Invited Speakers

  • Unravelling black holes with gravitational waves

    Chris van den Broeck
    Co-chair of the LIGO-Virgo Working Group on Testing General Relativity
    Van Swinderen Institute, University of Groningen, the Netherlands

    The ability to directly detect gravitational waves has opened up the possibility of empirically studying the detailed structure of black holes. In particular, a wealth of information is contained in the way a newly formed black hole oscillates ("ringdown"), which will enable an indirect test of the celebrated no-hair theorem. If a deviation is seen then this may be an indication of quantum effects near the horizon. Prompted by Hawking's information paradox, alternatives to standard black holes have been proposed, such as firewalls and fuzzballs, which would give rise to gravitational wave "echoes" long after the ringdown signal has died down. In the next few years, after the anticipated upgrades of the LIGO and Virgo detectors, such effects will become accessible, opening up a new chapter in the study of gravitation in the strong-field regime.

  • Lighting up Einstein's dark Universe

    Alessandra Silvestri
    Fellow of the Delta Institute for Theoretical Physics
    Lorentz Institute at the University of Leiden, the Netherlands

    It is now an exceptional time for modern cosmology, when we can observe the universe with high precision and connect cosmological measurements with theory. The excitement about the advances of observational cosmology is accompanied by the awareness that we face some major challenges: we still lack compelling theoretical models for dark matter, that accounts for the formation of the structure we see around us , and dark energy, that drives cosmic acceleration, as well as a deeper understanding of the mechanism that set up primordial conditions. I will discuss the theoretical aspects of these challenges and our approaches at shedding light on them, with particular focus on dark energy.

  • Cosmology and more with Euclid

    Henk Hoekstra
    Professor of Observational Cosmology
    Observatory at the University of Leiden, the Netherlands

    Euclid is an ESA M-class mission that will survey 15000 square degrees with HST-like resolution. It is scheduled for launch about 4 years from now and can be considered the z~1 equivalent of the highly successful SDSS. The main science driver of Euclid is to study the nature of dark energy, but it also enables unprecedented tests of our understanding of gravity on cosmological scales, tell us more about the nature of dark matter, the initial conditions of the Universe and constrain the combined mass of the neutrinos. It will also leave an amazing legacy of deep optical and NIR data that will impact many aspects of astronomy. In this talk I will provide an overview of the mission, focusing on weak lensing, one of the main probes that drives the design of this exciting project.

  • Information from the Cosmic Dark Ages

    Pratika Dayal
    Rosalind Franklin Assistant Professor
    Kapteyn Astronomical Institute in Groningen, the Netherlands

    Over the next few years, state-of-the-art-facilities such as the James Webb Space Telescope, the Low Frequency Array (Lofar) and the Square Kilometre Array (SKA) will yield petabytes of data from the "cosmic dark ages". Disentangling these diverse pieces of information into a global picture will require cutting-edge theoretical models. In this talk, I will highlight how we can combine galaxy data with 21cm observations from these earliest epochs to shed light on the dark ages of our Universe.

  • Bayesian Inference reconstruction of large scale structure and Information Theory classification of the Cosmic Web

    Florent Leclercq
    Research Fellow at the Imperial Centre for Inference and Cosmology (ICIC)
    Imperial College London, England

    Recent developments of Bayesian large-scale structure inference technology naturally bring in a connection between cosmic web analysis and information theory. I will discuss the Shannon entropy of structure-type probability distributions and the information gain due to Sloan Digital Sky Survey galaxies, propose a decision criterion for classifying structures in the presence of uncertainty, and introduce utility functions for the optimal choice of a cosmic web classifier, specific to the application of interest. As showcases, I will discuss the phase-space structure of nearby dark matter, the discrimination of dark energy models from the cosmic web and an approach inspired by supervised machine learning for predicting galaxy colours given their large-scale environment.