal auxiliary set includes a vector and a complex scalar. Is anyone aware of how to transform between ...
- 2,726
4
votes
1
answer
666
views
Is there either a Lagrangian or a Hamiltonian formulation of electromagnetism with continuous distributions of magnetic monopoles?
Maxwell's equations generalize very nicely if we add in magnetic monopoles: we get
$$\begin{align*}
\partial_\mu F^{\mu \nu} &= J^\nu \\
\partial_\mu \tilde{F}^{\mu \nu} &= \tilde{J}^\nu,
\end{...
- 48.4k
1
vote
1
answer
182
views
Electric Magnetic duality
In this paper http://arxiv.org/abs/hep-th/9705122 Section 2
We have $$S_A = \frac{1}{4g^2} \int{d^4x F_{\mu\nu}(A)F^{\mu\nu}(A)}$$
where $F_{\mu\nu}(A) = \partial_{[\mu A\nu]}$. Its Bianchi Identity ...
- 215
8
votes
1
answer
3k
views
${\cal N}=4$ supersymmetric yang-mills theory and S-duality
[Question suggested by @Lawrence B. Crowell's answer to the question on T-duality]
There are three parts to my question:
A. What is the action for ${\cal N}=4$ SUSY Yang-Mills and what is the physics ...
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