INFLUENCE ON SPACETIME STRUCTURE OF QUANTUM BACK REACTION

首先，由于霍金辐射的黑洞的蒸发已被研究的模型中提取的黑洞几何的最基本的功能;事件视界的存在。无论是采用二维量子引力还是模拟霍金辐射本质的移动镜像模型，都表明黑洞可以完全消失，而没有进一步的辐射，但留下稳定的残余物。在第二个项目中，研究了伴随粒子产生的相干场振荡问题。利用泛函薛定谔图像，对玻色量子场与经典振子场耦合所描述的量子系统的行为进行了有力的分析。在几个振荡周期上的短时间平均值表明粒子产生发生在粒子波数和振荡幅度的参数空间中的无限多个带区域中，称为参数共振带。因此，由于扰动玻恩率的navive估计是严重错误的初始大振幅振荡。这对暴胀后的再加热问题和超引力模型中的Polonyi问题有着重要的影响，但迄今为止都被忽略了;暴胀可能以更高温度的中间时期结束，这很容易实现GUT重子生成，同时抑制了成功核合成所需的引力子的产生。

Firstly, evaporation of the black hole due to Hawking radiation has been investigated in models that extract most essential features of the black hole geometry ; existence of the event horizon. By taking either a two dimensional dilaton gravity or the moving mirror model that mimics essence of the Hawking radiation, it was shown that the black hole can completely disappear without furthere radiation, but leaving behind stable remnants. In the second project the problem of coherent field oscillation accompanying particle production has been studied. The behavior of the quantum system described by bose quantum fields coupling to the classical oscillator field was shown to be analyzed vigorously by using a functional Schrodinger picture. The short time average over a few oscillation periods exhibits particle production taking place in infinitely many band regions in the parameter space of the particle wave number and the oscillation amplitude, known as the band of parametric resonance. Accordingly the navive estimate due to the perturbative Born rate is grossly wrong for an initial large amplitude oscillation. This has important effects hitherto ignored on the reheating problem after inflation and the Polonyi problem in supergravity models ; inflation may end with intermediate epoch of much higher temperatures that realizes readily the GUT baryogenesis at the same time suppressing production of gravitino required by successful nucleosynthesis.