The constant curvature black hole (Bañados black hole) in AdSd+1 is
ds2=H2ρ2+(ρ2−ρ2+)(−(1−H2r2)dt2+dr21−H2r2+r2dΩ2d−2)+dρ2ρ2−ρ2++ρ2dϕ2.
The AdS boundary is dSd−1×S1. More information about this geometry can be found in [1,2]. How to calculate its temperature at the horizon ρ=ρ+ by the Euclidean method? We can see that gtt depends on both coordinates ρ and r, but its temperature should be constant.
The following example shows the Euclidean method to calculate the Hawking temperature of a black hole described by the metric
ds2=−f(r)dt2+dr2g(r)+r2dΩ22,
where f=f0(r−rh)+⋯, and g=g0(r−rh)+⋯ near the horizon. Write the metric near the horizon as
ds2=κ2ρ2dτ2+dρ2+⋯.
To avoid conical singularity, the period of κτ must be 2π. The temperature is the inverse of the period of τ:
T=κ2π=√f0g04π.
Another way to calculate the temperature is by the following formula for surface gravity:
κ2=−12(∇aξb)(∇aξb),
where ξa=(∂t)a. For the constant curvature black hole described above, we have
κ|ρ=ρ+=κ|r=1/H=H.
So T=H/2π. But I want to know whether the Euclidean method still works for the constant curvature black hole.
[1] M. Bañados, Constant Curvature Black Holes, gr-qc/9703040.
[2] D. Marolf, M. Rangamani, and M.V. Raamsdonk, Holographic models of de Sitter QFTs, arXiv:1007.3996.