Unexorcized ghost in DGP brane world
摘要
The braneworld model of Dvali-Gabadadze-Porrati realizes the self-accelerating universe. However, it is known that this cosmological solution contains a spin-2 ghost. We study the possibility of avoiding the appearance of the ghost by slightly modifying the model, introducing the second brane. First we consider a simple model without stabilization of the separation of the brane. By changing the separation between the branes, we find we can erase the spin-2 ghost. However, this can be done only at the expense of the appearance of a spin-0 ghost instead. We discuss why these two different types of ghosts are correlated. Then, we examine a model with stabilization of the brane separation. Even in this case, we find that the correlation between spin-0 and spin-2 ghosts remains. As a result we find we cannot avoid the appearance of ghost by two-branes model.
关键词
引用
@article{arxiv.hep-th/0610282,
title = {Unexorcized ghost in DGP brane world},
author = {Keisuke Izumi and Kazuya Koyama and Takahiro Tanaka},
journal= {arXiv preprint arXiv:hep-th/0610282},
year = {2010}
}
备注
19 pages, 1 figure