The exploration of the universe has recently entered a new era thanks to the multi-
messenger paradigm, characterized by a continuous increase in the quantity and quality of …

An outstanding open issue in our quest for physics beyond Einstein is the unification of
general relativity (GR) and quantum physics. Loop quantum gravity (LQG) is a leading …

Loop quantum cosmology (LQC) is the result of applying principles of loop quantum gravity
(LQG) to cosmological settings. The distinguishing feature of LQC is the prominent role …

This article reviews the present status of the spin-foam approach to the quantization of
gravity. Special attention is payed to the pedagogical presentation of the recently-introduced …

The problem of describing the quantum behavior of gravity, and thus understanding
quantum spacetime, is still open. Loop quantum gravity is a well-developed approach to this …

We present the first direct and nonperturbative computation of the graviton spectral function
in quantum gravity. This is achieved with the help of a novel Lorentzian renormalization …

Colored tensor models have recently burst onto the scene as a promising conceptual and
computational tool in the investigation of problems of random geometry in dimension three …

We extend the definition of the “flipped” loop-quantum-gravity vertex to the case of a finite
Immirzi parameter γ. We cover both the Euclidean and Lorentzian cases. We show that the …

A bstract In the tetrad formulation of gravity, the so-called simplicity constraints play a central
role. They appear in the Hamiltonian analysis of the theory, and in the Lagrangian path …

Random matrix models generalize to Group Field Theories (GFT) whose Feynman graphs
are dual to higher dimensional topological spaces. The perturbative development of the …