## Abstract

Throughout its history, string theory has been intertwined with the theory of strong interactions. The AdS/CFT correspondence [1-3] has succeeded in making precise connections between conformal 4-dimensional gauge theories and superstring theories in 10 dimensions. This duality leads to a multitude of dynamical predictions about strongly coupled gauge theories. While many of these predictions are difficult to check, recent applications of methods of exact integrability to planar N = 4 SYM theory have produced some impressive tests of the correspondence for operators with high spin. When extended to theories at finite temperature, the correspondence serves as a theoretical laboratory for studying a novel state of matter: a gluonic plasma at very strong coupling. This appears to have surprising connections to the new state of matter, sQGP, which was observed at RHIC and will be further studied at the LHC. Breaking symmetries in the AdS/CFT correspondence is important for bringing it closer to the real world. Some of the supersymmetry may be broken by considering D3-branes at conical singularities; the case of the conifold is discussed in detail in these lectures. In this set-up, breaking of gauge symmetry typically leads to a resolution of the singularity. The associated breaking of global symmetry leads to the appearance of Goldstone bosons and global strings. Extensions of the gauge-string duality to confining gauge theories provide new geometrical viewpoints on such important phenomena as chiral symmetry breaking and dimensional transmutation, which are encoded in the dual smooth warped throat background. Embedding of the throat into flux compactifications of string theory allows for an interesting interplay between gauge-string duality and models of particle physics and cosmology. For example, D3-branes rolling in the throat might model inflation while various strings attracted to the bottom of the throat may describe cosmic strings. All of this raises hopes that the new window into strongly coupled gauge theory opened by the discovery of gauge-string dualities will one day lead to new striking connections between string theory and the real world.

Original language | English (US) |
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Title of host publication | String Theory and the Real World |

Subtitle of host publication | From Particle Physics to Astrophysics |

Publisher | Elsevier |

Pages | 611-613 |

Number of pages | 3 |

ISBN (Print) | 9780080548135 |

DOIs | |

State | Published - 2008 |

### Publication series

Name | Les Houches Summer School Proceedings |
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Volume | 87 |

ISSN (Print) | 0924-8099 |

## All Science Journal Classification (ASJC) codes

- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)