Browsing ODA Open Digital Archive by Author "Grøn, Øyvind"

Now showing items 21-28 of 28

    • On the relativity of rotation 

      Grøn, Øyvind (Nuovo cimento. B;(7), Journal article; Peer reviewed, 2010)
      The question whether rotational motion is relative according to the general theory of relativity is discussed. Einstein’s ambivalence concerning this question is pointed out. In the present article I defend Einstein’s way ...

    • On the statistical nature of distinct cycles in global warming variables 

      Seip, Knut Lehre; Grøn, Øyvind (Peer reviewed; Journal article; Journal article, 2017-01-10)
      Cycle times found in many oceanic time series have been explained with references to external mechanisms that act on the systems. Here we show that when we extract cycle times from 100 sets of paired random series, we find ...

    • Predictions of Spectral Parameters by Several Inflationary Universe Models in light of the Planck Results 

      Grøn, Øyvind (Universe;Volume 4, Issue 2, Journal article; Peer reviewed, 2018-01-29)
      I give a review of predictions of values of spectral parameters for a large number of inflationary models. The present review includes detailed deductions and information about the approximations that have been made, written ...

    • The Cosmic Causal Mass 

      Bræck, Simen; Grøn, Øyvind; Farup, Ivar (Journal article; Peer reviewed, 2017)
      In order to provide a better understanding of rotating universe models, and in particular the Gödel universe, we discuss the relationship between cosmic rotation and perfect inertial dragging. In this connection, the concept ...

    • The twin paradox and the principle of relativity 

      Grøn, Øyvind (Physica Scripta;87(3), Journal article; Peer reviewed, 2013-02-14)
      The twin paradox is intimately related to the principle of relativity. Two twins A and B meet, travel away from each other and meet again. From the point of view of A, B is the traveller. Thus, A predicts B to be younger ...

    • Universe models with negative bulk viscosity 

      Brevik, Iver Håkon; Grøn, Øyvind (Astrophysics and Space Science;347 (2), Journal article; Peer reviewed, 2013-10)
      The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339, 52 (2013)], where an attractively ...

    • Viscous Lambda CDM universe models 

      Grøn, Øyvind; Mostafapoor, Nouraddin (Astrophysics and Space Science;333 (2), Journal article; Peer reviewed, 2011-03-30)
      We explore flat ACDM models with bulk viscosity, and study the role of the bulk viscosity in the evolution of these universe models. The dynamical equations for these models are obtained and solved for some cases of ...

    • Warm inflation 

      Grøn, Øyvind (Universe;, Journal article; Peer reviewed, 2016)
      I show here that there are some interesting differences between the predictions of warm and cold inflation models focusing in particular upon the scalar spectral index ns and the tensor-to-scalar ratio r. The first thing ...