@article{20325, abstract = {Inferring genealogical relationships of wild populations is useful because it gives direct estimates of mating patterns and variance in reproductive success. Inference can be improved by including information about parentage shared between siblings, or by modelling phenotypes or population data related to mating. However, we currently lack a framework to infer parent–offspring relationships, sibships and population parameters in a single analysis. To address this, we here extend a previous method, Fractional Analysis of Paternity and Sibships, to include population data for the case where one parent is known. We illustrate this with the example of pollen dispersal in a natural hybrid zone population of the snapdragon Antirrhinum majus. Pollen dispersal is leptokurtic, with half of mating events occurring within 30 m, but with a long tail of mating events up to 859 m. Using simulations, we find that both sibship and population information substantially improve pedigree reconstruction, and that we can expect to resolve median dispersal distances with high accuracy.}, author = {Ellis, Thomas and Field, David and Barton, Nicholas H}, issn = {1365-294X}, journal = {Molecular Ecology}, number = {15}, publisher = {Wiley}, title = {{Joint estimation of paternity, sibships and pollen dispersal in a snapdragon hybrid zone}}, doi = {10.1111/mec.70051}, volume = {34}, year = {2025}, } @article{20327, abstract = {Confinement is a prominent phenomenon in condensed-matter and high-energy physics that has recently become the focus of quantum-simulation experiments of lattice gauge theories (LGTs). As such, a theoretical understanding of the effect of confinement on LGT dynamics is not only of fundamental importance but also can lend itself to upcoming experiments. Here we show how confinement in a Z2 LGT can be avoided by proximity to a resonance between the fermion mass and the electric field strength. Furthermore, we show that this local deconfinement can become global for certain initial conditions, where information transport occurs over the entire chain. In addition, we show how this can lead to strong quantum many-body scarring starting in different initial states. Our findings provide deeper insights into the nature of confinement in Z2 LGTs and can be tested on current and near-term quantum devices.}, author = {Desaules, Jean-Yves Marc and Iadecola, Thomas and Halimeh, Jad C.}, issn = {2469-9969}, journal = {Physical Review B}, number = {1}, publisher = {American Physical Society}, title = {{Mass-assisted local deconfinement in a confined Z2 lattice gauge theory}}, doi = {10.1103/mfg2-t6gb}, volume = {112}, year = {2025}, } @article{20329, abstract = {Nanocrystals (NCs) of various compositions have made important contributions to science and technology, with their impact recognized by the 2023 Nobel Prize in Chemistry for the discovery and synthesis of semiconductor quantum dots (QDs). Over four decades of research into NCs has led to numerous advancements in diverse fields, such as optoelectronics, catalysis, energy, medicine, and recently, quantum information and computing. The last 10 years since the predecessor perspective “Prospect of Nanoscience with Nanocrystals” was published in ACS Nano have seen NC research continuously evolve, yielding critical advances in fundamental understanding and practical applications. Mechanistic insights into NC formation have translated into precision control over NC size, shape, and composition. Emerging synthesis techniques have broadened the landscape of compounds obtainable in colloidal NC form. Sophistication in surface chemistry, jointly bolstered by theoretical models and experimental findings, has facilitated refined control over NC properties and represents a trusted gateway to enhanced NC stability and processability. The assembly of NCs into superlattices, along with two-dimensional (2D) photolithography and three-dimensional (3D) printing, has expanded their utility in creating materials with tailored properties. Applications of NCs are also flourishing, consolidating progress in fields targeted early on, such as optoelectronics and catalysis, and extending into areas ranging from quantum technology to phase-change memories. In this perspective, we review the extensive progress in research on NCs over the past decade and highlight key areas where future research may bring further breakthroughs.}, author = {Ibáñez, Maria and Boehme, Simon C. and Buonsanti, Raffaella and De Roo, Jonathan and Milliron, Delia J. and Ithurria, Sandrine and Rogach, Andrey L. and Cabot, Andreu and Yarema, Maksym and Cossairt, Brandi M. and Reiss, Peter and Talapin, Dmitri V. and Protesescu, Loredana and Hens, Zeger and Infante, Ivan and Bodnarchuk, Maryna I. and Ye, Xingchen and Wang, Yuanyuan and Zhang, Hao and Lhuillier, Emmanuel and Klimov, Victor I. and Utzat, Hendrik and Rainò, Gabriele and Kagan, Cherie R. and Cargnello, Matteo and Son, Jae Sung and Kovalenko, Maksym V.}, issn = {1936-086X}, journal = {ACS Nano}, number = {36}, pages = { 31969–32051}, publisher = {American Chemical Society}, title = {{Prospects of nanoscience with nanocrystals: 2025 edition}}, doi = {10.1021/acsnano.5c07838}, volume = {19}, year = {2025}, } @article{20330, abstract = {The evolution of sexual dimorphism (the difference in average trait values between females and males, SD), is often thought to be constrained by shared genetic architecture between the sexes. Indeed, it is commonly expected that SD should negatively correlate with the intersex correlation (the genetic correlation between effects of segregating variants in females and males, r fm), either because (1) traits with ancestrally low r fm are less constrained in their ability to respond to sex-specific selection and thus evolve to be more dimorphic, or because (2) sex-specific selection, driving sexual dimorphism evolution, also acts to reduce r fm. Despite the intuitive appeal and prominence of these ideas, their generality and the conditions in which they hold remain unclear. Here, we develop models incorporating sex-specific stabilizing selection, mutation and genetic drift to examine the relationship between r fm and SD. We show that the two commonly-discussed mechanisms with the potential to generate a negative correlation between SD and r fm could just as easily generate a positive association, since the standard line of reasoning hinges on a hidden assumption that sex-specific adaptation more frequently favors increased dimorphism than reduced dimorphism. Our results provide, to our knowledge, the first mechanistic framework for understanding the conditions under which a correlation between r fm and SD may arise and offer a compelling explanation for inconsistent empirical evidence. We also make the intriguing observation that—even when selection between the two sexes is identical—drift generates nonzero SD. We quantify this effect and discuss its significance.}, author = {Puixeu Sala, Gemma and Hayward, Laura}, issn = {1943-2631}, journal = {Genetics}, number = {3}, publisher = {Oxford University Press}, title = {{The relationship between sexual dimorphism and intersex correlation: Do models support intuition?}}, doi = {10.1093/genetics/iyaf175}, volume = {231}, year = {2025}, } @article{20331, abstract = {Here, we present a foundational investigation of charge transport through three BODIPY-based molecules using the scanning tunneling microscope–break junction (STM-BJ) technique. We demonstrate that molecular conductance through the BODIPY core can be measured by introducing aurophilic linkers at the 2,6-positions. By varying these linkers, we systematically modulate the frontier molecular orbital energies and fine-tune transport behavior. Our experimental results are supported by DFT-based calculations, which feature a new computationally efficient correction to standard PBE-level transmission predictions. Together, these findings establish the viability of BODIPY-based systems for molecular junction applications and lay the groundwork for future studies of their single-molecule optoelectronic properties.}, author = {York, Emma and Stone, Ilana and Shi, Wanzhuo and Roy, Xavier and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {36}, pages = {13697--13702}, publisher = {American Chemical Society}, title = {{Tuning conductance in BODIPY-based single-molecule junctions}}, doi = {10.1021/acs.nanolett.5c03764}, volume = {25}, year = {2025}, } @article{20349, abstract = {Oogenesis – the formation and development of an oocyte – is fundamental to reproduction and embryonic development. Due to its accessibility to genetic manipulations and the ability to culture and experimentally manipulate oocytes ex vivo, zebrafish has emerged as a powerful vertebrate model system for studying oogenesis. In this review, we provide a comprehensive overview of zebrafish oogenesis, from early germ cell formation to oocyte maturation and fertilization. We discuss recent advances in uncovering the molecular and cellular mechanisms driving this complex process and highlight key knowledge gaps that remain to be addressed.}, author = {Hofmann, Laura and Heisenberg, Carl-Philipp J}, issn = {1096-3634}, journal = {Seminars in Cell and Developmental Biology}, publisher = {Elsevier}, title = {{Decoding zebrafish oogenesis: From primordial germ cell development to fertilization}}, doi = {10.1016/j.semcdb.2025.103650}, volume = {175}, year = {2025}, } @article{20350, abstract = {Context. Rotation plays an important role in stellar evolution. However, the mechanisms behind the transport of angular momentum in stars at various stages of their evolution are not well understood. To improve our understanding of these processes, it is necessary to measure and validate the internal rotation profiles of stars across different stages of evolution and mass regimes. Aims. Our aim is to constrain the internal rotation profile of the 12-M⊙ β Cep pulsator HD 192575 from the observed pulsational multiplets and the asymmetries of their component frequencies. Methods. We updated the forward asteroseismic modelling of HD 192575 based on new TESS observations. We inverted the rotation profile from the symmetric part of the splittings and computed the multiplet asymmetries due to the Coriolis force and stellar deformation, which we treated perturbatively. We compared the computed asymmetries with the observed asymmetries. Results. Our new forward asteroseismic modelling is in agreement with previous results but with increased uncertainties, partially due to increased frequency precision, which required us to relax certain constraints. Ambiguity in the mode identification is the main source of the uncertainty, which also affects the inferred rotation profiles. Almost all acceptable rotation profiles occur in the regime below 0.4 d−1 and favour weak radial differential rotation, with a ratio of core to envelope rotation of less than 2. We find that the quality of the match between the observed and theoretically predicted mode asymmetries is strongly dependent on the mode identification and the internal structure of the star. Conclusions. Our results offer the first detailed rotation inversion for a β Cep pulsator. They show that the rotation profile and the mode asymmetries provide a valuable tool for further constraining the evolutionary properties of HD 192575, and in particular the details of angular momentum transport in massive stars.}, author = {Vanlaer, V. and Bowman, D. M. and Burssens, S. and Das, Srijan B and Bugnet, Lisa Annabelle and Mathis, S. and Aerts, C.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Interior rotation modelling of the β Cep pulsator HD 192575 including multiplet asymmetries}}, doi = {10.1051/0004-6361/202452885}, volume = {701}, year = {2025}, } @article{20351, abstract = {Rab GTPases organize intracellular trafficking and provide identity to organelles. Their spatiotemporal activation by guanine nucleotide exchange factors (GEFs) is tightly controlled to ensure fidelity. Our structural and functional comparison of the tri-longin domain RabGEFs Mon1-Ccz1 and Fuzzy-Inturned reveals the molecular basis for their target specificity. Both complexes rely on a conserved sequence motif of their substrate GTPases for the catalytic mechanism, while secondary interactions allow discrimination between targets. We also find that dimeric Mon1-Ccz1 from fungi and the metazoan homologs with the additional third subunit RMC1/Bulli bind membranes through electrostatic interactions via distinct interfaces. Protein-lipid interaction studies and functional characterization in flies reveal an essential function of RMC1/Bulli as mediator of GEF complex membrane recruitment. In the case of Fuzzy-Inturned, reconstitution experiments demonstrate that the BAR (Bin-Amphiphysin-Rvs) domain protein CiBAR1 can support membrane recruitment of the GEF. Collectively, our study demonstrates the molecular basis for the adaptation of TLD-RabGEFs to different cellular functions.}, author = {Wilmes, Stephan and Tönjes, Jesse and Drechsler, Maik and Ruf, Anita and Schäfer, Jan Hannes and Lürick, Anna and Januliene, Dovile and Apelt, Steven and Di Iorio, Daniele and Wegner, Seraphine V. and Loose, Martin and Moeller, Arne and Paululat, Achim and Kümmel, Daniel}, issn = {2375-2548}, journal = {Science Advances}, number = {35}, pages = {eadx2893}, publisher = {AAAS}, title = {{Mechanistic adaptation of the metazoan RabGEFs Mon1-Ccz1 and Fuzzy-Inturned}}, doi = {10.1126/sciadv.adx2893}, volume = {11}, year = {2025}, } @article{20352, abstract = {At high metallicity, a majority of massive stars have at least one close stellar companion. The evolution of such binaries is subject to strong interaction processes, which heavily impact the characteristics of their life-ending supernova and compact remnants. For the low-metallicity environments of high-redshift galaxies, constraints on the multiplicity properties of massive stars over the separation range leading to binary interaction are crucially missing. Here we show that the presence of massive stars in close binaries is ubiquitous, even at low metallicity. Using the Very Large Telescope, we obtained multi-epoch radial velocity measurements of a representative sample of 139 massive O-type stars across the Small Magellanic Cloud, which has a metal content of about one-fifth of the solar value. We find that 45% of them show radial velocity variations that demonstrate that they are members of close binary systems, and predominantly have orbital periods shorter than 1 year. Correcting for observational biases indicates that at least 70+11−6 % of the O stars in our sample are in close binaries, and that at least 68+7 −8% of all O stars interact with a companion star during their lifetime. We found no evidence supporting a statistically significant trend of the multiplicity properties with metallicity. Our results indicate that multiplicity and binary interactions govern the evolution of massive stars and determine their cosmic feedback and explosive fates.}, author = {Sana, H. and Shenar, T. and Bodensteiner, J. and Britavskiy, N. and Langer, N. and Lennon, D. J. and Mahy, L. and Mandel, I. and De Mink, S. E. and Patrick, L. R. and Villaseñor, J. I. and Dirickx, M. and Abdul-Masih, M. and Almeida, L. A. and Backs, F. and Berlanas, S. R. and Bernini-Peron, M. and Bowman, D. M. and Bronner, V. A. and Crowther, P. A. and Deshmukh, K. and Evans, C. J. and Fabry, M. and Gieles, M. and Gilkis, A. and González-Torà, G. and Gräfener, G. and Götberg, Ylva Louise Linsdotter and Hawcroft, C. and Hénault-Brunet, V. and Herrero, A. and Holgado, G. and Izzard, R. G. and De Koter, A. and Janssens, S. and Johnston, C. and Josiek, J. and Justham, S. and Kalari, V. M. and Klencki, J. and Kubát, J. and Kubátová, B. and Lefever, R. R. and Van Loon, J. Th and Ludwig, B. and Mackey, J. and Maíz Apellániz, J. and Maravelias, G. and Marchant, P. and Mazeh, T. and Menon, A. and Moe, M. and Najarro, F. and Oskinova, L. M. and Ovadia, R. and Pauli, D. and Pawlak, M. and Ramachandran, V. and Renzo, M. and Rocha, D. F. and Sander, A. A.C. and Schneider, F. R.N. and Schootemeijer, A. and Schösser, E. C. and Schürmann, C. and Sen, K. and Shahaf, S. and Simón-Díaz, S. and Van Son, L. A.C. and Stoop, M. and Toonen, S. and Tramper, F. and Valli, R. and Vigna-Gómez, A. and Vink, J. S. and Wang, C. and Willcox, R.}, issn = {2397-3366}, journal = {Nature Astronomy}, pages = {1337--1346}, publisher = {Springer Nature}, title = {{A high fraction of close massive binary stars at low metallicity}}, doi = {10.1038/s41550-025-02610-x}, volume = {9}, year = {2025}, } @article{20367, abstract = {We prove upper and lower bounds on the number of pairs of commuting n x n matrices with integer entries in [-T, T], as T -> . Our work uses Fourier analysis and leads to an analysis of exponential sums involving matrices over finite fields. These are bounded by combining a stratification result of Fouvry and Katz with a new result about the flatness of the commutator Lie bracket.}, author = {Browning, Timothy D and Sawin, Will and Wang, Victor}, issn = {1432-1807}, journal = {Mathematische Annalen}, pages = {1863–1880}, publisher = {Springer Nature}, title = {{Pairs of commuting integer matrices}}, doi = {10.1007/s00208-025-03285-5}, volume = {393}, year = {2025}, } @article{20370, abstract = {The Huntingtin protein (HTT), named for its role in Huntington’s disease, has been best understood as a scaffolding protein that promotes vesicle transport by molecular motors along microtubules. Here, we show that HTT also interacts with the actin cytoskeleton, and its loss of function disturbs the morphology and function of the axonal growth cone. We demonstrate that HTT organizes F-actin into bundles. Cryo–electron tomography (cryo-ET) and subtomogram averaging (STA) structural analyses reveal that HTT’s N-terminal HEAT and Bridge domains wrap around F-actin, while the C-terminal HEAT domain is displaced; furthermore, HTT dimerizes via the N-HEAT domain to bridge parallel actin filaments separated by ~20 nanometers. Our study provides the structural basis for understanding how HTT interacts with and organizes the actin cytoskeleton.}, author = {Carpentier, Rémi and Kim, Jaesung and Capizzi, Mariacristina and Kim, Hyeongju and Fäßler, Florian and Hansen, Jesse and Kim, Min Jeong and Denarier, Eric and Blot, Béatrice and Degennaro, Marine and Labou, Sophia and Arnal, Isabelle and Marcaida, Maria J. and Peraro, Matteo Dal and Kim, Doory and Schur, Florian KM and Song, Ji-Joon and Humbert, Sandrine}, issn = {2375-2548}, journal = {Science Advances}, number = {38}, publisher = {AAAS}, title = {{Structure of the Huntingtin F-actin complex reveals its role in cytoskeleton organization}}, doi = {10.1126/sciadv.adw4124}, volume = {11}, year = {2025}, } @article{20374, abstract = {Pioneer transcription factors (TFs) engage chromatinized DNA motifs. However, it is unclear how the resultant TF-nucleosome complexes are decoded by co-factors. In humans, the TF p53 regulates cell-cycle progression, apoptosis, and the DNA damage response, with a large fraction of p53-bound sites residing in nucleosome-harboring inaccessible chromatin. We examined the interaction of chromatin-bound p53 with co-factors belonging to the ubiquitin proteasome system (UPS). At two distinct motif locations on the nucleosome (super-helical location [SHL]−5.7 and SHL+5.9), the E3 ubiquitin ligase E6-E6AP was unable to bind nucleosome-engaged p53. The deubiquitinase USP7, on the other hand, readily engages nucleosome-bound p53 in vitro and in cells. A corresponding cryo-electron microscopy (cryo-EM) structure shows USP7 engaged with p53 and nucleosomes. Our work illustrates how chromatin imposes a co-factor-selective barrier for p53 interactors, whereby flexibly tethered interaction domains of co-factors and TFs govern compatibility between co-factors, TFs, and chromatin.}, author = {Chakraborty, Deyasini and Sandate, Colby R. and Isbel, Luke and Kempf, Georg and Weiss, Joscha and Cavadini, Simone and Kater, Lukas and Seebacher, Jan and Kozicka, Zuzanna and Stoos, Lisa and Grand, Ralph S. and Schübeler, Dirk and Michael, Alicia and Thomä, Nicolas H.}, issn = {1097-2765}, journal = {Molecular Cell}, number = {15}, pages = {2919--2936.e12}, publisher = {Elsevier}, title = {{Nucleosomes specify co-factor access to p53}}, doi = {10.1016/j.molcel.2025.06.027}, volume = {85}, year = {2025}, } @article{20402, abstract = {The recent classification of the onset of turbulence as a directed percolation (DP) phase transition has been applied to all major shear flows including pipe, channel, Couette and boundary layer flows. A cornerstone of the DP analogy is the memoryless (Poisson) property of turbulent sites. We here show that, for the classic case of channel flow, neither the decay nor the proliferation of turbulent stripes is memoryless. As demonstrated by a standard analysis of the respective survival curves, isolated channel stripes, in the immediate vicinity of the critical point, age. Consequently, the one to one mapping between turbulent stripes and active DP-sites is not fulfilled in this low Reynolds number regime. In addition, the interpretation of turbulence as a chaotic saddle with supertransient properties, the basis of recent theoretical progress, does not apply to individual localized stripes. The discrepancy between channel flow and the transition models established for pipe and Couette flow, illustrates that seemingly minor geometrical differences between flows can give rise to instabilities and growth mechanisms that fundamentally alter the nature of the transition to turbulence.}, author = {Vasudevan, Mukund and Paranjape, Chaitanya S and Sitte, Michael Philip and Yalniz, Gökhan and Hof, Björn}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Aging and memory of transitional turbulence}}, doi = {10.1038/s41467-025-63044-7}, volume = {16}, year = {2025}, } @article{20404, abstract = {Collagens are fundamental components of extracellular matrices, requiring precise intracellular post-translational modifications for proper function. Among the modifications, prolyl 4-hydroxylation is critical to stabilise the collagen triple helix. In humans, this reaction is mediated by collagen prolyl 4-hydroxylases (P4Hs). While humans possess three genes encoding these enzymes (P4H⍺s), Drosophila melanogaster harbour at least 26 candidates for collagen P4H⍺s despite its simple genome, and it is poorly understood which of them are actually working on collagen in the fly. In this study, we addressed this question by carrying out thorough bioinformatic and biochemical analyses. We demonstrate that among the 26 potential collagen P4H⍺s, PH4⍺EFB shares the highest homology with vertebrate collagen P4H⍺s. Furthermore, while collagen P4Hs and their substrates must exist in the same cells, our transcriptomic analyses at the tissue and single cell levels showed a global co-expression of PH4⍺EFB but not the other P4H⍺-related genes with the collagen IV genes. Moreover, expression of PH4⍺EFB during embryogenesis was found to precede that of collagen IV, presumably enabling efficient collagen modification by PH4⍺EFB. Finally, biochemical assays confirm that PH4⍺EFB binds collagen, supporting its direct role in collagen IV modification. Collectively, we identify PH4⍺EFB as the primary and potentially constitutive prolyl 4-hydroxylase responsible for collagen IV biosynthesis in Drosophila. Our findings highlight the remarkably simple nature of Drosophila collagen IV biosynthesis, which may serve as a blueprint for defining the minimal requirements for collagen engineering.}, author = {Ishikawa, Yoshihiro and Toups, Melissa A and Elkrewi, Marwan N and Zajac, Allison L. and Horne-Badovinac, Sally and Matsubayashi, Yutaka}, issn = {1569-1802}, journal = {Matrix Biology}, number = {11}, pages = {101--113}, publisher = {Springer Nature}, title = {{Evidence for the major role of PH4⍺EFB in the prolyl 4-hydroxylation of Drosophila collagen IV}}, doi = {10.1016/j.matbio.2025.09.002}, volume = {141}, year = {2025}, } @article{20405, abstract = {Dielectric breakdown of physical vacuum (Schwinger effect) is the textbook demonstration of compatibility of Relativity and Quantum theory. Although observing this effect is still practically unachievable, its analogue generalizations have been shown to be more readily attainable. This paper demonstrates that a gapped Dirac semiconductor, methylammonium lead-bromide perovskite (MAPbBr3), exhibits analogue dynamic Schwinger effect. Tunneling ionization under deep subgap mid-infrared irradiation leads to intense photoluminescence in the visible range, in full agreement with quasi-adiabatic theory. In addition to revealing a gapped extended system suitable for studying the analogue Schwinger effect, this observation holds great potential for nonperturbative field sensing, i.e., sensing electric fields through nonperturbative light-matter interactions. First, this paper illustrates this by measuring the local deviation from the nominally cubic phase of a perovskite single crystal, which can be interpreted in terms of frozen-in fields. Next, it is shown that analogue dynamic Schwinger effect can be used for nonperturbative amplification of nonparametric upconversion process in perovskites driven simultaneously by multiple optical fields. This discovery demonstrates the potential for material response beyond perturbation theory in the tunneling regime, offering extremely sensitive light detection and amplification across an ultrabroad spectral range not accessible by conventional devices.}, author = {Lorenc, Dusan and Volosniev, Artem and Zhumekenov, Ayan A. and Lee, Seungho and Ibáñez, Maria and Bakr, Osman M. and Lemeshko, Mikhail and Alpichshev, Zhanybek}, issn = {2330-4022}, journal = {ACS Photonics}, number = {9}, pages = {5220--5230}, publisher = {American Chemical Society}, title = {{Observation of analogue dynamic Schwinger effect and non-perturbative light sensing in lead halide perovskites}}, doi = {10.1021/acsphotonics.5c01360}, volume = {12}, year = {2025}, } @article{20406, abstract = {The origin of the rest-optical emission of compact, red, high-redshift sources known as little red dots (LRDs) poses a major puzzle. If interpreted as starlight, it would imply that LRDs constitute the densest stellar systems in the Universe. However, alternative models suggest active galactic nuclei (AGN) may instead power the rest-optical continuum. Here, we present JWST/NIRSpec, NIRCam, and MIRI observations from the RUBIES and PRIMER programs of The Cliff: a bright LRD at z = 3.55 with an exceptional Balmer break, twice as strong as that of any high-redshift source previously observed. The spectra also reveal broad hydrogen (Hα FWHM ∼ 1500 km s−1) and He I emission, but no significant metal lines. We demonstrate that massive evolved stellar populations cannot explain the observed spectrum, even when considering unusually steep and strong dust attenuation or reasonable variations in the initial mass function. Moreover, the formally best-fit stellar mass and compact size (M* ∼ 1010.5 M⊙,  re ∼ 40 pc) would imply densities at which near-monthly stellar collisions might lead to significant X-ray emission. We argue that the Balmer break, emission lines, and Hα absorption line are instead most plausibly explained by a black hole star (BH*) scenario, in which dense gas surrounds a powerful ionising source. In contrast to recently proposed BH* models of dust-reddened AGN, we show that spectral fits in the rest UV to near-infrared favour an intrinsically redder continuum over strong dust reddening. This may point to a super-Eddington accreting massive black hole or, possibly, the presence of (super)massive stars in a nuclear star cluster. The Cliff is the clearest evidence to date that at least some LRDs are not ultra-dense massive galaxies, and are instead powered by a central ionising source embedded in dense, absorbing gas.}, author = {De Graaff, Anna and Rix, Hans Walter and Naidu, Rohan P. and Labbé, Ivo and Wang, Bingjie and Leja, Joel and Matthee, Jorryt J and Katz, Harley and Greene, Jenny E. and Hviding, Raphael E. and Baggen, Josephine and Bezanson, Rachel and Boogaard, Leindert A. and Brammer, Gabriel and Dayal, Pratika and Van Dokkum, Pieter and Goulding, Andy D. and Hirschmann, Michaela and Maseda, Michael V. and Mcconachie, Ian and Miller, Tim B. and Nelson, Erica and Oesch, Pascal A. and Setton, David J. and Shivaei, Irene and Weibel, Andrea and Whitaker, Katherine E. and Williams, Christina C.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{A remarkable ruby: Absorption in dense gas, rather than evolved stars, drives the extreme Balmer break of a little red dot at z = 3.5}}, doi = {10.1051/0004-6361/202554681}, volume = {701}, year = {2025}, } @article{20407, abstract = {We suggest a new algorithm to estimate representations of compact Lie groups from finite samples of their orbits. Different from other reported techniques, our method allows the retrieval of the precise representation type as a direct sum of irreducible representations. Moreover, the knowledge of the representation type permits the reconstruction of its orbit, which is useful for identifying the Lie group that generates the action, from a finite list of candidates. Our algorithm is general for any compact Lie group, but only instantiations for SO(2), T^d, SU(2), and SO(3) are considered. Theoretical guarantees of robustness in terms of Hausdorff and Wasserstein distances are derived. Our tools are drawn from geometric measure theory, computational geometry, and optimization on matrix manifolds. The algorithm is tested for synthetic data up to dimension 32, as well as real-life applications in image analysis, harmonic analysis, density estimation, equivariant neural networks, chemical conformational spaces, and classical mechanics systems, achieving very accurate results.}, author = {Ennes, Henrique and Tinarrage, Raphaël}, issn = {1615-3383}, journal = {Foundations of Computational Mathematics}, publisher = {Springer Nature}, title = {{LieDetect: Detection of representation orbits of compact Lie groups from point clouds}}, doi = {10.1007/s10208-025-09728-4}, year = {2025}, } @article{20423, abstract = {For any d 2, we prove that there exists an integer n0(d) such that there exists an n × n magic square of dth powers for all n n0(d). In particular, we establish the existence of an n × n magic square of squares for all n 4, which settles a conjecture of Várilly-Alvarado. All previous approaches had been based on constructive methods and the existence of n × n magic squares of dth powers had only been known for sparse values of n. We prove our result by the Hardy-Littlewood circle method, which in this setting essentially reduces the problem to finding a sufficient number of disjoint linearly independent subsets of the columns of the coefficient matrix of the equations defining magic squares. We prove an optimal (up to a constant) lower bound for this quantity.}, author = {Rome, Nick and Yamagishi, Shuntaro}, issn = {2363-9555}, journal = {Research in Number Theory}, number = {4}, publisher = {Springer Nature}, title = {{On the existence of magic squares of powers}}, doi = {10.1007/s40993-025-00671-5}, volume = {11}, year = {2025}, } @article{20424, abstract = {Homeostasis relies on a precise balance of fate choices between renewal and differentiation. Although progress has been done to characterize the dynamics of single-cell fate choices, their underlying mechanistic basis often remains unclear. Concentrating on skin epidermis as a paradigm for multilayered tissues with complex fate choices, we develop a 3D vertex-based model with proliferation in the basal layer, showing that mechanical competition for space naturally gives rise to homeostasis and neutral drift dynamics that are seen experimentally. We then explore the effect of introducing mechanical heterogeneities between cellular subpopulations. We uncover that relatively small tension heterogeneities, reflected by distinct morphological changes in single-cell shapes, can be sufficient to heavily tilt cellular dynamics towards exponential growth. We thus derive a master relationship between cell shape and long-term clonal dynamics, which we validated during basal cell carcinoma initiation in mouse epidermis. Altogether, we propose a theoretical framework to link mechanical forces, quantitative cellular morphologies and cellular fate outcomes in complex tissues.}, author = {Sahu, Preeti and Monteiro-Ferreira, Sara and Canato, Sara and Soares, Raquel Maia and Sánchez-Danés, Adriana and Hannezo, Edouard B}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Mechanical control of cell fate decisions in the skin epidermis}}, doi = {10.1038/s41467-025-62882-9}, volume = {16}, year = {2025}, } @article{20425, abstract = {Ultraviolet (UV) radiation from accreting black holes ionizes the intergalactic gas around early quasars, carving out highly ionized bubbles in their surroundings. Any changes in a quasar’s luminosity are therefore predicted to produce outward-propagating ionization gradients, affecting the Lyα absorption opacity near the quasar’s systemic redshift. This “proximity effect” is well-documented in rest-UV quasar spectra but only provides a one-dimensional probe along our line of sight. Here we present deep spectroscopic observations with the James Webb Space Telescope (JWST) of galaxies in the background of a superluminous quasar at zQSO ≈ 6.3, which reveal the quasar’s “light echo” with Lyα tomography in the transverse direction. This transverse proximity effect is detected for the first time toward multiple galaxy sightlines, allowing us to map the extent and geometry of the quasar’s ionization cone. We obtain constraints on the orientation and inclination of the cone, as well as an upper limit on the obscured solid angle fraction of fobsc < 91%. Additionally, we find a timescale of the quasar’s UV radiation of tqso = 10^5.6+0.1-0.3 yr, which is significantly shorter than would be required to build up the central supermassive black hole (SMBH) with conventional growth models, but is consistent with independent measurements of the quasars’ duty cycle. Our inferred obscured fraction disfavors a scenario where short quasar lifetimes can be explained exclusively by geometric obscuration, and instead supports the idea that radiatively inefficient accretion or growth in initially heavily enshrouded cocoons plays a pivotal role in early SMBH growth. Our results pave the way for novel studies of quasars’ ionizing geometries and radiative histories at early cosmic times.}, author = {Eilers, Anna Christina and Yue, Minghao and Matthee, Jorryt J and Hennawi, Joseph F. and Davies, Frederick B. and Simcoe, Robert A. and Teague, Richard and Bordoloi, Rongmon and Brammer, Gabriel and Kang, Yi and Kashino, Daichi and Mackenzie, Ruari and Naidu, Rohan P. and Navarrete, Benjamín}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, number = {2}, publisher = {IOP Publishing}, title = {{The light echo of a high-redshift quasar mapped with Lyα tomography}}, doi = {10.3847/2041-8213/ae057a}, volume = {991}, year = {2025}, }