Physics

In this talk I will give updates on two projects: Firstly, Perimeter and Two Small Fish Ventures are currently supporting a group of five PSI alumni in writing a play themed around quantum science & technology, with the goal of enriching public discourse on these fields. On the one hand, we aim to inform the audience about key quantum concepts in an entertaining setting. On the other hand, we are exploring questions such as "Will we really have fault-tolerant quantum computers in five years? Which quantum research is better pursued in industry vs. academia? Who will benefit from commercialization? What drives scientists to do quantum research - for scientific understanding, or because 'today's theoretical physics is tomorrow's technology'?". Five characters debate different takes on these questions in a Douglas-Adams-inspired sci-fi setting.

Secondly, I will review recent developments in classical and quantum reservoir computing.

Area metrics define generalized geometric backgrounds to describe spacetime. They are suggested at various places in classical field theory and arise within different approaches to quantum gravity. On these grounds, after introducing the notion of an area metric, I will consider covariant area-metric actions to second order in fluctuations and derivatives. I will then show how these give rise to effective length-metric actions with a distinct nonlocal Weyl-curvature squared term beyond general relativity. Finally, I will point out possible implications and routes for phenomenology.

Non-local operators, supported on submanifolds of spacetime, often encode fascinating physical insights about a theory and can serve as order parameters for phase transitions. In this talk, we will explore various aspects of 1/2​ BPS surface operators in N=4 super Yang-Mills. Specifically, I will show how supergravity computes exactly the planar limit of certain correlation functions of surface operators, even though they receive nontrivial quantum corrections. In particular, we will compute correlation functions with Chiral Primary Operators by localizing N = 4 super Yang-Mills on S^4 to a deformed version of 2d Yang-Mills on S^2. These correlation functions, which have a finite number of quantum corrections, can also be computed perturbatively in four dimensions. I will show the exact agreement between these approaches and the corresponding supergravity result. This talk is based on 2406.08541, work in collaboration with Changha Choi and Jaume Gomis.