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Updated: Dec 24, 2025
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Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
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Classification of String Theories via Topological Phases
Justin Kaidi1, Julio Parra-Martinez1, Yuji Tachikawa2
1Mani L. Bhaumik Institute for Theoretical Physics, Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
Physical Review Letters
|April 14, 2020
Summary
The choice of string theory phases is explained by fermionic symmetry-protected topological phases. This framework clarifies existing theories and predicts new unoriented type 0 string theories.
Area of Science:
- String Theory
- Condensed Matter Physics
- High Energy Physics
Background:
- Gliozzi-Scherk-Olive (GSO) projections are crucial in constructing superstring theories.
- Understanding the different types of superstring theories (Type I, Type IIA, Type IIB, Type 0) is fundamental.
- Symmetry-Protected Topological (SPT) phases are a key concept in modern condensed matter physics.
Purpose of the Study:
- To provide a unified explanation for the phase choices in Gliozzi-Scherk-Olive projections.
- To connect the classification of string theories with concepts from topological phases of matter.
- To predict the existence and properties of previously uncharacterized string theories.
Main Methods:
- Analyzing the world sheet theory of strings.
- Utilizing the framework of fermionic symmetry-protected topological phases.
- Relating these phases to the construction of different superstring theories.
Main Results:
- The choice of GSO projection phases corresponds to specific fermionic SPT phases on the string's world sheet.
- This perspective naturally explains the existence of two Type II superstring theories.
- It predicts the existence of unoriented Type 0 string theories classified by n mod 8.
- It suggests a unique world sheet theory for Type I string theory.
Conclusions:
- Fermionic SPT phases offer a powerful new lens for understanding string theory constructions.
- This approach unifies aspects of string theory and topological phase classification.
- The results open avenues for exploring new string theory models and their properties.
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