论文标题
非标准宇宙学中的w弱瘦
WIMPy Leptogenesis in Non-Standard Cosmologies
论文作者
论文摘要
我们研究了非标准宇宙学时期的暗物质（DM）歼灭的宇宙不对称性的可能性。考虑到DM是弱相互作用的大粒子类型（WIMP），研究了通过瘦型生成途径产生的重子不对称途径，其中WIMP DM歼灭会产生非零的Lepton不对称。采用最小的粒子物理模型与非零的光中微子质量一起实现这一点，我们考虑了三种不同类型的非标准宇宙历史，即（i）快速扩展的宇宙，（ii）早期物质统治和（iii）（iii）标量的重力理论。通过求解包含这种非标准历史的适当的玻尔兹曼方程，我们发现允许的参数空间与DM遗物一致和观察到的Baryon不对称性一致，并且在某些情况下可能会降低DM质量。尽管这种较轻的DM可以在直接搜索实验中面临进一步的审查，但非标准的时代可以单独提供互补的探针。
We study the possibility of generating baryon asymmetry of the universe from dark matter (DM) annihilations during non-standard cosmological epochs. Considering the DM to be of weakly interacting massive particle (WIMP) type, the generation of baryon asymmetry via leptogenesis route is studied where WIMP DM annihilation produces a non-zero lepton asymmetry. Adopting a minimal particle physics model to realise this along with non-zero light neutrino masses, we consider three different types of non-standard cosmic history namely, (i) fast expanding universe, (ii) early matter domination and (iii) scalar-tensor theory of gravity. By solving the appropriate Boltzmann equations incorporating such non-standard history, we find that the allowed parameter space consistent with DM relic and observed baryon asymmetry gets enlarged with the possibility of lower DM mass in some scenarios. While such lighter DM can face further scrutiny at direct search experiments, the non-standard epochs offer complementary probes on their own.
