AI 中文总结
研究利用高红移伽马射线暴数据，通过假设共动GRB形成率与宇宙恒星形成率的关系及红移演化，对温暗物质粒子质量进行限制，在不同假设下得出相应下限，证明GRBs是早期宇宙有力探测器，更好理解两者关系可施加更严限制。
AI 中文摘要
冷暗物质范式成功解释了大尺度结构，但在小尺度上面临持续的紧张关系。具有keV尺度粒子的温暗物质（WDM）可以通过抑制小尺度结构形成来缓解这些问题。高红移处坍缩结构的存在对WDM粒子质量$m_x$设置了很强的下限。伽马射线暴（GRBs）因其极高的亮度是理想的高红移探测器。利用过去二十年积累的最新Swift GRB数据，通过保守假设共动GRB形成率与宇宙恒星形成率（SFR）成正比，并将额外的红移演化参数化为$(1 + z)^\alpha$，我们对$m_x$得出了稳健的限制。对118个红移$z < 10$且光度$L \geq 4.0×10^{52}\,\mathrm{erg\,s^{-1}}$的GRB进行最大似然分析，在95%置信水平（CL）下得到$m_x \gtrsim 1.3\,\mathrm{keV}$。当假设GRB率精确追踪SFR（即$\alpha = 0$）时，在相同CL下下限收紧到$m_x \gtrsim 3.4\,\mathrm{keV}$。这些稳健的限制表明GRBs是早期宇宙的有力探测器。更好地理解GRB率与SFR之间的关系将对WDM模型施加更严格的限制。
英文摘要
The cold dark matter paradigm successfully explains large-scale structure but faces persistent tensions on small scales. Warm dark matter (WDM) with $\mathrm{keV}$-scale particles can alleviate these issues by suppressing small-scale structure formation. The presence of collapsed structures at high redshifts places strong lower limits on the WDM particle mass $m_x$. Gamma-ray bursts (GRBs) are ideal high-redshift probes due to their extreme brightness. Using the most recent \emph{Swift} GRB data accumulated over the past two decades, we derive robust constraints on $m_x$ by conservatively assuming that the comoving GRB formation rate is proportional to the cosmic star formation rate (SFR), with an additional redshift evolution parameterized as $(1+z)^α$. Applying a maximum-likelihood analysis to 118 GRBs with redshift $z<10$ and luminosity $L\ge 4.0\times10^{52}\,\mathrm{erg\,s^{-1}}$, we obtain $m_x \gtrsim 1.23\,\mathrm{keV}$ and $α=1.57^{+1.14}_{-0.57}$ at the 95\% confidence level (CL). The no-evolution scenario ($α=0$), in which the GRB rate exactly traces the SFR without additional redshift evolution, is excluded at the $5σ$ level. Adopting the best-fit value $α=1.57$ as a prior tightens the lower limit on $m_x$ to $m_x \gtrsim 1.59\,\mathrm{keV}$ at the 95\% CL. These robust constraints demonstrate that GRBs are a powerful probe of the early Universe. A better understanding of the relationship between the GRB rate and the SFR would enable even tighter limits on WDM models.
Comments11 pages, 5 figures, 1 table. Accepted for publication in MNRAS
Journal refMon Not R Astron Soc (2026)
