In Brans–Dicke theory the Universe becomes divided after inflation into many exponentially large domains with different values of the effective gravitational constant. Such a process can be described by diffusion equations for the probability of finding a certain value of the inflaton and dilaton fields in a physical volume of the Universe. For a typical chaotic inflation potential, the solutio...

Between 1941 and 1962, scalar-tensor theories of gravitation were suggested four times by different scientists in four different countries. The earliest originator, the Swiss mathematician W. Scherrer, was virtually unknown until now whereas the chronologically latest pair gave their names to a multitude of publications on Brans–Dicke theory. P. Jordan, one of the pioneers of quantum mechanics ...

We present static cylindrically symmetric electrovac solutions in the framework of the Brans-Dicke theory and show that our solution yields some of the well-known solutions for special values of the parameters of the resulting metric functions.

We consider two-dimensional Brans-Dicke theory to study the initial singularity problem. It turns out that the initial curvature singularity can be finite for a certain Brans-Dicke constant ω by considering the quantum back reaction of the geometry. For ω = 1, the universe starts with the finite curvature scalar and evolves into the flat spacetime. Furthermore the divergent gravitational coupli...

The gravitational fields of vacuumless global and gauge string have been studied in Brans-Dicke theory under the weak field assumption of the field equations. It has been shown that the global vacuumless string has a repulsive gravitational effect whereas the gauge string has an attractive gravitational effect in BD theory.

In a natural extension of the Jordan{Brans{Dicke theory the scalar eld can couple much more strongly to dark than to visible matter. New limits on the coupling constants of the model are obtained from standard big{bang nucleosynthesis.

It is shown that a minimally coupled scalar field in Brans–Dicke theory yields a non–decelerated expansion for the present universe for open, flat and closed Friedmann-Robertson-Walker models.

We present a new exact solution in Brans-Dicke theory. The solution describes inhomogeneous plane-symmetric perfect fluid cosmological model with an equation of state p = γρ. Some main properties of the solution are discussed.

We argue that the geodesic hypothesis based on auto-parallels of the Levi-Civita connection may need refinement in theories of gravity with additional scalar fields. This argument is illustrated with a reformulation of the Brans-Dicke theory in terms of a spacetime connection with torsion determined dynamically in terms of the gradient of the Brans-Dicke scalar field. The perihelion shift in th...