Tootfinder

Emergence of a molecular quantum liquid in one dimension
Rajashri Parida, Biswajit Paul, Harish S. Adsule, Diptiman Sen, Tapan Mishra, Adhip Agarwala
https://arxiv.org/abs/2603.28635 https://arxiv.org/pdf/2603.28635 https://arxiv.org/html/2603.28635
arXiv:2603.28635v1 Announce Type: new
Abstract: We investigate the fate of a one-dimensional lattice superfluid formed by hard-core bosons, aka `atoms' (alternatively, a free spinless Fermi sea) subjected to nearest-neighbor attractive Hubbard-like interactions only in subgroups of two sites. The system, as expected, stabilizes a fluid of dimerized molecules at large attractive interactions. However, the composite molecules have an effective meek hopping scale and dominant repulsive interactions solely due to virtual quantum fluctuations. Interestingly, at an intermediate attractive potential, the system realizes a phase-separated region where the system is in an absorbing state. We show that this phase-separated region is due to an emergent attractive interaction between the dimers which leads to a local charge-density wave puddle where particles effectively cluster with local half-filling. Moreover the molecular superfluid gets spontaneously charge-ordered in the addition of an unpaired atom, reflecting the extreme sensitivity of the system to the existence of lone atoms. Using density-matrix renormalization group studies and effective low-energy Hamiltonians, we isolate the quantum processes to uncover the physics behind molecule formation in a strongly interacting one-dimensional system.
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A minimal wake-vortex model explains formation flight of flapping birds
Olivia Pomerenk, Kenneth S. Breuer
https://arxiv.org/abs/2602.22043 https://arxiv.org/pdf/2602.22043 https://arxiv.org/html/2602.22043
arXiv:2602.22043v1 Announce Type: new
Abstract: Collective patterns of motion emerge across biological taxa: insects swarm, fish school, and birds flock. In particular, large migratory birds form strikingly ordered V-shaped formations, which experiments and direct numerical simulations have demonstrated provide substantial energetic benefits during long-distance flight. However, the precise aerodynamic and morphological mechanisms underlying these benefits remain unclear. In this work, we develop a reduced-order model of the wake-vortex interactions between two flapping birds flying in tandem. The model retains essential unsteady flapping dynamics while remaining computationally tractable. By optimizing over a six-dimensional state space, which comprises the follower's three-dimensional relative position and three independent flapping parameters, we identify the energetically optimal leader-follower configuration of northern bald ibises. The predicted optimum agrees quantitatively with live-bird measurements. Because of its simplicity, the model allows for direct interrogation of the physical mechanisms responsible for this optimum. In particular, it isolates precisely how the follower's wing kinematics interact with the leader's wake to enhance aerodynamic efficiency. The model predicts an 11% reduction in total mechanical power for a follower in formation flight -- consistent with experimental estimates -- and shows that this saving arises from reductions in both induced and profile power, dominated by decreased profile power enabled primarily through reduced flapping amplitude and, secondarily, reduced upstroke flexion. These results provide a mechanistic explanation for the structure of V-formations and offer new insight into the aerodynamic principles governing collective flight.
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Press freedom is further going down the drain in Trumpistan.
(Sorry, behind a paywall. But the first few sentences are the most important anyway.)
https://www.washingtonpost.com/business/2026/03/23/pentagon-press-annex-policy-defeat/

Elon Musk and Sam Altman clashed on X after Musk shared a post about a man who committed a murder-suicide following delusional conversations with ChatGPT (Theo Wayt/The Information)
https://www.theinformation.com/briefings/musk-altman-tussle-reports-…

Musk and Altman Tussle Over Reports of ChatGPT-Linked Deaths
Elon Musk and Sam Altman traded barbs on X this week over media reports of deaths linked to OpenAI’s ChatGPT and other AI-related safety issues. On Monday, Musk shared a post about a man who committed a murder-suicide after a series of delusional conversations with ChatGPT, calling the story “diabolical” and saying that AI should “not pander to delusions.” On Tuesday, he followed up with

"#Gamification in #Libraries: A Bibliometric Study"
https://doi.org/10.18785/slis.1301.12