论文标题
在非标准宇宙学背景中的V型奇异点
Type V singularities in non-standard cosmological backgrounds
论文作者
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。最近的工作根据其力量将这种奇异性的适当分类为强大而虚弱，巨大的奇异性是突然，W和Big Freeze奇异性和强大的奇异性之类的奇异性，例如大RIP。尽管有广泛的文献讨论了许多非标准宇宙学中I型IV的发生，但在异国情调的宇宙学环境中尚未探索W区。因此，在这项工作中，我们从事同样的事情，并讨论了各种非标准宇宙学中W singularities的现状。我们考虑RS-II Braneworld宇宙学，这是F（R）重力宇宙学，可以使可行的延迟加速。我们还考虑了由于修改的面积 - 注入关系，普遍的不确定性原理，全息重新归一化和Chern-Simons重力（所有这些都可以用相同形式的改良弗里德曼方程形式偶然描述）。我们表明，在所有这些生动不同的宇宙学环境中，W-SINGULUITIS将在与通常的一般相对论宇宙学中完全不同的宇宙学环境中发生，如果一个人认为对量表因子的功率系列扩展Ansatz。我们还表明，如果人们考虑了比例因子的指数形式，那么RS-II Braneworld和Chern-Simons宇宙学中的V型奇异点发生在与标准宇宙学案例相同的条件下，当人们考虑F（R）重力案例时，条件存在显着差异。总体而言，这些结果令人惊讶，因为通常不会期望宇宙学奇异性在非标准宇宙学中几乎与通常的标准宇宙学中发生。
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. Recent work has seen a proper classification of such singularities into strong and weak based on their strength, with weak singularities being the likes of sudden, w and big freeze singularities and strong singularities like the big rip. While there has been an expansive literature which has discussed the occurrence of Type I-IV in many non-standard cosmologies, w-singularities have not yet been explored in exotic cosmological settings. So in this work we pursue the same and discuss the status quo of w-singularities in a variety of non-standard cosmologies. We consider the RS-II Braneworld cosmology, an F(R) gravity cosmology which gives viable late time acceleration. We also consider cosmologies due to modified area-entropy relations, generalized uncertainty principles, holographic renormalization and Chern-Simons gravity( all of which can be coincidentally described by the same form of the modified Friedmann equation). We show that w-singularities will occur in exactly the same conditions in all these vividly different cosmological settings as they do in the usual general relativistic cosmology if one considers a power series expansion ansatz for the scale factor. We also show that if one considers an exponential form of the scale factor then while Type V singularities in the RS-II Braneworld and Chern-Simons cosmologies occur in the same conditions as in the standard cosmology case, there is a significant difference in the conditions when one considers the f(R) gravity case. These results are surprising overall, as one would usually not expect cosmological singularities to occur in almost the same conditions in non-standard cosmologies as they do in the usual standard cosmology.
