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arXiv 0801.1199astro-ph
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统一标量场宇宙学中的动力学和混沌

Dynamics and chaos in the unified scalar field Cosmology

Georgios Lukes-Gerakopoulos, Spyros Basilakos, George Contopoulos

摘要:

本文在统一暗物质(UDM)框架下研究了封闭标量场FRW宇宙学模型的动力学。执行的理论以及数值分析,我们发现,有一个强烈的迹象表明与以前的研究混沌。我们发现,一个积极的空间曲率值是必不可少的混沌的外观,虽然李雅普诺夫数似乎是独立的曲率值。接近平坦的模型在很长一段时间后会表现出混沌行为,而纯平坦模型不会表现出任何混沌。此外,我们发现,在UDM方案中的一些半平坦模型表现出类似的动力学行为的Lambda宇宙学,尽管他们的混沌。最后,我们比较测量的哈勃参数的演化来自被动演化星系的微分年龄与预期的半平坦统一标量场宇宙学。在一组特定的初始条件下,我们发现UDM的标量场模型与观测数据吻合得很好。

英文摘要:

We study the dynamics of the closed scalar field FRW cosmological models in the framework of the so called Unified Dark Matter (UDM) scenario. Performing a theoretical as well as a numerical analysis we find that there is a strong indication of chaos in agreement with previous studies. We find that a positive value of the spatial curvature is essential for the appearance of chaoticity, though the Lyapunov number seems to be independent of the curvature value. Models that are close to flat exhibit a chaotic behavior after a long time while pure flat models do not exhibit any chaos. Moreover, we find that some of the semiflat models in the UDM scenario exhibit similar dynamical behavior with the Lambda cosmology despite their chaoticity. Finally, we compare the measured evolution of the Hubble parameter derived from the differential ages of passively evolving galaxies with that expected in the semiflat unified scalar field cosmology. Based on a specific set of initial conditions we find that the UDM scalar field model matches well the observational data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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