Hawking radiation as tunneling from the non-stationary (2+1)-dimensional black hole

Taking the unfixed background space-time and self-gravitational interaction into account, we discuss the Hawking radiation of the non-stationary (2 + 1)-dimensional black hole by the Hamilton-Jacobi method. The tunneling probability of the radiation particle is related not only to the change of Bekenstein-Hawking entropy but also to the integral to the black-hole mass, which does not satisfy the unitary theory and is different from Parikh and Wilczek's result. This implies the information loss in the black-hole evaporation is possible.