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String Theory | ||
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All Roads Lead to String Theory (Polchinski) | ||
Prior to the First Superstring Revolution
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Early History | S-Matrix Theory Regge Trajectory | |
Bosonic String Theory | Worldsheet String Bosonic String Theory String Perturbation Theory Tachyon Condensation | |
Supersymmetric Revolution | Supersymmetry RNS Formalism GS Formalism BPS | |
Superstring Revolutions
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First Superstring Revolution | GSO Projection Type II String Theory Type IIB String Theory Type IIA String Theory Type I String Theory Type H String Theory Type HO String Theory Type HE String Theory |
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Second Superstring Revolution | T-Duality D-Brane S-Duality Horava-Witten String Theory M-Theory Holographic Principle N=4 Super-Yang-Mills Theory AdS CFT BFSS Matrix Theory Matrix String Theory (2,0) Theory Twistor String Theory F-Theory String Field Theory Pure Spinor Formalism |
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After the Revolutions
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Phenomenology | String Theory Landscape Minimal Supersymmetric Standard Model String Phenomenology | |
Supersymmetry (SUSY) A postulated symmetry between bosonic and fermionic fields in Quantum Field Theoryies and String Theoryies.
The theory of Supsersymmetry has been incorporated in the Standard Model (MSSM), Yang-Mills Theory (Super-Yang-Mills Theory), and most famously String Theory (Superstring theory).
While Supersymmetry remains experimentally unconfirmed, one of its greatest achievements is that the MSSM (which also appears in realistic M-Theory vacua) predicts a Higgs of mass 125 GeV (which was measured by the LHC recently.), which is contrary to the Standard Model, which predicts such a mass to be rather unlikely.
Technical details[]
There are two types of supersymmetry; worldsheet supersymmetry, and spacetime supersymmetry.
Worldsheet supersymmetry[]
The RNS Formalism has explicit worldsheet supersymmetry. Since the RNS Action is given by adding the Polyakov Action to the Dirac Action, it is given by:
The supersymmetryic transformations on the worldsheet can therefore be (almost trivially, by taking variations of this above action) shown to be:
Spacetime Supersymmetry[]
The GS Formalism, or the Superspace Formalism, are with explicit spacetime supersymmetry. The supersymmetryic transformations on spacetime are (which is rather intuitive if you compare this to the RNS Worldsheet supersymmetry transformations) given by: