Nonvanishing cosmological constant of flat universe in brane-world scenario

The finite temperature effect is examined in Randall–Sundrum brane-world scenario with inclusion of the matter fields on the brane. At zero temperature it is found that the theory on the brane is conformally invariant, which guarantees AdS/CFT. At 4d effective action we derived a temperature-dependent nonvanishing cosmological constant at the flat spacetime limit of brane worldvolume. At the cosmological temperature 3 K the cosmological constant is roughly (0.0004 eV)4 which is within the upper bound of the recent experimental value (0.01 eV)4.