Tootfinder

Groupoid models for relative Cuntz-Pimsner algebras of groupoid correspondences
Ralf Meyer
https://arxiv.org/abs/2506.19569 https://a…

Groupoid models for relative Cuntz-Pimsner algebras of groupoid correspondences
A groupoid correspondence on an etale, locally compact groupoid induces a C*-correspondence on its groupoid C*-algebra. We show that the Cuntz-Pimsner algebra for this C*-correspondence relative to an ideal associated to an open invariant subset of the groupoid is again a groupoid C*-algebra for a certain groupoid. We describe this groupoid explicitly and characterise it by a universal property that specifies its actions on topological spaces. Our construction unifies the construction of groupo…

Fairphone 6: Beim neuen fairen Smartphone geht ohne Schraubendreher nichts mehr
Das niederländische Unternehmen Fairphone hat das Fairphone 6 vorgestellt. Das fairer produzierte Smartphone mutet abermals gereifter an.

Gravitational Baryogenesis Constraints on Nojiri-Odintsov $f(R)$ Gravity
Kalyan Malakar, Mrinnoy M Gohain, Kalyan Bhuyan
https://arxiv.org/abs/2506.18949 h…

Gravitational Baryogenesis Constraints on Nojiri-Odintsov $f(R)$ Gravity
This paper focuses on exploring the imbalance between matter and antimatter via the gravitational baryogenesis mechanism within the framework of Nojiri-Odintsov $f(R)$ gravity models in a spatially flat FLRW universe, where $R$ is the Ricci curvature scalar. This mechanism is based on \(\mathcal{CP}\)-violation generated via introducing an interaction between baryonic matter current (\(J^μ\)) and the derivative of curvature scalar (\(\partial_μR\)), which finally results in the baryon asymmet…

Open-closed 3d gravity as a random ensemble
Daniel L. Jafferis, Liza Rozenberg, Diandian Wang
https://arxiv.org/abs/2506.19817 https://

Open-closed 3d gravity as a random ensemble
We investigate an ensemble of boundary CFTs within the framework of a tensor model recently constructed to model 3d quantum gravity. The incorporation of CFT borders introduces new elements to the gravity theory. In particular, it leads to an open-closed extension of Virasoro TQFT, which in the classical limit gives rise to 3d gravity with tensionful end-of-the-world branes. It also provides predictions for off-shell manifolds with bordered asymptotic boundaries, such as the annulus wormhole. A…

Detection of subsurface structures with a vehicle-based atom gravity gradiometer
Xiaowei Zhang, Jiaqi Zhong, Muyan Wang, Huilin Wan, Hui Xiong, Dandan Jiang, Zhi Li, Dekai Mao, Bin Gao, Biao Tang, Xi Chen, Jin Wang, Mingsheng Zhan
https://arxiv.org/abs/2506.18506

Detection of subsurface structures with a vehicle-based atom gravity gradiometer
High-precision mobile gravity gradiometers are very useful in geodesy and geophysics. Atom gravity gradiometers (AGGs) could be among the most accurate mobile gravity gradiometers but are currently constrained by the trade-off between portability and sensitivity. Here, we present a high-sensitivity mobile AGG featuring an ultra-compact sensor head with a volume of only 94 L. In the laboratory, it achieves a sensitivity of 77 E/$\sqrt{Hz}$ (1 E=1$\times10^{-9}$/s$^2$) and a long-term stability o…

A field-level reaction for screened modified gravity
Daniela Saadeh, Kazuya Koyama, Xan Morice-Atkinson
https://arxiv.org/abs/2506.18876 https://

A field-level reaction for screened modified gravity
We present a field-level reaction framework to emulate the nonlinear effects of screened modified gravity on the cosmic web. This approach is designed to enable field-level inference with data from Stage IV cosmological surveys. Building on the reaction method, which models the nonlinear matter power spectrum in modified gravity as corrections to a "pseudo" $Λ$CDM cosmology, we extend the method to full field-level predictions by applying it to the output of $N$-body simulations, including bot…

Spotted this Progress Pride Graffiti at the weekend in a carpark that I often use. There's some awesome work there!
#Graffiti #ProgressPride #Pride

Ultra-low damping of the translational motion of a composite graphite particle in a magneto-gravitational trap
Connor E. Murphy (Department of Physics, Montana State University, Bozeman, MT), Cody Jessup (Department of Physics, Montana State University, Bozeman, MT), Tahereh Naderishahab (Department of Physics, Montana State University, Bozeman, MT), Leonardo R. Werneck (Department of Physics, University of Idaho, Moscow, ID), Zachariah B. Etienne (Department of Physics, University of …

Ultra-low damping of the translational motion of a composite graphite particle in a magneto-gravitational trap
We demonstrate an ultra-low dissipation, one-dimensional mechanical oscillator formed by levitating a millimeter-scale composite graphite particle in a room-temperature magneto-gravitational trap. The trap's magnetic field geometry, based on a linear quadrupole, eliminates first-order field gradients in the axial direction, yielding a low oscillation frequency with negligibly low eddy-current losses. Direct ring-down measurements under vacuum compare the damping of the vertical and axial motion…

On the reconstruction map in JT gravity
Chris Akers, Andrew Lucas, Amit Vikram
https://arxiv.org/abs/2506.18975 https://arxiv.org/pdf…

On the reconstruction map in JT gravity
An open question in AdS/CFT is how to reconstruct semiclassical bulk operators precisely enough that non-perturbative quantum effects can be computed. We propose a set of physically-motivated requirements for such a reconstruction map, and explicitly construct a map satisfying these requirements in Jackiw-Teitelboim (JT) gravity. Our map is found by canonically quantizing "action-angle" variables for JT gravity, which are chosen to ensure that the spectrum of the fundamental quantum theory matc…

Holographic dark energy models in $f(Q,T)$ gravity and cosmic constraint
Xuwei Zhang, Xiaofeng Yang, Yunliang Ren, Shuangnan Chen, Yangjun Shi, Cheng Cheng, Xiaolong He
https://arxiv.org/abs/2506.17933

Holographic dark energy models in $f(Q,T)$ gravity and cosmic constraint
In this work, we propose a new model that combines holographic dark energy with modified gravity $f(Q,T)$ to explore a possible explanation for the accelerated expansion of the universe. We incorporate the holographic principle into non-metric gravity with non-minimal matter coupling and introduce the Barrow holographic dark energy model to account for a tighter corrections, allowing for a more generalized discussion. Furthermore, we perform parameter estimation using the latest observational d…