| 10/27, 9:30-10:15 |
Robert Myers |
Perimeter |
The Geodesics Less Traveled: Holographic Scattering and Non-Minimal RT Surfaces |
| 10/27, 10:15-10:45 |
Jonathan Harper |
YITP Kyoto U |
An Introduction to Multi-invariants
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| 10/27, 11:30-12:15 |
Alex May |
Perimeter |
Cryptographic tests of the python's lunch conjecture
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| 10/27, 12:15-13:00 |
Fermi Ma |
UC Berkeley |
How to Construct Random Unitaries |
| 10/27, 14:45-15:30 |
Tomoyuki Morimae |
YITP Kyoto U |
Cryptographic Characterization of Quantum Advantage
|
| 10/27, 16:00-16:45 |
Zvika Brakerski |
Weizmann |
Computational Entanglement Theory
|
| 10/27, 16:45-17:30 |
Akihiro Ishibashi |
Nagoya U |
Semiclassical Einstein equations and instability from holography
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|
| 10/28, 9:30-10:15 |
Raphael Bousso |
UC Berkeley |
Holography in general spacetimes |
| 10/28, 10:15-10:45 |
Zixia Wei |
Harvard |
Observer-dependent holography from the state of the universe |
| 10/28, 11:30-12:15 |
Mari Banuls |
Max Planck Institute of Quantum Optics |
Tensor Network States: challenges and new entanglement-based approaches for real time dynamics
|
| 10/28, 12:15-13:00 |
Yoshinobu Kuramashi |
U Tsukuba |
Quantum field theories with tensor renormalization group
|
| 10/28, 14:45-15:30 |
Norihiro Iizuka |
Taiwan, Natl. Tsing Hua U. |
Genuine multi-entropy and holography
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|
| 10/29, 9:30-10:15 |
Robert Wald |
U Chicago |
Memory, Infrared Entanglement, and the Idealization of Scattering from Infinity
The memory effect refers to the fact that in four dimensional asymptotically flat pacetimes, at order 1/r a massless field generically will not return to the same value at late retarded times as it had at early retarded times. In electromagnetism and gravity, when memory is present, the late retarded time field will differ from the early retarded time field by an asymptotic symmetry. There is a direct relationship between memory and the charges that generate the asymptotic symmetries. These charges must commute with any gauge invariant local observables in the bulk spacetime, thereby effectively decohering bulk states into superselection sectors of eigenstates of the large gauge charges. It can thereby be seen that in QED, states corresponding to "incoming bare electrons" from infinity (i.e., electron states with no incoming electromagnetic radiation) do not correspond to physical states in the bulk. The physical bulk states correspond at infinitely early and late times to Faddeev-Kulish states, in which the electrons are infinitely entangled with soft photons so as to produce eigenstates of the large gauge charges. However, for a physical bulk state that is initially unentangled at $t=0$, this entanglement with soft photons will occur only logarithmically in time and should be completely negligible in the finite time required to do any realistic experiment in the bulk. In QED with massless charged particles, the Faddeev-Kulish construction yields singular states, and it does not appear that there are any limiting asymptotic states apart from the vacuum. In gravity, there are no eigenstates of the large gauge charges (apart from the vacuum), so it also appears that there are no limiting asymptotic states. In all cases, the behavior of states at asymptotic infinity is very different from the behavior of states at the large but finite times relevant to experiments in the bulk spacetime. Although the idealization of scattering theory from infinity can be very usefully applied to various “practical calculations” (such as obtaining inclusive cross-sections), this work highlights that there are serious difficulties in elevating scattering from infinity to a fundamental status in the formulation of a theory.
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| 10/29, 10:15-10:45 |
Naritaka Oshita |
YITP Kyoto U |
The Ringing of Black Holes: A Probe of Near-Horizon Physics
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| 10/29, 11:30-12:15 |
Masamichi Miyaji |
RIKEN |
Non-perturbative Hilbert space of JT gravity
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| 10/29, 12:15-13:00 |
Spenta Wadia |
ICTS |
Construction of a gauge invariant Hamiltonian evolution across the black hole horizon in asymptotically AdS spacetimes |
| 10/29, 14:45-15:30 |
Philipp Höhn |
OIST |
Relational entanglement entropies in gauge theory and gravity
Entanglement entropies in quantum field theory are typically computed using a regulator to control UV divergences. Recent work showed that describing regional field degrees of freedom relative to an “observer” in perturbative quantum gravity leads to an intrinsic regularization of entanglement entropies, sidestepping the need for introducing a regulator by hand. I will explain in which sense this is a relational definition of entanglement entropy, leading to the observation that gravitational entropies depend on the observer. The key for this observation is the identification of observers as quantum reference frames (QRFs). In the second part of the talk, I will then explain how such relational entanglement entropies also lead to advantages in gauge theory on a lattice, where UV divergences are absent. In this case, the QRFs are defined in terms of Wilson lines and, in contrast to previous nonrelational constructions, lead to regional factor algebras and ensuing fully distillable entanglement entropies. Finally, I will explain how one recovers the usual electric and magnetic center algebra constructions of nonrelational approaches as the part that all QRFs agree on and how this leads to an algebra and entropy hierarchy.
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| 10/29, 16:15-17:00 |
Kouichi Okunishi |
Osaka Metropolitan U |
Holographic Aspects of Dynamical Mean-Field Theory
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| 10/29, 17:00-17:45 |
Manoj Joshi |
IQOQI Innsbruck |
Entanglement studies in many-body quantum simulations
Recent progresses in quantum technologies have showcased several intriguing proof-of-principle demonstrations of entanglement-driven phenomena. In particular, studies have focused on the many-body dynamics of interacting spin models, the entanglement structure of ground and excited states, and the thermalization of isolated quantum systems under unitary
dynamics. Along these exciting research directions of quantum technologies, we present results of quantum simulations performed on a trapped-ion quantum simulator. We explore how large-scale entanglement in engineered quantum states reflects decades-old predictions from quantum field theory proposed by Bisognano and Wichmann [1]. In addition, we show results on symmetry restoration in an isolated quantum system undergoing near-unitary dynamics. By leveraging randomized measurements and classical shadows, we demonstrate how a quantum state that initially exhibits a broken symmetry can restore its symmetry under guided Hamiltonian dynamics. A noteworthy observation is that the time scale of symmetry restoration depends on the initial degree of asymmetry in the input quantum states [2].
[1] M. K. Joshi, et al. "Exploring large-scale entanglement in quantum simulation." Nature 624,539-544 (2023).
[2] L. K. Joshi, et al. "Observing the quantum Mpemba effect in quantum simulations." Physical Review Letters 133, 010402 (2024).
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|
| 10/30, 9:30-10:15 |
Michael Walter |
LMU Munich |
Monogamy of entanglement through the lens of computation |
| 10/30, 10:15-10:45 |
Atsushi Iwaki |
U Tokyo |
Targeting the most typical state among the thermal pure quantum states
|
| 10/30, 11:30-12:15 |
Mingpu Qin |
Shanghai Jiao Tong U |
Augmenting Density Matrix Renormalization Group with Clifford Circuits
|
| 10/30, 12:15-13:00 |
Chisa Hotta |
U Tokyo |
Realizing fictitiously bulk state in matrix product state representation |
| 10/30, 14:45-15:30 |
Erik Tonni |
SISSA |
Thermal entropy and entanglement transitions from modular objects
The reduced density matrix of a spatial subsystem can be written as the exponential of the modular Hamiltonian (a.k.a. entanglement Hamiltonian) and its eigenvalues provide the entanglement entropy. Hence, this operator contains a lot of information about the entanglement of the corresponding spatial bipartition. Within Algebraic Quantum Field Theory, the modular Hamiltonian and the modular conjugation are two essential tools of the Tomita-Takesaki modular theory,
In the first part of this talk, it is shown how the modular conjugation in a 2D CFT at finite temperature provides the thermal entropy of a single interval of finite length. Within the AdS/CFT correspondence, the gravitational dual interpretation of this result in terms of geodesic bit threads is also discussed, including its extension to higher dimensions for the case where the spatial subsystem is supported in a spherical region.
In the second part of the talk, considering the harmonic chain in its ground state and in large mass regime, the entanglement Hamiltonian of two disjoint blocks is explored, showing the it displays geometric transitions as the distance between two blocks of fixed lengths changes.
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|
| 10/31, 9:30-10:15 |
Netta Engelhardt |
MIT |
Observers and Complementarity in Holographic Maps |
| 10/31, 10:15-10:45 |
Alexander Jahn |
Freie U Berlin |
Emergent statistical mechanics in holographic random tensor networks
|
| 10/31, 11:30-12:15 |
Andreas Karch |
UT Austin |
Sharp Transitions for Subsystem Complexity
|
| 10/31, 12:15-13:00 |
Sandip Trivedi |
TIFR |
Horizon Thermodynamics and DeSitter Holography |
| 10/31, 14:45-15:30 |
Yasunori Nomura |
UC Berkeley |
Quantum Gravity in Closed Systems |
| 10/31, 16:15-17:00 |
Zhenbin Yang |
Tsinghua U |
Comments on the de Sitter Double Cone
We study the double cone geometry proposed by Saad, Shenker, and Stanford in de Sitter space. We demonstrate that with the inclusion of static patch observers, the double cone leads to a linear ramp consistent with random matrix behavior. This ramp arises from the relative time shift between two clocks located in opposite static patches.
|
| 10/31, 17:00-17:45 |
Go Yusa |
Tohoku U |
Progress in Laboratory Quantum Cosmology with Quantum Hall Systems
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|
| 11/1, 9:30-10:15 |
Jan de Boer |
U Amsterdam |
surgery and statistics |
| 11/1, 10:15-10:45 |
Shan-Ming Ruan |
Peking U |
Universal Time Evolution of Holographic and Quantum Complexity
|
| 11/1, 11:15-12:00 |
Vijay Balasubramanian |
U Penn |
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