Os limites do tempo em cosmologia

sábado, março 19, 2016

Limits of time in cosmology

Rugh, Svend E. and Zinkernagel, Henrik (2016) Limits of time in cosmology.[Preprint]
Download (289Kb)


    We provide a discussion of some main ideas in our project about the physical foundation of the time concept in cosmology. It is standard to point to the Planck scale (located at $\sim 10^{-43}$ seconds after a fictitious "Big Bang" point) as a limit for how far back we may extrapolate the standard cosmological model. In our work we have suggested that there are several other (physically motivated) interesting limits -- located at least thirty orders of magnitude before the Planck time -- where the physical basis of the cosmological model and its time concept is progressively weakened. Some of these limits are connected to phase transitions in the early universe which gradually undermine the notion of 'standard clocks' widely employed in cosmology. Such considerations lead to a 'scale problem' for time which becomes particularly acute above the electroweak phase transition (before $\sim 10^{-11}$ seconds). Other limits are due to problems of building up a cosmological reference frame, or even contemplating a sensible notion of proper time, if the early universe constituents become too quantum. This 'quantum problem' for time arises e.g. if a pure quantum phase is contemplated at the beginning of inflation at, say, $\sim 10^{-34}$ seconds.

    Export/Citation:EndNote | BibTeX | Dublin Core | ASCII/Text Citation (Chicago) | HTML Citation | OpenURL
    Social Networking:

    Item Type:Preprint
    Additional Information:To appear in "The Philosophy of Cosmology"; edited by K. Chamcham, J. Silk, J. Barrow and S. Saunders. Cambridge University Press, 2016
    Keywords:Cosmic measurement problem; Weyl's principle; relationism
    Subjects:Specific Sciences > Physics > Cosmology
    Specific Sciences > Physics > Quantum Field Theory
    Specific Sciences > Physics > Quantum Mechanics
    Specific Sciences > Physics > Relativity Theory
    Depositing User:Henrik Zinkernagel
    Date Deposited:17 Mar 2016 23:03
    Last Modified:17 Mar 2016 23:03
    Item ID:11972