The production of GWs during preheating in the Starobinsky model with a nonminimally coupled auxiliary scalar field is studied through the lattice simulation in this paper. We find that the GW spectrum \(\Omega _{\mathrm{gw}}\) grows fast with the increase of the absolute value of coupling parameter \(\xi \). This is because the resonant bands become broad with the increase of \(|\xi |\). When \(\xi <0\), \(\Omega _{\mathrm{gw}}\) begins to grow once the inflation ends and grows faster than the case of \(\xi >0\). \(\Omega _{\mathrm{gw}}\) reaches the maximum at \(\xi =-20\) (\(\xi =42\) for the case \(\xi >0\)) and then decreases with slight oscillation. Furthermore we find that the GWs produced in the era of preheating satisfy the limits from the Planck and next-generation CMB experiments.

本文通过晶格模拟研究了在具有最小耦合辅助标量场的Starobinsky模型中预热过程中GW的产生。我们发现GW谱\（\ Omega _ {\ mathrm {gw}} \）随着耦合参数\（\ xi \）绝对值的增加而快速增长。这是因为随着\（| \ xi | \）的增加，共振带变宽。当\（\ xi <0 \）时，一旦通货膨胀结束，\（\ Omega _ {\ mathrm {gw}} \\）开始增长，并且增长速度比\（\ xi> 0 \）快。\（\ Omega _ {\ mathrm {gw}} \）在\（\ xi = -20 \）（对于这种情况为\（\ xi = 42 \）达到最大值\（\ xi> 0 \）），然后随着轻微振荡而减小。此外，我们发现在预热时代生产的GW满足了普朗克和下一代CMB实验的限制。