As discussed in arXiv:1501.03298, Physics suggests that, close to cosmological singularities, the effective Planck length diverges, hence a "quantum point" becomes infinitely extended. We argue that, as a consequence, at the origin of times spacetime might reduce effectively to a single point and interactions disappear. This last point is supported by converging evidences in two different approaches to interacting quantum fiedls on Quantum Spacetime: the field operators evaluated at a "quantum point" converge to zero, and so do the lowest order expressions for interacting fields in the Yang Feldman approach, while, at all orders we find convergence to zero of the interacting field operators obtained adapting methods of perturbative Algebraic Quantum Field Theory to Quantum Spacetime, with a novel picture of the effective Lagrangian introduced in arXiv:1906.05855. This novel picture mantains the ultraviolet finiteness of the perturbation expansion but allows us to prove also the convergence in the adiabatic limit. It remains an open question whether the S matrix itself converges to unity and whether the limit in which the effective Planck length diverges is a unique initial condition or an unreachable limit, and only different asymptotics matter.

中文翻译：

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大爆炸时的量子时空和宇宙，相互作用的消失和自由度的衰减

正如 arXiv:1501.03298 中所讨论的，物理学表明，接近宇宙奇点时，有效普朗克长度发散，因此“量子点”变得无限延伸。我们认为，因此，在时间的起源处，时空可能会有效地减少到一个点并且相互作用消失。最后一点得到了在量子时空相互作用量子场的两种不同方法的收敛证据的支持：在“量子点”评估的场算子收敛为零，杨费尔德曼方法中相互作用场的最低阶表达式也是如此，同时，在所有阶次中，我们发现相互作用的场算子收敛到零，获得了将微扰代数量子场论的方法与量子时空相适应，在 arXiv:1906.05855 中引入了有效拉格朗日函数的新颖图片。这幅新图保持了扰动膨胀的紫外有限性，但也允许我们证明绝热极限的收敛。S 矩阵本身是否收敛到 1 以及有效普朗克长度发散的极限是唯一的初始条件还是无法达到的极限，这仍然是一个悬而未决的问题，只有不同的渐近性才重要。