Zoom link:  https://conecta.csic.es/rooms/hjm-saz-u5h-aif/join

11:30h     First Talk 

Speaker: Ana Achúcarro (Instituut-Lorentz, Universiteit Leiden, The Netherlands) 

Title: Multifield inflation, an update.

Abstract: Inflation remains the favoured explanation for the origin of the primordial density fluctuations that seeded all large-scale structures in the universe.  It provides a discovery window for new physics at the highest energies, probing particle physics beyond the standard model and quantum gravity.  After a general introduction, I will discuss --among others-- some inflationary scenarios where multifield effects conspire to mimic "single-field behaviour"  consistent with current observations. The geometry and curvature of field space turn out to play an essential role in these scenarios, their stability and predictions.

15:00h     Second Talk

Speaker:  Flaminia Giacomini (University of Rome Tor Vergata, Italy)

Title: Beyond Subsystems: From Gauge Theories to Quantum Reference Frames

Abstract: Many concepts in quantum information rely on a division of the world into subsystems, encoded in the tensor-product structure of the Hilbert space. In gauge theories, however, gauge constraints obstruct a straightforward decomposition into local subsystems, motivating an algebraic approach in which locality is described in terms of algebras of observables.

Quantum reference frames reveal a different challenge: even when a tensor-product structure can be defined, the identification of subsystems can depend on the observer's quantum reference frame. Comparing the information accessible from different perspectives therefore requires extending standard information-theoretic notions beyond a single fixed tensor-product structure. After an introduction to the main elements characterizing quantum reference frames, I will discuss how an algebraic approach allows us to quantify correlations between subsystems defined relative to different quantum reference frames, and discuss how the usual notion of subsystem should be modified when a tensor-product structure is not available.