In this presentation we will report on a new information theoretic perspective for understanding the Exact Renormalization Group (ERG). In particular, by utilizing the picture of an ERG flow as a functional diffusion process, we shall outline how renormalization can be understood as an inverse process dual to a dynamical Bayesian inference scheme. A salient feature of this correspondence is that it identifies the Fisher information metric as an emergent renormalization scale related to the precision with which nearby points in model/theory space can be differentiated. This introduces new possibilities for the implementation of renormalization to systems with spatially non-local interactions, or even systems without any notion of spatial locality at all.
Recent developments on the black hole information problem have shown how the quantum extremal surface (QES) prescription may be used to obtain a Page curve and reproduce the Hayden-Preskill decoding criterion. In this talk, I will use the QES prescription to study when the information content of an object which falls into a black hole may be recovered in the radiation, in a model of JT gravity. I will show how the backreaction on the geometry created by the infalling object can be solved exactly in this model and how this allows us to reproduce the decoding criterion but with some refinements.
Floccinihilipilification is defined by the Oxford English dictionary as "the action or habit of estimating something as worthless".
By cutting away worthless new physics models, we are left with a list of possibly valuable ones. To this end, we first describe a bottom-up list of all anomaly-free semi-simple gauge extensions of the Standard Model whose fermionic content is that of the Standard Model plus three right-handed neutrinos. Secondly, we discuss the B3-L2 Z' solution to b->s l+ l- anomalies, and whether or not recent LHCb data has rendered it worthless.
In this talk, I will discuss the importance of precisely constraining various anomalous couplings in the electroweak sector from an Effective Field Theory (EFT) standpoint upon considering various di-boson and Higgs-strahlung processes. I will emphasise the importance of considering higher order corrections in perturbation theory in obtaining such constraints. The importance of matching UV-complete models with EFTs will be discussed. Finally, I will shift gears and try to impress upon the audience the need for higher-order corrections in perturbation theory in physics beyond the Standard Model of particle physics. I will specifically focus on the importance of considering next-to-leading order electroweak corrections in the relic abundance calculations for an extended Higgs model.
Quantum gravity is undoubtfully one of the most important missing pieces in the understanding of the mathematical structure of our universe.
The impossibility of consistently quantizing gravity via perturbative quantum field theory has led to a plethora of different proposals, from asymptotically safe gravity to non-local gravity, loop quantum gravity, and string theory. Different approaches face different problems and have succeeded in different areas. Yet, on the conceptual side, it is not obvious that all these frameworks are inequivalent or unrelated: some theories may be low-energy approximations of others, or could even provide different mathematical descriptions of the same physics. On the technical side, the knowledge gained in an approach could be useful to investigate certain aspects of others.
In this spirit, I will review progress in connecting and contrasting two theories: asymptotically safe gravity and string theory. Specifically, I will discuss how to test asymptotic safety using stringy swampland constraints, and how techniques developed in the context of asymptotically safe gravity can be exploited to compute cosmological higher-derivative corrections to all orders in string theory.
Numerical lattice calculations provide a powerful method for systematically estimating finite-volume Euclidean correlators. To connect to physical observables, one must analyze the role of the Euclidean signature and finite volume, as well as other systematic effects. In this seminar, I will review work on interpreting multi-hadron observables as spectral functions, given by inverting the Laplace transform on a particular lattice correlator. I will describe methods for regulating this notoriously ill-posed problem by targeting a smeared spectral function. This “smearing" turns out to be of great physical importance, e.g. for defining the infinite-volume limit and for implementing the required i-epsilon pole prescription. I will further discuss how this can be understood as an extension of the famous work of Maiani and Testa on Euclidean correlators. These methods are expected to be most relevant in quantities with many hadronic intermediate states including long distance contributions to heavy meson mixing and decays.