Training Programs (TEOSP)

Axion-like particles can form clouds around rotating supermassive black holes through superradiant instability. Via axion-photon coupling, these clouds can imprint time-dependent oscillations on the observed electric vector position angle. I will present constraints on such clouds around M87* and Sgr A* using 2017 Event Horizon Telescope polarimetric data. The analysis is based on conjugate closure trace products, which are non-imaging and insensitive to dominant calibration systematics such as station gains and polarization leakage. I will highlight the contrast between the relatively stable M87* data and the highly variable Sgr A* case, and discuss the prospects of applying this pipeline to future EHT and more sensitive next-generation EHT observations.

The regularisation of entanglement entropy is integral to the possibility of it sourcing the Bekenstein-Hawking entropy. This regularisation ought to come from quantum gravity, which if covariant, can induce a regularisation scheme inapplicable directly on hypersurfaces, but instead suited to application over spacetime volumes. As such, the calculation of entanglement entropy should be similarly situated over spacetime volumes. I will explain how this can be done via a spectral equation using spacetime correlators, and briefly show an example calculation in causal set theory, a discrete theory of quantum gravity. There, a modified entanglement entropy scaling was obtained, due to the discreteness.

Modern physics is built upon three fundamental frameworks: quantum theory, general relativity, and information theory. In this talk, I will first introduce the field of relativistic quantum information, an operational framework that studies quantum information in relativistic settings by bringing together these three subjects. In particular, I will discuss the use of particle detectors—specifically, the Unruh–DeWitt model—to operationally define particles and extract resources from the quantum vacuum. Central to this talk is the protocol of magic harvesting, in which non-stabilizer resources essential for quantum advantage are extracted from the vacuum state of a quantum field. As an example, I will present our recent work showing that the amount of harvested magic, quantified by the mana, can serve as a probe of spacetime geometry, with particular emphasis on its dependence on the curvature and dimensionality of Anti-de Sitter space, as well as on the scaling dimensions of operators in conformal field theories.

Deformation quantization is a mathematical approach to understanding the quantization of classical mechanical systems. This talk will outline the procedure of deformation quantization and how it connects to the mathematical study of deformation theory. Time permitting, we will discuss some examples, connect these ideas to bulk-boundary systems, and explore higher dimensional analogues.

As a continuation of the canonical formulation of Loop Quantum Gravity, I will present an introduction to its covariant, path‑integral formulation in terms of spinfoams. Starting from the interpretation of spin networks as quantum states of geometry, I will explain how spinfoams arise as histories interpolating between such states and how they define transition amplitudes encoding the dynamics of quantum spacetime. I will outline the conceptual shift from Hamiltonian evolution to a sum‑over‑histories description, emphasizing background independence and the role of boundary data. I will then discuss how gravity can be understood as a constrained BF theory and highlight the role of the simplicity constraints in selecting the gravitational sector. Finally, I will briefly comment on the geometric interpretation of spinfoam amplitudes, the semiclassical limit, and the current status and open issues of the covariant approach.

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.