Abstract

A solution to the Einstein equations for a closed null string with axial symmetry that is radially increases its size is found. The possibility of choosing the ideal gas of null strings as a dominant source of gravity is confirmed in the study of the null string inflation mechanism in Friedmann–Robertson–Walker spaces. The absence of a limit transition between the solution that is found and the solution for a closed circular null string that is radially changing its size is shown. This indicates the stability of the configuration of a closed circular null string during its motion in an external gravitational field. It is noted that part of the characteristics of the null string gas, such as the ability to form a domain structure and existence of stable polarized states (multi-string systems), are independent of the shape of null string, but the dynamics of the test null string in a field of such multi-string system has singularities.

中文翻译：

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径向对称且尺寸增大的闭合空弦的爱因斯坦方程组的解

摘要

找到了一个爱因斯坦方程组的解决方案，它的轴向对称性为零，并且径向增大，该零弦闭合。在Friedmann-Robertson-Walker空间的零弦膨胀机制的研究中，确定了选择零弦理想气体作为主要重力来源的可能性。示出了在找到的解与径向改变其大小的闭合圆形空弦的解之间没有极限过渡。这表明在外部重力场中封闭的圆形空弦在运动过程中结构的稳定性。请注意，空串气体的部分特性（例如形成畴结构的能力和稳定的极化态（多串系统）的存在）与空串的形状无关，