标题： 弗里德曼-勒梅特-罗伯逊-沃尔克型宇宙与真空能量密度 显示英文标题

标题： FRW-Type Universe With Vacuum Energy Density

摘要： 我们考虑了一个宇宙学常数形式为$\Lambda=3\alpha\frac{\dot R^2}{R^2}+\bt\frac{\ddot R}{R} \alpha, \bt=\rm const.$的宇宙学模型。宇宙学常数被发现随着$t^{-2}$而减少，粒子产生速率小于稳态值。 我们发现这种行为给出$\frac{\Lambda_{Pl}}{\Lambda_p}=10^{120}$，其中$\Lambda_{Pl}$是$\Lambda$在普朗克时间的值。 在辐射主导时期具有$\bt=3\alpha$和在物质主导时期具有$\bt=6\alpha$的解等价于 FRW 结果。 我们找到了一个具有$\bt=3-3\alpha$的德西特型膨胀解。 标准模型的一些问题可能通过爱因斯坦方程中的上述宇宙学常数得到解决。 由于观测表明真空能量密度的贡献在范围$0.40<\Omega^\Lambda<0.76$内，因此得到$4<\beta<12$。 如果$\alpha=0$，则宇宙的最小年龄为$H_p^{-1}$（$H_p$是当前的哈勃常数）且具有$\beta=\infty$。 显示英文摘要

摘要： We have considered a cosmological model with a cosmological constant of the form $\Lambda=3\alpha\frac{\dot R^2}{R^2}+\bt\frac{\ddot R}{R} \alpha, \bt=\rm const.$ The cosmological constant is found to decrease as $t^{-2}$ and the rate of particle creation is smaller than the Steady State value. We have found that this behavior gives $\frac{\Lambda_{Pl}}{\Lambda_p}=10^{120}$ where $\Lambda_{Pl}$ is the value of $\Lambda$ at Planck time. Solutions with $\bt=3\alpha$ in the radiation dominated era and $\bt=6\alpha$ in the matter dominated era are equivalent to the FRW results. We have found an inflationary solution of the de-Sitter type with $\bt=3-3\alpha$. Some problems of the Standard Model may be resolved with the presence of the above cosmological constant in the Einstein's equation. Since observations suggest a contribution of the vacuum energy density in the range $0.40<\Omega^\Lambda<0.76$, one gets $4<\beta<12$. If $\alpha=0$ the minimum age of the universe is found to be $H_p^{-1}$ ($H_p$ is the present Hubble constant) with $\beta=\infty$.