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Resummation of massive gravity.
Four-dimensional covariant nonlinear theories of massive gravity are constructed which are ghost-free in the decoupling limit to all orders, and the Hamiltonian constraint is maintained at least up to and including quartic order in nonlinearities, hence excluding the possibility of the Boulware-Deser ghost up to this order.
DBI and the Galileon reunited
We derive the relativistic generalization of the Galileon, by studying the brane position modulus of a relativistic probe brane embedded in a five- dimensional bulk. In the appropriate Galilean
Searching for weather in brown dwarfs
We have used an innovative tunable filter technique to carry out a search for the variability signatures of meteorological processes in the atmospheres of two nearby brown dwarfs. We find no evidence
Cascading gravity: extending the Dvali-Gabadadze-Porrati model to higher dimension.
We present a generalization of the Dvali-Gabadadze-Porrati scenario to higher codimensions which, unlike previous attempts, is free of ghost instabilities. The 4D propagator is made regular by
Primordial non-Gaussianity, statistics of collapsed objects, and the integrated Sachs-Wolfe effect
Any hint of non-Gaussianity in the cosmological initial conditions will provide us with a unique window into the physics of the early Universe. We show that the impact of a small local primordial
Cascading gravity and degravitation
We construct a cascading brane model of gravity in which the behavior of the gravitational force law interpolates from (n+4)-dimensional to (n+3)-dimensional all the way down to 4-dimensional from
Cosmological stability bound in massive gravity and bigravity
We give a simple derivation of a cosmological bound on the graviton mass for spatially flat FRW solutions in massive gravity with an FRW reference metric and for bigravity theories. This bound comes
New positivity bounds from full crossing symmetry
Abstract Positivity bounds are powerful tools to constrain effective field theories. Utilizing the partial wave expansion in the dispersion relation and the full crossing symmetry of the scattering
Enhanced non-Gaussianity from excited initial states
We use the techniques of effective field theory in an expanding universe to examine the effect of choosing an excited inflationary initial state built over the Bunch–Davies state on the CMB