https://doi.org/10.1140/epjc/s10052-015-3463-0
Regular Article - Theoretical Physics
Ghosts in the self-accelerating DGP branch with Gauss–Bonnet effect
1
Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei, 10617, Taiwan
2
Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
3
Departamento de Física, Universidade da Beira Interior, 6200, Covilhã, Portugal
4
Centro de Matemática e Aplicações da Universidade da Beira Interior (CMA-UBI), 6200, Covilhã, Portugal
5
Department of Theoretical Physics, University of the Basque Country UPV/EHU, P.O. Box 644, 48080, Bilbao, Spain
6
IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
7
Graduate Institute of Astrophysics, National Taiwan University, Taipei, 10617, Taiwan
8
Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, Stanford, CA, 94305, USA
* e-mail: izumi@phys.ntu.edu.tw
Received:
10
February
2015
Accepted:
15
May
2015
Published online:
3
June
2015
The Dvali–Gabadadze–Porrati brane-world model provides a possible approach to address the late-time cosmic acceleration. However, it has subsequently been pointed out that a ghost instability will arise on the self-accelerating branch. Here, we carefully investigate whether this ghost problem could be possibly cured by introducing the Gauss–Bonnet term in the five-dimensional bulk action, a natural generalization to the Dvali–Gabadadze–Porrati model. Our analysis is carried out for a background where a de Sitter brane is embedded in an anti–de Sitter bulk. Our result shows that the ghost excitations cannot be avoided even in this modified model.
© The Author(s), 2015
