论文标题
轴心景观中的随机轴承暗物质
Stochastic Axion Dark Matter in Axion Landscape
论文作者
论文摘要
我们研究了轴心景观中的随机轴轴暗物质情景，其中其中一个轴是轻巧而稳定的，因此可以解释暗物质。如果电势处的轴质量是沿方向曲率的典型值，则可以通过二次质量项近似电势。另一方面，如果轴突质量恰好在最小值的附近被抑制，则可以通过四分之一的电势加上抑制的二次角度近似，与二次情况相比，最初的角度和轴突丰度可以被显着抑制。我们通过考虑各种观察性约束来描述可行的参数区域，并发现允许更广泛的通货膨胀量表。同样，如果在一定范围内抑制电势的曲率，则可以延迟相干振荡的发作。然后，可能具有较小的衰减常数的斧头暗物质。我们还讨论了在随机轴心方案中实现山顶初始条件的πNFLATION机制。
We study the stochastic axion dark matter scenario in the axion landscape, where one of the axions is light and stable and therefore explains dark matter. If the axion mass at the potential is a typical value of the curvature along the direction, the potential can be well approximated by a quadratic mass term. On the other hand, if the axion mass happens to be suppressed in the vicinity of the minimum, the potential may be approximated by a quartic potential plus a suppressed quadratic one, for which the initial angle, and thus the axion abundance, can be significantly suppressed compared to the quadratic case. We delineate the viable parameter region by taking account of various observational constraints, and find that a broader range of the inflation scale is allowed. Also, if the curvature of the potential is suppressed over a certain range of the potential, the onset of coherent oscillations can be delayed. Then, the axion dark matter with a small decay constant is possible. We also discuss the πnflation mechanism to realize the hilltop initial condition in the stochastic axion scenario.
