Eur. Phys. J. C (2014) 74: 2802
https://doi.org/10.1140/epjc/s10052-014-2802-x

Letter

Is Eddington–Born–Infeld theory really free of cosmological singularities?

¹ Department of Theoretical Physics, University of the Basque Country UPV/EHU, P.O. Box 644, 48080 , Bilbao, Spain
² IKERBASQUE, Basque Foundation for Science, 48011 , Bilbao, Spain
³ Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
⁴ LeCosPA, National Taiwan University, Taipei, 10617, Taiwan
⁵ Graduate Institute of Astrophysics, National Taiwan University, Taipei, 10617, Taiwan
⁶ Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, Stanford, CA, 94305, USA

^* e-mail: pisinchen@phys.ntu.edu.tw
^** e-mail: chen@slac.stanford.edu

Received: 25 July 2013
Accepted: 14 February 2014
Published online: 27 March 2014

Abstract

The Eddington-inspired-Born–Infeld (EiBI) theory has recently been resurrected. Such a theory is characterized by being equivalent to Einstein theory in vacuum but differing from it in the presence of matter. One of the virtues of the theory is that it avoids the Big Bang singularity for a radiation-filled universe. In this paper, we analyze singularity avoidance in this kind of model. More precisely, we analyze the behavior of a homogeneous and isotropic universe filled with phantom energy in addition to the dark and baryonic matter. Unlike the Big Bang singularity that can be avoided in this kind of model through a bounce or a loitering effect on the physical metric, we find that the Big Rip singularity is unavoidable in the EiBI phantom model even though it can be postponed towards a slightly further future cosmic time as compared with the same singularity in other models based on the standard general relativity and with the same matter content as described above.