The present paper is an investigation of dark energy scenarios of cosmological models in recently proposed modified non-metricity gravity theory with boundary term in a flat FLRW spacetime universe. We have considered an arbitrary function , where is the non-metricity scalar, is the boundary term given by , and are the model parameters, which is quadratic in both and , for the action. We have investigated the dark energy features of the model with observational constraints on an specific Hubble function , where is present value of Hubble constant, are arbitrary parameters with . We have found a transit phase (decelerated in past and accelerated at present) expanding universe model and have found the behaviour of dark energy equation of state (EoS) as and Om diagnostic analysis of the model shows the quintessence behaviour at present and cosmological constant scenario at late-time universe. We have also, analyzed the statefinder parameters for the classification of dark energy models during expansion and also, we have estimated the present age of the universe that are found very closed to the recent observations.

中文翻译：

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具有观测约束的 f(Q,B) 引力理论中的精髓行为暗能量模型

本文研究了最近提出的带有边界项的修正非度量引力理论中平坦 FLRW 时空宇宙中宇宙学模型的暗能量场景。我们考虑了一个任意函数 ，其中 是非度量标量， 是由 给出的边界项， 是模型参数，对于动作来说，它在 和 中都是二次的。我们研究了模型的暗能量特征，并对特定哈勃函数 进行了观测约束，其中 是哈勃常数的现值，是任意参数。我们发现了一个过渡阶段（过去减速，现在加速）膨胀宇宙模型，并发现了暗能量状态方程（EoS）的行为，该模型的 Om 诊断分析显示了当前的典型行为和宇宙常数场景在晚期宇宙。我们还分析了膨胀过程中暗能量模型分类的寻态器参数，并且还估计了宇宙当前的年龄，发现该年龄与最近的观测结果非常接近。