603 citations · 6.9k across the 129 of their papers we have counts for
58 papers · 1 filter
Superconductive or superfluid condensation in curved spacetime
Leonardo Modesto
We provide a proof of unitarity for quantum field theory in a general spacetime. Our argument expresses the Bogoliubov transformations in terms of a unitary squeezing operator rela…
Form factors, spectral and Källén-Lehmann representation in nonlocal quantum gravity
Fabio Briscese, Gianluca Calcagni, Leonardo Modesto +1
We discuss the conical region of convergence of exponential and asymptotically polynomial form factors and their integral representations. Then, we calculate the spectral represent…
Path integral and conformal instability in nonlocal quantum gravity
Gianluca Calcagni, Leonardo Modesto
We introduce the Lorentzian path integral of nonlocal quantum gravity. After introducing the functional measure, the Faddeev-Popov sector and the field correlators, we move to pert…
Renormalizability of nonlocal quantum gravity coupled to matter
Gianluca Calcagni, Breno L. Giacchini, Leonardo Modesto +2
We extensively study the ultraviolet quantum properties of a nonlocal action for gravity nonminimally coupled to matter. The theory unifies matter and gravity in an action principl…
Quantum field theory with ghost pairs
Jiangfan Liu, Leonardo Modesto, Gianluca Calcagni
We explicitly show that general local higher-derivative theories with only complex conjugate ghosts and normal real particles are unitary at any perturbative order in the loop expa…
Stringballs and Planckballs for Dark Matter
Zhongyou Mo, Tibério de Paula Netto, Nicolò Burzillà +1
As a follow up of the seminal work by Guiot, Borquez, Deur, and Werner on "Graviballs and Dark Matter", we explicitly show that contrary to Einstein's gravity, in string theory, lo…
Universal leading quantum correction to the Newton potential
Tibério de Paula Netto, Leonardo Modesto, Ilya L. Shapiro
The derivation of effective quantum gravity corrections to Newton's potential is an important step in the whole effective quantum field theory approach. We hereby add new strong ar…
Tree-level scattering amplitudes in nonlocal field theories
Leonardo Modesto, Gianluca Calcagni
We prove in two ways that, for a special class of nonlocal field theories consistent with linear and non-linear stability at the classical level, and with unitarity and super-renor…
Renormalization Group in Six-derivative Quantum Gravity
Leslaw Rachwal, Leonardo Modesto, Aleksandr Pinzul +1
The exact one-loop beta functions for the four-derivative terms (Weyl tensor squared, Ricci scalar squared and the Gauss-Bonnet) are derived for the minimal six-derivative quantum…
The Higgs mechanism in nonlocal field theory
Leonardo Modesto
We provide an example of nonlocal scalar electrodynamics that allows the same Higgs mechanism so successful in local field theory. The nonlocal action is structured in order to hav…
Non-unitarity of Minkowskian non-local quantum field theories
Fabio Briscese, Leonardo Modesto
We show that Minkowskian non-local quantum field theories are not unitary. We consider a simple one loop diagram for a scalar non-local field and show that the imaginary part of th…
Unattainability of the Trans-Planckian regime in Nonlocal Quantum Gravity
Fabio Briscese, Leonardo Modesto
Based on the ultraviolet asymptotic freedom of nonlocal quantum gravity, we show that the trans-Planckian energy regime is unattainable in laboratory experiments. As physical impli…
Non-local Starobinsky inflation in the light of future CMB
K. Sravan Kumar, Leonardo Modesto
Analytic infinite derivative (AID) non-local quadratic curvature gravity in Weyl basis is known to be ghost free, superrenormalizable or finite and perturbatively Unitary and as su…
A Firepoint at the Black Hole Singularity
Ali Akil, Oscar Dahlsten, Leonardo Modesto
In his original derivation, Hawking showed that a Schwarzschild black hole is unstable at quantum level and it evolves to a final thermal mixed state violating unitarity. There are…
Entanglement swapping in black holes: restoring predictability
Ali Akil, Oscar Dahlsten, Leonardo Modesto
Hawking's black hole evaporation process suggests that we may need to choose between quantum unitarity and other basic physical principles such as no-signalling, entanglement monog…
Causality in Nonlocal Gravity
Stefano Giaccari, Leonardo Modesto
We study the causal structure of a class of weakly nonlocal gravitational theories (eventually coupled to matter) that are compatible with perturbative unitarity and finiteness at…
Reflection positivity in nonlocal gravity
Marios Christodoulou, Leonardo Modesto
Contrary to recent claims in the literature, a simple test for reflection positivite, which we call perturbative reflection positivity in the coincidence limit, is shown to be sati…
Non-perturbative spectrum of non-local gravity
Gianluca Calcagni, Leonardo Modesto, Giuseppe Nardelli
We investigate the non-perturbative degrees of freedom of a class of weakly non-local gravitational theories that have been proposed as an ultraviolet completion of general relativ…
Initial conditions and degrees of freedom of non-local gravity
Gianluca Calcagni, Leonardo Modesto, Giuseppe Nardelli
We prove the equivalence between non-local gravity with an arbitrary form factor and a non-local gravitational system with an extra rank-2 symmetric tensor. Thanks to this reformul…
Finite conformal quantum gravity and spacetime singularities
Leonardo Modesto, Leslaw Rachwal
We show that a class of finite quantum non-local gravitational theories is conformally invariant at classical as well as at quantum level. This is actually a range of conformal ano…
Finite quantum gravity in dS and AdS spacetimes
Alexey S. Koshelev, K. Sravan Kumar, Leonardo Modesto +1
We hereby study the properties of a large class of weakly nonlocal gravitational theories around the (anti-) de Sitter spacetime background. In particular, we explicitly prove that…
Renormalization group in super-renormalizable quantum gravity
Leonardo Modesto, Leslaw Rachwal, Ilya L. Shapiro
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 calcu…
Finite Conformal Quantum Gravity and Nonsingular Spacetimes
Leonardo Modesto, Leslaw Rachwal
We explicitly prove that a class of finite quantum gravitational theories (in odd as well as in even dimension) is actually a range of anomaly-free conformally invariant theories i…
Classical and Quantum Nonlocal Supergravity
Stefano Giaccari, Leonardo Modesto
We derive the N=1 supersymmetric extension for a class of weakly nonlocal four dimensional gravitational theories.The construction is explicitly done in the superspace and the tree…