Complexity: Between Field Theory and Gravity

Contribution List

1. Integrability and complexity in quantum spin chains

Ben Craps

22/05/2023, 10:30

There is a widespread perception that dynamical evolution of integrable systems should be simpler in a quantifiable sense than the evolution of generic systems, though demonstrating this relation between integrability and reduced complexity in practice has remained elusive. We provide a connection of this sort by constructing a specific matrix in terms of the eigenvectors of a given quantum...

2. Quantum Black Holes and Holographic Complexity

Antonia Frassino

22/05/2023, 12:00

In this talk, I will explore how quantum effects impact certain black holes and take into account their gravitational backreaction. Specifically, I will delve into the description of a quantum BTZ black hole (quBTZ). My discussion will include an analysis of the thermodynamic properties of these black holes. Additionally, I will examine the various complexity proposals for the quBTZ and reveal...

3. Spacetime as a quantum circuit?

Mario Flory

22/05/2023, 15:00

We propose finite cutoff regions of holographic spacetimes as mapping between boundary states at different times and Wilsonian cutoffs. If the complexity of those quantum circuits is given by the gravitational action, we are led to equations of motion for the cutoff surface that obtain a particular geometric form, where solutions are given in terms of surfaces with constant scalar curvature....

4. Cost of holographic path integrals

Andrew Rolph

22/05/2023, 16:30

In this talk, I will introduce holographic proposals for computational cost. If complexity is the length of the shortest path between two states, then cost is the length of a general, not-necessarily-shortest path. To highlight the differences from the holographic state complexity programme: (1) the boundary dual is cost, the "off-shell" version of complexity, (2) we consider all functions on...

5. A bulk manifestation of Krylov complexity

Adrián Sánchez Garrido

23/05/2023, 10:30

The double-scaled SYK (DSSYK) model provides an analytically tractable instance of low-dimensional holography in which the existence of an expansion in terms of chord diagrams allows for an explicit construction of both the bulk Hilbert space and the Hamiltonian of JT gravity from the boundary theory. In this talk, I will present recent results that build up on this framework and propose a...

6. State dependence of Krylov complexity in 2d CFT

Arnab Kundu

23/05/2023, 12:00

We compute the Krylov Complexity of a light operator O_L in an eigenstate of a 2d CFT at large central charge. The eigenstate corresponds to a primary operator O_H under the state-operator correspondence. We observe that the behaviour of K-complexity is different (either bounded or exponential) depending on whether the scaling dimension of O_H is below or above the critical dimension h_H=c/24,...

7. Volume complexity of dS bubbles

Roberto Auzzi

23/05/2023, 15:00

Holographic volume complexity growth in dS stretched horizon holography has a hyperfast behaviour, which leads to a divergence in a finite time. This is very different from AdS, where the complexity rate approaches a constant value. I'll discuss holographic volume complexity in a class of asymptotically AdS geometries with dS bubbles in their interior. With the exception of the static bubble...

8. Large N Qudit Complexity and Symmetry Resolution in AdS3

René Meyer

23/05/2023, 16:30

The fact black holes carry statistical entropy proportional to their horizon area implies that quantum information concepts are geometrized in gravity. This idea obtains a particular manifestation in the AdS/CFT correspondence, where it is believed that the quantum information content in the dual field theory state can be used to reconstruct the bulk space-time geometry. The calculation of...

9. Holographic Complexity Beyond Proposals and AdS Holography

Michal Heller

24/05/2023, 10:30

10. Gravitation from optimized computation

Andrew Svesko

24/05/2023, 12:00

Inspired by the universality of computation, I advocate for a notion of spacetime complexity, where gravity arises as a consequence of spacetime optimizing the computational cost of its own quantum dynamics. This principle is realized in the context of holography, where complexity is understood in terms of state preparation via Euclidean path integrals, and the linearized equations of motion...

11. Lorentzian threads for generalized complexity

Elena Cáceres

24/05/2023, 15:00

It was recently shown that the maximal-volume prescription for calculating holographic complexity (CV) is just one out of an infinite class of observables that display the required behavior to be the gravitational duals of complexity. This approach, later extended to include complexity-action, has enlarged and changed our understanding of holographic complexity. Many questions arise in this...

12. Holographic entanglement entropy and complexity in the context of braneworld models

Juan Hernandez

24/05/2023, 16:30

We overview some lessons about entanglement entropy and holographic complexity in various braneworld models. In particular, we focus on the easy island model, interpreting the leading contribution of the entanglement entropy and complexity in the island phase. We also look at black holes with end-of-the world branes behind the horizon, and consider consequences of the Lloyd bound on complexity...