A Bosonic Model of Quantum Holography

We analyze a model of qubits which we argue has an emergent quantum gravitational description similar to the fermionic Sachdev-Ye-Kitaev (SYK) model. The model we consider is known as the quantum $q$-spin model because it features $q$-local interactions between qubits. It was previously studied as a model of a quantum spin glass, and while we find that the model is glassy for $q=2$, $q=3$, and likely $q=4$, we also find evidence for previously unexpected SYK-like behavior for the quenched free energy down to the lowest temperatures for $q \geq 5$. This SYK-like physics includes power-law correlation functions and an extensive low temperature entropy, so we refer to the model as Spin SYK. The model is generic in that it includes all possible $q$-body couplings, lacks most symmetries, and has no spatial structure, so our results can be construed as establishing a certain ubiquity of quantum holography in systems dominated by many-body interactions. Furthermore, we discuss a generalized family of models which includes Spin SYK and which provably exhibit SYK-like physics in the solvable limit of large local Hilbert space dimension. We also comment on implications of a bosonic system with SYK-like properties for the study of holography, Hamiltonian complexity, and related topics

Emergent Spectral Form Factors in Sonic Systems

We study the spectral form factor (SFF) for hydrodynamic systems with a sound pole, a large class including any fluid with momentum conservation and energy conservation, or any extended system with spontaneously broken continuous symmetry. We study such systems in a finite volume cavity and find that the logarithm of the hydrodynamic enhancement is closely related to the spectral form factor of a quantum particle moving in the selfsame cavity. Depending upon the dimensionality and nature of the effective single-particle physics, we exhibit a range of behaviors including an intricate resonance phenomenon, emergent integrability in the SFF, and anomalously large fluctuations of the SFF.Comment: 26 page

Payment for ecosystem services markets on Aboriginal land in Cape York Pensinsula: potential and constraints

[Extract] In the global arena, improving environmental outcomes at the same time as ensuring social equity outcomes for disadvantaged landholder groups has become increasingly important. This is especially true in regions with pressing environmental problems populated by low-income indigenous land stewards. The ability of Payment for Ecosystem Services (PES) schemes to lift poor people out of poverty and, in particular, the potential for PES schemes to improve social and welfare conditions in remote Australian indigenous communities is increasingly being recognized. Based on research in Cape York, Australia, this paper argues that a new approach to environmental management is needed to incorporate PES market participation by indigenous landowners. This is because the current framework for environmental management on Cape York is failing on two fronts: it is delivering suboptimal environmental outcomes and constraining the economic development aspirations of traditional owners. Current barriers to participation by indigenous communities in the Cape York Peninsula in PES markets — including legislative constraints and the existence of weak Aboriginal land and property rights — must be overcome

Characteristics of a Multi-User Tutoring Architecture

Intelligent tutor systems have been quite successful in instruction of individuals (Koedinger, Anderson, Hadley, & Mark, 1997; Ritter, Kulikowich, Lei, McGuire, & Morgan, 2007; Vanlehn, et al., 2005), but multiple challenges exist when attempting to tutor a team. Sottilare, Holden, Brawner, and Goldberg (2011) describe some of the architectural challenges of team tutoring at a high level in terms of functional requirements. In this paper we describe specific challenges in terms of implementing a team architecture within the Generalized Intelligent Framework for Tutoring (GIFT), including simultaneous startup and synchronization with distributed team members, maintaining state of multiple users, and timing feedback for teams and individuals appropriately

Spectral statistics of a minimal quantum glass model

Glasses have the interesting feature of being neither integrable nor fully chaotic. They thermalize quickly within a subspace but thermalize much more slowly across the full space due to high free energy barriers which partition the configuration space into sectors. Past works have examined the Rosenzweig-Porter (RP) model as a minimal quantum model which transitions from localized to chaotic behavior. In this work we generalize the RP model in such a way that it becomes a minimal model which transitions from glassy to chaotic behavior, which we term the "Block Rosenzweig-Porter" (BRP) model. We calculate the spectral form factors of both models at all timescales. Whereas the RP model exhibits a crossover from localized to ergodic behavior at the Thouless timescale, the new BRP model instead crosses over from glassy to fully chaotic behavior, as seen by a change in the slope of the ramp of the spectral form factor.Comment: 41 pages, 10 figure

Good Timing for Computational Models of Narrative Discourse

The temporal order in which story events are presented in discourse can greatly impact how readers experience narrative; however, it remains unclear how narrative systems can leverage temporal order to affect comprehension and experience. We define structural properties of discourse which provide a basis for computational narratologists to reason about good timing, such as when readers learn about event relationships

Substantial Doubt Remains about the Efficacy of Anti-Amyloid Antibodies

Alzheimer's disease (AD) is a prevalent, progressive, and ultimately fatal neurodegenerative disorder that is defined pathologically by the accumulation of amyloid plaques and tau neurofibrillary tangles in the brain. There remains an unmet need for therapies that can halt or slow the course of AD. To address this need, the FDA has provided a mechanism, under its Accelerated Approval pathway, for potential therapeutics to be approved based in part on their ability to reduce brain amyloid. Through this pathway, two monoclonal anti-amyloid antibodies, aducanumab and lecanemab, have been approved for clinical use. More recently, another amyloid-lowering antibody, donanemab, generated a statistically significant outcome in a phase 3 clinical trial and will shortly come under FDA review. While these monoclonal antibodies are not yet routinely used in clinical practice, the series of recent positive clinical trials has fostered enthusiasm amongst some AD experts. Here, we discuss three key limitations regarding recent anti-amyloid clinical trials: (1) there is little to no evidence that amyloid reduction correlates with clinical outcome, (2) the reported efficacy of anti-amyloid therapies may be partly, or wholly, explained by functional unblinding, and (3) donanemab in its phase 3 trial had no effect on tau burden, the pathological hallmark more closely related to cognition. Taken together, these observations call into question the efficacy of anti-amyloid therapies.Comment: 11 pages, 2 figures; Update 11/18/2023: Added subheadings to manuscript to improve readability, added a new data point to Figure 1A and Figure 2 for the recently published A4 clinical tria