57 citations · 91 across the 5 of their papers we have counts for
11 papers
On the discovery of Birkhoff's theorem
Nils Voje Johansen, Finn Ravndal
Birkhoff showed in 1923 that the Schwarzschild solution for the metric from a point particle was also valid in the a priori non-static case as long as the spherical symmetry was ma…
Scalar Field Fluctuations between Parallel Plates
Konrad Tywoniuk, Finn Ravndal
Quantum fluctuations of a scalar field and its derivatives are calculated when the field is confined between two parallel plates satisfying Dirichlet or Neumann boundary conditions…
Scalar Gravitation and Extra Dimensions
Finn Ravndal
Gunnar Nordstrom constructed the first relativistic theory of gravitation formulated in terms of interactions with a scalar field. It was an important precursor to Einstein's gener…
Higher order corrections to the Newtonian potential in the Randall-Sundrum model
Petter Callin, Finn Ravndal
The general formalism for calculating the Newtonian potential in fine-tuned or critical Randall-Sundrum braneworlds is outlined. It is based on using the full tensor structure of t…
Dynamics of the scalar field in 5-dimensional Kaluza-Klein theory
Ingunn Kathrine Wehus, Finn Ravndal
Using the language of differential forms, the Kaluza-Klein theory in 4+1 dimensions is derived. This theory unifies electromagnetic and gravitational interactions in four dimension…
Problems with the Casimir Vacuum Energy
Finn Ravndal
A critical look is taken at the calculation of the Casimir effect. The boundary conditions play an important role and should be imposed in a physical way. An acceptable result for…