标题： 螺旋星系的银河系旋转曲线与f(R,T)引力理论中的暗物质 显示英文标题

标题： Galactic rotation curves of spiral galaxies and dark matter in f(R,T) gravity theory

摘要： 星系旋转曲线是星系内引力场状态的有力指示器。 这些曲线的平坦性表明星系及其星系团中存在暗物质。 在本文中，我们专注于在$f(\mathcal{R},T)$引力框架下解释螺旋星系的旋转曲线的可能性，而无需假定暗物质的存在，其中引力拉格朗日量由$\mathcal{R}$的任意函数、里奇标量和$T$的能量-动量张量的迹$T_{\mu\nu}$表示。 我们在这种引力理论中推导了静态球对称时空的引力场方程，并使用一种物质与几何之间具有最小耦合的特定模型来求解度规系数。 考虑了一个在稳定圆轨道上运动的质点的轨道运动，并借助所考虑的模型研究了其切向速度的行为。 我们通过为测试粒子生成并拟合旋转曲线，将该模型预测的理论结果与十九个星系的观测结果进行比较，以检验该模型的可行性。 观察到该模型几乎可以成功地解释这些星系在远离星系中心的大距离处的星系动力学，而无需暗物质。 显示英文摘要

摘要： Galactic rotation curve is a powerful indicator of the state of the gravitational field within a galaxy. The flatness of these curves indicates the presence of dark matter in galaxies and their clusters. In this paper, we focus on the possibility of explaining the rotation curves of spiral galaxies without postulating the existence of dark matter in the framework of $f(\mathcal{R},T)$ gravity, where the gravitational Lagrangian is written by an arbitrary function of $\mathcal{R}$, the Ricci scalar and of $T$, the trace of energy-momentum tensor $T_{\mu\nu}$. We derive the gravitational field equations in this gravity theory for the static spherically symmetric spacetime and solve the equations for metric coefficients using a specific model that has minimal coupling between matter and geometry. The orbital motion of a massive test particle moving in a stable circular orbit is considered and the behavior of its tangential velocity with the help of the considered model is studied. We compare the theoretical result predicted by the model with observations of a sample of nineteen galaxies by generating and fitting rotation curves for the test particle to check the viability of the model. It is observed that the model could almost successfully explain the galactic dynamics of these galaxies without the need of dark matter at large distances from the galactic center.