Tootfinder

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.

Man kann schon froh sein, dass das Stuttgarter Rathaus nicht einfach empfiehlt ein Auto mit Klimaanlage zu kaufen und sich im Auto aufzuhalten, falls es im Freien und in den Wohnungen zu heiß werden sollte.
https://xn--baw-joa.social/@stuttgart/114773217894293845

Landeshauptstadt Stuttgart (@stuttgart@bawü.social)
Attached: 4 images Ein fortlaufender Hitzeaktionsplan der Landeshauptstadt soll dazu beitragen, Stuttgart noch besser für Hitzeperioden zu wappnen.☀️ Schwerpunkte des Hitzeaktionsplans: ▶️Strukturen, um die Hitzeprävention fest in den städtischen Abläufen zu verankern. ▶️Informationen und Tipps für den Alltag in der Hitze. ▶️Kostenloses Trinkwasser und kühle Aufenthaltsorte. ▶️Gesundheits‐ und Sozialsysteme werden gezielt gestärkt, um hitzebedingte Gesundheitsris…

Towards Large-Scale Condensed Phase Simulations using Machine Learned Energy Functions
Eric D. Boittier, Silvan K\"aser, Markus Meuwly
https://arxiv.org/abs/2506.23272

Towards Large-Scale Condensed Phase Simulations using Machine Learned Energy Functions
Accurate, yet computationally efficient energy functions are essential for state-of-the art molecular dynamics (MD) studies of condensed phase systems. Here, a generic workflow based on a combination of machine learning-based and empirical representations of intra- and intermolecular interactions is presented. The total energy is decomposed into internal contributions, and electrostatic and van der Waals interactions between monomers. The monomer potential energy surface is described using a ne…

Oh, look, the clown is clowning.
https://mstdn.social/@minimarket/114689532947840091

MINIMARKET ONLINE LTD (@minimarket@mstdn.social)
Attached: 1 image Despite evidence that the conflict between Israel and Iran is escalating, U.S. President Donald Trump expressed optimism on Sunday that peace would come soon and cited the possibility that Russia's Vladimir Putin could help. In a social media post, Trump said there were many unspecified meetings about the issue happening and encouraged the two countries to make a deal. #us #usa #news #minimarketonlineltd #minimarket #America #AmericaNews #trump #Ukraine #russia #UkraineW…

"Wir sind nicht die richtige Adresse für die Art von Gesinnung, die ihr habt." 😳
Sind am Ende die Grünen gar nicht die richtige Partei für mich?!
https://www.mannheimer-morgen.de/orte/mann…

Grüne Jugend Mannheim weist Kritik an Bundessprecherin Nietzard zurück
Nach dem Eklat um einen Pullover mit dem Aufdruck „ACAB“ weist die GJ Mannheim Kritik an der Grünen-Politikerin Jette Nietzard als „überzogen“ zurück. Es handle sich um Systemkritik, nicht um Diffamierung der Polizei.

Cofibrant generation of pure monomorphisms in presheaf categories
Sean Cox, Jonathan Feigert, Mark Kamsma, Marcos Mazari-Armida, Ji\v{r}\'i Rosick\'y
https://arxiv.org/abs/2506.20278

Cofibrant generation of pure monomorphisms in presheaf categories
We characterise when the pure monomorphisms in a presheaf category $\mathbf{Set}^\mathcal{C}$ are cofibrantly generated in terms of the category $\mathcal{C}$. In particular, when $\mathcal{C}$ is a monoid $S$ this characterises cofibrant generation of pure monomorphisms between sets with an $S$-action in terms of $S$: this happens if and only if for all $a, b \in S$ there is $c \in S$ such that $a = cb$ or $ca = b$. We give a model-theoretic proof: we prove that our characterisation is equival…

This https://arxiv.org/abs/2408.14058 has been replaced.
initial toot: https://mastoxiv.page/@arXi…

Phantom chain simulations for fracture of star polymer networks on the effect of arm molecular weight
This study investigated the fracture of star polymer networks made from prepolymers with various arm molecular weights in the range $2 \leq N_a \leq 0$, for node functionalities $3 \leq f \leq 8$ and conversion ratios $0.6\leqϕ_c\leq0.95$ by phantom chain simulations. The networks were created via end-linking reactions of star polymers dispersed in a simulation box with a fixed monomer density $ρ=8$. The resultant networks were alternatively subjected to energy minimization and uniaxial stret…

Non-uniform bounds for non-normal approximation via Stein's method with applications to the Curie--Weiss model and the imitative monomer-dimer model
L\^e V\v{a}n Th\`anh, Nguyen Ngoc Tu
https://arxiv.org/abs/2506.17061

Non-uniform bounds for non-normal approximation via Stein's method with applications to the Curie--Weiss model and the imitative monomer-dimer model
This paper establishes a non-uniform Berry--Esseen bound for non-normal approximation using Stein's method. The main theorem generalizes the result of the authors in [Comptes Rendus Mathematique, 2024] to the context of non-normal approximation. As an application of the main result, we derive non-uniform Berry--Esseen bounds in non-central limit theorems for the magnetization in the Curie--Weiss model and the imitative monomer-dimer model. These extend some existing results in the literature, i…

On pure monomorphisms and pure epimorphisms in accessible categories
Leonid Positselski
https://arxiv.org/abs/2506.13374 https://arxi…

On pure monomorphisms and pure epimorphisms in accessible categories
In all $κ$-accessible additive categories, $κ$-pure monomorphisms and $κ$-pure epimorphisms are well-behaved, as shown in our previous paper arXiv:2311.02418. This is known to be not always true in $κ$-accessible nonadditive categories. Nevertheless, mild assumptions on a $κ$-accessible category are sufficient to prove good properties of $κ$-pure monomorphisms and $κ$-pure epimorphisms. In particular, in a $κ$-accessible category with finite products, all $κ$-pure monomorphisms are $κ…

This https://arxiv.org/abs/2409.10438 has been replaced.
link: https://scholar.google.com/scholar?q=a

A functorial approach to $n$-abelian categories
We develop a functorial approach to the study of $n$-abelian categories by reformulating their axioms in terms of their categories of finitely presented functors. Such an approach allows the use of classical homological algebra and representation theory techniques to understand higher homological algebra. As an application, we present two possible generalizations of the axioms "every monomorphism is a kernel" and "every epimorphism is a cokernel" of an abelian category to $n$-abelian categories…