论文标题

渐近宇宙学中的奇异性形成与状态不均匀方程式

Singularity formation in asymptotically safe cosmology with inhomogeneous equation of state

论文作者

Trivedi, Oem, Khlopov, Maxim

论文摘要

最近,人们对宇宙学奇异性的兴趣已经显着增长,尤其是随着宇宙和黑暗能量的延迟加速,对未来的奇异性。虽然此类探索以前是在各种修饰的重力和重力启发的宇宙学(除标准的一般相对论宇宙学)中进行的,但直到现在,直到现在,在重新分析群体的宇宙学方法中,还没有采取这种努力,因此我们在这一旅程中已经采取了这种努力。在这项工作中,我们考虑在渐近安全的宇宙学中宇宙学奇异性的形成,其中切断量表与哈勃参数成正比。我们也考虑了一种充满动机的状态方程式(EOS)的不均匀形式。我们首先深入研究了这种宇宙学的一些基本知识,并表明这种情况允许幻影和普遍进化的典型形式之间的过渡。然后,我们证明,对于各种版本的EOS,可以在这种宇宙学中具有I型I -type IV奇异性,并且可以在有限的时间和无限时间内发生奇点。这些奇异性发生的条件与标准宇宙学中发生的情况显着不同,配方更加参与。有趣的是,这种差异无需宇宙学模型中的任何自由参数,这通常是当人们通过各种修改的重力/ QG启发的宇宙学方法进行相同追求时观察到的。此外,我们表明,在这种宇宙学中,诸如保形异常效应和F(r)重力效应之类的通常的奇异性去除方法并没有太大的希望。

Interest in cosmological singularities has remarkably grown in recent times, particularly on future singularities with the discovery of late-time acceleration of the universe and dark energy. While such explorations have previously been done in various modified gravity and quantum gravitationally inspired cosmologies (besides standard general relativistic cosmology), no such an endeavour has been taken up till now in the realms of renormalization group approaches to cosmology and we have hence took up on this journey. In this work, we consider the formation of cosmological singularities in an asymptotically safe cosmology where the cut off scale is proportional to the Hubble parameter. We consider a well motivated inhomogeneous form of the equation of state(EOS) as well. We firstly delve into some basics of this cosmology and show that such a scenario permits a transition between phantom and quintessence forms of universal evolution. We then show that one can have Type I - Type IV singularities in such a cosmology for various version of the EOS and that the singularities can occur both in finite and infinite time. The conditions in which these singularities occur is significantly different than how they occur in the standard cosmology, with the formulations being even more involved. Interestingly this difference comes about without the need of any free parameters in the cosmological models, which is usually what one observes when one goes for the same pursuit via various modified gravity/ QG inspired cosmological approaches. Furthermore, we showed that usual singularity removal methods like conformal anomaly effects and f(R) gravity effects do not offer much hope for singularity removal in this cosmology.

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