• Corpus ID: 249954028

Second-order energy-momentum tensor of a scalar field

  title={Second-order energy-momentum tensor of a scalar field},
  author={Inyong Cho and Jinn-Ouk Gong and Seung Hun Oh},
We investigate the second-order effective energy-momentum tensor (2EMT) constructed by the quadratic terms of the linear scalar cosmological perturbations while the universe is dominated by a scalar field. We show that 2EMT is gauge dependent. We then study 2EMT in three (longitudinal, spatially flat, and comoving) gauge conditions in the slow-roll stage of inflation. We find that 2EMT exhibits an effective fluid of w = − 1 / 3 on super-horizon scales in all of those gauge conditions.