Category: Quantum Gravity

Solitons and quantum gravity in the Hawking radiation

The fact that solitons may have a role in quantum gravity is intriguing.

In a paper in ArXiv, by Leone Di Mauro Villari, Giulia Marcucci, Maria Chiara Braidotti (all of them top complexlight students), and CC, a toy model concerning Hawking radiation by moving black holes is proposed.

Within a simple one-dimensional theory, based on solitons of the Sine-Gordon equation, the authors claim that Hawking emission may be extracted by the concomitant observation of gravitational and electromagnetic waves emitted by colliding black holes. The effect is due to the black-hole-velocity dependent emission spectrum (figure above), which results into an electromagnetic frequency chirp detected by the observer.

Black holes evaporate, black holes are solitons, solitons evaporate !

The fact that black holes are solitons is not very well known. Abdus Salam and others outlined this issue several years ago. Stephen Hawking predicted that Black Holes evaporate, and this is a quantum effect on classical gravity governed by the highly nonlinear Einstein-Hilbert equations.

Leone Villari, Ewan Wright, Fabio Biancalana and Claudio Conti report on the possibility that all types of classical solitons may evaporate in the quantum regime. A paper in the arXiv contains the theory on the exact quantization of the nonlinear Schroedinger equation: solitons emit a blackbody radiation spectrum at a temperature given by the same formula of Hawking!

This result is intriguing. On one hand, because it represents the first theoretical prediction of the Hawking radiation in a fully nonlinear quantum field theory. The standard Hawking theory relies on the quantization of a linear field in a curved background. The theory may hence provide insights for a true quantum gravity based on the complete quantization of the Einstein-Hilbert equations.

On the other hand, the result is also important because the Hawking radiation from a quantum soliton may furnish a novel highly tunable quantum source with many possible applications.

Generalized Uncertainty Principle and the Photon (Templeton project)

In recent years, researchers question about the limits of the uncertainty relation.

Hints from quantum gravity theories suggest that the Heisenberg principle should be generalized.

Some considered implications in high energy physics, others have considered the mechanical motion of massive objects to look for possible tests of these supposed limits to the most important paradigm of quantum mechanics.

In a project funded by the John Templeton Foundation (grant number 58277), we consider the case of the photon, and study the possible way a generalized uncertainty principle may play a role in modern photonics, nonlinear and quantum optics.

The project started at 1 September 2015 and ended at 31 May 2018

The Quest for Quantum Gravity in Optics

The Math of Irreversibility

Black holes evaporate, black holes are solitons, solitons evaporate !

Time Travel is NOT Possible (press release)

The Quest for Quantum Gravity in Optics

Quantum gravity challenges inspire a great variety of scientists, and photonics is opening several interesting and related directions.

In a paper posted in the ArXiv, Maria Chiara Braidotti, Ziad Musslimani and Claudio Conti show the way the generalized uncertainty principle, introduced for studying physics at the Planck scale, has a role in optics, and may stimulate unexpected applications for high resolution imaging and ultrafast propagation.

The picture shows a representation of the generalized uncertainty principle (G-UP) and the difference with the standard Heisenberg principle (H-UP), further details in our paper in the ArXiv.