2009/01/31 by Shinji Mukohyama
Physics and Astronomy · #Astrophysical Phenomena and Observations #Black hole (networking) #Condensation #High-Energy Particle Collisions Research #Lorentz transformation #Order (exchange) #Planck #Planck scale #Pulsars and Gravitational Waves Research #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1126-6708/2009/09/070
published as JHEP 0909:070,2009 · 17 pages; comment on negative energy added, gauged ghost condensation considered (v2); version accepted for publication in JHEP (v3)
arxiv created 2009/09/06 · openalex publication_date 2009/09/15 · arxiv updated 2014/11/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Dubovsky and Sibiryakov recently proposed a scenario in which particles of different species propagate with different speeds due to their direct couplings to ghost condensate. It was argued that this extended version of ghost condensate allows a gedanken experiment leading to violation of the generalized second law. However, in the original ghost condensate scenario, difference in propagation speeds is suppressed by M2/MPl2, where M is the order parameter of spontaneous Lorentz breaking and MPl is the Planck scale. In this case the energy transfer necessary for the gedanken experiment is so slow that the timescale of decrease of entropy, if any, is always longer than the Jeans timescale of ghost condensate. Hence the generalized second law is not violated by the gedanken experiment in the original ghost condensate scenario. This conclusion trivially extends to gauged ghost condensation by taking into account accretion of gauged ghost condensate into a black hole.