Related papers: Radio Tests of GR
In the framework of a transient accretion disk at the core of a gamma-ray burst we compute possible periods of Lense-Thirring precession. Next, we evaluate the putative gravitational waves associated with such dynamical setup. Assuming a…
In this paper, we focus on testing gravity theories in the radiative regime using pulsar timing array observations. After reviewing current techniques to measure the dispersion and alternative polarization of gravitational waves, we extend…
This work aims to explore the possibilities of determining the long-period part of the precession-nutation of the Earth with techniques other than very long baseline interferometry (VLBI). Lunar laser ranging (LLR) is chosen for its…
Shapiro time delay is one of the fundamental tests of general relativity and post-Newtonian theories of gravity. Consequently, its measurements can be used to probe the parameter $\gamma$ which is related to spacetime curvature produced by…
The most precise measurements are done at present by timing of radiopulsars in binary systems with two neutron stars. The timing measurements of the Taylor-Hulse pulsar B1913+16 gave the most precise results on testing of general relativity…
We describe in this paper a new binary millisecond pulsar, PSR J1738+0333. Using Arecibo, we have achieved good timing accuracy for this object, about 220 ns for 1-hour integrations over 100 MHz. This allowed us to measure a precise proper…
We review the status of tests of spacetime symmetries with gravity. Recent theoretical and experimental work has involved gravitational wave signals, precision solar-system tests, and sensitive laboratory tests searching for violations of…
Compact galactic and extragalactic radio sources can be imaged with an unsurpassed angular resolution of a few ten micro-arcseconds, adopting the observing technique of global millimeter VLBI. Here we present the Global Millimeter VLBI…
Based on published data, we have produced a sample of 256 radio sources whose trigonometric parallaxes and proper motions were measured by VLBI. This sample contains Galactic masers associated with massive protostars and stars in active…
A method has been developed for precision measurement of the gravitational frequency shift of communication radio signals between the spacecraft and the ground tracking station based on the maximum likelihood principle, using the Rao-Cramer…
One of the main objectives of the Cosmic Lens All-Sky Survey (CLASS) collaboration has been to find gravitational lens (GL) systems at radio wavelengths that are suitable for the determination of time delays between image pairs. The survey…
Observations of gravitational waves (GWs) by the advanced LIGO--Virgo detectors provide us with ground breaking opportunities to test predictions of Einstein's theory of general relativity (GR) in the strong field regime. In this article,…
The Gravity Probe B (GP-B) Experiment of NASA was aimed to test the theoretical predictions of Einstein's 1916 relativistic tensor theory of gravity in curved space-time (General Relativity (GR)) concerning the spin axis precession of a…
The Hubble constant value is currently known to 10% accuracy unless assumptions are made for the cosmology (Sandage et al. 2006). Gravitational lens systems provide another probe of the Hubble constant using time delay measurements.…
To test the theory of gravity one needs to test, on one hand, how space and time are distorted by matter and, on the other hand, how matter moves in a distorted space-time. Current observations provide tight constraints on the motion of…
We study the effect of retardation of gravity in binary pulsars. It appears in pulsar timing formula as a periodic excess time delay to the Shapiro effect. The retardation of gravity effect can be large enough for observation in binary…
In a modified gravity theory, the propagation equation of gravitational waves will be presented in a non-standard way. Therefore this tenor mode perturbation of time-space, as a complement to the scalar mode perturbation, provides a unique…
The degree of beaming in Gamma-Ray Bursts (GRBs) is currently unknown. The uncertainty in the gamma-ray beaming angle, theta, leaves the total energy release (proportional to theta^2) and the event rate per galaxy (proportional to…
It has been shown in the literature that detections of gravitational waves (GWs) emitted by binary sources can provide measurements of luminosity distance. The events followed by electromagnetic counterparts are, then, suitable for probing…
Very long baseline interferometry (VLBI) provides the resolution needed to make precision measurements of a pulsar's parallax and proper motion. In making these measurements, the astronomer is faced with difficult calibration problems and a…