We discuss aspects of non-perturbative unitarity in quantum field theory. The additional
ghost degrees of freedom arising in “truncations” of an effective action at a finite order in …

We suggest and briefly review a new sort of superrenormalizable models of higher
derivative quantum gravity. The higher derivative terms in the action can be introduced in …

We study the gravity-mediated scattering of scalar fields based on a parameterization of the
Lorentzian quantum effective action. We demonstrate that the interplay of infinite towers of …

A bstract Resumming quantum fluctuations at the level of the gravitational path integral is
expected to result in non-local effective actions and thus in a non-trivial momentum …

We propose a class of multidimensional higher derivative theories of gravity without extra
real degrees of freedom besides the graviton field. The propagator shows up the usual real …

A bstract We discuss some properties of recently proposed models of a ghost-free gravity.
For this purpose we study solutions of linearized gravitational equations in the framework of …

We explicitly prove that the Weyl conformal symmetry solves the black hole singularity
problem, otherwise unavoidable in a generally covariant local or non-local gravitational …

We construct a ultraviolet completion of the bosonic sector of 11-dimensional supergravity
motivated by string field theory. We start from a general class of theories characterized by an …

One of the main advantages of super-renormalizable higher derivative quantum gravity
models is the possibility to derive exact beta functions, by making perturbative one-loop …

It is shown that polynomial gravity theories with more than four derivatives in each scalar
and tensor sectors have a regular weak-field limit, without curvature singularities. This is …