发表机构
Universidade Federal da Paraíba; Universidade Estadual do Sudoeste da Bahia; Universidade Federal do Maranhão（帕拉伊巴联邦大学; 巴伊亚西南州立大学; 马拉尼昂联邦大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究二维旋转排水浴缸声学视界中模拟霍金辐射的环流与操作稀疏性，求解径向散射问题，发现旋转增强粒子数通量并硬化谱，时间重叠依赖于操作时钟。
AI 中文摘要
时间稀疏性是将发射量子间的平均间隔与特征单量子时标进行比较的量。我们在二维空间中研究旋转排水浴缸声学视界的该操作量。霍金温度由径向排水口决定，与环流无关，而几何捕获宽度和透射谱则依赖于环流。因此，几何黑体基准预测，随着环流增加，时间间隔会减小。随后，我们求解径向散射问题，计算收敛的灰体修正后的粒子数通量与能量通量，包括超辐射扇区。在环流与排水口的比值为1时，热时钟稀疏性为0.44，而基于谱的稀疏性为1.82；前者在比值约0.40处穿过时间重叠基准，后者在所有采样的环流比值下均保持在1以上。我们还表明，分箱稀疏性定义在二维空间中具有对数红外敏感性。因此，旋转会增强粒子数通量，同时使谱变硬，使得时间重叠本质上依赖于用于分辨发射量子的操作时钟。
英文摘要
Temporal sparsity compares the mean interval between emitted quanta with a characteristic single-quantum timescale. We study this operational quantity for the rotating draining-bathtub acoustic horizon in two spatial dimensions. The Hawking temperature is fixed by the radial drain and does not depend on circulation, while the geometric capture width and the transmission spectrum do. A geometric black-body benchmark therefore predicts reduced temporal separation as circulation increases. We then solve the radial scattering problem and compute converged greybody-corrected number and energy fluxes, including the superradiant sector. At a circulation-to-drain ratio of unity, the thermal-clock sparsity is 0.44 whereas the spectrum-based sparsity is 1.82. The former crosses the temporal-overlap benchmark near a ratio of 0.40, while the latter remains above unity at all sampled circulation ratios. We also show that the binned sparsity definition is logarithmically infrared sensitive in two spatial dimensions. Rotation therefore enhances the number flux while hardening the spectrum, making temporal overlap intrinsically dependent on the operational clock used to resolve the emitted quanta.
Comments9 pages and 3 figures
