Questions tagged [string-theory]
A class of theories that attempt to explain all existing particles (including force carriers) as vibrational modes of extended objects, such as the 1-dimensional fundamental string. PLEASE DO NOT USE THIS TAG for non-relativistic material strings, such as, e.g., a guitar string.
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How to get $T_{M2}=2\pi (2\pi \ell_p)^{-3}$?
In 11-dimensional supergravity, we have $$16\pi G_{11}=2\kappa^2_{11}=\frac{1}{2\pi}(2\pi \ell_p)^9$$ by comparing the Einstein-Hilbert action
$$S=\frac{1}{16\pi G_D}\int \sqrt{-g}R d^D x$$ with ...
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How to obtain the Virasoro decendent $\alpha_{-1}^2|0\rangle$?
It was known that $$[L_m,\alpha_n]=-n \alpha_{m+n}$$
For a virasoro primary states $|\alpha\rangle$, one could act on the $L_{-n}$ raising operator to obtain the decendents $L_{-n} |\alpha \rangle$.
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Motion integrals of string theory
My advisor has told me about a problem that has been present for the past 40 years, yet, unfortunately, I can't find anything specific on it neither had he provided any source.
Introduction
Define ...
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What is the difference between these two vector supermultiplets?
The authors (Becker-Becker-Schwarz) in the book "String theory and M-theory" say on page 257 (and some other pages) that $D=10$ vector supermultiplet (in the light-cone gauge notation) is $...
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Some details concerning Kaluza-Klein number
Consider bosonic string theory compactified on a circle of radius $R$ so that the coordinate $X^{25}$ is compact and the remaining coordinates are noncompact. The spectrum is described by the mass ...
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When was the Regge trajectories first proven with $J\sim M^2$?
In Regge's original papers in 1959 and 1960, the function between spin and energy was shown, however, the inequality was proven for a bound of $\frac{1}{\sqrt{E}}\sim \frac{1}{M}$, which is also what'...
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Question on basic strings in curved spaces
Recently when studying strings on curved spaces I arrived at a question that I wasn't able to answer myself. In the particular setup I'm using, I'm considering the Polyakov action $$S = - \frac{T}{2}\...
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SUSY QM as point-particle limit of Superstrings
There is a pretty clear resemblance between the Lagrangians for SUSY QM (1-dim susy sigma model) and various superstring theories (2-dim susy sigma models).
Again intuitively, one should expect the ...
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Global conformal gauge
I'm reading the Blumenhagen-Lust-Theisen book on string theory. On page 18, They want to discuss whether a global conformal flat metric can exist, namely
$$
h_{\alpha\beta}=e^{2\phi}\eta_{\alpha\beta}
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What is the relationship between $g_s$ and $\alpha'$?
On page 300 in the book "string theory and M-theory" by M. Becker-Becker-Schwarz, the author mentions
"we have described in previous chapters that how various superstring theories ...
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Magnetic dual of M2 branes and M5 branes?
Why do we say: the M2 branes and M branes are magnetic dual?
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Field redefinition to absorb counter term
Consider the following string action
$$S = \frac{1}{4\pi\alpha'} \int d^2\xi \bigg[\alpha'\eta_{\mu\nu}\partial_\alpha Y^\mu\partial^\alpha Y^\nu - \frac{(\alpha')^2}{3}R_{\mu\alpha\nu\beta}(X_0) Y^\...
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String theory suppose world-sheet is globally conformally flat?
It is known that every 2-dimensinal Lorentzian manifold is conformally flat and in general it's not globally conformally flat.
(Here, globally conformally flat means there are a global coordinates ...
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String theory without coordinates
I'm sorry but I'm not good at English. If you find any sentence or word doesn't make sense, please comment.
Is there any string theory's book or review reference that doesn't use coordinate-depending ...
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Dine-Seiberg moduli
The Dine-Seiberg problem requires $\lim _{\Phi \to \infty } V(\Phi )=0$ where $V$ is the scalar superpotential. And in type IIB SUGRA, your moduli are essentially the axiodilaton, Kahler moduli and ...
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