Über die Möglichkeit einer Welt mit konstanter negativer Krümmung des Raumes

  title={{\"U}ber die M{\"o}glichkeit einer Welt mit konstanter negativer Kr{\"u}mmung des Raumes},
  author={Alfred Friedmann},
  journal={Zeitschrift f{\"u}r Physik},
  • A. Friedmann
  • Published 1 December 1924
  • Physics
  • Zeitschrift für Physik

Exploring the early universe through the CMB sky

Vlak na het ontstaan van het heelal zijn de omstandigheden extreem: hoge dichtheid, hoge temperatuur en dus enorme energie domineren het heelal. Daan Meerburg onderzocht de natuurkundige processen

Cosmological consequences of theories of modified gravity

Our theoretical understanding of the dynamical evolution of the Universe has certainly improved during the recently established era of precision cosmology. However, the nature of the dark sector

Thermodynamics of Irreversible Particle Creation Phenomena and Its Cosmological Consequence

The study of particle creation phenomena at the expense of the gravitational field is of great research interest. It might solve the cosmological puzzle singlehandedly, without the need for either

The Multi-Bang Universe: The Never-Ending Realm of Galaxies

A new cosmological model is proposed for the dynamics of the Universe and the formation and evolution of galaxies. It is shown that the matter of the Universe contracts and expands in cycles, and

Gravitation and cosmology with York time

[Shortened abstract:] In this thesis we investigate a solution to the `problem of time' in canonical quantum gravity by splitting spacetime into surfaces of constant mean curvature parameterised by

The Status of Cosmic Topology after Planck Data

In the last decade, the study of the overall shape of the universe, called Cosmic Topology, has become testable by astronomical observations, especially the data from the Cosmic Microwave Background

On the cosmological propagation of high energy particles in magnetic fields

In the present work the connection between high energy particles and cosmic magnetic fields is explored. Particularly, the focus lies on the propagation of ultra-high energy cosmic rays (UHECRs) and

Studies of inflation and dark energy with coupled scalar fields

Currently there is no definitive description for the accelerated expansion of the Universe at both early and late times; we know these two periods as the epochs of inflation and dark energy.

Noether analysis of Scalar-Tensor Cosmology

A scalar--tensor theory of gravity, containing an arbitrary coupling function $F(\phi)$ and a general potential $V(\phi)$, is considered in the context of a spatially flat FLRW model. The use of

Einstein's cosmological considerations

The objective of this paper is not simply to present an historical overview of Einstein's cosmological considerations, but to discuss the central role they played in shaping the paradigm of