We review recent progress in massive gravity. We start by showing how different theories of
massive gravity emerge from a higher-dimensional theory of general relativity, leading to the …

This review is dedicated to recent progress in the field of classical, interacting, massive spin-
2 theories, with a focus on ghost-free bimetric theory. We will outline its history and its …

We present a formulation of ghost-free massive gravity with flat reference metric that exhibits
the full nonlinear constraint algebraically, in a way that can be directly implemented for …

We study the cosmological consequences of a recently proposed nonlocal modification of
general relativity, obtained by adding a term m 2 R□− 2 R to the Einstein-Hilbert action. The …

A bstract We provide a full analysis of ghost free higher derivative field theories with coupled
degrees of freedom. Assuming the absence of gauge symmetries, we derive the degeneracy …

We investigate the minimal theory of massive gravity (MTMG) recently introduced. After
reviewing the original construction based on its Hamiltonian in the vielbein formalism, we …

We study a theory of massive tensor gravitons which predicts blue-tilted and largely
amplified primordial gravitational waves. After inflation, while their mass is significant until it …

Cosmological perturbations of Friedmann-Robertson-Walker solutions in ghost free massive
bigravity, including also a second matter sector, are studied in detail. At early time, we find …

We study the cosmological dynamics of a recently proposed infrared modification of the
Einstein equations, based on the introduction of a nonlocal term constructed with m2gμν□ …

A bstract We consider the branch of the projectable Hořava-Lifshitz model which exhibits
ghost instabilities in the low energy limit. It turns out that, due to the Lorentz violating …