@article{Boblest:2011:Twin, author={Sebastian Boblest and Thomas Müller and Günter Wunner}, title={Twin paradox in de Sitter spacetime}, journal={European Journal of Physics}, volume={32}, number={5}, pages={1117}, url={http://stacks.iop.org/0143-0807/32/i=5/a=001}, year={2011}, abstract={The 'twin paradox' of special relativity offers the possibility of making interstellar flights within a lifetime. For very long journeys with velocities close to the speed of light, however, we have to take into account the expansion of the universe. Inspired by the work of Rindler on hyperbolic motion in curved spacetime, we study the worldline of a uniformly accelerated observer in de Sitter spacetime and the communication between the travelling observer and an observer at rest. This paper is intended to give graduate students who are familiar with special relativity and have some basic experience of general relativity a deeper insight into accelerated motion in general relativity, into the relationship between the proper times of different observers and the propagation of light signals between them, and into the use of compactification to describe the global structure of a relativistic model.} }