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 …

Abstract The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders
about the fundamental theory of nature at play in the extreme gravity regime, where the …

Quasinormal modes are eigenmodes of dissipative systems. Perturbations of classical
gravitational backgrounds involving black holes or branes naturally lead to quasinormal …

The existence of a fundamental scale, a lower bound to any output of a position
measurement, seems to be a model-independent feature of quantum gravity. In fact, different …

Quantum theory seems to be a universal framework for physical theories. In fact, most of the
interactions found in Nature are already successfully accommodated into this framework …

We study the operator that corresponds to the measurement of volume, in non-perturbative
quantum gravity, and we compute its spectrum. The operator is constructed in the loop …

KAGRA is a newly build gravitational wave observatory, a laser interferometer with 3 km arm
length, located in Kamioka, Gifu, Japan. In this paper, one of a series of articles featuring …

During the last twenty-five years evidence has been mounting that a black-hole surface area
has a discrete spectrum. Moreover, it is widely believed that area eigenvalues are uniformly …

Traversable wormholes necessarily require violations of the averaged null energy condition,
this being the definition of “exotic matter.” However, the theorems which guarantee the …

Spacetimes with horizons show a resemblance to thermodynamic systems and it is possible
to associate the notions of temperature and entropy with them. Several aspects of this …