采用两种新的乌龟坐标变换,用改进的Damour-Ruffini方法研究了动态Kinnersley黑洞的Hawking辐射.在新乌龟坐标变换下,将Klein-Gordon方程在视界附近变换成平直时空的标准波动方程形式,得到了黑洞的表面引力及Hawking温度,该温度在黑洞表面不同点有不同的值.值得注意的是,旧的乌龟坐标变换存在量纲错误,新乌龟坐标变换没有量纲问题,选不同的旧乌龟坐标变换计算同一黑洞所得结果不同,但是采用不同的新乌龟坐标变换所得结果仍然不同.
With two new tortoise coordinate transformations,Hawking effect from a dynamical Kinnersley black hole is investigated by using the improved Damour-Ruffini method.After the tortoise coordinate transformation,the Klein-Gordon equation can be written in the standard form at the event horizon.Then extending the outgoing wave from outside to inside of the horizon analytically,the surface gravity and the Hawking temperature can be obtained automatically.It is found that Hawking temperature of different points on the surface are different.There is a problem of dimension in the usual tortoise coordinate and the results are different from those of the same black hole by using two different tortoise coordinate transformations.The results obtained by using two new tortoise coordinate transformations are still different.