According to the Brans–Dicke theory, the value of the gravitational constant G which we measure at present is determined by the value of the Brans–Dicke scalar field φ at the end of inflation. However, due to quantum fluctuations of the scalar fields produced during inflation, the gravitational constant G(φ) may take different values in different exponentially large parts of the Universe. We in...

The basic motivation of this work is to attempt to explain the rapid primordial inflation and the observed slow late-time inflation by using the BransDicke theory of gravity. We show that the ratio of these two inflation parameters is proportional to the square root of the Brans-Dicke parameter ω (ω ≫ 1). We also calculate the Hubble parameter H and the time variation of the time dependent Newt...

We measured the net work performed at hind limb joints in running turkeys to determine the source of mechanical power for acceleration. We tested the hypothesis that net mechanical work per step increases in proportion to acceleration at all four major hind limb joints (hip, knee, ankle and tarsometatarsal-phalangeal joint). This hypothesis was based on the idea that all hind limb muscles shoul...

The quantum state of a wormhole can be represented by a path integral over all asymptotically Euclidean four-geometries and all matter fields which have prescribed values, the arguments of the wave function, on a three-surface S which divides the spacetime manifold into two disconnected parts. The ground-state wave function is picked out by requiring that there be no matter excitations in the a...

We review the arguments supporting the existence of a maximal acceleration for a massive particle and show that different values of this upper limit can be predicted in different physical situations. ∗E-mail: [email protected]

40 41 To successfully intercept or avoid moving objects, we must compensate for the sensorimotor 42 delays associated with visual processing and motor movement. While straightforward in the 43 case of constant velocity motion, it is unclear how humans compensate for accelerations, as 44 our visual system is relatively poor at detecting changes in velocity. Work on free falling 45 objects sugges...

When a powerful laser beam is focussed on a free electron the acceleration of the latter is so violent that the interaction is nonlinear. We review the prospects for experimental studies of nonlinear electrodynamics of a single electron, with emphasis on the most accessible effect, non-linear Thomson scattering. We also speculate on the possibility of laboratory studies of a novel effect relate...

Nowadays, metropolitan railway systems are in great demand, so they offer highfrequency services for the most part of the day. Therefore there are only a few hours during night available to carry out maintenance tasks. This research develops a system that records the vertical accelerations undergone by the bogies of in-service railway vehicles. As accelerations are measured during regular servi...

Variability and stability of walking of eight transfemoral amputees and eight healthy controls was studied under four conditions: walking inside on a smooth terrain, walking while performing a dual-task and walking outside on (ir)regular surfaces. Trunk accelerations were recorded with a tri-axial accelerometer. Walking speed, mean and coefficient of variation of stride times (ST) and the root ...

OBJECTIVE Shocks and vibrations experienced while using a hand-rim wheelchair can contribute to discomfort, fatigue and injury. The aim of this study was to compare the seat forces and head accelerations experienced by manual wheelchair users during independent curb descent landings in a standard and 3 suspension-type rigid-frame wheelchairs. DESIGN EXPERIMENTAL repeated measures analysis ...