论文标题
各向同性宇宙的聚合物动力学在Ashtekar和音量变量中
Polymer dynamics of isotropic universe in Ashtekar and in volume variables
论文作者
论文摘要
我们根据标准的Ashtekar-Barbero-immirzi连接及其共轭动量以及新的广义坐标共轭与宇宙体积分析了各向同性宇宙的半经典和量子聚合物动力学。我们研究了在表示形式中出现的结果弹跳宇宙学的性质，并且我们表明，只有在实施体积变量时，大弹跳才是宇宙学动力学的内在截止，而在标准连接方面，宇宙弹跳能量密度是由准备好的波袋的初始条件固定的。作为一种现象学的意义，我们将粒子的创造引入了耗散术语，并研究了两个制剂中熵的产生。然后，我们将获得的动力学与循环量子宇宙学中出现的动力学进行了比较，在循环量子宇宙学中，大反弹性质的差异与固定最小区域特征值相同或在物理表示中。我们得出的结论是，Ashtekar-Barbero-immirzi连接的特权特征表明，聚合物框架中的自然场景是一个很大的反弹，这并不是普遍的截止。但是，通过基本运算符的聚合物和环量子宇宙学性质之间的并行性，我们还开发了一些考虑因素，有利于在半经典级别上$ \barμ$ loop量子宇宙学方案的生存能力。
We analyze the semiclassical and quantum polymer dynamics of the isotropic Universe in terms of both the standard Ashtekar-Barbero-Immirzi connection and its conjugate momentum and also of the new generalized coordinate conjugate to the Universe volume. We study the properties of the resulting bouncing cosmology that emerges in both the representations and we show that the Big Bounce is an intrinsic cut-off on the cosmological dynamics only when the volume variable is implemented, while in terms of the standard connection the Universe Bounce energy density is fixed by the initial conditions on the prepared wavepacket. As a phenomenological implication, we introduce particle creation as a dissipative term and study the production of entropy in the two formulations. Then, we compare the obtained dynamics with what emerges in Loop Quantum Cosmology, where the same difference in the nature of the Big Bounce is associated to fixing a minimum area eigenvalue in a comoving or in a physical representation. We conclude that the privileged character of the Ashtekar-Barbero-Immirzi connection suggests that the natural scenario in the polymer framework is a Big Bounce that is not a Universal cut-off. However, by a parallelism between the polymer and Loop Quantum Cosmology properties of the basic operators, we also develop some considerations in favour of the viability of the $\barμ$ scheme of Loop Quantum Cosmology on a semiclassical level.
