General Relativity and Gravitation

, Volume 42, Issue 11, pp 2743–2750 | Cite as

Why does the universe expand?

Research Article

Abstract

The purpose of the paper is fivefold: (a) Argue that the question in the title can be presented in a meaningful manner and that it requires an answer. (b) Discuss the conventional answers and explain why they are unsatisfactory. (c) Suggest that a key ingredient in the answer could be the instability arising due to the ‘wrong’ sign in the Hilbert action for the kinetic energy term corresponding to expansion factor. (d) Describe how this idea connects up with another peculiar feature of our universe, viz. it spontaneously became more and more classical in the course of evolution. (e) Provide a speculative but plausible scenario, based on the thermodynamic perspective of gravity, in which one has the hope for relating the thermodynamic and cosmological arrows of time.

Keywords

Cosmological arrow of time Thermosynamical arrow of time Horizon thermodynamics Equipartition 

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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.IUCAAGaneshkhind, PuneIndia

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