三维德西特时空中施温格对的无质量费米子电流
Massless fermionic current of Schwinger pairs in 3D de Sitter spacetime
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中文总结 AI 辅助
研究三维德西特时空中由恒定电场产生无质量费米子及感应电流，通过假设邦奇 - 戴维斯真空并采用绝热正则化推导表达式，分析不同场强下电流特性，突出维度作用，阐明自旋与红外物理关系，为后续研究提供基础。
中文摘要 AI 辅助
在德西特（dS）时空中，在U(1)规范场存在下从真空中产生对，为探索弯曲背景下的量子场论提供了一个重要场景。本文研究了(1 + 2)维dS时空中由恒定电场产生的无质量费米子产生及相关感应电流。假设邦奇 - 戴维斯真空并采用绝热正则化，首次推导出dS₃中无质量费米子感应电流的有限表达式。产生的费米子产生与外部电场相反的净电流。在强场 regime，感应电流呈现预期的半经典缩放并在平坦时空极限下重现标准施温格行为。在弱场 regime，电流与电场强度呈线性关系。进一步表明感应电流在整个参数空间中保持单调，与dS₄不同，不表现出任何符号变化。结果突出了维度的作用并阐明了dS中自旋与红外物理之间的相互作用，为包括反作用效应、拓扑大质量费米子和随时间变化的电磁背景等未来研究提供了一致基础。
英文摘要
Pair creation from the vacuum in the presence of a U(1) gauge field in de Sitter $(\mathrm{dS})$ spacetime provides an important setting for exploring quantum field theory in curved backgrounds. In this work, we investigate massless fermion production and the associated induced current generated by a constant electric field in (1+2)-dimensional $\mathrm{dS}$ spacetime. Assuming the Bunch--Davies vacuum and employing adiabatic regularization, we derive, for the first time, a finite expression for the induced current of massless fermions in $\mathrm{dS}_{3}$. The produced fermions generate a net current opposite to the external electric field. In the strong-field regime, the induced current exhibits the expected semiclassical scaling and reproduces the standard Schwinger behavior in the flat-spacetime limit. In the weak-field regime, the current is linear in the electric-field strength. This behavior is characteristic of the fermionic nature of the particles, since the corresponding bosonic case exhibits infrared hyperconductivity, which is absent in our study. We further show that the induced current remains monotonic throughout the parameter space and, unlike in $\mathrm{dS}_4$, does not exhibit any sign change. Our results thus highlight the role of dimensionality and clarify the interplay between spin and infrared physics in $\mathrm{dS}$. This work provides a consistent basis for future investigations including backreaction effects, topologically massive fermions, and time-dependent electromagnetic backgrounds.
