Scientific Series

The amplituhedron was introduced by Arkani-Hamed and Trnka as a geometric object which "encodes" scattering amplitudes in N=4 SYM theory. One of their motivations was the Britto-Cachazo-Feng-Witten (BCFW) recursion for amplitudes, which in particular produced many different formulas for the same…

I will discuss some aspects of quantum mechanics at late time in de Sitter space, focusing on the norm of the no-boundary state in semiclassical gravity.

Gravitational-wave observations by LIGO and Virgo are revealing a population of merging stellar-mass binary black holes. Thus far, the broad connection between the inferred population and the physics that underlies black hole formation remains elusive. The O4a run of the LVK has more than doubled…

Measurement is a fundamental ingredient of quantum theory, and reasonably well-understood in non-relativistic quantum mechanics. In contrast, relativistic requirements of locality and causality have provided a challenge for measurement in quantum field theory, as highlighted by Sorkin's seminal work…

Optimal transport (OT) theory, first conceived to solve problems of moving dirt, has since evolved into a powerful mathematical framework with far-reaching applications across machine learning, probability and statistics, and theoretical physics. In particle physics, OT underpins many modern machine…

I will review an analogy between spectral theory of automorphic forms on hyperbolic d-manifolds and conformal field theory in d-1 dimensions. Building on this analogy, I will use the conformal bootstrap to prove a new bound on certain triple product L-functions. I will discuss in which sense the…

Although we will never get the same level of details for exoplanets as we do for Solar System bodies, the large diversity of exoplanets revealed by exoplanet hunting missions, e.g. Kepler and TESS, provide thousands of study cases to refine formation and evolution pathways as well as theories of how…

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…

The theory of quiver varieties provides a fundamental bridge between representation theory, enumerative geometry, and physics. From 3d mirror symmetry, any quiver variety comes with a dual variety known as the Coulomb branch. A conjecture proposed by Bullimore-Dimofte-Gaiotto-Hilburn-Kim and…

In the search for a consistent and renormalizable quantum theory of gravity, a conservative possibility is that gravity admits a field-theoretic description valid up to arbitrarily high energies. This amounts to going beyond the perturbative non-renormalizability of general relativity and it can be…

Neutron stars are ultra-dense remnants of massive stellar cores, observable across the electromagnetic spectrum. Their emission reflects a delicate interplay of magnetic, thermal, and structural processes under extreme conditions of density, temperature, and magnetic fields—regimes unattainable in…