发表机构
Kuvempu University; Government First Grade College Shikaripura（库文普大学; 希卡里普拉政府第一级学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究探讨对数与指数型芬斯勒-兰德斯-佐佐木（FRS）宇宙学模型的晚期膨胀历史，结合多类观测数据约束并利用statefinder诊断区分模型，发现二者虽背景膨胀历史相似但高阶运动学特征差异显著。
AI 中文摘要
本研究探讨对数型与指数型芬斯勒-兰德斯-佐佐木（FRS）宇宙学模型的晚期膨胀历史及几何诊断，利用宇宙计时器、重子声学振荡（BAO）与Pantheon+ Ia型超新星对两种模型场景进行约束，同时考虑基线拟合及经本地SH0ES距离阶梯先验校准的构型。在校准前的情形中，两种模型均能一致描述晚期膨胀历史；引入SH0ES先验后，推断出的哈勃常数增大且推断出的声学尺度发生改变，反映了本地距离阶梯校准与BAO距离尺度的相互作用。宇宙学重构显示，在中等红移处存在从减速到加速的平滑过渡；在观测相关的红移范围内，两种模型均表现出非幻影的类 quintessence 有效暗能量部分。最后，statefinder 诊断可区分两种FRS几何：对数模型仍相对接近标准平直ΛCDM的不动点，而指数模型则遵循不同的动力学轨迹。这些结果表明，尽管两种FRS构造的背景膨胀历史相似，却可呈现出显著不同的高阶运动学特征。
英文摘要
In this work, we investigate the late-time expansion history and geometric diagnostics of logarithmic and exponential Finsler--Randers--Sasaki (FRS) cosmological models. We constrain both scenarios using cosmic chronometers, Baryon acoustic oscillations, and Pantheon+ Type~Ia supernovae, considering baseline fits as well as configurations calibrated with the local SH0ES distance-ladder prior. In the uncalibrated case, both profiles provide consistent descriptions of the late-time expansion history. Incorporating the SH0ES prior increases the inferred Hubble constant and modifies the inferred acoustic scale, reflecting the interplay between the local distance-ladder calibration and the BAO distance scale. Cosmographic reconstructions reveal a smooth transition from deceleration to acceleration at intermediate redshifts. Over the observationally relevant redshift range, both models exhibit a non-phantom, quintessence-like effective dark-energy sector. Finally, statefinder diagnostics distinguish the two FRS geometries: the logarithmic model remains relatively close to the canonical flat $Λ\mathrm{CDM}$ fixed point, whereas the exponential model follows a distinct dynamical trajectory. These results demonstrate that, despite their similar background expansion histories, the two FRS constructions can exhibit substantially different higher-order kinematic signatures.
