Tootfinder

from my link log —
Tiling with three polygons is undecidable.
https://arxiv.org/abs/2409.11582
saved 2024-11-21 https://dotat.at/…

Tiling with Three Polygons is Undecidable
We prove that the following problem is co-RE-complete and thus undecidable: given three simple polygons, is there a tiling of the plane where every tile is an isometry of one of the three polygons (either allowing or forbidding reflections)? This result improves on the best previous construction which requires five polygons.

Microstructural and preliminary optical and microwave characterization of erbium doped CaMoO$_4$ thin films
Ignas Masiulionis, Bonnie Y. X. Lin, Sagar Kumar Seth, Gregory D. Grant, Wanda L. Lindquist, Sungjoon Kim, Junghwa Kim, Angel Yanguas-Gil, Jeffrey W. Elam, Jiefei Zhang, James M. LeBeau, David D. Awschalom, Supratik Guha
https://arxi…

Microstructural and preliminary optical and microwave characterization of erbium doped CaMoO$_4$ thin films
This work explores erbium-doped calcium molybdate (CaMoO$_4$) thin films grown on silicon and yttria stabilized zirconia (YSZ) substrates, as a potential solid state system for C-band (utilizing the $\sim$1.5 $μ$m Er$^{3+}$ 4f-4f transition) quantum emitters for quantum network applications. Through molecular beam epitaxial growth experiments and electron microscopy, X-ray diffraction and reflection electron diffraction studies, we identify an incorporation limited deposition regime that enabl…

Officials from various European countries took to social media to share their reactions following the Alaska summit.
"Putin got his red carpet treatment with Trump, Trump got nothing,"
German diplomat Wolfgang Ischinger wrote on X.
"As was to be feared: no ceasefire, no peace. No real progress
— clearly 1:0 for Putin
— no new sanctions.
For the Ukrainians: nothing.
For Europe: deeply disappointing."
During the post-summit …

'Clearly 1:0 to Putin' — European officials react to Alaska Summit
"Putin got his red carpet treatment with Trump, Trump got nothing. ... For the Ukrainians: nothing. For Europe: deeply disappointing."

Sources: the US has started issuing licenses to Nvidia to export H20 chips to China following weeks of inaction, after Jensen Huang met Trump on Wednesday (Financial Times)
https://www.ft.com/content/e9c52f00-9bde-4840-801e-ba66c792df9e

Spin decoherence dynamics of Er$^{3 }$ in CeO$_2$ film
Sagar Kumar Seth, Jonah Nagura, Vrindaa Somjit, Aneesh Bapat, Xinhao Li, Gregory D. Grant, Ignas Masiulionis, Xu Han, F. Joseph Heremans, Giulia Galli, David D. Awschalom, Supratik Guha, Jiefei Zhang
https://arxiv.org/abs/2508.12429

Spin decoherence dynamics of Er$^{3+}$ in CeO$_2$ film
Developing telecom-compatible spin-photon interfaces is essential towards scalable quantum networks. Erbium ions (Er$^{3+}$) exhibit a unique combination of a telecom (1.5 $μ$m) optical transition and an effective spin-$1/2$ ground state, but identifying a host that enables heterogeneous device integration while preserving long optical and spin coherence remains an open challenge. We explore a new platform of Er$^{3+}$:CeO$_2$ films on silicon, offering low nuclear spin density and the potenti…

Finding subdigraphs in digraphs of bounded directed treewidth
Raul Lopes, Ignasi Sau
https://arxiv.org/abs/2508.13830 https://arxiv.org/pdf/2508.13830

Finding subdigraphs in digraphs of bounded directed treewidth
It is well known that directed treewidth does not enjoy the nice algorithmic properties of its undirected counterpart. There exist, however, some positive results that, essentially, present XP algorithms for the problem of finding, in a given digraph $D$, a subdigraph isomorphic to a digraph $H$ that can be formed by the union of $k$ directed paths (with some extra properties), parameterized by $k$ and the directed treewidth of $D$. Our motivation is to tackle the following question: Are there …

Unveiling ignis fatuus - #Microlightning between microbubbles: https://www.pnas.org/doi/full/10.1073/pnas.2521255122 -> New theory may at last explain a swamp’s ghostly will-o’-the-wisps: https://www.snexplores.org/article/swamp-gas-methane-will-o-wisp-chemistry = https://www.sciencenews.org/article/spark-will-o-the-wisps - methane bubbles spark tiny zaps of electricity that may ignite cool flames of the gas. (Has nothing - obvious, at least - to do with astronomy ... but fun nonetheless.)

Domain coarsening in fractonic systems: a cascade of critical exponents
Jacopo Gliozzi, Federico Balducci, Giuseppe De Tomasi
https://arxiv.org/abs/2509.04556 https://

Domain coarsening in fractonic systems: a cascade of critical exponents
We study the dynamics of domain growth when multipole moments of the order parameter are conserved. Following a quench into the ordered phase of the Ising model, the typical size of domains grows with time as $R(t) \sim t^{1/2}$ in the absence of conserved quantities. When the order parameter is conserved, the domain growth slows to $R(t) \sim t^{1/3}$. Conservation of higher moments of the order parameter fundamentally modifies this behavior: coarsening proceeds via anomalously slow growth. We…

📣 Starting today: Science Maps. Bibliometrics between understanding and visualization
Together with Marcus John, I organize a small series on science mapping for our workgroup "WG Visualization" at Competence Network Bibliometrics. We hop to gether traditional, current, and critical perspectives on one of the most established and iconic forms of visualizing data in #Bibliometrics and #NetworkAnalysis.
More talks will be announced soon!
Today, Katy Börner will kickoff our series with a presentation about "Mapping and Modeling Science, Technology, and Education". You can find further info and registration under the following link:
#vosviewer #Scientometrics #Gephi #DataVisualization #DataViz #Informetrics #STI2025 #Bibliometrie #ResearchAssessment

:)
#linux #linuxmeme #memes #lemmy