Tootfinder

This https://arxiv.org/abs/2504.08648 has been replaced.
initial toot: https://mastoxiv.page/@ar…

Rational constitutive law for the viscous stress tensor in incompressible two-phase flows: Derivation and tests against a 3D benchmark experiment
We analyze the representation of viscous stresses in the one-fluid formulation of the two-phase Navier-Stokes equations, the model on which all computational approaches making use of a fixed mesh to discretize the flow field are grounded. Recognizing that the Navier-Stokes-like equations that are actually solved in these approaches imply a spatial filtering, we show by considering a specific two-dimensional flow configuration that the proper representation of the viscous stress tensor requires …

$F$-injectivity does not imply $F$-fullness in normal domains
Alessandro De Stefani, Thomas Polstra, Austyn Simpson
https://arxiv.org/abs/2506.00646 https:…

$F$-injectivity does not imply $F$-fullness in normal domains
We construct examples of noetherian three-dimensional local geometrically normal domains of prime characteristic which are $F$-injective but not $F$-full. Along the way, we find examples of two-dimensional local geometrically normal domains which are $F$-injective but not $F$-anti-nilpotent. A crucial theme of our constructions is the behavior of $F$-injectivity along a purely inseparable finite base change.

No Trade Under Verifiable Information
Spyros Galanis
https://arxiv.org/abs/2506.04944 https://arxiv.org/pdf/2506.04944

No Trade Under Verifiable Information
No trade theorems examine conditions under which agents cannot agree to disagree on the value of a security which pays according to some state of nature, thus preventing any mutual agreement to trade. A large literature has examined conditions which imply no trade, such as relaxing the common prior and common knowledge assumptions, as well as allowing for agents who are boundedly rational or ambiguity averse. We contribute to this literature by examining conditions on the private information of…

Thinking about LLMs in the context of Philip Anderson's classic paper More is Different
the reductionist hypothesis does not by any means imply a "constructionist" one: The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe.

This https://arxiv.org/abs/2009.14324 has been replaced.
link: https://scholar.google.com/scholar?q=a

Characterizing Jacobians via the KP equation and via flexes and degenerate trisecants to the Kummer variety: an algebro-geometric approach
This paper is withdrawn since we found a flaw in the proof of Theorem 4, asserting that the base locus of the complete linear system of an ample line bundle on a complex abelian variety is reduced. The error is in page 7, line $ -14$, where we claim that the divisor "mathcal E" on the variety $X$ is linearly equivalent to zero. This is untrue. For instance, it would imply that, for a non-torsion point $x$ on an abelian surface $A$, letting $E_x$, $E_{-x}$, and $E_0$ the exceptional curves in th…

Jazzaria – Uncertain Horizon
#byncnd

$\text{NS}_{\omega_1}$ saturated, $\Delta_1 ( \{ \omega_1 \} )$-definable and a $\Delta^1_4$-definable well-order of the reals
Stefan Hoffelner
https://arxiv.org/abs/2507.01183

$\text{NS}_{ω_1}$ saturated, $Δ_1 ( \{ ω_1 \} )$-definable and a $Δ^1_4$-definable well-order of the reals
Assuming $M_1$, the canonical inner model with one Woodin cardinal exists, we construct a model in which the nonstationary ideal on $ω_1$ is $\aleph_2$-saturated, $Δ_1$-definable with $ω_1$ as the only parameter and there is a $Σ^1_{4}$-definable well-order of the reals. This implies that contrary to the assumption that $NS_{ω_1}$ is $\aleph_1$-dense, the assumption of $NS_{ω_1}$ being saturated and $Δ_1$-definable does not imply any nice structural properties for the projective subsets …

This https://arxiv.org/abs/2411.09063 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

The typical elasticity of a quadratic order
For an atomic domain $D$, the $elasticity$ $ρ(D)$ of $D$ is defined as $\sup\{r/s: π_1\cdots π_r = ρ_1 \cdots ρ_s,~ \text{where each $π_i, ρ_j$ is irreducible}\}$; the elasticity provides a concrete measure of the failure of unique factorization in $D$. Fix a quadratic number field $K$ with discriminant $Δ_K$, and for each positive integer $f$, let $\mathcal{O}_f = \mathbb{Z} + f\mathcal{O}_K$ denote the order of conductor $f$ in $K$. Results of Halter-Koch imply that $\mathcal{O}_f$ ha…

When are exact categories co-exact?
James Richard Andrew Gray
https://arxiv.org/abs/2506.23413 https://arxiv.org/pdf/2506.23413

When are exact categories co-exact?
We show that opposite category of a cocomplete pretopos is ideally exact and arithmetical. We do this by showing that there are conditions common to additive and lextensive categories which, in the exact context, imply that: pushouts of monomorphisms along arbitrary morphisms exist and are pullbacks; monomorphisms are stable under pushout; co-reflexive-relations are co-effective-equivalence-relations; and coprotomodularity holds.

This https://arxiv.org/abs/2410.02270 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Beyond the ensemble paradigm in low dimensional quantum gravity: Schwarzian density, quantum chaos and wormhole contributions
Based on periodic orbit theory we address the individual-system versus ensemble interpretation of quantum gravity from a quantum chaos perspective. To this end we show that the spectrum of geodesic motion on high-dimensional hyperbolic manifolds, described by the Selberg trace formula, displays a Schwarzian ($\sinh 2π\sqrt{E}$) mean level density. Due to its chaotic classical limit, this quantum system also shows all universal signatures of quantum chaos. These two properties imply a possible …

Reweighted Spectral Partitioning Works: Bounds for Special Graph Classes
Jack Spalding-Jamieson
https://arxiv.org/abs/2506.01228 https://

Reweighted Spectral Partitioning Works: Bounds for Special Graph Classes
Spectral partitioning is a method that can be used to compute small sparse cuts or small edge-separators in a wide variety of graph classes, by computing the second-smallest eigenvalue (and eigenvector) of the Laplacian matrix. Upper bounds on this eigenvalue for certain graph classes imply that the method obtains small edge-separators for these classes, usually with a sub-optimal dependence on the maximum degree. In this work, we show that a related method, called reweighted spectral partition…

Implications of the evidence for direct $\mathbf{CP}$ violation in $D\to \pi^ \pi^-$ decays
Rahul Sinha, Thomas E. Browder, N. G. Deshpande, Dibyakrupa Sahoo, Nita Sinha
https://arxiv.org/abs/2505.24338

Implications of the evidence for direct $\mathbf{CP}$ violation in $D\to π^+π^-$ decays
The observation of CP violation in the difference of CP asymmetries between $D\to K^+K^-$ and $D\to π^+π^-$ has raised a debate whether the observed asymmetries can be regarded as a signal of physics beyond the standard model (SM). In this letter we show that the measured observables for $D\to ππ$ unambiguously imply a very large penguin contribution that is larger than $10\%$ of the amplitude for $D^0\toπ^+ π^-$ at a significance greater than $3.3σ$. We present arguments based only on u…

Position: Certified Robustness Does Not (Yet) Imply Model Security
Andrew C. Cullen, Paul Montague, Sarah M. Erfani, Benjamin I. P. Rubinstein
https://arxiv.org/abs/2506.13024

Position: Certified Robustness Does Not (Yet) Imply Model Security
While certified robustness is widely promoted as a solution to adversarial examples in Artificial Intelligence systems, significant challenges remain before these techniques can be meaningfully deployed in real-world applications. We identify critical gaps in current research, including the paradox of detection without distinction, the lack of clear criteria for practitioners to evaluate certification schemes, and the potential security risks arising from users' expectations surrounding ``guara…

Topological nodal $i$-wave superconductivity in PtBi$_2$
Susmita Changdar, Oleksandr Suvorov, Andrii Kuibarov, Setti Thirupathaiah, Grigoriy Shipunov, Saicharan Aswartham, Sabine Wurmehl, Iryna Kovalchuk, Klaus Koepernik, Carsten Timm, Bernd B\"uchner, Ion Cosma Fulga, Sergey Borisenko, Jeroen van den Brink
https://arxiv.or…

Topological nodal $i$-wave superconductivity in PtBi$_2$
Most superconducting materials are well-understood and conventional in the sense that the pairs of electrons that cause the superconductivity by their condensation have the highest possible symmetry. Famous exceptions are the enigmatic high-$T_c$ cuprate superconductors. Nodes in their superconducting gap are the fingerprint of their unconventional character and imply superconducting pairing of $d$-wave symmetry. Here, using angle-resolved photoemission spectroscopy, we observe that the Weyl se…

Oh, boo, am I irrationally angry about genocide?
Do gently fuck off. https://autistics.life/@VulcanTourist/114659503436582815

This https://arxiv.org/abs/2303.06701 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_eco…

Composite Sorting
This paper introduces an assignment model with concave costs of skill gaps, which arise generally when firms mitigate costs of mismatch as in Stigler (1939) and Laffont and Tirole (1986, 1991). Concave costs of skill gaps imply that the output function is neither supermodular nor submodular. We thus introduce a tractable model that interpolates between the polar canonical cases of supermodularity and submodularity. We characterize sorting, wages, and comparative statics and show these substanti…

This https://arxiv.org/abs/2009.14324 has been replaced.
link: https://scholar.google.com/scholar?q=a

Characterizing Jacobians via the KP equation and via flexes and degenerate trisecants to the Kummer variety: an algebro-geometric approach
This paper is withdrawn since we found a flaw in the proof of Theorem 4, asserting that the base locus of the complete linear system of an ample line bundle on a complex abelian variety is reduced. The error is in page 7, line $ -14$, where we claim that the divisor "mathcal E" on the variety $X$ is linearly equivalent to zero. This is untrue. For instance, it would imply that, for a non-torsion point $x$ on an abelian surface $A$, letting $E_x$, $E_{-x}$, and $E_0$ the exceptional curves in th…

From Worst-Case Hardness of $\mathsf{NP}$ to Quantum Cryptography via Quantum Indistinguishability Obfuscation
Tomoyuki Morimae, Yuki Shirakawa, Takashi Yamakawa
https://arxiv.org/abs/2506.19542

From Worst-Case Hardness of $\mathsf{NP}$ to Quantum Cryptography via Quantum Indistinguishability Obfuscation
Indistinguishability obfuscation (iO) has emerged as a powerful cryptographic primitive with many implications. While classical iO, combined with the infinitely-often worst-case hardness of $\mathsf{NP}$, is known to imply one-way functions (OWFs) and a range of advanced cryptographic primitives, the cryptographic implications of quantum iO remain poorly understood. In this work, we initiate a study of the power of quantum iO. We define several natural variants of quantum iO, distinguished by w…

A free boundary approach to non-scattering obstacles with vanishing contrast
Mikko Salo, Henrik Shahgholian
https://arxiv.org/abs/2506.22328 https://

A free boundary approach to non-scattering obstacles with vanishing contrast
Motivated by questions in inverse scattering theory, we develop free boundary methods in obstacle problems where both the solution and the right hand side of the equation may have varying sign. The key condition that prevents the appearance of corners is that the right hand side should be related to a harmonic polynomial. In this setting we prove new free boundary results not found in existing literature. Notably, our results imply that piecewise $C^1$ or convex penetrable obstacles in two dime…

I picked up my phone this morning and Screen Time reports that WhatsApp has been used for 27min.
I *did not* use the app.
This would imply that Screen Time reports background activities, right? Is that confirmed?
If that's confirmed, what is WhatApp doin? There has been some exchanges on the groups (say low tens of messages).

This https://arxiv.org/abs/2409.20359 has been replaced.
link: https://scholar.google.com/scholar?q=a

Curvature estimates for minimal hypersurfaces in the Heisenberg group
This paper examines minimal hypersurfaces in sub-Riemannian Heisenberg groups. We extend the celebrated Simons formula and Kato inequality to the sub-Riemannian setting, and we apply them to obtain integral curvature estimates for stable hypersurfaces. These results lead to structural conditions that imply a Bernstein-type rigidity theorem for smooth, non-characteristic hypersurfaces in the second Heisenberg group.

On graph automorphisms related to Snort
Rylo Ashmore, Beth Ann Austin, Alfie M. Davies, Danny Dyer, William Kellough
https://arxiv.org/abs/2506.20669 https…

On graph automorphisms related to Snort
We study the outcomes of various positions of the game Snort. When played on graphs admitting an automorphism of order two that maps vertices outside of their closed neighbourhoods (called opposable graphs), the second player has a winning strategy. We give a necessary and sufficient condition for a graph to be opposable, and prove that the property of being opposable is preserved by several graph products. We show examples that a graph being second-player win does not imply that the graph is o…

Conductive homogeneity of locally symmetric polygon-based self-similar sets
J. Kigami amd Y. Ota
https://arxiv.org/abs/2505.23057 https://

Conductive homogeneity of locally symmetric polygon-based self-similar sets
We provide a rich family of self-similar sets, called locally symmetric polygon-based self-similar sets, as examples of metric spaces having conductive homogeneity, which was introduced as a sufficient condition for the construction of counterparts of ``Sobolev spaces'' on compact metric spaces. In particular, our results imply the existence of ``Brownian motions'' on our family of self-similar sets at the same time. Unlike the known examples like the Sierpinski carpet by Barlow-Bass, unconstra…

SlimRAG: Retrieval without Graphs via Entity-Aware Context Selection
Jiale Zhang, Jiaxiang Chen, Zhucong Li, Jie Ding, Kui Zhao, Zenglin Xu, Xin Pang, Yinghui Xu
https://arxiv.org/abs/2506.17288

SlimRAG: Retrieval without Graphs via Entity-Aware Context Selection
Retrieval-Augmented Generation (RAG) enhances language models by incorporating external knowledge at inference time. However, graph-based RAG systems often suffer from structural overhead and imprecise retrieval: they require costly pipelines for entity linking and relation extraction, yet frequently return subgraphs filled with loosely related or tangential content. This stems from a fundamental flaw -- semantic similarity does not imply semantic relevance. We introduce SlimRAG, a lightweight …

Position: Certified Robustness Does Not (Yet) Imply Model Security
Andrew C. Cullen, Paul Montague, Sarah M. Erfani, Benjamin I. P. Rubinstein
https://arxiv.org/abs/2506.13024

Position: Certified Robustness Does Not (Yet) Imply Model Security
While certified robustness is widely promoted as a solution to adversarial examples in Artificial Intelligence systems, significant challenges remain before these techniques can be meaningfully deployed in real-world applications. We identify critical gaps in current research, including the paradox of detection without distinction, the lack of clear criteria for practitioners to evaluate certification schemes, and the potential security risks arising from users' expectations surrounding ``guara…

A panoramic view of exponential attractors
Radoslaw Czaja, Stefanie Sonner
https://arxiv.org/abs/2506.10388 https://arxiv.org/pdf/250…

A panoramic view of exponential attractors
We state necessary and sufficient conditions for the existence of $T$-discrete exponential attractors for semigroups in complete metric spaces. These conditions are formulated in terms of a covering condition for iterates of the absorbing set under the time evolution of the semigroup and imply the existence and finite-dimensionality of the global attractor. We then review, generalize and compare existing construction methods for exponential attractors and show that they all imply the covering c…

Resonances of recurrence time of monitored quantum walks
Ruoyu Yin, Qingyuan Wang, Sabine Tornow, Eli Barkai
https://arxiv.org/abs/2506.19832 https://

Resonances of recurrence time of monitored quantum walks
The recurrence time is the time a process first returns to its initial state. Using quantum walks on a graph, the recurrence time is defined through stroboscopic monitoring of the arrival of the particle to a node of the system. When the time interval between repeated measurements is tuned in such a way that eigenvalues of the unitary become degenerate, the mean recurrence time exhibits resonances. These resonances imply faster mean recurrence times, which were recorded on quantum computers. Th…

The Unreasonable Effectiveness of Mathematical Experiments: What Makes Mathematics Work
Asvin G
https://arxiv.org/abs/2506.19787 https://

The Unreasonable Effectiveness of Mathematical Experiments: What Makes Mathematics Work
This essay proposes a reconceptualization of mathematics as an experimental science exploring patterns in computation and what the advent of AI-assited provers might imply in light of this reconceptualization. Beginning with Voevodsky's crisis of confidence, where a major result remained in limbo for 24 years, neither proven nor refuted, we argue that mathematics is not the discovery of eternal truths but theory-building in response to computational experiments. Just as physicists build theorie…

Trump's message on the government's Truth Social website imply, publicly, that the bombings in Tehran were in service of the US position in forthcoming negotiations.
Which, diplomatically, is unconventional.

Universal inverse Radon transforms: Complexity of Radon transforms and the hybrid functions
I. V. Anikin
https://arxiv.org/abs/2506.18911 https://

Universal inverse Radon transforms: Complexity of Radon transforms and the hybrid functions
For the reconstruction problem, the universal representation of inverse Radon transforms may imply the needed complexity of the direct Radon transforms which leads to the additional contributions. Meanwhile, in the standard theory of generalized functions, if the origin function which generates the Radon image is a pure-real function, as a rule the complexity of Radon transform becomes in question. In the letter, we demonstrate that the Fourier method together with the hybrid (Wigner-like) func…

Efficient Difference-in-Differences and Event Study Estimators
Xiaohong Chen, Pedro H. C. Sant'Anna, Haitian Xie
https://arxiv.org/abs/2506.17729 https…

Efficient Difference-in-Differences and Event Study Estimators
This paper investigates efficient Difference-in-Differences (DiD) and Event Study (ES) estimation using short panel data sets within the heterogeneous treatment effect framework, free from parametric functional form assumptions and allowing for variation in treatment timing. We provide an equivalent characterization of the DiD potential outcome model using sequential conditional moment restrictions on observables, which shows that the DiD identification assumptions typically imply nonparametric…

This https://arxiv.org/abs/2505.19184 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_csCL_…

When Two LLMs Debate, Both Think They'll Win
Can LLMs accurately adjust their confidence when facing opposition? Building on previous studies measuring calibration on static fact-based question-answering tasks, we evaluate Large Language Models (LLMs) in a dynamic, adversarial debate setting, uniquely combining two realistic factors: (a) a multi-turn format requiring models to update beliefs as new information emerges, and (b) a zero-sum structure to control for task-related uncertainty, since mutual high-confidence claims imply systemati…

State updates and useful qubits in relativistic quantum information
Jos\'e Polo-G\'omez, T. Rick Perche, Eduardo Mart\'in-Mart\'inez
https://arxiv.org/abs/2506.18906

State updates and useful qubits in relativistic quantum information
We address the longstanding challenge of consistently updating quantum states after selective measurements in a relativistic spacetime. Standard updates along the future lightcones preserve causality but break correlations between causally disconnected parties, whereas updates along the past lightcone either imply retrocausality or do not respect the causal propagation of information. We introduce a minimal extension of multipartite states to encode subsystem-specific contextual information. Th…

Do cell culturing influence the radiosensitizing effect of gold nanoparticles part 1: scrutinizing recent evidence for data consistency
Hans Rabus, Oswald Msosa Mkanda
https://arxiv.org/abs/2506.19372

Do cell culturing influence the radiosensitizing effect of gold nanoparticles part 1: scrutinizing recent evidence for data consistency
In radiobiological experiments, the cells can either float in suspension or adhere to the walls of the sample holder. When irradiation is performed in the presence of dose modifying agents such as gold nanoparticles (AuNPs), the different shapes of the floating or adherent cells may imply a different dose to the nucleus, with biological consequences such as cell survival. Recently, it has been reported that the survival rate varies by up to a factor of 1.5 for the two cell geometries and by up …

Zeeman-type spin splittings in strained d-wave altermagnets
Yahui Zhai, Longju Yu, Jian Lv, Wei Zhang, Hong Jian Zhao
https://arxiv.org/abs/2506.07447 http…

Zeeman-type spin splittings in strained d-wave altermagnets
Recently, altermagnetic materials have become rather attractive because such materials showcase combined advantages of ferromagnets (e.g., spin current) and antiferromagnets (e.g., low stray field and ultrafast spin dynamics). Symmetry arguments imply that d-wave altermagnets may host strain-induced nonrelativistic Zeeman-type spin splittings (ZSSs), but a theoretical, numerical, and experimental justification remains lacking. In the present work, we work with collinear spin point groups (SPGs)…

How attention simplifies mental representations for planning
Jason da Silva Castanheira, Nicholas Shea, Stephen M. Fleming
https://arxiv.org/abs/2506.09520

How attention simplifies mental representations for planning
Human planning is efficient -- it frugally deploys limited cognitive resources to accomplish difficult tasks -- and flexible -- adapting to novel problems and environments. Computational approaches suggest that people construct simplified mental representations of their environment, balancing the complexity of a task representation with its utility. These models imply a nested optimisation in which planning shapes perception, and perception shapes planning -- but the perceptual and attentional …

Partial comonotonicity and distortion riskmetrics
Muqiao Huang
https://arxiv.org/abs/2506.07472 https://arxiv.org/pdf/2506.07472

Partial comonotonicity and distortion riskmetrics
We establish a connection between subclasses of distortion riskmetrics and dependence structures, ensuring their additivity. A new notion of positive dependence, called partial comonotonicity, is developed, which nests the existing concepts of comonotonicity and single-point concentration. For two random variables, being comonotonic with a third one does not imply that they are comonotonic; instead, this defines an instance of partial comonotonicity. Any specific instance of partial comonotonic…

Contact magnetic geodesic and sub-Riemannian flows on $V_{n,2}$ and integrable cases of a heavy rigid body with a gyrostat
Bozidar Jovanovic
https://arxiv.org/abs/2506.13101

Contact magnetic geodesic and sub-Riemannian flows on $V_{n,2}$ and integrable cases of a heavy rigid body with a gyrostat
We prove the integrability of magnetic geodesic flows of $SO(n)$--invariant Riemannian metrics on the rank two Stefel variety $V_{n,2}$ with respect to the magnetic field $η\, dα$, where $α$ is the standard contact form on $V_{n,2}$ and $η$ is a real parameter. Also, we prove the integrability of magnetic sub-Riemannian geodesic flows for $SO(n)$-invariant sub-Riemannian structures on $V_{n,2}$. All statements in the limit $η=0$ imply the integrability of the problems without the influence…

Reduced-weight near-cloaks for underwater invisibility
Davide Enrico Quadrelli, Sebastiano Cominelli, Gabriele Cazzulani, Francesco Braghin
https://arxiv.org/abs/2506.07593

Reduced-weight near-cloaks for underwater invisibility
Limiting the total weight of an acoustic cloak is of fundamental importance in underwater applications, where buoyancy of the cloaked object is desirable. Unfortunately, it is well known that traditional cloaking strategies imply either a mass tending to infinity or a total weight equal to the Archimedes' force, thus making a perfect cloak that preserves the buoyancy of the target impossible. In this paper, we discuss strategies to reduce the weight of the cloak seeking a good compromise betwee…

Ramanujan's partition generating functions modulo $\ell$
Kathrin Bringmann, William Craig, Ken Ono
https://arxiv.org/abs/2506.06101 https://

Ramanujan's partition generating functions modulo $\ell$
For the partition function $p(n)$, Ramanujan proved the striking identities $$ P_5(q):=\sum_{n\geq 0} p(5n+4)q^n =5\prod_{n\geq 1} \frac{\left(q^5;q^5\right)_{\infty}^5}{(q;q)_{\infty}^6}, $$ $$ P_7(q):=\sum_{n\geq 0} p(7n+5)q^n =7\prod_{n\geq 1}\frac{\left(q^7;q^7\right)_{\infty}^3}{(q;q)_{\infty}^4}+49q \prod_{n\geq 1}\frac{\left(q^7;q^7\right)_{\infty}^7}{(q;q)_{\infty}^8}, $$ where $(q;q)_{\infty}:=\prod_{n\geq 1}(1-q^n).$ As these identities imply his celebrated congruences modulo 5 …

Failing Banks
Sergio Correia, Stephan Luck, Emil Verner
https://arxiv.org/abs/2506.06082 https://arxiv.org/pdf/2506.06082

Failing Banks
Why do banks fail? We create a panel covering most commercial banks from 1863 through 2024 to study the history of failing banks in the United States. Failing banks are characterized by rising asset losses, deteriorating solvency, and an increasing reliance on expensive noncore funding. These commonalities imply that bank failures are highly predictable using simple accounting metrics from publicly available financial statements. Failures with runs were common before deposit insurance, but thes…