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在谐和条件下的相对论宇宙论——Ⅱ.宇宙中的Poynting矢量与红移 被引量:5
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作者 黄超光 周培源 《中国科学(A辑)》 CSCD 1990年第4期416-422,共7页
星系中恒星发射的电磁辐射是宇宙中电磁方程的解,其中每一恒星被当作一个电偶极子来处理,代表光强的Poynting矢量在各向同性共动坐标系、Robertson-Walker坐标系和标准球坐标系中有不同的形式,作为一级近似,在所有这些坐标系中,速度-距... 星系中恒星发射的电磁辐射是宇宙中电磁方程的解,其中每一恒星被当作一个电偶极子来处理,代表光强的Poynting矢量在各向同性共动坐标系、Robertson-Walker坐标系和标准球坐标系中有不同的形式,作为一级近似,在所有这些坐标系中,速度-距离(或红移-光强)关系都是相同的,但在二级近似下,它们是有区别的。本文所得到红移-光强关系还依赖于退行星系中恒星的数目,或者说依赖于星系的质量,从这-相对论宇宙论的处理,我们可以看到这是一种通过动力学及电磁学的途径处理问题的方法,而不是通常的几何学的处理。 展开更多
关键词 相对论宇宙论 谐和条件 红移 光强
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From the elasticity theory to cosmology and vice versa 被引量:1
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作者 LEVRINO Luca TARTAGLIA Angelo 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第4期597-603,共7页
The paper shows how a generalization of the elasticity theory to four dimensions and to space-time allows for a consistent description of the homogeneous and isotropic universe,including the accelerated expansion.The ... The paper shows how a generalization of the elasticity theory to four dimensions and to space-time allows for a consistent description of the homogeneous and isotropic universe,including the accelerated expansion.The analogy is manifested by the inclusion in the traditional Lagrangian of general relativity of an additional term accounting for the strain induced in the manifold(i.e.in space-time)by the curvature,be it induced by the presence of a texture defect or by a matter/energy distribution.The additional term is su?cient to account for various observed features of the universe and to give a simple interpretation for the so called dark energy.Then,we show how the same approach can be adopted back in three dimensions to obtain the equilibrium configuration of a given solid subject to strain induced by defects or applied forces.Finally,it is shown how concepts coming from the familiar elasticity theory can inspire new approaches to cosmology and in return how methods appropriated to General Relativity can be applied back to classical problems of elastic deformations in three dimensions. 展开更多
关键词 deformable solids COSMOLOGY elastic strain Lagrangian density and tensors
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