Two-dimensional dilaton gravity and spacetimes with finite curvature at the horizon away from the Hawking temperature

curvature at the horizon away from the Hawking temperature O. B. Zaslavskii Department of Physics, Kharkov State University, Svobody Sq.4, Kharkov 310077, Ukraine E-mail: [email protected] It is shown that static solutions with a finite curvature at the horizon may exist in dilaton gravity at temperatures T 6= TH (including T = 0) where TH is the Hawking one. Hawking radiation is absent and the state of a system represents thermal excitation over the Boulware vacuum. The horizon remains unattainable for a observer because of thermal divergences in the stress-energy of quantum fields there. However, the curvature at the horizon is finite, when measured from outside, since these divergences are compensated by those in gradients of a dilaton field. Spacetimes under consideration are geodesically incomplete and the coupling between dilaton and gravity diverges at the horizon, so we have ”singularity without singularity”. PACS: 04.60Kz, 04.70.Dy