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Questions tagged [string-theory]

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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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Question 1: is it always possible to write the metric in that form? Is it sufficient the local conformally-flat form to obtain the volume? Question 2: Is the volume form in (4.1) well-defined? Going ...
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D. Tong's notes on string theory (PDF), subsection 5.1.1, feature the following in introducing the symmetries used in the Faddeev-Popov method: We have two gauge symmetries: diffeomorphisms and Weyl ...
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Inspired by "if a metastable de Sitter space lasting for cosmological durations really is impossible in string theory, then dark energy needs to be explained in some other way, e.g. via ...
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Generally, when you evaluate the 3 open string tachyon tree-level amplitude in CFT, you do a conformal transformation mapping the worldsheet to the upper half of the complex plane and the incoming and ...
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Can a universe with only one spatial dimension and one time dimension still have meaningful physics? For example, can quantum fields in 1+1 dimensions produce effects similar to higher dimensions, or ...
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Consider the following bosonic NS-NS sector of closed string worldsheet action, having the following spacetime fields - metric tensor $G_{\mu\nu}(x)$ Kalb-Ramond Field $B_{\mu\nu}(x)$ and scalar ...
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What is Mathematical formulation of Holographic principle The holographic principle is a property of quantum gravity and string theories which states that the description of a volume of space can ...
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Reading the book$^{\dagger}$ Chern-Simons Theory, Matrix Models, and Topological Strings by Marcos Marino, I'm trying to understand the argument in 7.3.2: here are my main questions which can also be ...
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I am computing the EOM of the Nambu-Goto action $$S[X] = -T\int d^2 \sigma \sqrt{-\det{(\partial_a X^\mu \partial_b X_\mu)}}$$ and I want to write this in a specific form using the second fundamental ...
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The Regge trajectory in QCD is given by $$m=\sqrt{\frac{J}{\alpha}-\alpha_0},$$ where $m$ is the mass and $J$ is the angular momentum of the hadrons, $\alpha=(4\pi\sigma)^{-1}$ is the inverse QCD ...
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As I understand it, string theory (incorporating bosons and fermions) "works" in $9+1=10$ spacetime dimensions. In the context of dual resonance theory, I've read descriptions of why that is "...
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In Polchinski's book, it states that the corresponding operators of $|1\rangle, |-1\rangle$ are $\delta(\beta),\delta(\gamma)$, and suggests that it can be shown by path integral. I'm a little ...
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This query stems from Witten's paper, ''Solutions of Four-Dimensional Field Theories via M Theory'' (hep-th/9703166). Specifically, consider Type IIA string theory, and suppose one has a stack of NS5 ...
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The definition of Pohlmeyer invariants in flat-space (as per eq-2.16 in Urs Schreiber's DDF and Pohlmeyer invariants of (super)string) is the following: $$ Z^{\mu_1...\mu_N} (\mathcal{P}) = \frac{1}{...
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The definition of Pohlmeyer invariants in flat-space (as per eq-2.16 in Urs Schreiber's DDF and Pohlmeyer invariants of (super)string) is the following: $$ Z^{\mu_1...\mu_N} (\mathcal{P}) = \frac{1}{...
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