The Status of the KSS Bound and its Possible Violations (How Perfect Can a Fluid Be?)

2008/01/01 by Antonio Dobado, Felipe J. Llanes-Estrada, Juan Miguel Torres Rincón +5 · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Noncommutative and Quantum Gravity Theories #Quantum Chromodynamics and Particle Interactions #hep-ph

paper · pdf · doi:10.1063/1.2972009

published as AIPConf.Proc.1031:221-231,2008 · 10 pages, 5figs, Invited talk at "10 years of AdS/CFT Correspondence", Buenos Aires, Dec. 2007, honoring Juan Maldacena

openalex publication_date 2008/01/01 · arxiv created 2008/04/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29

Abstract

In this work we briefly review the Kovtun-Son-Starinet (KSS) computation of the ratio /s for quantum field theories with gravitational dual and the related conjecture that it is bound from below by 1/4. We discuss the validity of the bound and the nature of its possible violations, its relevance for RHIC, its connection with phase transitions and other related issues.

Citations

• The ratio of viscosity to entropy density in a pion gas satisfies the KSS holographic bound
• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics

Cited by

• Transport coefficients from extremal Gauss-Bonnet black holes
• Lovelock theories, holography and the fate of the viscosity bound
• Five easy pieces: The dynamics of quarks in strongly coupled plasmas

Related

• Resurrecting the Strong KSS Conjecture
• Universal ratio as lower bound
• Densities of States and the CKN Bound
• Weak Gravity Conjecture, Central Charges and η/s
• Violation of the KSS Bound in Holographic Bjorken-Flow