Thermodynamics of warped AdS3_3 black hole in the brick wall method

The statistical entropy of a scalar field on the warped AdS$_3$ black hole in the cosmological topologically massive gravity is calculated based on the brick-wall method, which is different from the Wald's entropy formula giving the modified area law due to the higher-derivative corrections in that the entropy still satisfies the area law. It means that the entropy for scalar excitations on this background is independent of higher-order derivative terms or the conventional brick wall method has some limitations to take into account the higher-derivative terms.Comment: 12 pages, 1 figure; v2. to appear in Phys. Lett. B; v3. typos correcte

Future singularity free accelerating expansion with the modified Poisson brackets

We show that the second accelerating expansion of the universe appears smoothly from the decelerating universe remarkably after the initial inflation in the two-dimensional soluble semi-classical dilaton gravity along with the modified Poisson brackets of noncommutativity between the relevant fields. However, the ordinary solution coming from the equations of motion following the conventional Poisson algebra describes permanent accelerating universe without any phase change. In this modified model, it turns out that the phase transition is related to the noncommutative Poisson algebra.Comment: 13 pages, 2 figures; v2. to appear in Phys. Rev.