Conference

Many researchers in quantum gravity favour the notion of a quantum foam, coined by Wheeler 70 years ago to capture "whatever becomes of spacetime at the Planck scale". The underlying idea is that the quantum fluctuations of spacetime are so large that a description based on smooth metrics is no longer adequate. Equally popular is the notion that spacetime as we know it should "emerge" from this primordial quantum foam, alongside interesting quantum-gravitational effects. These ideas are enticing, but remain speculative unless backed up by quantitative analysis and modelling within a coherent, nonperturbative formulation of quantum gravity. Fully nonperturbative computational tools are available in the form of 'lattice quantum gravity 2.0', based on causal dynamical triangulations. The power and beauty of this methodology lies in its use of curved, dynamical lattices, incorporating the principles of quantum field theory and general relativity from the outset. This has produced quantitative blueprints of both quantum foam and spacetime emergence, and a concrete perspective on what it means to “solve" quantum gravity. [arXiv:2501.17972]

Synchronization is a fundamental phenomenon in complex systems and nonlinear dynamics, driving coordinated behavior across a wide range of natural and artificial systems. From the synchronized flashing of fireflies to the coordinated oscillations in brain networks, the study of synchronization has revealed profound insights into how order emerges in interacting systems. While often associated with order and coherence, synchronization in complex networks can exhibit surprising behaviors, challenging traditional perspectives and revealing new facets of dynamical organization.In this talk, I will first review key contributions from our group to the understanding of synchronization in systems of mobile oscillators. These systems, characterized by the interplay between dynamical states and the physical motion of the oscillators, provide a rich platform to explore novel forms of synchronization.Furthermore, I will highlight the pivotal role of symmetries in shaping synchronization and its breakdown in brain networks. Our work has uncovered how symmetry-breaking mechanisms drive the emergence of localized activity patterns and how symmetry-based principles can be used to design interventions for desynchronization. 

A hypothetical primordial black hole population may constitute a fraction of dark matter. These black holes can interact and merge, emitting gravitational waves with rates and source properties that differ from those of astrophysical black hole mergers. I will review the collisional processes that drive the formation and coalescence of primordial black hole binaries in the early and late universe. These processes provide key constraints on the merger rates of these binaries and on the contribution of primordial black holes to the dark matter fraction.