Skip to main content

Questions tagged [duality]

The tag has no usage guidance.

0 votes
0 answers
19 views

Symmetry group and dualities

Let's say two quantum models $M_1$ and $M_2$ are dual to each other and let their symmetry groups be $S_1$ and $S_2$ respectively. Is it necessary for $S_1$ to be isomorphic to $S_2$? (I thought so ...
1 vote
2 answers
227 views

Are dual bases and the Hodge dual "entirely distinct" uses of the word "dual", as per MTW?

NB: Basis one-forms and contravariant basis vectors (which, following Menzel, I am calling reciprocal) are the same thing. See, for example, the Mathematical Appendix to Gravitation and Inertia, by ...
3 votes
0 answers
43 views

Physical observables in the XY/sine-Gordon duality

My question is, during the duality map, real physical quantities seem to acquire a prefactor of $i$ and become purely imaginary. And I feel uncomfortable. Take bosonic current for example. Consider ...
2 votes
3 answers
60 views

What is the dual asymptotic spacetime of a CFT on a particular flat manifold?

According to AdS/CFT correspondence, the dual theory of a boundary CFT on flat spacetime is defined on an asymptotically AdS spacetime. The nature of the bulk spacetime depends on the topology of the ...
4 votes
1 answer
151 views

Derivation of self-dual gravity formulae

I am trying to read and understand this paper by Monteiro, Stark-Muchao, and Wikeley about self-dual yang-mills and self-dual gravity. In the introduction to this paper, they review a way to ...
10 votes
0 answers
407 views

How does one actually apply the M-theory/heterotic duality "fiberwise"?

It seems to be generally accepted ([1], [2]) that one can apply the duality between a $T^3$ compactification of heterotic string theory and a $\mathrm{K3}$ compactification of M-theory "fiberwise&...
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 ...
2 votes
2 answers
122 views

How to see that the Ising CFT has $c = 1/2$ while the quantum XY CFT has $c = 1$ via Jordan-Wigner?

It is well known that the CFT at the critical point of the 1+1d transverse field Ising model has central charge 1/2. This can be attributed to the fact that, after a Jordan-Wigner transformation, the ...
2 votes
1 answer
224 views

Implications of M-Theory on the correctness of String Theory

So we know that there are 5 types of string theories (Type 1, Type IIA, Type IIB, $SO(32)$ heterotic, and $E_8 \times E_8$ heterotic). It was shown that these 5 types are just limits of something ...
1 vote
2 answers
339 views

Some questions about the compact boson in David Tong's notes on Gauge Theory

The notes can be found at http://www.damtp.cam.ac.uk/user/tong/gaugetheory.html. In Sec. 7.5.1, T-Duality, around Eq. 7.51, it says that the Bianchi identity $\partial_\mu(\epsilon^{\mu\nu}\partial_\...
1 vote
1 answer
81 views

Electromagnetic duality and vector/pseudovector transformation properties

One consequence of electromagnetic duality (see e.g., https://doi.org/10.1038/s41467-023-36420-4) is that if we have a system described by permittivity and permeability profile $(\varepsilon, \mu)(\...
15 votes
1 answer
773 views

Realization of: CFT generating function = AdS partition function

An important aspect of the AdS/CFT correspondence is the recipe to compute correlation functions of a boundary operator $\mathcal{O} $ in terms of the supergravity fields in the interior of the $AdS_{...
7 votes
1 answer
846 views

T-Duality between Type HE String theory and Type HO string theory

My question is regarding the T-Duality between the 2 Type H string theories. I know that the Type II String theories are T-dual to each other because T-Duality changes the sign of the Gamma Matrix so $...
9 votes
2 answers
1k views

"$\theta$-$\phi$ duality" and $T$-duality -- is the free fermion theory self-dual?

When bosonizing an interacting spinless Luttinger liquid, the action can be written as \begin{equation} S=\frac{K}{2\pi}\int dx d\tau\ (\partial_\mu\phi)^2 = \frac{1}{2\pi K}\int dx d\tau\ (\partial_\...
1 vote
2 answers
109 views

Why $N\to \infty$ limit implies $g_s \to 0$ in holographic QCD?

One basic difficulty in QCD is that it does not contain a small dimensionless quantity that would allow for perturbative calculation of low-energy observables. A remarkable feature of holographic ...

15 30 50 per page
1
2 3 4 5
17