论文标题
BBN和重组之间是否保守熵？
Was Entropy Conserved between BBN and Recombination?
论文作者
论文摘要
我们通过考虑将大量粒子腐烂成光子和其他相对论物种的混合物，测试了大爆炸核合成和重组之间熵保护的假设。我们采用普朗克温度和极化各向异性，凝岛/FIRAS光谱失真界限以及观察到的原始氘丰度以限制这些衰变情况。如果将衰减粒子能量的$ 56 \％$和$ 71 \％$ $转移到光子中，则重组时的$ n _ {\ mathrm {eff}} $将最小变化，而Planck数据仅允许大量的熵注入。如果光子是通过衰减注入的，则添加光谱失真界限将限制粒子的衰减速率为$γ_y> 1.91 \ times10^{ - 6} \ text {s}^{ - 1} $ at $ 95 \％$ pustrort Levers（c.l.）。我们发现，衰减粒子能量密度的限制通过在原始氘丰度上包含边界可以显着增强，从而使粒子最多可以在衰减前的宇宙能量密度最多贡献$ 2.35 \％$（$ 95 \％$ c.l.）。
We test the assumption of entropy conservation between Big Bang nucleosynthesis and recombination by considering a massive particle that decays into a mixture of photons and other relativistic species. We employ Planck temperature and polarization anisotropies, COBE/FIRAS spectral distortion bounds, and the observed primordial deuterium abundance to constrain these decay scenarios. If between $56\%$ and $71\%$ of the decaying particle's energy is transferred to photons, then $N_{\mathrm{eff}}$ at recombination is minimally altered, and Planck data alone allows for significant entropy injection. If photons are injected by the decay, the addition of spectral distortion bounds restricts the decay rate of the particle to be $Γ_Y > 1.91\times10^{-6} \text{s}^{-1}$ at $95\%$ confidence level (C.L.). We find that constraints on the energy density of the decaying particle are significantly enhanced by the inclusion of bounds on the primordial deuterium abundance, allowing the particle to contribute at most $2.35\%$ ($95\%$ C.L.) of the energy density of the universe before decaying.
