Related papers: Constraints on Gravitational Dipole Radiation from…

Some of the theoretical challenges posed by the general relativistic description of binary systems of compact objects (neutron stars or black holes) are reviewed. We recall the various ways one can use the theory of the motion, and of the…

We calculate the rate of energy loss from compact astrophysical objects due to a scalar field in screened modified gravity models of the chameleon, dilaton and symmetron types. The cosmological evolution of the field results in a…

We study the gravitational Faraday rotation, on linearly polarized light rays emitted by a pulsar, orbiting another compact object. We relate the rotation angle to the orbital phase of the emitting pulsar, as well as to other parameters…

Binary pulsars are excellent laboratories to test the building blocks of Einstein's theory of General Relativity. One of these is Lorentz symmetry which states that physical phenomena appear the same for all inertially moving observers. We…

The magnetosphere of, and electromagnetic (EM) radiation from pulsars are usually described in the framework of classical electrodynamics. For some pulsars, however, whose emission heights are relatively close to the surface of the neutron…

The concept of Gravitational Dipole is introduced starting from the recent discovery of negative gravitational mass (gr-qc/0005107 and physics/0205089). A simple experiment, a gravitational wave transmitter, to test this new concept of…

Binary pulsars are a powerful tool for probing strong gravity that still outperforms direct gravitational wave observations in a number of directions due to the remarkable accuracy of the pulsar timing. They can constrain very precisely the…

This talk reviews the constraints imposed by binary-pulsar data on gravity theories, and notably on "scalar-tensor" theories which are the most natural alternatives to general relativity. Because neutron stars have a strong gravitational…

Pulsars are wonderful gravitational probes. Their tiny size and stellar mass give their rotation periods a stablility comparable to that of atomic frequency standards. This is especially true of the rapidly rotating "millisecond pulsars"…

We consider the scenario where dark matter (DM) is represented by an ultra-light classical scalar field performing coherent periodic oscillations. We point out that such DM perturbs the dynamics of binary systems either through its…

Millisecond pulsars are extremely precise celestial clocks: as they rotate, the beamed radio waves emitted along the axis of their magnetic field can be detected with radio telescopes, which allows for tracking subtle changes in the…

Dipole fields are common in electromagnetism and may be viewed as the result of a positive and negative charge (or pole) which are close together. A dipole field in gravity is not expected to exist because negative mass has never been…

The final-parsec problem has long posed a central challenge in understanding the merger of supermassive black hole binaries. In this paper, we investigate a scenario in which a dark scalar or vector field is sourced by eccentric binaries,…

Testing of the gravitation equations, proposed by one of the authors earlier, by a binary pulsar is considered. It has been shown that the formulas for the gravitation radiation of the system resulting from the equations do not contradict…

Binary pulsars allow us to carry out precision tests of gravity and have placed stringent bounds on a broad class of theories beyond general relativity. Current and future radio telescopes, such as FAST, SKA, and MeerKAT, may find a new…

In Einstein's general relativity, gravity is mediated by a massless metric field. The extension of general relativity to consistently include a mass for the graviton has profound implications for gravitation and cosmology. Salient features…

The extreme-gravity collisions of binaries with one black hole and one neutron star provide for excellent tests of general relativity. We here study how well one can constrain theories beyond general relativity with additional scalar fields…

We compute the scalar gravitational radiation from a binary pulsar system in the simplest model that exhibits the Vainshtein mechanism. The mechanism is successful in screening the effect from scalar fields conformally coupled to matter,…

This talk reviews the constraints imposed by binary-pulsar data on gravity theories, focusing on ``tensor-scalar'' ones which are the best motivated alternatives to general relativity. We recall that binary-pulsar tests are qualitatively…

We introduce a modified divergence law for the energy-momentum tensor in the theory of unimodular relativity. Consequently, an additional equation for the measure field follows from the divergence of the field equations. The equations of…