标题： 预热弹跳宇宙 显示英文标题

标题： Preheating a bouncing universe

摘要： 预热描述的是宇宙标量场能量迅速沉积到其他轻场激发态的阶段。 这一阶段的特点是由于参数共振导致的指数级粒子产生。 我们在这个物质反弹宇宙学框架下研究这个过程。 我们的结果表明，反弹宇宙学中的预热过程比暴胀宇宙学中的预热过程更有效。 在弱耦合极限下，预热周期会加倍。 对于正常耦合的情况，轻场的反作用可能导致在反弹点之前发生热化。 如果预期curvaton场直接预热宇宙，由于较大的耦合系数，物质反弹curvaton情景可能会受到严格限制。 然而，通过几何预热过程，这种担忧可以大大缓解。 显示英文摘要

摘要： Preheating describes the stage of rapidly depositing the energy of cosmological scalar field into excitations of other light fields. This stage is characterized by exponential particle production due to the parametric resonance. We study this process in the frame of matter bounce cosmology. Our results show that the preheating process in bouncing cosmology is even more efficient than that in inflationary cosmology. In the limit of weak coupling, the period of preheating is doubled. For the case of normal coupling, the back-reaction of light fields can lead to thermalization before the bouncing point. The scenario of matter bounce curvaton could be tightly constrained due to a large coupling coefficient if the curvaton field is expected to preheat the universe directly. However, this concern can be greatly relaxed through the process of geometric preheating.