发表机构
National University of Singapore（新加坡国立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对宇宙大尺度各向异性与暴胀图景的潜在矛盾，通过放宽时空挠率为零的限制，提出挠率暴胀理论，解释了各向异性的自然起源及在当今宇宙大尺度的信号来源。
AI 中文摘要
近期多项观测分析表明宇宙中可能存在大尺度各向异性，通常认为这会与早期宇宙的暴胀图景相矛盾。本文证明情况并非如此：若放宽“时空挠率必须为零”的人为限制，在挠率暴胀理论中这类各向异性会自然产生，几乎不可避免。对挠率时空采用“1+3”分解分析时，这一点最为清晰，会自然引出内禀挠率和外禀挠率的概念。暴胀子的各向异性量子涨落会产生各向异性的外禀挠率场，该场在整个暴胀 era 中增长，尽管空间截面的内禀几何以常规方式各向化。内禀挠率（会随暴胀消失）与外禀挠率的竞争，会在暴胀早期产生一段短时间间隔，期间存在挠率诱导的能流，该能流会在超视界模式中留下各向异性信号，最终在当今宇宙的大尺度上显现。
英文摘要
Several recent observational analyses have suggested the possible existence of anisotropy in our Universe. It is often thought that this would contradict the inflationary picture. We have argued that this is not the case: if we relax the artificial restriction that spacetime torsion must be zero, then such anisotropies arise naturally, indeed almost inevitably, in a theory of torsional Inflation. This is seen most clearly if one uses a ``$1\,+\,3\,$'' analysis of a torsional spacetime, leading naturally to concepts of intrinsic torsion and extrinsic torsion. An anisotropic quantum fluctuation of the inflaton leads to an extrinsic torsion field which is anisotropic and which grows throughout the inflationary era, even though the intrinsic geometry of the spatial sections is isotropised in the conventional manner. This leads to an anisotropic Hubble field at the \emph{end} of Inflation. The anisotropy takes a very specific and characteristic form, which in principle could be observable on relatively short cosmic scales. On the other hand, an unusual feature of torsional geometry leads to a short interval, \emph{early} in the inflationary era, during which there is a torsion-induced energy flux, which leaves an anisotropic signal in superhorizon modes and thus ultimately at very large scales in the present Universe. Thus in principle torsion can explain anisotropies both on relatively short cosmic scales and also at the largest scales.
CommentsReferences added, 28 pages, one figure
