Tootfinder

Pattern formation in a coupled driven diffusive system
G. E. Freire Oliveira, R. Dickman, M. O. Lavrentovich, R. K. P. Zia
https://arxiv.org/abs/2509.00220 https://

Pattern formation in a coupled driven diffusive system
We investigate pattern formation in a driven mixture of two repulsive particles by introducing a Field-based Lattice Model (FLM), a hybrid model that combines aspects of the driven Widom-Rowlison lattice gas (DWRLG) and its statistical field theory \cite{DWRLG1,DWRLG2}. We find that the FLM effectively captures the bulk behavior of the DWRLG in both low- and high-density phases, suggesting that phase transitions in these models may share a universality class. Under the effect of the drive, the …

From Density Functional Theory to Spin Hamiltonians: Magnetism in $d^5$ Honeycomb Compound OsCl$_3$
Ritwik Das, Indra Dasgupta
https://arxiv.org/abs/2506.22279

From Density Functional Theory to Spin Hamiltonians: Magnetism in $d^5$ Honeycomb Compound OsCl$_3$
Magnetism in strongly correlated honeycomb systems with $d^5$ electronic configuration has garnered significant attention due to its potential to realize the Kitaev spin liquid state, characterized by exotic properties. However, real materials exhibit not only Kitaev exchange interactions but also other magnetic exchanges, which may drive the transition from a spin liquid phase to a long-range ordered ground state. This work focuses on modelling the effective spin Hamiltonian for two-dimensiona…

Strain-Controlled Topological Phase Transitions and Chern Number Reversal in Two-Dimensional Altermagnets
Zesen Fu, Mengli Hu, Aolin Li, Haiming Duan, Junwei Liu, Fangping Ouyang
https://arxiv.org/abs/2507.22474

Strain-Controlled Topological Phase Transitions and Chern Number Reversal in Two-Dimensional Altermagnets
We present a theoretical and first-principles study of a two-dimensional altermagnet exhibiting spin-valley locking and strain-tunable topological phases. By constructing a minimal tight-binding model constrained by altermagnetic symmetry, we show that biaxial strain can drive a transition from a trivial insulator to a type-II quantum spin Hall (QSH) phase. Furthermore, we derive an analytical strain-induced perturbation theory that identifies two critical curves, dividing the phase space into …

Phonons Drive the Topological Phase Transition in Quasi-One-Dimensional Bi$_4$I$_4$
Wenjie Hu, Jiayi Gong, Yuhui Qiu, Lexian Yang, Jin-Jian Zhou, Yugui Yao
https://arxiv.org/abs/2508.17268

Phonons Drive the Topological Phase Transition in Quasi-One-Dimensional Bi$_4$I$_4$
Quasi-one-dimensional bismuth halides offer an exceptional platform for exploring diverse topological phases, yet the nature of the room-temperature topological phase transition in Bi$_4$I$_4$ remains unresolved. While theory predicts the high-temperature $β$-phase to be a strong topological insulator (TI), experiments observe a weak TI. Here we resolve this discrepancy by revealing the critical but previously overlooked role of electron-phonon coupling in driving the topological phase transit…

The effect of droplet configurations within the Functional Renormalization Group of low-dimensional Ising models
Ivan Balog, Lucija Nora Farka\v{s}, Maroje Marohni\'c, Gilles Tarjus
https://arxiv.org/abs/2506.23415

The effect of droplet configurations within the Functional Renormalization Group of low-dimensional Ising models
We explore the application of the nonperturbative functional renormalization group (NPFRG) within its most common approximation scheme based on truncations of the derivative expansion to the $Z_2$-symmetric scalar $φ^4$ theory as the lower critical dimension $d_{\rm lc}$ is approached. We aim to assess whether the NPFRG - a broad, nonspecialized method which is accurate in $d\geq 2$ - can capture the effect of the localized (droplet) excitations that drive the disappearance of the phase transi…

Laboratory observation of internal gravity wave turbulence in a three-dimensional, large-scale facility
Nicolas Lanchon, Samuel Boury, Pierre-Philippe Cortet
https://arxiv.org/abs/2508.19792

Laboratory observation of internal gravity wave turbulence in a three-dimensional, large-scale facility
The search for solutions to the theory of weakly non-linear internal gravity wave turbulence is an active research topic. It is notably stimulated by the fact that this regime could drive fine-scale ocean dynamics for which the identification of a physical model could yield improved parametrizations in global oceanic models. In this context, analytical works lead to diverse predictions and the experimental observation of a regime of developed weakly-non-linear internal wave turbulence constitut…

Sense of Belonging and Intent to Persist: Mediating Role of Motivation and Moderating Role of Gender in Physics and Astronomy Graduate Students
Swagata Sarkar, N. Sanjay Rebello
https://arxiv.org/abs/2508.20948

Sense of Belonging and Intent to Persist: Mediating Role of Motivation and Moderating Role of Gender in Physics and Astronomy Graduate Students
This study investigates how graduate students' sense of belonging (SB) influences their intent to persist (IP) in physics and astronomy programs, and how this relationship is shaped by the basic psychological needs that drive motivation-autonomy, competence, and relatedness-as well as gender. Grounded in self-determination theory, the analysis treats these three needs as mediators and gender as a moderator. A quantitative survey was administered to graduate students in the Department of Physics…

Synaptic bundle theory for spike-driven sensor-motor system: More than eight independent synaptic bundles collapse reward-STDP learning
Takeshi Kobayashi, Shogo Yonekura, Yasuo Kuniyoshi
https://arxiv.org/abs/2508.14492

Synaptic bundle theory for spike-driven sensor-motor system: More than eight independent synaptic bundles collapse reward-STDP learning
Neuronal spikes directly drive muscles and endow animals with agile movements, but applying the spike-based control signals to actuators in artificial sensor-motor systems inevitably causes a collapse of learning. We developed a system that can vary \emph{the number of independent synaptic bundles} in sensor-to-motor connections. This paper demonstrates the following four findings: (i) Learning collapses once the number of motor neurons or the number of independent synaptic bundles exceeds a cr…

LLM coding is the opposite of DRY
An important principle in software engineering is DRY: Don't Repeat Yourself. We recognize that having the same code copied in more than one place is bad for several reasons:
1. It makes the entire codebase harder to read.
2. It increases maintenance burden, since any problems in the duplicated code need to be solved in more than one place.
3. Because it becomes possible for the copies to drift apart if changes to one aren't transferred to the other (maybe the person making the change has forgotten there was a copy) it makes the code more error-prone and harder to debug.
All modern programming languages make it almost entirely unnecessary to repeat code: we can move the repeated code into a "function" or "module" and then reference it from all the different places it's needed. At a larger scale, someone might write an open-source "library" of such functions or modules and instead of re-implementing that functionality ourselves, we can use their code, with an acknowledgement. Using another person's library this way is complicated, because now you're dependent on them: if they stop maintaining it or introduce bugs, you've inherited a problem, but still, you could always copy their project and maintain your own version, and it would be not much more work than if you had implemented stuff yourself from the start. It's a little more complicated than this, but the basic principle holds, and it's a foundational one for software development in general and the open-source movement in particular. The network of "citations" as open-source software builds on other open-source software and people contribute patches to each others' projects is a lot of what makes the movement into a community, and it can lead to collaborations that drive further development. So the DRY principle is important at both small and large scales.
Unfortunately, the current crop of hyped-up LLM coding systems from the big players are antithetical to DRY at all scales:
- At the library scale, they train on open source software but then (with some unknown frequency) replicate parts of it line-for-line *without* any citation [1]. The person who was using the LLM has no way of knowing that this happened, or even any way to check for it. In theory the LLM company could build a system for this, but it's not likely to be profitable unless the courts actually start punishing these license violations, which doesn't seem likely based on results so far and the difficulty of finding out that the violations are happening. By creating these copies (and also mash-ups, along with lots of less-problematic stuff), the LLM users (enabled and encouraged by the LLM-peddlers) are directly undermining the DRY principle. If we see what the big AI companies claim to want, which is a massive shift towards machine-authored code, DRY at the library scale will effectively be dead, with each new project simply re-implementing the functionality it needs instead of every using a library. This might seem to have some upside, since dependency hell is a thing, but the downside in terms of comprehensibility and therefore maintainability, correctness, and security will be massive. The eventual lack of new high-quality DRY-respecting code to train the models on will only make this problem worse.
- At the module & function level, AI is probably prone to re-writing rather than re-using the functions or needs, especially with a workflow where a human prompts it for many independent completions. This part I don't have direct evidence for, since I don't use LLM coding models myself except in very specific circumstances because it's not generally ethical to do so. I do know that when it tries to call existing functions, it often guesses incorrectly about the parameters they need, which I'm sure is a headache and source of bugs for the vibe coders out there. An AI could be designed to take more context into account and use existing lookup tools to get accurate function signatures and use them when generating function calls, but even though that would probably significantly improve output quality, I suspect it's the kind of thing that would be seen as too-baroque and thus not a priority. Would love to hear I'm wrong about any of this, but I suspect the consequences are that any medium-or-larger sized codebase written with LLM tools will have significant bloat from duplicate functionality, and will have places where better use of existing libraries would have made the code simpler. At a fundamental level, a principle like DRY is not something that current LLM training techniques are able to learn, and while they can imitate it from their training sets to some degree when asked for large amounts of code, when prompted for many smaller chunks, they're asymptotically likely to violate it.
I think this is an important critique in part because it cuts against the argument that "LLMs are the modern compliers, if you reject them you're just like the people who wanted to keep hand-writing assembly code, and you'll be just as obsolete." Compilers actually represented a great win for abstraction, encapsulation, and DRY in general, and they supported and are integral to open source development, whereas LLMs are set to do the opposite.
[1] to see what this looks like in action in prose, see the example on page 30 of the NYTimes copyright complaint against OpenAI (#AI #GenAI #LLMs #VibeCoding

From Theory to Practice: Advancing Multi-Robot Path Planning Algorithms and Applications
Teng Guo
https://arxiv.org/abs/2506.09914 https://

From Theory to Practice: Advancing Multi-Robot Path Planning Algorithms and Applications
The labeled MRPP (Multi-Robot Path Planning) problem involves routing robots from start to goal configurations efficiently while avoiding collisions. Despite progress in solution quality and runtime, its complexity and industrial relevance continue to drive research. This dissertation introduces scalable MRPP methods with provable guarantees and practical heuristics. First, we study dense MRPP on 2D grids, relevant to warehouse and parcel systems. We propose the Rubik Table method, achieving …

Hydrodynamic instabilities in driven chiral suspensions
Seema Chahal, Brato Chakrabarti
https://arxiv.org/abs/2508.17879 https://arxiv.org/pdf/2508.17879…

Hydrodynamic instabilities in driven chiral suspensions
Active Stokesian suspensions are conventionally understood to generate dipolar stresses that destabilize aligned states in the bulk and drive system-wide spatiotemporally chaotic flows. Here, we report dynamics in suspensions of torque-driven spinning chiral particles that exhibit a distinct and previously unrecognized route to collective dynamics. Using a mean-field kinetic theory, stability analysis, and nonlinear simulations, we demonstrate how flows driven by torque monopoles and self-propu…

Systematics from NICER Pulse Profiles Drive Uncertainty in Multi-Messenger Inference of the Neutron Star Equation of State
Bhaskar Biswas, Prasanta Char
https://arxiv.org/abs/2507.12540

Systematics from NICER Pulse Profiles Drive Uncertainty in Multi-Messenger Inference of the Neutron Star Equation of State
We present new constraints on the neutron star equation of state (EOS) and mass distribution using a unified Bayesian inference framework that incorporates latest NICER measurements, including PSR J0614$-$3329, alongside gravitational wave data, radio pulsar masses, and nuclear theory. By systematically comparing four inference scenarios--varying in the inclusion of PSR J0614$-$3329 and in the pulse profile model used for PSR J0030+0451--we quantify the impact of observational and modeling choi…

Rotation Errors Due to Field Quantization for Simultaneously Driven Atoms
Hunter Lindemann, Shanon Vuglar, Julio Gea-Banacloche
https://arxiv.org/abs/2508.06769 https://

Rotation Errors Due to Field Quantization for Simultaneously Driven Atoms
When an electromagnetic field in a coherent or quasiclassical (e.g., squeezed) state is used to simultaneously drive an ensemble of two-level atoms, the quantum nature of the field will, in general, cause the final state of the atoms to differ from the one predicted for a totally classical field. This is a potential source of error in quantum logic gates in which the gate is the rotation of the atoms by a laser. In this paper, we use second order perturbation theory to find how this error scale…

Interfacial instability of confined 3D active droplets
Bennett C. Sessa, Federico Cao, Robert A. Pelcovits, Thomas R. Powers, Guillaume Duclos
https://arxiv.org/abs/2506.17532

Interfacial instability of confined 3D active droplets
Instabilities of fluid-fluid interfaces are ubiquitous in passive soft matter. Adding activity to the interface or either fluid can dramatically change the stability of the interface. Using experiment and theory, we investigate the interfacial instability of a deformable 3D active nematic liquid crystal droplet in the isotropic phase surrounded by a passive fluid and confined between two parallel plates. Spontaneous active flows drive the growth of undulations along the active/passive interface…

Synchronous polarization switching at sub-coercive fields through stochastic resonance in ferroelectric thin-film capacitors
Vivek Dey, Thejas Basavarajappa, Manikantan R. S., Kevin Renji Jacob, Jonnalagadda Nikhila, Arvind Ajoy, Pavan Nukala
https://arxiv.org/abs/2508.12017

Synchronous polarization switching at sub-coercive fields through stochastic resonance in ferroelectric thin-film capacitors
Stochastic resonance (SR) is a phenomenon by which the presence of noise in a non-linear system allows for detection of a weak sub-threshold signal, or in a bi-stable system allows for sub-coercive switching between the two states. Simple theory suggests that SR occurs when the Kramers rate (rk) of the bistable system, which is a function of noise and applied voltage, is twice the drive frequency (fsignal). Here, we demonstrate the synchronous switching of polarization with a sub-coercive volta…

This https://arxiv.org/abs/2501.00194 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qbi…

Minimal Models for RNA Simulations
The increasing importance of RNA as a prime player in biology can hardly be overstated. Problems in RNA, such as folding and RNA-RNA interactions that drive phase separation, require cations. Because experiments alone cannot reveal the dynamics of cation-RNA interactions, well calibrated theory and computations are needed to predict how ions control the behavior of RNA. The perspective describes the development and use of coarse-grained models at different resolutions. We focus on single- and t…

A microscopically reversible kinetic theory of flocking
Ruben Lier
https://arxiv.org/abs/2508.09274 https://arxiv.org/pdf/2508.09274

A microscopically reversible kinetic theory of flocking
We formulate a kinetic theory of two species of hard spheres which can undergo collisions converting chemical energy into kinetic energy. As the two species represent birds and air, this reactive collision mimics birds flapping their wings, allowing for their propulsion. We demand microscopic reversibility of the reactive collisions. We then introduce a chemostat to drive the system out of equilibrium. When the chemostat is sufficiently turned on and one restricts to grazing interspecies collis…

Dynamic Coupling of Infiltration-Soil Moisture Feedback:Emergent Vegetation Patterns in a Water-Vegetation Model
Juan Yan, Xiaoli Wang, Guohong Zhang, Yuan Yuan
https://arxiv.org/abs/2508.01755

Dynamic Coupling of Infiltration-Soil Moisture Feedback:Emergent Vegetation Patterns in a Water-Vegetation Model
We present a modified water-vegetation model to investigate the mechanistic relationship between infiltration-soil moisture feedback and vegetation pattern in arid/semi-arid ecosystems. Employing Turing pattern formation theory, we drive conditions for diffusion-induced instability and analyze spatiotemporal dynamics near Turing-Hopf bifurcation points. Our key findings include: (i) The system exhibits rich dynamics including multiple stable equilibria, supercritical/subcritical Hopf bifurcatio…

Observation of Momentum-Band Topology in PT-Symmetric acoustic Floquet Lattices
Shuaishuai Tong, Qicheng Zhang, Gaohan Li, Kun Zhang, Chun Xie, Chunyin Qiu
https://arxiv.org/abs/2507.04068

Observation of Momentum-Band Topology in PT-Symmetric acoustic Floquet Lattices
Momentum-band topology, which transcends conventional topological band theory, unlocks new topological phases that host fascinating temporal interface states. However, direct bulk experimental evidence of such emerging band topology is still lacking due to the great challenges in resolving eigenstates and topological invariants of time-varying systems. Here, we present a comprehensive study on the momentum-band topology in a PT-symmetric Floquet lattice, where the drive-induced momentum gap can…

Phase transitions induced by resonant light: a phenomenological approach
A. Kudlis, L. S. Ricco, H. Sigur{\dh}sson, I. A. Shelykh
https://arxiv.org/abs/2506.05964

Phase transitions induced by resonant light: a phenomenological approach
We present a phenomenological framework to describe a subclass of light-induced phase transitions (LIPTs) in condensed matter systems, specifically those mediated by the resonant generation of excitons. Our approach extends the classical Landau theory by introducing dynamic coupling between the system's order parameter and complex excitonic fields, along with Langevin-type forces that drive the system toward states of minimal free energy. The model is applied in the context of all-optical reson…