Training Programs (TEOSP)

Formulations of gravity as a constrained topological theory not only help us understand its variables and symmetries, but also are especially useful for quantization. In the first part of this talk, I will present the EPRL (Engle-Pereira-Rovelli-Livine) model, which is a spinfoam quantization of the four-dimensional Einstein-Cartan-Holst gravity that relies exactly on its relation to a topological theory. Namely, it transforms the simplicity constraints, distinguishing the continuum gravitational theory from its topological counterpart, into a condition on states in the Hilbert space, which is imposed after quantization. The second part of the talk will be concerned with my ongoing work on a different formulation of general relativity, which emerges from a topological theory through a different mechanism: gauging the Lorentz symmetry. I will overview the relationship between these theories in the continuum, as well as mention the current progress in their discretization.

In this broad-audience talk, I will discuss the basics of gravitational wave theory and the major achievements in the field following the direct observation of the first gravitational wave signal in 2015. Then, I will discuss how gravitational wave data are used to test the validity of general relativity and motivate my current research on the subject.

This panel discussion brings together researchers to share insights on effective scholarly writing. Each panelist will highlight two well-written papers: one of their own and one by other authors. Through moderated questions and open audience discussion, panelists will discuss what makes these papers effective, strategies for structuring papers and communicating ideas, and common pitfalls to avoid in academic writing.

This talk will be a brief and interactive introduction to my current research and the cosmological concepts that go along with it. I will assume limited prior knowledge of GR and cosmology so that even students in unrelated fields can learn something interesting.

When dealing with QFTs or with quantum mechanical systems in the thermodynamic limit, one encounters uncountable Hilbert spaces. These are mathematically wilder and physically less realistic than their countable counterparts. In this talk, we will explore how vacua encode a choice to reduce the Hilbert Space in size. In spite of the mathematically sounding intro, we’ll see this has interesting physical implications.

The connected wedge theorem states that in order to have a scattering process in the bulk, it is necessary to have O(1/G_N) mutual information between certain “decision” regions in the boundary theory. While this large mutual information is not generally sufficient to imply scattering, previous literature showed that for a certain class of geometries, bulk scattering is implied by a certain relation between two (possibly non-minimal) Ryu–Takayanagi surfaces. In this work, we show that the 2-to-2 version of the theorem becomes an equivalence in pure AdS3: large mutual information between appropriate boundary subregions is both necessary and sufficient for bulk scattering. This result allows us to extend previous findings to a broader class of asymptotically AdS3 spacetimes, which we illustrate with the spinning conical defect geometry. In contrast, we find that matter sources can disrupt this converse relation, and that the n-to-n version of the theorem with n>2 lacks a converse even in the AdS3 vacuum.