Self-focusing of helicity drives finite-time singularities in inviscid flows
Mokhtar Adda-Bedia, Sergio Rica
https://arxiv.org/abs/2605.17569 https://arxiv.org/pdf/2605.17569 https://arxiv.org/html/2605.17569
arXiv:2605.17569v1 Announce Type: new
Abstract: This paper deals with the longstanding quest of the possible existence of finite-time singularities in the equations governing the dynamics of inviscid fluids, namely, Euler equations. Here, two contributions are brought for the case of perfect fluids with finite initial energy. First, a self-similar velocity field inspired by Leray Ansatz is proposed which allows for a separation of variables that transforms the original partial differential Euler equations to a nonlinear system of ordinary differential equations. This system can be solved semi-analytically and allows a continuum set of solutions parametrised by a self-similar exponent, $\nu$. Second, we use the conservation laws of Euler equations to select the possible finite-time singular solutions and the related self-similar exponents. We find that the helicity is the driving mechanism of the blow-up through a self-focusing mechanism. The flow near the singularity separates into two phases. A first phase is within a tubular region that shrinks as a power-law $(t_c-t)^\nu$, with $t_c$ the blow-up time, where the helicity is focused. This region is separated by a sharp interface from an outer region where the vorticity, and thus helicity, is identically zero. We found that the finite-time singularity may be either point-like or line-like depending on the dynamics of the tubular region along its axis of symmetry. Incidentally for a point-like singularity we recover the Leray scaling $\nu=1/2$ paving the way to a generalisation of this approach for the Navier-Stokes equations. Finally, we conjecture that if the helicity vanishes initially, no finite-time singularity would be possible, since in this case the singularity occurs at infinite time from the initial condition.
toXiv_bot_toot
This pair of Numberphlle videos is amazing. The progressions here make me think of how snowflakes can end up with global symmetry.
https://www.youtube.com/watch?v=UiX4CFIiegM
This is neat. Always like a good argument by symmetry.
https://en.wikipedia.org/wiki/Bertrand's_ballot_theorem
Crosslisted article(s) found for physics.atom-ph. https://arxiv.org/list/physics.atom-ph/new
[1/1]:
- Accidental Symmetry in the Tavis-Cummings Model via the Schwinger Boson Representation
Plato Deliyannis, Iman Marvian
Replaced article(s) found for cs.IT. https://arxiv.org/list/cs.IT/new
[1/1]:
- Optimal Proximity Gap for Folded Reed--Solomon Codes via Subspace Designs
Fernando Granha Jeronimo, Lenny Liu, Pranav Rajpal
https://arxiv.org/abs/2601.10047 https://mastoxiv.page/@arXiv_csIT_bot/115903956641689136
- Breaking Symmetry in D2D Coded Caching: Optimal Communication with Low Subpacketization
Xiang Zhang, Giuseppe Caire, Mingyue Ji
https://arxiv.org/abs/2602.12220 https://mastoxiv.page/@arXiv_csIT_bot/116062725600909840
- A New Approach to Code Smoothing Bounds
Tsuyoshi Miezaki, Yusaku Nishimura, Katsuyuki Takashima
https://arxiv.org/abs/2603.18077 https://mastoxiv.page/@arXiv_csIT_bot/116260380391748925
- Fluid Antenna Systems Enabling 6G HRLLC With Port Switching Delay
Xusheng Zhu, Kai-Kit Wong, Hao Xu, Chenguang Rao, Hyundong Shin
https://arxiv.org/abs/2605.06275 https://mastoxiv.page/@arXiv_csIT_bot/116537839161835575
- Accurate Estimation of Mutual Information in High Dimensional Data
Eslam Abdelaleem, K. Michael Martini, Ilya Nemenman
https://arxiv.org/abs/2506.00330 https://mastoxiv.page/@arXiv_physicsdataan_bot/114618315134354611
- SDQM: Synthetic Data Quality Metric for Object Detection Dataset Evaluation
Ayush Zenith, Arnold Zumbrun, Neel Raut, Jing Lin
https://arxiv.org/abs/2510.06596 https://mastoxiv.page/@arXiv_csCV_bot/115343628773188610
- SEDULity: A Proof-of-Learning Framework for Distributed and Secure Blockchains with Efficient Use...
Weihang Cao, Mustafa Doger, Sennur Ulukus
https://arxiv.org/abs/2512.13666 https://mastoxiv.page/@arXiv_csCR_bot/115729118798706696
- A theory of learning data statistics in diffusion models, from easy to hard
Lorenzo Bardone, Claudia Merger, Sebastian Goldt
https://arxiv.org/abs/2603.12901 https://mastoxiv.page/@arXiv_statML_bot/116237842977106276
- On the independence number of de Bruijn graphs
Pietro Majer, Matteo Novaga
https://arxiv.org/abs/2604.14671 https://mastoxiv.page/@arXiv_mathCO_bot/116419097221023806
- Information bottleneck for learning the phase space of dynamics from high-dimensional experimenta...
K. Michael Martini, Eslam Abdelaleem, Paarth Gulati, Ilya Nemenman
https://arxiv.org/abs/2604.24662 https://mastoxiv.page/@arXiv_physicsdataan_bot/116481236697063671
- Improved Amenability Bounds for Local Coordination Games
Ron Peretz, Dean Kraizberg
https://arxiv.org/abs/2606.01963 https://mastoxiv.page/@arXiv_csGT_bot/116679490095124433
toXiv_bot_toot
Super-Link Fragility in Asymmetric W-Class States under Quantum Noise
Sougata Bhattacharyya, Fatih Ozaydin, Sovik Roy
https://arxiv.org/abs/2606.12307 https://arxiv.org/pdf/2606.12307 https://arxiv.org/html/2606.12307
arXiv:2606.12307v1 Announce Type: new
Abstract: The asymmetric three-qubit W-class state $|\overline{W_3^L}\rangle$ defines an isosceles entanglement-network geometry, (a) two vertex-base (VB) links form stronger bipartite connections, (b) while the base-base (BB) link is weaker. This suggests that concentrating entanglement into a super-link may be advantageous for quantum-network tasks. Here, we show that this intuition is incomplete. We analytically compare the bipartite concurrence dynamics of the symmetric |W> state and the asymmetric $|\overline{W_3^L}\rangle$ state, which differ both in entanglement-network geometry and excitation sector under standard noise models. In the absence of noise, the concurrence hierarchy is C_{VB} > C_W > C_{BB}$. Under phase damping, this hierarchy is preserved for all noise strengths and no entanglement sudden death occurs. Under amplitude damping, however, the hierarchy is reordered. The symmetric |W> state becomes the most robust, while the base-base concurrence of $|\overline{W_3^L}\rangle$ vanishes at the finite threshold of parameter $\gamma$. We term this reordering as the \textit{Super-Link Fragility Effect}. The same structural asymmetry that produces a stronger vertex-base link also makes it more vulnerable to energy dissipation when coupled with multi-excitation amplitudes. Under depolarization, the asymmetry advantage is erased, with $C_W$ and $C_{VB}$ sharing the same sudden-death threshold for some value of the parameter p, while $C_{BB}$ disappears earlier at some other value of the parameter p. The generalized amplitude damping channel continuously connects the damping-dominated regime to the pure-excitation limit, where the initial hierarchy is restored. These results show that entanglement robustness in $W$-class resources is controlled not by initial concurrence alone, but by the joint structure of entanglement-network geometry, excitation sector, and noise symmetry.
toXiv_bot_toot
Symmetry-Selective Stabilization of Charge-Density Wave in ScV$_6$Sn$_6$
A. Korshunov, C. -Y. Lim, J. Corral-Sertal, G. Garbarino, D. Chernyshov, A. Rajapitamahuni, C. Yi, S. Roychowdhury, C. Shekhar, C. Felser, V. Pardo, Ella M. Schmidt, S. Blanco-Canosa
https://arxiv.org/abs/2606.05866
"Robotics has long taken cues from biology to figure out how it should move. Humanoid #robots copy our limbs. Quadrupeds borrow from dogs and horses. Small crawlers take cues from insects. That approach has produced impressive machines, but it also carries a bias. #Designers often start by asking β¦
Relaxation of Incommensurate Structures via Quantum Models
Mengfan Tu, Huajie Chen, Daniel Massatt
https://arxiv.org/abs/2606.31104 https://arxiv.org/pdf/2606.31104 https://arxiv.org/html/2606.31104
arXiv:2606.31104v1 Announce Type: new
Abstract: Accurately modeling structural relaxation in incommensurate systems is intrinsically challenging due to the absence of global translational symmetry. In this work, we develop a variational quantum framework for structural relaxation in incommensurate Schr\"{o}dinger models, where displacement fields are formulated on the configuration space and the electronic Hamiltonian is represented in reciprocal space. This yields well-defined relaxed energy, local density of states, and forces through thermodynamic limits. We propose an anisotropic scattering-channel approximation, and prove exponential convergence of the approximate equilibria. Numerical experiments are performed to support the analysis and show that the model captures domain-wall formation and its impact on the electronic spectrum.
toXiv_bot_toot
Weird sunset vibes although sun still has almost two hours to go, but dark clouds and haze make for some strong contrasts.
Also a nice symmetry between the sun and it's reflection on the water, plus the clouds and dark ground.
#Ireland #Sunset #Ocean
$E_\infty^{1,2}$-type Lieb-Schultz-Mattis anomalies, deconfined quantum critical points, and non-invertible symmetry breaking
Hao-Ran Zhang, Hanlin Lin, Shuo Yang, Qing-Rui Wang
https://arxiv.org/abs/2606.06343
Dosimetric Quantification of a Commercial Dual-Tube kV X-Ray System for Preclinical FLASH Research
Luka Matej Devenica, Lixiang Guo, Mohammad Rezaee, Ken Kang-Hsin Wang
https://arxiv.org/abs/2606.23401 https://arxiv.org/pdf/2606.23401 https://arxiv.org/html/2606.23401
arXiv:2606.23401v1 Announce Type: new
Abstract: A kV dual tube system has been disseminated as a commercial research platform for preclinical FLASH radiotherapy (RT). Because the tubes are arranged in a parallel opposed geometry, both output symmetry and time resolved tube synchronization are critical for achieving sufficiently high dose rates (DR) and reproducible study results. We quantified tube output asymmetry observed in depth dose measurements as well as tube synchronization and evaluated their impact on FLASH studies. The dual-tube system defines dose per pulse as the combined single pulse output from both tubes, with DR given by dose per pulse/pulse length. 3D dose distributions were reconstructed from film measurements to assess the impact of output discrepancies. Pulse synchronization between tubes was characterized using a scintillator with 1 ms resolution. We showed >20% discrepancies in output at nominally equal mA/ms settings. After we compensated such discrepancy by decreasing the current of the tube with higher output, the inter tube output difference was reduced to <1%, restoring symmetrical depth dose. We further simulated an in vivo intestinal irradiation in which naive tube settings resulted in >22% of the organ volume receiving >102% of the prescribed dose, compared with <7% when output compensation was applied. We identified a 10.2 /- 7.0ms synchronization jitter between tubes, which disproportionately impacts the DR at low dose-per-pulse settings, particularly relevant for fractionated studies. Corresponding quality assurance (QA) was designed to monitor tube synchronization over time. We quantified the dosimetric impact of asymmetric output and synchronization and demonstrated implications for preclinical studies. The proposed methodology and QA would mitigate and monitor these effects, ensuring study reproducibility.
toXiv_bot_toot
Identical-Particle Symmetry-Enabled Complete Coherent Control of Ultracold Atomic and Molecular Collisions
Jing-Chen Zhang, Adrien Devolder, Timur V. Tscherbul, Paul Brumer, Yu Liu
https://arxiv.org/abs/2607.01620
Close shot of Trillium in Treman State Park
#photo #photography #forest #forestfriday
Replaced article(s) found for physics.atom-ph. https://arxiv.org/list/physics.atom-ph/new
[1/1]:
- Dual Magnetic and Electric Dipole Symmetry: Pseudo Angular Momentum in Parity Space and the Elect...
Michael E. Tobar
@arXiv_physicsfludyn_bot@mastoxiv.page
