标题： 一类IIB紧化中的暗辐射和超重暗物质的弦环起源 显示英文标题

标题： A string loop origin for dark radiation and superheavy dark matter in type IIB compactifications

摘要： 本文研究了弦环修正在微扰模稳定情景下的意义，重点关注它们在揭示晚期宇宙暗辐射起源中的作用及其与暗物质的相关性。更具体地说，我们提供了详细的分析，在这种分析中，Kähler模 sector 中归一化场的质量层次由整数通量的尺度和量子修正确定。 此外，我们计算了之前被低估的模衰变为轴子的衰变率贡献，这些轴子表现为暗辐射，并强调了它们与上述高阶修正的联系。 根据最长寿粒子通过Giudice-Masiero机制衰变为标准模型自由度的衰变率，提出了两种对比的再加热情景（低尺度和高尺度），而有效中微子物种数量 $\Delta N_{eff}$ 仍低于相应的界限。 最后，基于重标量场的衰变，提出了一种非热暗物质情景，其中主要的产生机制被研究，导致暗物质候选粒子质量范围从几 $GeV$ 到 $10^{12}\; GeV$。 显示英文摘要

摘要： In this article we study the significance of string loop corrections, in a perturbative moduli stabilization scenario, focusing on their role in unraveling the origin of dark radiation in the late cosmological epoch and their correlation to dark matter. More specifically, a detailed analysis is provided in which the mass hierarchy of the normalized fields in the K{\"a}hler moduli sector is determined by the scales of the integer fluxes and the quantum corrections. Furthermore, we compute the previously underestimated contributions to the decay rates of moduli to axions, which behave as dark radiation, highlighting their connection to the aforementioned higher-order corrections. Two contrasting reheating scenarios (low-scale and high-scale) are provided, depending on the decay rate of the longest-lived particle into the Standard Model degrees of freedom through a Giudice-Masiero mechanism, while the effective number of neutrino species $\Delta N_{eff}$ remains below the respective bounds. Finally, a non-thermal dark matter scenario is proposed based on the decays of heavy scalar fields, where the main production mechanisms are investigated, leading to a dark matter candidate mass ranging from a few $GeV$ up to $10^{12}\; GeV$.