Week 15.01.2024 – 21.01.2024

A review of the concept of Krylov Complexity(K- Complexity) will be presented. One feature of K-Complexity is that its definition does not involve a tolerance parameter. I will describe some general properties of K-Complexity, its behavior when interpolating among various types of systems: free, strongly integrable and chaotic ones. Finally for a certain low dimensional system in a certain state I will describe an explicit derivation of the geometric bulk dual of K complexity.

I will discuss our recent calculations of the observables involved in the scattering of two black holes or neutron stars at fourth post-Minkowskian order (three loops) using the Worldline Quantum Field Theory (WQFT) framework. These 4PM observables now include both spin-orbit and adiabatic tidal corrections — inclusion of the latter necessitates a renormalization of the underlying classical effective field theory (EFT). I will also explain how the Effective-One-Body (EOB) may be used to resum the observables, and provide input data for future-generation gravitational waveform models.