Cosmological particle production, causal thermodynamics, and inflationary expansion
Cosmological particle production, causal thermodynamics, and inflationary expansion
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DOI：
10.1103/physrevd.61.083511
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发表时间：
1999-10
影响因子：
5
通讯作者：
W. Zimdahl
中科院分区：
文献类型：
--
作者：
W. Zimdahl
结合宇宙粒子的创造和一个有效的粘性流体压力的事实，后者代表了一个动态的自由度内的二阶Israel-Stewart理论不完美的流体之间的等价性，我们重新考虑在流体宇宙学加速膨胀的可能性。我们发现一个固有的自我限制的有效体压的大小，这是由于绝热（等熵）粒子生产。对于一个生产率的平方依赖于哈勃率，我们确认存在的解决方案，描述了一个平稳过渡，从通货膨胀到noninflation的行为，并讨论其解释内的衰减真空能量密度的模型。给出了一种有效非理想流体动力学的最小耦合标量场的替代公式。讨论了相应的势，并找到了标量场的熵等价。
Combining the equivalence between cosmological particle creation and an effective viscous fluid pressure with the fact that the latter represents a dynamical degree of freedom within the second-order Israel-Stewart theory for imperfect fluids, we reconsider the possibility of accelerated expansion in fluid cosmology. We find an inherent self-limitation for the magnitude of an effective bulk pressure which is due to adiabatic (isentropic) particle production. For a production rate which depends quadratically on the Hubble rate we confirm the existence of solutions which describe a smooth transition from inflationary to noninflationary behavior and discuss their interpretation within the model of a decaying vacuum energy density. An alternative formulation of the effective imperfect fluid dynamics in terms of a minimally coupled scalar field is given. The corresponding potential is discussed and an entropy equivalent for the scalar field is found.