@unpublished{21737, abstract = {In calculus, l'Hopital's rule provides a simple way to evaluate the limits of quotient functions when both the numerator and denominator vanish. But what happens when we move beyond real functions on a real interval? In this article, we study when the quotient of two complex-valued functions in higher dimension can be defined continuously at the points where both functions vanish. Surprisingly, the answer is far subtler than in the real-valued setting. We provide a complete characterization for the continuity of the quotient function. We also point out why extending this result to smoother quotients remains an intriguing challenge.}, author = {Chern, Albert and Ishida, Sadashige}, booktitle = {arXiv}, keywords = {l’Hopital theorem, complex functions}, title = {{L'Hopital rules for complex-valued functions in higher dimensions}}, doi = {10.48550/ARXIV.2602.09958}, year = {2026}, } @article{21745, abstract = {The small DAHe and DAe spectral classes comprise isolated, hydrogen-dominated atmosphere white dwarfs that exhibit variable photometric flux and Balmer line emission. These mysterious systems offer unique insight into the complex interplay between magnetic fields, stellar rotation and atmospheric activity in single white dwarfs. DAHe stars have detectable magnetic fields through Zeeman-split spectral lines, whereas DAe stars lack such splitting. We report the first discovery and characterization of magnetism in the DAe white dwarf WD J165335.21−100116.33 with new time-resolved spectropolarimetry from FORS2. We detect a weak but variable longitudinal magnetic field with values Bz > −9.2 ± 2.4 kG and Bz < −2.2 ± 1.0 kG. Independent ZTF and ATLAS photometry reveal a consistent period of P = 80.3070 ± 0.0007 h. Time-resolved optical spectroscopy obtained with six ground-based instruments demonstrates strong modulation in the strength of the Hα and Hβ Balmer line emission with P = 80.2922 ± 0.0108 h. The photometric flux and Balmer emission strength vary in antiphase, with the strongest magnetic detections coinciding with phases of low photometric flux and strong line emission. These characteristicssupport the theory that a magnetically active, temperature-inverted spot/region is producing an optically thin chromospheric emission region. Comparison with other DAe and DAHe white dwarfsreveals all systems have a strikingly similar antiphase phenomenology, reinforcing the theory that they are subject to a unified physical mechanism. With the detection of a weak magnetic field, we reclassify WD J165335.21−100116.33 as a low-field DAHe white dwarf. }, author = {Elms, Abbigail K. and Bagnulo, Stefano and Tremblay, Pier Emmanuel and Cunningham, Tim and Munday, James and Landstreet, John and El-Badry, Kareem and Caiazzo, Ilaria and Melis, Carl and Pinter, Viktoria and Weinberger, Alycia}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {1}, publisher = {Oxford University Press}, title = {{Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653−1001}}, doi = {10.1093/mnras/stag505}, volume = {548}, year = {2026}, } @article{21747, abstract = {Entanglement does not always require one particle per party. It was predicted some 30 years ago that a single photon traversing a beam splitter could violate a Bell inequality. Although initially debated, single-photon nonlocality was eventually demonstrated via homodyne measurements. Here, we present an alternate realization that avoids the complexity of homodyne measurements and potential loopholes in their implementation. We violate a Bell inequality by performing joint measurements on two copies of the same single-photon entangled state, where one photon acts as a phase reference for the other, making it self-referential. We observe CHSH parameters of 2.71 = 0.09 and 2.23 = 0.07, depending on the joint measurements implemented. This offers a perspective on single-photon nonlocality and a more accessible experimental route, potentially applicable to general mode-entangled states in diverse platforms.}, author = {Kun, Daniel and Strömberg, Karl T and Dakić, Borivoje and Walther, Philip and Rozema, Lee A.}, issn = {2334-2536}, journal = {Optica}, number = {4}, pages = {745--751}, publisher = {Optica Publishing Group}, title = {{Testing single-photon entanglement using self-referential measurements}}, doi = {10.1364/OPTICA.586172}, volume = {13}, year = {2026}, } @article{21748, abstract = {Cells are defined by lipid membranes that differ in their structure across the tree of life. While the membranes of most bacteria and eukaryotes consist of single-headed bilayer lipids, the membranes of archaea are composed of mixtures of single-headed bilayer lipids and double-headed bolalipids. Archaeal bolalipids can adopt straight or u-shaped conformations, enabling them—together with bilayer lipids—to control whether membranes form bilayer or monolayer structures. Yet, the physical principles governing archaeal membranes remain largely unexplored, especially how membrane structure couples to externally imposed curvature during membrane remodeling. Here, we perform coarse-grained molecular dynamics simulations of toroidal vesicles to systematically probe the effects of all relevant combinations of mean and Gaussian curvatures on shape stability and lipid organization. We find that soft bilayer membranes can sustain all curvatures induced, whereas rigid bolalipid monolayer membranes either transition to different vesicle shapes or rupture. Bilayer-mimicking u-shaped bolalipids and bilayer lipids are spatially accumulated in regions of high mean membrane curvature independent of Gaussian curvature. Our work identifies curvature–composition coupling as a physical signature of archaeal membrane remodeling.}, author = {Frey, Felix F and Santana de Freitas Amaral, Miguel and Šarić, Anđela}, issn = {1089-7690}, journal = {Journal of Chemical Physics}, number = {14}, publisher = {AIP Publishing}, title = {{Cracking donuts and sorting lipids: Geometry controls archaeal membrane stability and lipid organization}}, doi = {10.1063/5.0325170}, volume = {164}, year = {2026}, } @article{21749, abstract = {The collagen triple helix assembles hierarchically into bundled oligomers, solvated networks, and fibers. Synthetic peptide assemblies, driven by supramolecular interactions, can form single triple helices through intrahelical amino acid pairs; however, the principles guiding interhelical associations into higher-order structures remain unclear. Here, we incorporate cation−π and electrostatic charge pairs to probe interhelical interactions and elucidate the mechanisms driving triple helix assembly into fibrils, nanotubes, and nanosheets. Introducing cation−π pairs into a fibrillating collagen mimetic resulted in D-periodic fibrils with pH-sensitive gelation. By alternating the presentation of electrostatic and cation−π pairs, the assembly of another D-periodic fibril featuring inner and outer triple-helical layers was resolved by cryo electron microscopy to a resolution of 8 Å. At physiological pH, antiparallel association of these triple helices leads to the formation of nanotubes. The packing behavior of triple helices correlates with the interhelical interactions, where parallel associations favor fibril formation and antiparallel interactions drive nanotube and nanosheet assembly. These self-assembling triple-helical peptides demonstrate how packing of higher-order structures can be tailored with supramolecular interactions and establish the relationship of different hierarchical collagen-mimetic assemblies as pH-dependent.}, author = {Cole, Carson C. and Kreutzberger, Mark A.B. and Klein, Kevin and Cahue, Kiana A. and Pogostin, Brett H. and Farsheed, Adam C. and Swain, Joseph W.R. and Bui, Thi H. and Dey, Arghadip and Makhoul, Jonathan T. and Dubackic, Marija and Pal, Antara and Olsson, Ulf and Šarić, Anđela and Egelman, Edward H. and Hartgerink, Jeffrey D.}, issn = {1526-4602}, journal = {Biomacromolecules}, number = {4}, pages = {2956--2965}, publisher = {American Chemical Society}, title = {{Supramolecular assembly of collagen-mimetic eptide D-periodic fibrils and nanoassemblies}}, doi = {10.1021/acs.biomac.6c00345}, volume = {27}, year = {2026}, } @article{21750, abstract = {Liquid-like superionic conductors, with highly mobile ions in a rigid framework, offer intrinsically low lattice thermal conductivity without compromising electronic transport. Argyrodite-type Ag8SnSe6 exhibits a melt-like Ag sublattice that drives lattice thermal conductivity (κL) below 0.2 watts per meter per kelvin, yet its low carrier concentration limits the power factor. Here, interstitial Ag atoms raise the Fermi level into the conduction band, substantially increasing the electron concentration. Simultaneously, the formation of a secondary Ag2Se phase generates lattice distortions that enhance phonon scattering. A pronounced mismatch between electronic (~200 nanometers) and phononic (~0.22 nanometers) mean free paths decouples charge and heat transport, enabling concurrent suppression of κL and retention of high electrical conductivity. This coupled electronic-phononic modulation yields a record ZT of 0.72 at ambient temperature and a peak ZT of 1.1 at 735 kelvins, with an average ZTavg of 0.72 over 320 to 735 kelvins. A unicouple device achieves 6.3% efficiency under a 357-kelvin gradient, highlighting a practical strategy for high-performance midtemperature thermoelectrics.}, author = {Li, Mengyao and Zhao, Xueke and Zhang, Yu and Yu, Jing and Liu, Xuyang and Jia, Mochen and Song, Hongzhang and Wang, Dongyang and Arbiol, Jordi and Ibáñez, Maria and Shan, Chongxin and Cabot, Andreu and Wang, Ziyu}, issn = {2375-2548}, journal = {Science Advances}, number = {15}, publisher = {AAAS}, title = {{Electronic-phononic decoupling and Fermi-level tuning enable high thermoelectric performance in Ag8SnSe6}}, doi = {10.1126/sciadv.aec9073}, volume = {12}, year = {2026}, } @article{21752, abstract = {Epithelial tissues function as multicellular communities that preserve tissue integrity while adapting to diverse environmental stresses by altering cell behaviors. A striking manifestation of such adaptability is cell plasticity, the ability of differentiated cells to revert to stem-like states or adopt alternative fates. Once considered rare and confined to highly regenerative species, cell plasticity is now recognized across the metazoan tree. In early-branching animals such as sponges and cnidarians, transdifferentiation and dedifferentiation are integral to life-cycle transitions and regeneration, whereas in more complex organisms, these processes typically emerge under stress, including stem cell loss or environmental perturbations. Here, we examine epithelial cell plasticity through evolutionary, cellular, and molecular perspectives. Focusing on the intestinal epithelium, we explore findings from mammalian and Drosophila models showing that progenitors and even terminally differentiated cells can dedifferentiate in response to external stimuli that disrupt homeostasis, such as pathogen infection and nutrient fluctuations. We further discuss conserved mechanisms involving intercellular signaling (e.g., Notch, EGFR, and JAK-STAT) and chromatin states primed for reprogramming, modulated by metabolic cues. Together, these insights position cell plasticity as an ancient environmental adaptation strategy, shaped by conserved molecular toolkits and refined by species- and cell lineage-specific innovations.}, author = {Nagai, Hiroki and Nakajima, Yu Ichiro}, issn = {1096-3634}, journal = {Seminars in Cell and Developmental Biology}, publisher = {Elsevier}, title = {{Epithelial cell plasticity in metazoans: Evolutionary insights into roles and mechanisms}}, doi = {10.1016/j.semcdb.2026.103670}, volume = {179-180}, year = {2026}, } @article{21755, abstract = {Tropical shallow clouds are a major source of uncertainty in Earth's climate sensitivity, especially through their spatial arrangement, which global climate models do not represent. Efforts to understand their organization have partly relied on classifying observed scenes, identifying four patterns as archetypal regimes. Here we analyze geostationary satellite imagery of the western tropical Atlantic using the L‐function, a tool based on point pattern theory that quantifies cloud organization across spatial scales. Classical examples of the four patterns show distinct L‐function fingerprints, revealing their characteristic clustering and regularity scales and aiding physical interpretation. Yet, when evaluating many scenes at fixed spatial scales, the L‐function distribution lacks the distinct modes expected from discrete regimes. This is corroborated by analyses of other organization indices employing diverse approaches, from inter‐cloud nearest‐neighbor distances to fractal analysis. Implications for the parameterization of mesoscale cloud organization in climate models are discussed.}, author = {Biagioli, Giovanni and Mandorli, Giulio and Freischem, Lilli Johanna and Casallas Garcia, Alejandro and Tompkins, Adrian Mark}, issn = {1944-8007}, journal = {Geophysical Research Letters}, number = {8}, publisher = {Wiley}, title = {{Spatial patterns of shallow clouds: Challenging the concept of defined regimes}}, doi = {10.1029/2025gl119921}, volume = {53}, year = {2026}, } @article{21760, abstract = {3I/ATLAS is the third interstellar object discovered to date, following 1I/‘Oumuamua and 2I/Borisov. Its unusually high excess velocity and active cometary nature make it a key probe of the Galactic population of icy planetesimals. Understanding its origin requires its past trajectory through the Galaxy to be traced and the possible role of stellar encounters to be assessed, both as a potential origin and a perturber to its orbit. We integrated the orbit of 3I/ATLAS backward in time for 10 Myr, together with a sample of Gaia DR3 stars with high-quality astrometry and radial velocities, to identify close passages within 2 pc. We identify 93 nominal encounters, 62 of which are significant at the 2σ level. However, none of these encounters produced any meaningful perturbation. The strongest perturber Gaia DR3 6863591389529611264 at 0.30 pc and with a relative velocity of 35 km s−1, imparted only a velocity change of ∣Δv∣ ≃ 5 × 10−4 km s−1 to the orbit of 3I/ATLAS. Our results indicate that no stellar flybys within the past 10 Myr and 500 pc contained in Gaia DR3 can account for the present trajectory of 3I/ATLAS or be associated with its origin. We further show that 3I/ATLAS is kinematically consistent with a thin-disk population, despite its large peculiar velocity.}, author = {Pérez-Couto, X. and Torres Rodriguez, Santiago and Villaver, E. and Mustill, A. J. and Manteiga, M.}, issn = {1538-4357}, journal = {The Astrophysical Journal}, number = {2}, publisher = {IOP Publishing}, title = {{3I/ATLAS: In search of the witnesses to its voyage}}, doi = {10.3847/1538-4357/ae56ff}, volume = {1001}, year = {2026}, } @article{21764, abstract = {Colloidal fluids can exhibit complex phase behavior and determining phase diagrams via experiments or computer simulations can be laborious. We demonstrate that the dispersion relation ω(k), obtained from dynamical density functional theory for the uniform density system, is a highly versatile tool for predicting where in the phase diagram complex crystals form. The sign of ω(k) determines whether density modes with wave number k grow or decay over time. We demonstrate the predictive power by investigating the complex phase behavior of particles interacting via core-shoulder pair potentials. With complementary Monte Carlo simulations, we show that regions of the phase diagram where ωðkÞ has one or several unstable (growing) wave numbers are also where crystalline phases occur. Going further, by tuning these unstable wave numbers via the interaction-potential and state-point parameters, we design systems with quasicrystals in the phase diagram. We identify a system with a certain shoulder range exhibiting at least ten different phases. Our general approach accelerates considerably the mapping of complex phase diagrams, crucial for the design of new materials.}, author = {Wassermair, Michael and Kahl, Gerhard and Roth, Roland and Archer, Andrew J.}, issn = {1079-7114}, journal = {Physical Review Letters}, number = {14}, publisher = {American Physical Society}, title = {{Navigating complex phase diagrams in soft matter systems}}, doi = {10.1103/nbvt-fgjy}, volume = {136}, year = {2026}, } @article{21765, abstract = {Dielectric particles of the same material exchange electrical charge during collisions or sliding contacts, yet the underlying charge-exchange mechanism is still not understood. The fact that particles can become highly charged as a result of this effect has significant consequences for many settings, both in nature and industry, such as thunderstorms, volcanic eruptions, particle aggregation during meteorite and planet formation, and the clogging of industrial granular systems. Toward understanding these systems, great efforts have been made to develop precise in situ measurements for particle charge, e.g., to determine ensemble charge distributions or measure exchange during individual contacts. Here, we present experimental results concerning the particle size scaling of the stationary-state charge distributions of oxide particles in the sub-millimeter range. We measure the charge distributions for large ensembles of monodisperse ZrO2:SiO2 composite spheres, ranging from 172 to 545µ⁢m in diameter. These distributions are non-Gaussian and collapse to a single master curve when plotted as functions of the surface charge density Σ=𝑞/4⁢𝜋⁢𝑅2. X-ray fluorescence and atomic force microscopy measurements show that the differences in the measured charge distributions are not due to variations in chemical composition or surface roughness, but rather to size alone. Our findings provide constraints on microscopic models for charge exchange, namely that they should lead to steady-state distributions that are non-Gaussian and scale in a specific way with particle size.}, author = {Lara, Macarena and Flores, Marcos and Castillo, Gustavo and Tassara, Santiago and Waitukaitis, Scott R and Mujica, Nicolás}, issn = {2475-9953}, journal = {Physical Review Materials}, number = {4}, publisher = {American Physical Society}, title = {{Particle size scaling of non-Gaussian granular charge distributions}}, doi = {10.1103/qw6t-xqdw}, volume = {10}, year = {2026}, } @article{21766, abstract = {We provide a new characterisation of the decades old open problem of extending bilipschitz mappings given on a Euclidean separated net. In particular, this allows for the complete positive solution of the open problem in dimension two. Along the way, we develop a set of tools for bilipschitz extensions of mappings between subsets of Euclidean spaces.}, author = {Dymond, Michael and Kaluza, Vojtech}, issn = {2737-114X}, journal = {Annales Fennici Mathematici}, keywords = {Lipschitz, bilipschitz, extension, separated net.}, number = {1}, pages = {237--260}, publisher = {Finnish Mathematical Society}, title = {{Extending bilipschitz mappings between separated nets}}, doi = {10.54330/afm.181562}, volume = {51}, year = {2026}, } @article{21767, abstract = {The involvement of non-scientific staff in discussions about animal welfare and scientific quality is essential for biomedical research progress. In this study, we developed a survey to collect the self-perception of animal care staff (ACS) and laboratory technicians about their involvement in scientific planning and conduct. Participants were contacted to complete an anonymous online questionnaire. We obtained 850 responses, mainly from Europe: 564 from ACS and 286 from laboratory technicians. Job satisfaction was assessed as positive by ACS and laboratory technicians despite the low frequency of culture of care activities and mental health meetings. Both groups expressed their desire to be trained in research planning and conduct; however, regular training was not reported. In addition, the inability to act on animal welfare concerns owing to experimental reasons was reported by both groups. Over half of the participants felt valued and appreciated by the lead scientists or animal facility manager; however, it is not clear how they are acknowledged, as their names on the authors list or in the manuscript acknowledgments are barely included. Our results indicated that involvement of ACS and laboratory technicians in planning and conducting studies would improve their understanding of how experiments are done, and therefore communication processes, work satisfaction, animal welfare, and scientific quality. Finally, we provided recommendations to improve the engagement of ACS and laboratory technicians in discussions about animal research planning and conduct.}, author = {Gonzalez-Uarquin, Fernando and Jirkof, Paulin and Bert, Bettina and Hawkins, Penny and Angelovski, Ljupco and Baumgart, Jan and Baumgart, Nadine and Cevik, Özge S. and Franco, Nuno H. and Horata, Erdal and Kaura, Rohish and Neuhaus, Winfried and Riso, Brigida and Smith, Adrian J. and Sotiropoulos, Athanassia and Vitale, Augusto and Schober, Sophie}, issn = {1758-1117}, journal = {Laboratory Animals}, publisher = {SAGE Publications}, title = {{Building bridges: Involvement of animal care staff and laboratory technicians in experimental planning and conduct of animal studies for better job satisfaction and science}}, doi = {10.1177/00236772251400976}, year = {2026}, } @article{21776, abstract = {Pyridyl motifs equipped with N-substituents can be powerful ligands for catalysis, yet their broader adoption is limited by the lack of a practical method to prepare these scaffolds. We report a modular, robust, and versatile Buchwald–Hartwig amination protocol that enables the rapid synthesis of bipyridine, phenanthroline, terpyridine, and pybox ligands bearing dialkylamine, diarylamine, and heteroaromatic N-substituents. These conditions streamline ligand library synthesis and will facilitate systematic studies in catalysis and related applications.}, author = {Petrik, Adam and Bena, Aleksander and Baunis, Haralds and Kelch, Riley M. and Yoon, Tehshik P. and Pieber, Bartholomäus}, issn = {1615-4169}, journal = {Advanced Synthesis & Catalysis}, number = {9}, publisher = {Wiley}, title = {{Facile access to N-substituted pyridyl ligands}}, doi = {10.1002/adsc.70417}, volume = {368}, year = {2026}, } @article{21778, abstract = {We prove that every 𝐿-bilipschitz mapping ℤ 2 → ℝ2 canbe extended to a 𝐶(𝐿)-bilipschitz mapping ℝ2 → ℝ2,and we provide a polynomial upper bound for 𝐶(𝐿).Moreover, we extend the result to every separated netin ℝ2 instead of ℤ 2, with the upper bound gaininga polynomial dependence on the separation and netconstants associated to the given separated net. Thisanswers an Oberwolfach question of Navas from 2015and is also a positive solution of the two-dimensionalform of a decades old open (in all dimensions at leasttwo) problem due to Alestalo Trotsenko and Väisälä.}, author = {Dymond, Michael and Kaluza, Vojtech}, issn = {1469-7750}, journal = {Journal of the London Mathematical Society}, number = {4}, publisher = {Wiley}, title = {{Planar bilipschitz extension from separated nets}}, doi = {10.1112/jlms.70540}, volume = {113}, year = {2026}, } @article{21779, abstract = {Acidomycin is an anti-mycobacterial antibiotic with a unique mode of action, targeting the biotin biosynthesis pathway. Despite being highly active against mycobacteria in vitro, its development as an anti-tubercular agent has been hindered due to suboptimal pharmacokinetics. Engineering of the acidomycin biosynthesis may yield new analogues with improved pharmacological properties. Here, we describe the identification of the acidomycin biosynthetic gene cluster (BGC) in a Streptomyces bacterium isolated from the rhizosphere of Edelweiss. Notably, the acidomycin BGC is located in proximity to the genes for the biosynthesis of stravidins, secondary metabolites targeting a different enzyme in the biotin biosynthesis pathway, and two genes for streptavidins, proteins that strongly bind and sequester biotin. The identity of the acidomycin BGC was confirmed via both gene knock-out and heterologous expression, which suggested that the fatty acid required for the formation of acidomycin's acyl chain is most likely scavenged from the biotin biosynthesis pathway. CRISPR/Cas9-assisted knock-out of the cytochrome P450-encoding gene in the acidomycin BGC resulted in a significant decrease in its yield but did not abrogate the biosynthesis completely.}, author = {Vignolle, Anna and Zehl, Martin and Garzón, Jaime Felipe Guerrero and Schneider, Olha and Gafriller, Johannes and Grienke, Ulrike and Kirkegaard, Rasmus H. and Zotchev, Sergey B.}, issn = {1751-7915}, journal = {Microbial Biotechnology}, number = {4}, publisher = {Wiley}, title = {{Identification and characterisation of the gene cluster governing biosynthesis of the anti-mycobacterial antibiotic acidomycin}}, doi = {10.1111/1751-7915.70357}, volume = {19}, year = {2026}, } @article{21780, abstract = {It is predicted that half or more of all cataclysmic variables (CVs) should have evolved past the period minimum and now exist as so-called period bouncers where a white dwarf should be accreting from a Roche lobe filling substellar companion. However, this prediction stands in stark contrast to observations, where only a few per cent of CVs are found in this evolutionary phase. A potential solution to this discrepancy is that a magnetic field emerges from within the white dwarf after the system has reached the period minimum. The transfer of angular momentum from the spin of the white dwarf into the orbit then pushes the two stars apart, detaching them for potentially billions of years. Here we present the discovery of ZTF J021804.16+071152.93, a detached 0.69 +- 0.01 M⁠, 19 MG magnetic white dwarf plus 37 +- 5MJup brown dwarf binary with an orbital period of 1.7 h. The kinematics of the system indicate that it is a high probability member of the Galactic thick disc. However, this strongly disagrees with the much younger age of the system obtained from the white dwarf parameters, implying that the system may have been accreting in the past. This system is therefore consistent with having detached as a result of the emergence of the magnetic field of the white dwarf when the system was still mass transferring, and may represent the ultimate fate for many (perhaps even most) CVs.}, author = {Parsons, S. G. and Brown, A. J. and Casewell, S. L. and Littlefair, S. P. and van Roestel, Joannes C and Rebassa-Mansergas, A. and Murillo-Ojeda, R. and Zorotovic, M. and Schreiber, M. R. and Bagnulo, S. and Stroet, M. A. and Castro Segura, N. and Dhillon, V. S. and Dyer, M. J. and Garbutt, J. A. and Green, M. J. and Jarvis, D. and Kennedy, M. R. and Kerry, P. and Mccormac, J. and Munday, J. and Pelisoli, I. and Pike, E. and Sahman, D. I. and Yates, A.}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {4}, publisher = {Oxford University Press}, title = {{ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables}}, doi = {10.1093/mnras/stag521}, volume = {547}, year = {2026}, } @article{21781, abstract = {Given a set A of n points (vertices) in general position in the plane, the complete geometric graph Kn[A] consists of all (n2) segments (edges) between the elements of A. It is known that the edge set of every complete geometric graph on n vertices can be partitioned into O(n3∕2) crossing-free paths (or matchings). We strengthen this result under various additional assumptions on the point set. In particular, we prove that for a set A of n randomly selected points, uniformly distributed in [0,1]2, with probability tending to 1 as n→∞, the edge set of Kn[A] can be covered by O(nlogn) crossing-free paths and by O(n√logn) crossing-free matchings. On the other hand, we construct n-element point sets such that covering the edge set of Kn[A] requires a quadratic number of monotone paths.}, author = {Dumitrescu, Adrian and Pach, János and Saghafian, Morteza and Scott, Alex}, issn = {2996-220X}, journal = {Combinatorics and Number Theory}, number = {1}, pages = {73--82}, publisher = {Mathematical Sciences Publishers}, title = {{Covering complete geometric graphs by monotone paths}}, doi = {10.2140/cnt.2026.15.73}, volume = {15}, year = {2026}, } @article{21798, abstract = {Phase singularities—points carrying quantized topological charge—are universal features found across diverse wave systems from superfluids and superconductors to acoustic and optical fields1,2,3,4. Ensembles of these singularities exhibit distance correlations resembling particles in liquids5,6,7,8, extensively studied for their role in exotic material phases9,10,11. By contrast, the full correlations in phase space that govern the system evolution have remained unexplored and experimentally inaccessible. Here we directly measure the ultrafast dynamics of optical singularity ensembles, capturing their full phase-space correlations, presenting the joint distance–velocity distribution. Our observations show a breakdown of the particle-singularity analogy12: phase singularities accelerate towards formally divergent velocities in the moment before annihilation7,13,14, indicated by measurements of velocities exceeding the speed of light. These apparent superluminal velocities are paradoxically amplified by the slow group velocity of hyperbolic phonon polaritons in our material platform, hexagonal boron nitride membranes15,16,17,18,19. We demonstrate these phenomena using combined hardware and algorithmic advances in ultrafast electron microscopy18,20,21,22,23,24,25, achieving spatial and temporal resolutions, each an order of magnitude below the polaritonic wavelength and cycle period. Our findings deepen our understanding of phase singularities and their universality, enabling to probe topological defect dynamics at previously unattainable timescales.}, author = {Bucher, T. and Gorlach, A. and Niedermayr, A. and Yan, Q. and Nahari, H. and Wang, K. and Ruimy, R. and Adiv, Y. and Yannai, M. and Abudi, T. L. and Janzen, E. and Spaegele, C. and Roques-Carmes, Charles and Edgar, J. H. and Koppens, F. H. L. and Vanacore, G. M. and H. Sheinfux, H. and Tsesses, S. and Kaminer, I.}, issn = {1476-4687}, journal = {Nature}, number = {8107}, pages = {920--926}, publisher = {Springer Nature}, title = {{Superluminal correlations in ensembles of optical phase singularities}}, doi = {10.1038/s41586-026-10209-z}, volume = {651}, year = {2026}, } @misc{21800, abstract = {LAMMPS input scripts to simulate toroidal vesicles composed of pure bolalipid membranes and archaeal mixture membranes for the following publication: "Cracking donuts and sorting lipids: geometry controls archaeal membrane stability and lipid organization" by Felix Frey, Miguel Amaral, and Andela Saric.}, author = {Frey, Felix F and Santana de Freitas Amaral, Miguel and Šarić, Anđela}, publisher = {Zenodo}, title = {{Cracking donuts and sorting lipids: Geometry controls archaeal membrane stability and lipid organization}}, doi = {10.5281/ZENODO.18772086}, year = {2026}, }