71 research outputs found

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

    Full text link
    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

    Quantum gravity phenomenology at the dawn of the multi-messenger era—A review

    Get PDF
    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 experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.publishedVersio

    Cosmology with the Laser Interferometer Space Antenna

    Get PDF
    The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravitational-wave backgrounds and their implications for early universe and particle physics, from the MeV to the Planck scale. However, the range of potential cosmological applications of gravitational wave observations extends well beyond these two objectives. This publication presents a summary of the state of the art in LISA cosmology, theory and methods, and identifies new opportunities to use gravitational wave observations by LISA to probe the universe

    Quantum gravity phenomenology at the dawn of the multi-messenger era -- A review

    Get PDF
    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 experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers

    Computational Methods for Pigmented Skin Lesion Classification in Images: Review and Future Trends

    Get PDF
    Skin cancer is considered as one of the most common types of cancer in several countries, and its incidence rate has increased in recent years. Melanoma cases have caused an increasing number of deaths worldwide, since this type of skin cancer is the most aggressive compared to other types. Computational methods have been developed to assist dermatologists in early diagnosis of skin cancer. An overview of the main and current computational methods that have been proposed for pattern analysis and pigmented skin lesion classification is addressed in this review. In addition, a discussion about the application of such methods, as well as future trends, is also provided. Several methods for feature extraction from both macroscopic and dermoscopic images and models for feature selection are introduced and discussed. Furthermore, classification algorithms and evaluation procedures are described, and performance results for lesion classification and pattern analysis are given

    Radiation Absorption and Use Efficiency in Additive Intercropping of Maize and Bean in Zanjan Region

    No full text
    Improvement of resource use efficiency is a basic approach for sustainable agriculture. Applying intercropping systems, in which resources such as water, radiation and nutrients are used optimally, is one of these strategies. In order to evaluate radiation absorption and use efficiency in additive intercropping of maize-bean, an experiment was carried out in 2010, based on completely randomized blocks design with three replications, at Research Farm of Zanjan University. Treatments included different ratios of additive intercropping system (sowing 20, 40, 60 and 80% of common bean optimum density + optimum density of maize) and monoculture of these crops. Dry matter and leaf area of both crops were measured during the growth period. Results showed that the absorbed radiation by canopy of maize-bean intercropping in all treatments was higher than the monoculture of maize and bean, because the surface of canopy increases to absorb radiation. for intercropping system and result in more absorption of radiation compared to monoculture. The values of LERPAR were more than 1 in all intercropping treatments, which indicates the advantage of intercropping cultivation in comparison with monoculture system based on radiation absorption. Higher values of radiation use efficiency for maize and bean under intercropping system in comparison with monoculture of these crops confirmed the optimum use of radiation resource in intercropping system. Regarding the efficiency of radiation absorption by different intercropping treatments, the additive cultivation of 60% bean with 100% maize was identified as the best cropping pattern

    Steering Self Assembly of Three Dimensional Iptycenes on Au 111 by Tuning Molecule Surface Interactions

    No full text
    Self assembly of three dimensional molecules is scarcely studied on surfaces. Their modes of adsorption can exhibit far greater variability compared to nearly planar molecules that adsorb mostly flat on surfaces. This additional degree of freedom can have decisive consequences for the expression of intermolecular binding motifs, hence the formation of supramolecular structures. The determining molecule surface interactions can be widely tuned, thereby providing a new powerful lever for crystal engineering in two dimensions. Here, we study the self assembly of triptycene derivatives with anthracene blades on Au 111 by Scanning Tunneling Microscopy, Near Edge X ray Absorption Fine Structure and Density Functional Theory. The impact of molecule surface interactions was experimentally tested by comparing pristine with iodine passivated Au 111 surfaces. Thereby, we observed a fundamental change of the adsorption mode that triggered self assembly of an entirely different structur
    corecore