We consider the double pulsar binary system as a laboratory to locally test the orbital effects induced by an uniform cosmological constant $Λ$ in the framework of the known general relativistic laws of gravity, and the DGP braneworld model of gravity independently of the cosmological acceleration itself for which they were introduced. We, first, construct the ratio R=Delta\dotω/Delta P of the discrepancies between the phenomenologically determined periastron rate \dotωand orbital period and their predicted values from the 1PN approximation and the third Kepler law. Then, we compare its value R = (0.3 +/- 4) \times 10^-11 s^-2, compatible with zero within the errors, to the ratios R_Lambda and R_DGP of the effects induced on the apsidal rate and the orbital period by Lambda and the DGP gravity; we find them neatly incompatible with R being R_Lambda = (3.4 +/- 0.3) \times 10^-8 s^-2 and R_DGP = (1.4 +/- 0.1) \times 10^-7 s^-2, respectively. Such a result, which for the case of Lambda is valid also for any other Hooke-like exotic force proportional to r, is in agreement with other negative local tests recently performed in the Solar System with the ratios of the non-Newtonian/Einsteinian perihelion precessions for several pairs of planets.
Prospects of constraining the dense matter equation of state from the timing analysis of pulsars in double neutron star binaries: the cases of PSR J0737-3039A and PSR J1757-1854
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
Binary-pulsar tests of strong-field gravity and gravitational radiation damping
本次演讲回顾了双星脉冲星数据对引力理论的约束，重点是“标量张量”理论，这是广义相对论的最佳替代方案。我们还记得，双星脉冲星实验与太阳系实验在性质上是不同的，这是因为在像中子星这样的致密天体中可能出现非微扰强场效应，而且人们可以观察到引力辐射阻尼效应。在太阳系中，有些理论与广义相对论是严格不可区分的，但它们已被脉冲双星观测所排除。在过去的几个月里，发表了一些令人印象深刻的新实验数据。今天，最具约束力的脉冲双星不再是著名的（赫尔斯-泰勒）PSR B 1913 +16，而是中子星-白矮星系统PSR J 1141 -6545。特别是，在“理论空间”的一个区域，太阳能系统测试被认为是最严格的限制; PSR J1141-6545现在几乎同样强大。我们还评论了未来干涉仪探测引力波的可能标量场效应。引力子的标量伙伴的存在可能会被LISA空间实验检测到，但我们已经知道它对LIGO和VIRGO的影响可以忽略不计，因此广义相对论波模板可以安全地用于这些地面干涉仪。
Upper limits on microhertz gravitational waves from supermassive black-hole binaries using PSR J1909-3744 data from the second IPTA data release
Xinjiang Astronomical Observatories, Chinese Academy of Sciences（中国科学院新疆天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Institute of Optoelectronic Technology, Lishui University（丽水学院光电技术研究所）
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…
Constraints of general screened modified gravities from comprehensive analysis of binary pulsars
利用双星系统进行重力测量已成为当前的一个重要课题。屏蔽修正引力理论是一种具有屏蔽机制的标量-张量理论，以满足严格的太阳系实验要求。本文研究了屏蔽机制对双星轨道动力学的影响，并详细计算了屏蔽机制中的五个后开普勒（PK）参数。这些参数不同于广义相对论（GR）的参数，并且这些差异被标量电荷量化，这导致了该理论中的偶极辐射。我们分别结合了十个二元双星的PK参数的观测值，中子星（NS）-白矮星（WD）双星中的偶极辐射导致了对GR偏差的更严格的约束。对NS和WD标量电荷最严格的约束系统是PSR~ B 1913 $+$ 16和PSR ~ B 1913。J1738 $+$ 0333。所有的测试结果排除了显着的强场偏差，并显示出良好的协议与GR。
