277 citations · 1k across the 23 of their papers we have counts for
7 papers · 1 filter
Gauge-independent approach to inflation in quadratic gravity
Adrian Palomares, Ying-li Zhang, Jinsu Kim
We investigate the scalar sector of linear cosmological perturbations in quadratic gravity. Working in the Einstein frame, we derive the equations of motion in a gauge-independent…
Primordial Tensor Perturbation in Double Inflationary Scenario with a Break
Shi Pi, Misao Sasaki, Ying-li Zhang
We study the primordial tensor perturbation produced from the double inflationary scenario with an intermediate break stage. Because of the transitions, the power spectrum deviates…
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…
Hartle-Hawking no-boundary proposal in dRGT massive gravity: Making inflation exponentially more probable
Misao Sasaki, Dong-han Yeom, Ying-li Zhang
It is known that the no-boundary proposal in the traditional Einstein gravity does not prefer inflation, that is, the probability of realizing a large number of e-folds is exponent…
Screening of cosmological constant in non-local cosmology
Ying-li Zhang, Misao Sasaki
We consider a model of non-local gravity with a large bare cosmological constant, , and study its cosmological solutions. The model is characterized by a function $f(ψ)=f_0 e^{α…
Screening of cosmological constant in non-local gravity
Shin'ichi Nojiri, Sergei D. Odintsov, Misao Sasaki +1
We discuss a possible mechanism to screen a cosmological constant in non-local gravity. We find that in a simple model of of non-local gravity with the Lagrangian of the form, $R+f…