277 citations · 1k across the 23 of their papers we have counts for
4 papers · 1 filter
Stable solutions of inflation driven by vector fields
Razieh Emami, Shinji Mukohyama, Ryo Namba +1
Many models of inflation driven by vector fields alone have been known to be plagued by pathological behaviors, namely ghost and/or gradient instabilities. In this work, we seek a…
Effective gravitational couplings for cosmological perturbations in generalized Proca theories
Antonio De Felice, Lavinia Heisenberg, Ryotaro Kase +3
We consider the finite interactions of the generalized Proca theory including the sixth-order Lagrangian and derive the full linear perturbation equations of motion on the flat Fri…
Screening fifth forces in generalized Proca theories
Antonio De Felice, Lavinia Heisenberg, Ryotaro Kase +3
For a massive vector field with derivative self-interactions, the breaking of the gauge invariance allows the propagation of a longitudinal mode in addition to the two transverse m…
Acausality in Nonlocal Gravity Theory
Ying-li Zhang, Kazuya Koyama, Misao Sasaki +1
We investigate the nonlocal gravity theory by deriving nonlocal equations of motion using the traditional variation principle in a homogeneous background. We focus on a class of mo…