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. 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.Comment: Submitted to CQG for the Focus Issue on "Quantum Gravity Phenomenology in the Multi-Messenger Era: Challenges and Perspectives". Please contact us to express interesst of endorsement of this white pape

Competition between a prochlorophyte and a cyanobacterium under various phosphorus regimes:Comparison with the Droop model

The ecophysiology and competitive behavior of the prochlorophyte Prochlorothrix hollandica Burger-Wiersma, Stal et Mur, and the cyanobacterium Planktothrix agardhii Anagn. et Kom. were investigated in phosphorus-limited continuous cultures. When the species we-re exposed to successive saturating-pulses of P, the maximal P uptake rate decreased linearly with an increase in the P cell quota. Prochlorothrix had a higher maximal P uptake rate, a lower half-saturation constant for P uptake, higher maximal cell quota for P, and slightly lower minimal cell quota for P than Planktothrix. These data indicate that Prochlorothrix is an affinity and storage strategist, at least when compared to Planktothrix. On the other hand, Prochlorothrix had a lower maximal growth rate than Planktothrix. On the basis of these ecophysiological parameters, we developed a Droop model to predict the time course and outcome of competition under various P regimes. The model predictions were in line with the results of competition experiments under three different P-limited conditions (continuous P supply, 4-day pulse period, 12-day pulse period). Prochlorothrix competitively displaced Planktothrix under both a constant and a pulsed P supply, and competitive displacement of Planktothrix was slowest in the experiment with a 12-day pulse period. In the pulsed experiments, the mean filament lengths and chl a fluorescence of the species oscillated at the same frequency as the pulse additions. In contrast to the Droop model, the predictions of the Monod model were not in line with the outcome of the competition experiments. Our results demonstrate that Prochlorothrix is a very good competitor for P and that the time course and outcome of competition for P in a variable environment can be predicted on the basis of the P uptake and storage characteristics of the species