标题： IIB紧致化中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： 在本文中，我们研究了在微扰模量稳定情景中，弦环修正对揭示晚期宇宙时代暗辐射的起源及其与暗物质相关性的意义。 更具体地说，提供了一项详尽的分析，其中Kähler模量部分中归一化场的质量层次由整数通量和量子修正参数$\eta$的尺度决定。 此外，计算了之前被低估的模量到轴子的衰变率贡献，这些轴子表现出暗辐射的行为，突显了它们与上述高阶修正之间的联系。 根据最长寿命粒子通过Giudice-Masiero机制衰变成标准模型自由度的衰变率，提供了两种对比的再加热场景（低能标和高能标），同时有效中微子种类数$\Delta N_{eff}$低于相应的限制。 最后，基于重标量场的衰变提出了一种非热暗物质场景，其中主要的产生机制被研究，导致暗物质候选者的质量从几个$GeV$到$10^{11}\; GeV$。 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, on unraveling the origin of dark radiation in the late cosmological times and its correlation to dark matter. More specifically, a scrutinized analysis is provided where the mass hierarchy of the normalized fields in the K{\"a}hler moduli sector is determined by the integer fluxes and the scale of the quantum correction's parameter $\eta$. Furthermore, the previously underestimated contributions to the decay rates of moduli to axions, which behave as dark radiation, are computed 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 to Standard model degrees of freedom through a Giudice-Masiero mechanism, while the effective number of neutrino species $\Delta N_{eff}$ lays below the respected bounds. Finally, a non-thermal dark matter scenario is proposed based on the decays of the heavy scalar fields, where the main production mechanisms are investigated, leading to dark matter candidate's mass laying from a few $GeV$ up to $10^{11}\; GeV$.