Showing papers on "Big Rip published in 1978"

Baryon number of the universe

Abstract: We consider the possibility that the observed particle-antiparticle imbalance in the universe is due to baryon-numbers, C, and CP nonconservation. We make general observations and describe a framework for making quantitative estimates.

The Whirl Theory of the Origin of Structure in the Universe

Abstract: There are at least two reasons for examining different theories of galaxy formation: (i) We do not know the initial conditions in the early Universe; (ii) We do not know which forces were most important for the origin and evolution of initial perturbations. The first reason forces us to deal with perturbations of different types, i.e. adiabatic, turbulent and entropy perturbations. The second makes it necessary to examine the influence of non-gravitational forces — for instance, local vortices. The whirl theory of the formation of stroduces — by means of initial conditions — non-potential vortex perturbations.

The Large Scale Structure of the Universe

Abstract: Our current picture of how matter and radiation are distributed in the Universe on a large scale is derived from a wide variety of different types of observation. In this chapter, we concentrate upon the large-scale distribution of matter and radiation in the Universe and deal with galaxies and clusters of galaxies in Chaps. 3 and 4 respectively. The observations described in this chapter provide much of the essential underpinning of modern cosmological research.

Gravitational Waves in a Bianchi Type I Universe

Abstract: Tensor perturbation equations in a diagonal Bianchi type-I universe are derived in a preliminary study of the propagation of gravitational waves in anisotropic universes. Exact solutions to these equations are obtained for an axisymmetric Kasner background, in which wave propagation is along the symmetry axis. Near the singularity the universe behaves like a generalized Kasner solution and at large time like it possesses a directed stream of radiation with energy density equal to pressure. It is shown to be equivalent to thee linear limit of the Einstein-Rosen or Gowdy T/sup 3/ solution. The back reaction of gravitational waves on a type-I universe with matter is also studied in the long- and short-wavelength limits. High-frequency waves with sufficient energy could reverse the contracting axis of the universe into expansion, while waves propagating in all directions could bring about isotropization of the background. Long-wavelength perturbations act like an effective anisotropy potential which induces ''small oscillations'' on the background. The universe with such long waves can be shown to be equivalent to the weak-field limit of a ''corner run'' solution in the type-IX and type-VII/sub 0/ universes.

Is the universe expanding

Abstract: It is shown that spherically symmetric static general relativistic cosmological space-times can reproduce the same cosmological observations as the currently favored Friedmann-Robertson-Walker universes, if the usual assumptions are made about the local physical laws determining the behavior of matter, provided that the universe is inhomogeneous and our galaxy is situated close to one of its centers. Only (i) unverifiable a priori assumptions, (ii) detailed physical and astrophysical arguments, or (iii) observation of the time variation of cosmological quantities can lead us to conclude that the universe we live in is not such a static space-time.

Dynamics in the Gödel universe

Abstract: We present a complete description of the dynamics of test particles in the Godel universe in terms of Fermi co-ordinates. We show that, much as for the Friedmann universes, the Godel universe has a simple Newtonian counterpart possessing the salient features of the Godel universe, including the same nonrelativistic dynamics.

On the Creation of Scalar Particles in Some Anisotropic Universe

Abstract: Because of an importance of the particle creation (especially, its possible fulfilment of the black-body law with a definite temperature) in an early universe to various other cosmological problems, we study how the creation of scalar particles occurs in the Bianchi­ type I anisotropic universe adopted in our previous works on the quantized scalar field. It is shown that, as in a special isotropic case dealt with in recent papers, the creation may occur at the sacrifice of the requirement that the quantization procedure should reproduce the usual theory for a free field in the limit when the anisotropic universe changes into the Minkowski space-time. It is further shown that the creation occurs in accordance with the black-body law only in a 2-dimensional hyper-surface relating to the anisotropic cosmic expansion, provided that we fix two arbitrary constants appearing in a general expression for the Feynman propagator in terms of a procedure similar to that in the isotropic case. A speculation on the isotropization of our model-universe is also made from the standpoint of seeking the attainment of the thermal equilibrium in the whole universe.