We consider axially symmetric SU(2) Yang-Mills-Higgs (YMH) multi-monopoles in Brans-Dicke theory for winding number n > 1. In analogy to the spherically symmetric n = 1 solutions, we find that the axially symmetric solutions exist for higher values of the gravitational coupling than in the pure Einstein gravity case. For large values of the gravitational coupling, the solutions collapse to form...

We analyze the observational constraints on the effective Brans-Dicke parameter and on the temporal variation of the effective gravitational constant within the context of the oscillating G model, a cosmological model based on a massive scalar field non-minimally coupled to gravity. We show that these local constraints cannot be satisfied simultaneously once the values of the free parameters en...

We consider axially symmetric SU(2) Yang-Mills-Higgs (YMH) multi-monopoles in Brans-Dicke theory for winding number n > 1. In analogy to the spherically symmetric n = 1 solutions, we find that the axially symmetric solutions exist for higher values of the gravitational coupling than in the pure Einstein gravity case. For large values of the gravitational coupling, the solutions collapse to form...

The rst ideas of a varying Newton's coupling G come from 1937, when P. A. M. Dirac introduced his famous Large Numbers Hypothesis [1, 2]. In the 60s, in an attempt to reconciliate Mach Principle with General Relativity (GR), Brans and Dicke developed their well known scalar-tensor theory of gravity [3]. Following Jordan's ideas, Brans and Dicke generalized GR including a varying G, whose dynami...

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 consider the classical fluctuations of the gravitational constant generated by bubbles in the inflationary universe. For extended inflation, we demonstrate numerically how and how large fluctuations are produced during bubbleexpansion. The amplitude of the fluctuations depends on the Brans-Dicke parameter ω: if ω is of the order of unity, the amplitude becomes of the order of unity within on...