In the paper, we present an accelerating cosmological model in $f(R,\mathcal{L}_{m})$ gravity with the parameter constrained through the cosmological data sets. At the beginning, we have employed a functional form of $f(R,\mathcal{L}_{m}) =\frac{R}{2}+αR^2+\mathcal{L}_{m}^β$, where $α$ and $β$ are model parameters. This model is well motivated from the Starobinsky model in $f(R)$ gravity and the power law form of $f(\mathcal{L}_{m})$. The Hubble parameter has been derived with some algebraic manipulation and constrained by Hubble data and Pantheon$^{+}$ data. With the constraint parameters, present value of deceleration parameter has been obtained to as $q_{0}\approx-0.63$ with the transition at $z_{t}\approx0.7$. It shows the early deceleration and late time acceleration behaviour. The present value of other geometric parameters such as the jerk and snap parameter are obtained to be $j_{0}\approx0.78$ and $s_{0}\approx 0.1$ respectively. The state finder diagnostic test gives the quintessence behaviour at present and converging to $Λ$CDM at late times. Moreover the $Om(z)$ diagnostics gives negative slope which shows that the model favours the state finder diagnostic result. Also the current age of Universe has been obtained as, $t_{0} = 13.64~~Gyrs$. The equation of state parameter also shows the quintessence behaviour. Based on the present analysis, it indicates that the $f(R,\mathcal{L}_{m})$ gravitational theory may be another alternative to study the dark energy models.
Constraining Anisotropic Cosmological Model in $f(\mathcal{R},\mathscr{L}_m)$ Gravity
关于目前宇宙学方面的观测证据告诉我们，在大尺度上，宇宙中存在着非常小的各向异性。在本文中，我们试图研究具有各向同性物质分布的局部旋转对称（LRS）均匀Bianchi-I时空。这是在$f(\mathcal{R},\mathscr{L}_m)$重力框架内完成的。特别地，我们考虑一个非线性$f(\mathcal{R},\mathscr{L}_m)$模型，$f(\mathcal{R},\mathscr{L}_m)=\dfrac{1}{2}\mathcal{R}+\mathscr{L}_m^{\,α}$。此外，状态方程参数$ω$，这是在确定宇宙的当前阶段的重要材料是受约束的。为了约束模型参数和状态方程参数，我们使用了57个哈勃数据点和1048个Pantheon Ia型超新星数据样本。并且，对于我们的统计分析，我们使用Markoc Chain Monte Carlo（MCMC）模拟。此外，在所获得的参数值的帮助下，我们测量了我们的模型的各向异性参数。
St. Xavier’s College, Tribhuvan University（圣泽维尔学院，特里布文大学）；Holographic Himalaya（全息喜马拉雅）；Department of Physics and Astronomy, Ohio University（俄亥俄大学物理与天文学系）；Tri-Chandra Multiple Campus, Tribhuvan University（特里昌德拉多校区，特里布文大学）；Emmy Noether Group for Theoretical Quantum Systems Design, Technical University of Munich（埃米·诺特理论量子系统设计组，慕尼黑工业大学）
Implications from simulated strong gravitational lensing systems: constraining cosmological parameters using Gaussian Processes
强引力透镜系统（SGL）将宇宙学信息编码为源/透镜距离比$\mathcal{D}_{\rm obs}=\mathcal{D}_{\rm ls}/\mathcal{D}_{\rm s}$，可用于精确约束宇宙学参数。在本文中，基于未来的测量390强透镜系统从即将到来的LSST调查，我们已经成功地重建的距离比$\mathcal{D}_{\rm obs}$（与源红移$z_s\sim 4.0$），直接从数据，而不假设任何参数的形式。最近开发的方法的基础上，模型无关的重建方法，高斯过程（GP）被用于我们的研究这些强透镜系统。我们的研究结果表明，独立测量的物质密度参数（$Ω_m$），可以预期从这样强的透镜统计。更具体地说，可以预期在一致性$Λ$ CDM模型中以$ΔΩ_m\sim0.015$的精度估计$Ω_m$，该模型提供了与普朗克2015结果相当的$Ω_m$约束。在修正的引力理论（DGP）框架下，未来LSST巡天的390个可探测星系透镜体将导致$ΔΩ_m\sim0.030$的严格拟合。\textbf{Finally, we have discussed three possible sources of systematic errors (sample incompleteness, the determination of length of lens redshift bin, and t…
Accelerating parameter estimation for parameterized tests of general relativity with gravitational-wave observations
National Institute of Technology Agartala（阿加塔拉国立技术学院）；Pennsylvania State University（宾夕法尼亚州立大学）；University of Glasgow（格拉斯哥大学）；University of California, Berkeley（加州大学伯克利分校）；Northwestern University（西北大学）
Constraining the gravitational-wave breathing mode with LVK antenna patterns and GWTC data
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；The International Centre for Theoretical Physics Asia-Pacific, University of Chinese Academy of Sciences（亚洲太平洋理论物理中心，中国科学院大学）；Missouri University of Science and Technology（密苏里科技大学）
Constraining Lorentz symmetry breaking in bumblebee gravity with extreme mass-ratio inspirals
Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences（中国科学院大学杭州高等研究院）；Hunan Normal University（湖南师范大学）；Beijing Normal University（北京师范大学）；Yangzhou University（扬州大学）
The effect of gravitational decoupling on constraining the mass and radius for the secondary component of GW190814 and other self-bound strange stars in f(Q)-gravity theory
Constraining viscous fluid models in $f(Q)$ gravity with data
Wolkite University（沃尔基特大学）；National Institute for Theoretical and Computational Sciences (NITheCS)（国家理论与计算科学研究所）；Universidad de Salamanca（萨拉曼卡大学）；North-West University（西北大学）；University of Cape Town（开普敦大学）
