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A. Marciano

Publications and source records attributed to A. Marciano.

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White Paper and Roadmap for Quantum Gravity Phenomenology in the Multi-Messenger Era

The unification of quantum mechanics and general relativity has long been elusive. Only recently have empirical predictions of various possible theories of quantum gravity been put to test, where a clear signal of quantum properties of gravity is still missing. The dawn of multi-messenger high-energy astrophysics has been tremendously beneficial, as it allows us to study particles with much higher energies and travelling much longer distances than possible in terrestrial experiments, but more progress is needed on several fronts. A thorough appraisal of current strategies and experimental frameworks, regarding quantum gravity phenomenology, is provided here. Our aim is twofold: a description of tentative multimessenger explorations, plus a focus on future detection experiments. As the outlook of the network of researchers that formed through the COST Action CA18108 ``Quantum gravity phenomenology in the multi-messenger approach (QG-MM)'', in this work we give an overview of the desiderata that future theoretical frameworks, observational facilities, and data-sharing policies should satisfy in order to advance the cause of quantum gravity phenomenology.

gr-qc

A modern guide to {\rm $θ$}-Poincaré

Motivated by the recent interest in underground experiments phenomenology, we review the main aspects of one specific non-commutative space-time model, based on the Groenewold-Moyal plane algebra, the $θ$-Poincaré space-time. In the $θ$-Poincaré scenario, the Lorentz co-algebra is deformed introducing a non-commutativity of space-time coordinates. In such a theory, a new quantum field theory in non-commutative space-time can be reformulated. Tackling on several conceptual misunderstanding and technical mistakes in the literature, we will focus on several issues such: $i)$ the construction of fields theories in $θ$-Poincaré; $ii)$ the unitarity of the S-matrix; $iii)$ the violation of locality, $iv)$ the violation of the spin statistic theorem and the Pauli principle; $v)$ the observables for underground experiments.

hep-ph

Cosmological Casimir effect with maximum planckian momentum and accelerating universe

We develop here a mechanism that, without making use of a cosmological constant, reproduces an accelerating universe. This is done by taking into account Casimir vacuum energy density, assuming that the underlying theory allows a maximum momentum, that turns out to be the leading contribution term to Einstein equations in a large expanding FRW universe. As stated in numerous quantum gravity studies, we postulate that maximum momentum is related to the existence of the Planck length as a fundamental length. This insight, together with the assumption of a Planck scale correction to the energy/momentum dispersion-relation on a FRW background, is used here to calculate Casimir vacuum energy. We show that, under these hypothesis, an accelerated universe expansion is obtained. As last step we analyze the compatibility of the resulting model with experimental data, writing down the equation of state for Casimir energy and pressure and observing that this equation of state belongs to a class of models that naturally fits cosmological observations. We emphasize that our result relies, once a fundamental length is introduced in Casimir effect, just on general arguments thus it is independent on an explicit form of the energy-momentum dispersion relation.

gr-qc