The semiclassical approach to quantum gravity would yield the Schrödinger formalism for the wave function of metric perturbations or gravitons plus quantum gravity correcting terms in pure gravity; thus, in the inflationary scenario, we should expect correcting effects to the relic graviton (Zel'dovich) spectrum of the order of (λ/m 2 P l). These, on the other hand, could possibly be measured i...

We present the first simultaneous space-time measurements for gravity wave turbulence in a large laboratory flume. We found that the slopes of k and omega wave spectra depend on wave intensity. This cannot be explained by any existing theory considering wave turbulence as the result of either breaking events or weakly nonlinear wave interactions. Instead, we show that random waves and breaking ...

Steady and unsteady two-dimensional free surface flows subjected to one or multiple disturbances are considered. Flow configurations involving either a single fluid or two layers of fluid of different but constant densities, are examined. Both the effects of gravity and surface tension are included. Fully nonlinear boundary integral equation techniques based on Cauchy’s integral formula are use...

We report the observation of capillary wave turbulence on the surface of a fluid layer in a low-gravity environment. In such conditions, the fluid covers all the internal surface of the spherical container which is submitted to random forcing. The surface wave amplitude displays power-law spectrum over two decades in frequency, corresponding to wavelength from mm to a few cm. This spectrum is f...

Clinoforms on coasts exposed to ocean waves form from sand exported from the shoreface during extreme wave conditions and deposited where wave action diminishes. Elsewhere, it is shown that, during upper 5-percentile wave conditions, wave-induced shear stresses exceed the sediment threshold of motion to below the clinoform rollovers. Experiments and theory suggest that, where bed sediments are ...

We provide a method to determine the motion of a classical massive particle in a background geometry of 2-dimensional gravity theories, for which the Birkhoo theorem holds. In particular, we get the particle trajectory in a continuous class of 2-dimensional dilaton gravity theories that includes the Callan-Giddings-Harvey-Strominger (CGHS) model, the Jackiw-Teitelboim (JT) model, and the d-dime...

We clarify the relation between 2-form Einstein gravity and its topological version. The physical space of the topological version is contained in that of the Einstein gravity. Moreover a new vector field is introduced into 2-form Einstein gravity to restore the large symmetry of its topological version. The wave function of the universe is obtained for each model. † Talk given at the Workshop ...