We give a short personally-biased review on the recent progress in our understanding of gravitational radiation reaction acting on a point particle orbiting a black hole. The main motivation of this study is to obtain sufficiently precise gravitational waveforms from inspiraling binary compact stars with a large mass ratio. For this purpose, various new concepts and techniques have been develop...

Gravitational waves are propagating fluctuations of gravitational fields, that is, ”ripples” in spacetime, generated mainly by moving massive bodies. These distortions of spacetime travel with the speed of light. Every body in the path of such a wave feels a tidal gravitational force that acts perpendicular to the waves direction of propagation; these forces change the distance between points, ...

We use high-resolution, three-dimensional hydrodynamics simulations to study the hydrodynamic and gravitational interaction between stellar companions embedded within a differentially rotating common envelope. Specifically, we evaluate the contributions of the non-axisymmetric gravitational tides and pressure forces to the drag force and, hence, to the dissipation rate and the mass accumulated ...

Vacuum fluctuations have observable consequences, like the Casimir force appearing between two mirrors in vacuum. This force is now measured with good accuracy and agreement with theory. We discuss the meaning and consequences of these statements by emphasizing their relation with the problem of vacuum energy, one of the main unsolved problems at the interface between gravitational and

Richard C. Tolman analyzed the relation between a temperature gradient and a gravitational field in an equilibrium situation. In 2012, Tolman’s law was generalized to a non-equilibrium situation for a simple dilute relativistic fluid. The result in that scenario, obtained by introducing the gravitational force through the molecular acceleration, couples the heat flux with the metric coefficient...

Phase separation of a two-dimensional van derWaals fluid subject to a gravitational force is studied by numerical simulations based on lattice Boltzmannmethods (LBM) implemented with a finite difference scheme. A growth exponent α=1 is measured in the direction of the external force. PACS: 47.11.-j, 47.20.Hw, 05.70.Ln

The recent discovery that the Earth is retarding each year by a fraction of a second its revolution around the Sun led to investigations and speculations about the cause of such a defect in what was thought to be a perfect clock. The emission of thermal radiation by the Sun cannot justify this discrepancy even if a fraction of unknown dark matter is added to increase the Sun mass loss. The incr...