124 citations · 360 across the 7 of their papers we have counts for
8 papers
Eccentricities and the Stability of Closely-Spaced Five-Planet Systems
Pierre Gratia, Jack J. Lissauer
Observations of exoplanets have revealed that systems with planets on closely-spaced orbits are common, which motivates the question "How closely can planets orbit to one another a…
Outer-planet scattering can gently tilt an inner planetary system
Pierre Gratia, Daniel Fabrycky
Chaotic dynamics are expected during and after planet formation, and a leading mechanism to explain large eccentricities of gas giant exoplanets is planet-planet gravitational scat…
Double screening
Pierre Gratia, Wayne Hu, Austin Joyce +1
Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broa…
Hidden Sector Dark Matter Models for the Galactic Center Gamma-Ray Excess
Asher Berlin, Pierre Gratia, Dan Hooper +1
The gamma-ray excess observed from the Galactic Center can be interpreted as dark matter particles annihilating into Standard Model fermions with a cross section near that expected…
Self-accelerating Massive Gravity: Bimetric Determinant Singularities
Pierre Gratia, Wayne Hu, Mark Wyman
The existence of two metrics in massive gravity theories in principle allows solutions where there are singularities in new scalar invariants jointly constructed from them. These c…
Self-accelerating Massive Gravity: How Zweibeins Walk through Determinant Singularities
Pierre Gratia, Wayne Hu, Mark Wyman
The theory of massive gravity possesses ambiguities when the spacetime metric evolves far from the non-dynamical fiducial metric used to define it. We explicitly construct a spheri…
Self-accelerating Massive Gravity: Time for Field Fluctuations
Mark Wyman, Wayne Hu, Pierre Gratia
The ghost-free theory of massive gravity has exact solutions where the effective stress energy generated by the graviton mass term is a cosmological constant for any isotropic metr…
Self-accelerating Massive Gravity: Exact solutions for any isotropic matter distribution
Pierre Gratia, Wayne Hu, Mark Wyman
We present an exact solution to the equations of massive gravity that displays cosmological constant-like behavior for any spherically symmetric distribution of matter, including a…