Title: Smooth magnetogenesis Show Chinese title

Title: 平滑磁生成

Abstract: In the Ratra scenario of inflationary magnetogenesis, the kinematic coupling between the photon and the inflaton undergoes a nonanalytical jump at the end of inflation. Using smooth interpolating analytical forms of the coupling function, we show that such unphysical jump does not invalidate the main prediction of the model, which still represents a viable mechanism for explaining cosmic magnetization. Nevertheless, there is a spurious result associated with the nonanaliticity of the coupling, to wit, the prediction that the spectrum of created photons has a power-law decay in the ultraviolet regime. This issue is discussed using both semiclassical approximation and smooth coupling functions. Show Chinese abstract

Abstract: 在Ratra暴胀磁化情景中，光子与暴胀子之间的运动学耦合在暴胀结束时会发生非解析跳跃。通过使用耦合函数的平滑插值解析形式，我们表明这种非物理跳跃并不会使模型的主要预测失效，该模型仍然代表了一种可行的宇宙磁化机制。然而，由于耦合的非解析性，确实存在一个虚假的结果，即所预测的产生的光子谱在紫外区域具有幂律衰减。这一问题使用半经典近似和光滑耦合函数进行了讨论。