标题： 熵产生与坍缩宇宙中的热力学时间箭头 显示英文标题

标题： Entropy Production and Thermodynamic Arrow of Time in a Recollapsing Universe

摘要： 我们通过量子力学计算大质量标量场的熵产生，研究了在时间对称再坍缩宇宙中的热力学时间箭头。 发现尽管哈密顿量相对于宇宙的最大膨胀具有时间反演对称性，但熵产生是普遍存在的，标量场的总熵单调增加。 我们得出结论，由于物质场与引力的参数相互作用，热力学时间箭头在膨胀后随后再坍缩的宇宙中仍然是一个普遍现象。 显示英文摘要

摘要： We investigate the thermodynamic arrow of time in a time-symmetrically recollapsing universe by calculating quantum mechanically the entropy production of a massive scalar field. It is found that even though the Hamiltonian has a time-reversal symmetry with respect to the maximum expansion of the universe, the entropy production is generic and the total entropy of the scalar field increases monotonically. We conclude that the thermodynamic arrow of time is a universal phenomenon even in the expanding and subsequently recollapsing universe due to the parametric interaction of matter field with gravity.