More Like this

1. BPS chaos

   https://doi.org/10.21468/SciPostPhys.18.2.072  

   Chen, Yiming; Lin, Henry W; Shenker, Steve (January 2025, SciPost Physics)

   Black holes are chaotic quantum systems that are expected to exhibit random matrix statistics in their finite energy spectrum. Lin, Maldacena, Rozenberg and Shan (LMRS) have proposed a related characterization of chaos for the ground states of BPS black holes with finite area horizons. On a separate front, the “fuzzball program” has uncovered large families of horizon-free geometries that account for the entropy of holographic BPS systems, but only in situations with sufficient supersymmetry to exclude finite area horizons. The highly structured, non-random nature of these solutions seems in tension with strong chaos. We verify this intuition by performing analytic and numerical calculations of the LMRS diagnostic in the corresponding boundary quantum system. In particular we examine the 1/2 and 1/4-BPS sectors of\mathcal{N}=4 $𝒩=4$SYM, and the two charge sector of the D1-D5 CFT. We find evidence that these systems are only weakly chaotic, with a Thouless time determining the onset of chaos that grows as a power ofN $N$. In contrast, finite horizon area BPS black holes should be strongly chaotic, with a Thouless time of order one. In this case, finite energy chaotic states become BPS asN $N$is decreased through the recently discovered “fortuity” mechanism. Hence they can plausibly retain their strongly chaotic character. 

   more » « less
2. Cellular Chaos: Statistically Self-Similar Structures Based on Chaos Game

   https://doi.org/10.1115/1.4063987  

   Hill, Noah; Ebert, Matt; Maurice, Mena; Krishnamurthy, Vinayak (May 2024, Journal of Computing and Information Science in Engineering)

   Abstract We present a novel methodology to generate mechanical structures based on fractal geometry using the chaos game, which generates self-similar point-sets within a polygon. Using the Voronoi decomposition of these points, we are able to generate groups of self-similar structures that can be related back to their chaos game parameters, namely, the polygonal domain, fractional distance, and number of samples. Our approach explores the use of forward design of generative structures, which in some cases can be easier to use for designing than inverse generative design techniques. To this end, the central hypothesis of our work is that structures generated using the chaos game can generate families of self-similar structures that, while not identical, exhibit similar mechanical behavior in a statistical sense. We present a systematic study of these self-similar structures through modal analysis and tensile loading and demonstrate a preliminary confirmation of our hypothesis. 

   more » « less
3. Speck of chaos

   https://doi.org/10.1103/PhysRevResearch.2.043034  

   Santos, Lea F.; Pérez-Bernal, Francisco; Torres-Herrera, E. Jonathan (October 2020, Physical Review Research)

   null (Ed.)
4. Chaos in celestial CFT

   https://doi.org/10.1007/JHEP08(2022)106  

   Pasterski, Sabrina; Verlinde, Herman (August 2022, Journal of High Energy Physics)

   A bstract Celestial holography proposes a duality between gravitational scattering in asymptotically flat space-time and a conformal field theory living on the celestial sphere. Its dictionary relates the infinite dimensional space-time symmetry group to Ward identities of the CFT. The spontaneous breaking of these asymptotic symmetries governs the dynamics of the soft sector in the CFT. Here we show that this sector encodes non-trivial backreaction effects that exhibit characteristics of maximal quantum chaos. A key element in the derivation is the identification of the Hilbert space of celestial CFT, defined through radial quantization, with that of a constantly accelerating Rindler observer. From the point of view of the bulk, Rindler particles exhibit Lyapunov behavior due to shockwave interactions that shift the observer horizon. From the point of view of the boundary, the superrotation Goldstone modes affect the relevant representations of the celestial Virasoro symmetry in a manner that induces Lyapunov behavior of out-of-time-ordered celestial correlators. 

   more » « less
5. Quantum Chaos is Quantum

   https://doi.org/10.22331/q-2021-05-04-453  

   Leone, Lorenzo; Oliviero, Salvatore F.; Zhou, You; Hamma, Alioscia (May 2021, Quantum)

   null (Ed.)

   It is well known that a quantum circuit on N qubits composed of Clifford gates with the addition of k non Clifford gates can be simulated on a classical computer by an algorithm scaling as poly ( N ) exp ⁡ ( k ) \cite{bravyi2016improved}. We show that, for a quantum circuit to simulate quantum chaotic behavior, it is both necessary and sufficient that k = Θ ( N ) . This result implies the impossibility of simulating quantum chaos on a classical computer. 

   more » « less