Astronomy Reports ( IF 1 ) Pub Date : 2020-12-30 , DOI: 10.1134/s1063772920340016 G. S. Bisnovatyi-Kogan , S. A. Panafidina
Abstract
Propagation of a strong shock wave in the expanding universe is studied using approximate analytic and exact numerical solution of self-similar equations. Both solutions have similar properties, which change qualitatively, depending on the adiabatic powers γ. In the interval \(1 < \gamma < {{\gamma }_{{{\text{cr}}}}} \sim 1.16\) analytic and numeric solutions fill all the space without any voids and they are rather close to each other. At larger \(\gamma > {{\gamma }_{{{\text{cr}}}}}\) a pressure becomes zero at finite radius, and a spherical void appears around the origin in both solutions. All matter is collected in thin layer behind the shock wave front. The structure of this layer qualitatively depends on γ. At the inner edge of the layer the pressure is always zero, but the density at this edge is jumping from zero to infinity at \(\gamma \approx 1.4\) in both solutions.
中文翻译:
具有球状空隙的均匀膨胀宇宙中的强震
摘要
利用近似解析和自相似方程的精确数值解,研究了强冲击波在膨胀宇宙中的传播。两种解决方案都具有相似的性质,这些性质根据绝热系数γ发生质的变化。在间隔((1 <\ gamma <{{\ gamma __ {{{\ text {cr}}}}} \ sim 1.16 \)中,解析解和数值解填充了所有空间,没有任何空隙,它们非常接近彼此。在较大的\(\ gamma> {{\ gamma} _ {{{\ text {cr}}}}} \\)压力在有限半径处变为零,并且在两个解中的原点周围均出现球形空隙。所有物质都被收集在冲击波前部后面的薄层中。该层的结构定性地取决于γ。在层的内边缘,压力始终为零,但在两种解决方案中,该边缘处的密度都从零跃升为\(\ gamma \约1.4 \)处的无穷大。