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arXiv 0710.4438gr-qcastro-phhep-th
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引力的修正作用:理论与现象学

Modified Actions for Gravity: Theory and Phenomenology

Thomas P. Sotiriou

摘要:

本论文致力于研究引力理论,这些理论可以看作是对广义相对论的修正或推广。动机考虑这样的理论,源于宇宙学,高能物理学和天体物理学是彻底讨论(宇宙学问题,暗能量和暗物质的问题,缺乏成功迄今在获得一个成功的制定量子引力)。引力理论应遵循的基本原则,以及它们的几何解释,在一个广泛的角度进行了分析,突出了广义相对论的基本假设,并提出了可能的修改。一些这样的可能的修改,集中在某些特定类别的理论:标量张量理论,度量f(R)理论,Palatini f(R)理论,度量仿射f(R)理论和高斯-邦纳理论。对这些理论的特点进行了充分的探讨,并对它们之间的动态等价问题进行了探讨。此外,在每个理论的领域内的宇宙学现象进行了讨论,它表明,他们可以潜在地解决众所周知的宇宙学问题。一些可行性标准:宇宙学观测,太阳系测试,稳定性标准,存在的精确解常见的真空或物质配置等最后,在该领域的未来前景的修改重力进行了讨论,并探讨了超越试错法修改重力的可能性。

英文摘要:

This thesis is devoted to the study of gravitational theories which can be seen as modifications or generalisations of General Relativity. The motivation for considering such theories, stemming from Cosmology, High Energy Physics and Astrophysics is thoroughly discussed (cosmological problems, dark energy and dark matter problems, the lack of success so far in obtaining a successful formulation for Quantum Gravity). The basic principles which a gravitational theory should follow, and their geometrical interpretation, are analysed in a broad perspective which highlights the basic assumptions of General Relativity and suggests possible modifications which might be made. A number of such possible modifications are presented, focusing on certain specific classes of theories: scalar-tensor theories, metric f(R) theories, Palatini f(R) theories, metric-affine f(R) theories and Gauss--Bonnet theories. The characteristics of these theories are fully explored and attention is payed to issues of dynamical equivalence between them. Also, cosmological phenomenology within the realm of each of the theories is discussed and it is shown that they can potentially address the well-known cosmological problems. A number of viability criteria are presented: cosmological observations, Solar System tests, stability criteria, existence of exact solutions for common vacuum or matter configurations etc. Finally, future perspectives in the field of modified gravity are discussed and the possibility for going beyond a trial-and-error approach to modified gravity is explored.

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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