In this paper I study the probability distribution of the gravitational force in gravitational systems through numerical experiments. I show that Kandrup’s (1980) and Antonuccio-Delogu & Atrio-Barandela’s (1992) theories describe correctly the stochastic force probability distribution respectively in inhomogeneous and clustered systems. I find equations for the probability distribution of stoch...

Global topological defects produce nonzero stress-energy throughout spacetime, and as a result can have observable gravitational innuence on surrounding matter. Gravitational eeects of global strings are used to place bounds on their cosmic abundance. The minimum separation between global strings is estimated by considering the defects' contribution to the cosmolog-ical energy density. More rig...

A widely used assumption within the gravitational-wave community has so far been that a test mass acts like a rigid body for frequencies in the detection band, i.e. for frequencies far below the first internal resonance. In this article we demonstrate that localized forces, applied for example by a photon pressure actuator, can result in a non-negligible elastic deformation of the test masses. ...

2014 Low-density structures such as colloidal aggregates become increasingly easy to deform mechanically as their size increases. We use recently-proposed scaling properties of such aggregates to investigate the effects of thermal fluctuations and of gravitational forces on such structures. For typical colloidal aggregates, made of 100 A particles, the diameter may not exceed 103 to 104 particl...

A fundamental component of the Global Positioning System is the calculation of a highly accurate predicted orbit for each of the constellation spacecraft on a regular basis. In general, the parameters used to describe these orbits are not stable and need to be constantly updated. Being able to predict changes, and also being able to calculate the orbit after the fact, relies upon a combination ...

High-power Fabry-Perot cavities with suspended mirrors are employed in gravitational wave detection. The mirrors in such interferometers are subject to forces and torques that are exerted by light pressure. This article derives a closed-form expression for the static torsional stiffness due to this effect. The torsional stiffness is shown to scale as the fourth power of the beam spot size. In p...

We argue that “effective” superluminal travel, potentially caused by the tipping over of light cones in Einstein gravity, is always associated with violations of the null energy condition (NEC). This is most easily seen by working perturbatively around Minkowski spacetime, where we use linearized Einstein gravity to show that the NEC forces the light cones to contract (narrow). Given the NEC, t...

An explicit formulation of Mach’s principle is given, yielding a finite gravitational background. Its value appears to be the same as the local acceleration in systems of various levels of hierarchy, which indicates that Machian forces control the formation of local structure. The large-scale chain structure can be interpreted in the same way. The level and scale at which the transition from th...

We show that gravitational effects of global cosmic 3-branes can be responsible for compactification from six to four space-time dimensions, naturally producing the observed hierarchy between electroweak and gravitational forces. The finite radius of the transverse dimensions follows from Einstein’s equation, and is exponentially large compared with the scales associated with the 3-brane. The s...

We investigate a relativistic self-interacting gas in the field of an external pp gravitational wave. Based on symmetry considerations we ask for those forces which are able to compensate the imprint of the gravitational wave on the macroscopic 4-acceleration of the gaseous fluid. We establish an exactly solvable toy model according to which the stationary states which characterize such a situa...