Can the Arrow of Time Be Understood from Quantum Cosmology?

  • Claus Kiefer
Part of the Fundamental Theories of Physics book series (FTPH, volume 172)


I address the question whether the origin of the observed arrow of time can be derived from quantum cosmology. After a general discussion of entropy in cosmology and some numerical estimates, I give a brief introduction into quantum geometrodynamics and argue that this may provide a sufficient framework for studying this question. I then show that a natural boundary condition of low initial entropy can be imposed on the universal wave function. The arrow of time is then correlated with the size of the Universe and emerges from an increasing amount of decoherence due to entanglement with unobserved degrees of freedom. Remarks are also made concerning the arrow of time in multiverse pictures and scenarios motivated by dark energy.


Black Hole Dark Energy Quantum Gravity Event Horizon Gravitational Wave 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



I thank Max Dörner and Tobias Guggenmoser for a careful reading of this manuscript.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Institut für Theoretische PhysikUniversität zu KölnKölnGermany

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