Physics – High Energy Physics – High Energy Physics - Theory
Scientific paper
2005-11-28
Int.J.Mod.Phys.D16:1053-1074,2007
Physics
High Energy Physics
High Energy Physics - Theory
New original material
Scientific paper
10.1142/S0218271807010596
We compute the quantum string entropy S_s(m, H) from the microscopic string density of states rho_s (m,H) of mass m in de Sitter space-time. We find for high m, a {\bf new} phase transition at the critical string temperature T_s= (1/2 pi k_B)L c^2/alpha', higher than the flat space (Hagedorn) temperature t_s. (L = c/H, the Hubble constant H acts at the transition as producing a smaller string constant alpha' and thus, a higher tension). T_s is the precise quantum dual of the semiclassical (QFT Hawking-Gibbons) de Sitter temperature T_sem = hbar c /(2\pi k_B L). We find a new formula for the full de Sitter entropy S_sem (H), as a function of the usual Bekenstein-Hawking entropy S_sem^(0)(H). For L << l_{Planck}, ie. for low H << c/l_Planck, S_{sem}^{(0)}(H) is the leading term, but for high H near c/l_Planck, a new phase transition operates and the whole entropy S_sem (H) is drastically different from the Bekenstein-Hawking entropy S_sem^(0)(H). We compute the string quantum emission cross section by a black hole in de Sitter (or asymptotically de Sitter) space-time (bhdS). For T_sem ~ bhdS << T_s, (early evaporation stage), it shows the QFT Hawking emission with temperature T_sem ~ bhdS, (semiclassical regime). For T_sem ~ bhdS near T_{s}, it exhibits a phase transition into a string de Sitter state of size L_s = l_s^2/L}, l_s= \sqrt{\hbar alpha'/c), and string de Sitter temperature T_s. Instead of featuring a single pole singularity in the temperature (Carlitz transition), it features a square root branch point (de Vega-Sanchez transition). New bounds on the black hole radius r_g emerge in the bhdS string regime: it can become r_g = L_s/2, or it can reach a more quantum value, r_g = 0.365 l_s.
Bouchareb Adel
Medrano Marina Ramon
Sanchez Norma G.
No associations
LandOfFree
Semiclassical (Quantum Field Theory) and Quantum (String) de Sitter Regimes: New Results does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Semiclassical (Quantum Field Theory) and Quantum (String) de Sitter Regimes: New Results, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiclassical (Quantum Field Theory) and Quantum (String) de Sitter Regimes: New Results will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-25351