A braneworld puzzle about entropy bounds and a maximal temperature
arXiv:hep-th/0404230 · doi:10.1103/PhysRevD.71.124015
Abstract
Entropy bounds applied to a system of N species of light quantum fields in thermal equilibrium at temperature T are saturated in four dimensions at a maximal temperature T_max=M_Planck/N^1/2. We show that the correct setup for understanding the reason for the saturation is a cosmological setup, and that a possible explanation is the copious production of black holes at this maximal temperature. The proposed explanation implies, if correct, that N light fields cannot be in thermal equilibrium at temperatures T above T_max. However, we have been unable to identify a concrete mechanism that is efficient and quick enough to prevent the universe from exceeding this limiting temperature. The same issues can be studied in the framework of AdS/CFT by using a brane moving in a five dimensional AdS-Schwarzschild space to model a radiation dominated universe. In this case we show that T_max is the temperature at which the brane just reaches the horizon of the black hole, and that entropy bounds and the generalized second law of thermodynamics seem to be violated when the brane continues to fall into the black hole. We find, again, that the known physical mechanisms, including black hole production, are not efficient enough to prevent the brane from falling into the black hole. We propose several possible explanations for the apparent violation of entropy bounds, but none is a conclusive one.
16 pages
References in corpus (33)
- An Alternative to Compactification
- The Large N Limit of Superconformal Field Theories and Supergravity
- Large N Field Theories, String Theory and Gravity
- The World as a Hologram
- The holographic principle
- Eternal Black Holes in AdS
- The Einstein Equations on the 3-Brane World
- A Covariant Entropy Conjecture
- Brane-world gravity
- AdS/CFT and gravity
- Dynamics of Anti-de Sitter Domain Walls
- Holography in General Space-times
- Cosmic Holography
- Brane-world cosmology
- Entropy Bounds and Black Hole Remnants
- Mirage Cosmology
- The Holographic Principle for General Backgrounds
- Holography, Cosmology and the Second Law of Thermodynamics
- Friedmann-Robertson-Walker brane cosmological equations from the five-dimensional bulk (A)dS black hole
- CFT and Entropy on the Brane
- Cosmology vs. Holography
- Relating Friedmann equation to Cardy formula in universes with cosmological constant
- Pre-bangian origin of our entropy and time arrow
- The Generalized Second Law of Thermodynamics in Cosmology
- A Causal Entropy Bound
- Friedmann equation and Cardy formula correspondence in brane universes
- Non-Archimedean character of quantum buoyancy and the generalized second law of thermodynamics
- CFT, Holography, and Causal Entropy Bound
- The Shortest Scale of Quantum Field Theory
- Perfect mirrors and the self-accelerating box paradox
- Brane Worlds, String Cosmology, and AdS/CFT
- Generalized Second Law in String Cosmology
- The Boulware State and the Generalised Second Law of Thermodynamics