X iv : a st ro - p h / 03 03 28 3 v 1 1 3 M ar 2 00 3 STOCHASTIC EVOLUTION OF COSMOLOGICAL PARAMETERS IN THE EARLY UNIVERSE
نویسندگان
چکیده
We develop a stochastic formulation of cosmology in the early universe, after considering the scatter in the redshift-apparent magnitude diagram in the early epochs as an observational evidence for the non-deterministic evolution of early universe. We consider the stochastic evolution of density parameter in the early universe after the inflationary phase qualitatively, under the assumption of fluctuating w factor in the equation of state, in the Fokker-Planck formalism. Since the scale factor for the universe depends on the energy density, from the coupled Friedmann equations we calculated the two variable probability distribution function assuming a flat space geometry.
منابع مشابه
ar X iv : a st ro - p h / 03 03 50 0 v 1 2 1 M ar 2 00 3 The world according to the Hubble Space Telescope
The Hubble Space Telescope (HST), in its thirteen years of operation, has allowed us to observe properties of the universe humans have been able, until very recently, to probe only with their thoughts. This review presents a brief summary of a few of the highlights of HST discoveries, discusses their physical implications, and identifies unsolved problems. A broad range of topics is covered, fr...
متن کاملar X iv : a st ro - p h / 03 11 09 3 v 1 4 N ov 2 00 3 Massive scalar fields in the early Universe ∗
We discuss the role of gravitational excitons/radions in different cosmological scenarios. Gravitational excitons are massive moduli fields which describe conformal excitations of the internal spaces and which, due to their Planck-scale suppressed coupling to matter fields, are WIMPs. It is demonstrated that, depending on the concrete scenario, observational cosmological data set strong restric...
متن کاملar X iv : a st ro - p h / 01 03 17 3 v 1 1 2 M ar 2 00 1 SIGNALS OF PRIMORDIAL PHASE TRANSITIONS ON CMB MAPS
The analysis of the CMB anisotropies is a rich source of cosmological informations. In our study, we simulated the signals produced by the relics of a first order phase transition occured during an inflationary epoch in the early Universe. These relics are bubbles of true vacuum that leave a characteristic non-Gaussian imprint on the CMB. We use different statistical estimators in order to eval...
متن کاملar X iv : a st ro - p h / 03 01 01 2 v 1 1 J an 2 00 3 The State of the Universe : Cosmological Parameters 2002 ⋆
In the past decade, observational cosmology has had one of the most exciting periods in the past century. The precision with which we have been able to measure cosmological parameters has increased tremendously, while at the same time, we have been surprised beyond our wildest dreams by the results. I review here recent measurements of the expansion rate, geometry, age , matter content, and equ...
متن کاملar X iv : a st ro - p h / 03 05 46 5 v 1 2 3 M ay 2 00 3 Sunyaev - Zel ’ dovich cluster surveys using a large beam
Sunyaev Zel’dovich cluster surveys can be used to constrain cosmological parameters. Extracting clusters from the primary anisotropies and the unresolved background from very faint clusters is simple when the telescope beam size is small (∼ 1′), but could be difficult if the beam is larger (∼ 8′). By reference to examples, we show that this is possible by carefully designing the depth of the su...
متن کامل