@unpublished{21700, abstract = {We provide a theoretical framework to describe the dynamics of a free-electron beam interacting with quantized bound systems in arbitrary electromagnetic environments. This expands the quantum optics toolbox to incorporate free-electron beams for applications in highly tunable quantum control, imaging, and spectroscopy at the nanoscale. The framework recovers previously studied results and shows that electromagnetic environments can amplify the intrinsically weak coupling between a free-electron and a bound electron to reach previously inaccessible interaction regimes. We leverage this enhanced coupling for experimentally feasible protocols in coherent qubit control and towards the nondestructive readout and projective control of the electron beam's quantum-number statistics. Our framework is broadly applicable to microwave-frequency qubits, optical nanophotonics, cavity quantum electrodynamics, and emerging platforms at the interface of electron microscopy and quantum information.}, author = {Grzesik, Jakob M. and Karnieli, Aviv and Roques-Carmes, Charles and Black, Dylan S. and Lê, Trung Kiên and Solgaard, Olav and Fan, Shanhui and Vučković, Jelena}, booktitle = {arXiv}, title = {{A general framework for interactions between electron beams and quantum optical systems}}, doi = {10.48550/arXiv.2601.21385}, year = {2026}, } @unpublished{21701, abstract = {Polarization-resolved control and measurement of the optical field are essential for a wide range of photonic systems, including coherent communication, polarimetric sensing, and quantum information processing. We present a photonic integrated circuit that enables the generation and analysis of arbitrary polarization states. The device provides reconfigurable access to the full polarization degree of freedom of coherent light within a single integrated platform. We experimentally demonstrate arbitrary polarization state generation spanning the Poincare sphere, as well as Stokes vector measurement on chip. Unlike conventional Stokes measurements that rely on direct detection, polarization analysis utilizing this architecture is intrinsically non-destructive, preserving the optical signal for further optical domain processing. The devices are fabricated in a commercial foundry using CMOS-compatible processes, enabling scalable and reproducible integration. By combining polarization generation and analysis in a compact and stable photonic circuit, this work eliminates the need for external polarization optics and provides a foundation for robust, polarization-enabled photonic integrated systems.}, author = {Valdez, Carson G. and Kroo, Anne R. and Miller, Anna J. and Roques-Carmes, Charles and Miller, David A. B. and Solgaard, Olav}, booktitle = {arXiv}, title = {{Integrated photonic polarization synthesizer and analyzer}}, doi = {10.48550/arXiv.2602.17024}, year = {2026}, } @unpublished{21291, abstract = {The complexity and specificity of movement in vertebrates is driven by a rich diversity of spinal motor and interneuron cell types. During development, eleven spinal cord progenitor domains generate an equivalent number of cardinal neuron types. How progenitor domains, individual progenitors, and post-mitotic diversity relate is still unknown. We performed high-resolution, single-progenitor cell lineage tracing in the embryonic mouse spinal cord using mosaic analysis with double markers (MADM). Our quantitative study of lineage progression revealed that spinal cord progenitors undergo highly variable numbers of proliferative, neurogenic, and gliogenic cell divisions. The nascent clonally-related neurons migrate radially over large distances, span the dorsoventral axis, and even cross the midline, demonstrating striking bilaterality. Molecular and morphometric analysis indicate high levels of progenitor multipotency, with an individual progenitor capable of producing several molecularly and morphologically distinct neuron types, as well as astrocytes. These findings redefine spinal cord development as a process in which lineage variability — rather than rigid progenitor identity — drives the generation of cellular diversity.}, author = {Gobeil, Sophie A and Da Silveira Neto, Francisco and Silvestrelli, Giulia and Smits, Matthijs Geert and Streicher, Carmen and Cheung, Giselle T and Hippenmeyer, Simon and Sweeney, Lora Beatrice Jaeger}, booktitle = {bioRxiv}, title = {{Lineage origin of spinal cord cell type diversity}}, doi = {10.64898/2026.02.12.705305}, year = {2026}, } @article{21449, abstract = {Three-dimensional (3D) crystals offer a route to scaling up trapped-ion systems for quantum sensing and quantum simulation applications; however, engineering coherent spin-motion couplings and effective spin-spin interactions in large crystals poses technical challenges associated with decoherence and prolonged timescales to generate appreciable entanglement. Here, we explore the possibility of speeding up these interactions in 3D crystals via parametric amplification. For this purpose, we derive a general Hamiltonian for the parametric amplification of spin-motion coupling that is broadly applicable to normal modes with motion transverse to or along the spatial extent of the crystal. Unlike in lower-dimensional crystals, we find that the ability to faithfully (uniformly) amplify the spin-spin interactions in 3D crystals depends on the physical implementation of the spin-motion coupling. We consider the light-shift gate, and the so-called phase-insensitive and phase-sensitive Mølmer-Sørensen (MS) gates, and we find that only the phase-sensitive MS gate can be faithfully amplified in general 3D crystals. We discuss a situation where nonuniform amplification can be advantageous. We also reconsider the effect of counter-rotating terms on parametric amplification and find that they are not as detrimental as previous studies suggest.}, author = {Hawaldar, Samarth and Nikhil, N. and Rey, Ana Maria and Bollinger, John J. and Shankar, Athreya}, issn = {2331-7019}, journal = {Physical Review Applied}, number = {3}, publisher = {American Physical Society}, title = {{Parametric amplification of spin-motion coupling in three-dimensional trapped-ion crystals}}, doi = {10.1103/h1m9-h3yw}, volume = {25}, year = {2026}, } @inproceedings{21134, abstract = {The Nakamoto consensus protocol underlying the Bitcoin blockchain uses proof of work as a voting mechanism. Honest miners who contribute hashing power towards securing the chain try to extend the longest chain they are aware of. Despite its simplicity, Nakamoto consensus achieves meaningful security guarantees assuming that at any point in time, a majority of the hashing power is controlled by honest parties. This also holds under “resource variability”, i.e., if the total hashing power varies greatly over time. Proofs of space (PoSpace) have been suggested as a more sustainable replacement for proofs of work. Unfortunately, no construction of a “longest-chain” blockchain based on PoSpace, that is secure under dynamic availability, is known. In this work, we prove that without additional assumptions no such protocol exists. We exactly quantify this impossibility result by proving a bound on the length of the fork required for double spending as a function of the adversarial capabilities. This bound holds for any chain selection rule, and we also show a chain selection rule (albeit a very strange one) that almost matches this bound. The Nakamoto consensus protocol underlying the Bitcoin blockchain uses proof of work as a voting mechanism. Honest miners who contribute hashing power towards securing the chain try to extend the longest chain they are aware of. Despite its simplicity, Nakamoto consensus achieves meaningful security guarantees assuming that at any point in time, a majority of the hashing power is controlled by honest parties. This also holds under “resource variability”, i.e., if the total hashing power varies greatly over time. Proofs of space (PoSpace) have been suggested as a more sustainable replacement for proofs of work. Unfortunately, no construction of a “longest-chain” blockchain based on PoSpace, that is secure under dynamic availability, is known. In this work, we prove that without additional assumptions no such protocol exists. We exactly quantify this impossibility result by proving a bound on the length of the fork required for double spending as a function of the adversarial capabilities. This bound holds for any chain selection rule, and we also show a chain selection rule (albeit a very strange one) that almost matches this bound. Concretely, we consider a security game in which the honest parties at any point control 0 > 1 times more space than the adversary. The adversary can change the honest space by a factor 1+- E with every block (dynamic availability), and “replotting” the space (which allows answering two challenges using the same space) takes as much time as p blocks. We prove that no matter what chain selection rule is used, in this game the adversary can create a fork of length o^2 . p/E that will be picked as the winner by the chain selection rule. We also provide an upper bound that matches the lower bound up to a factor o. There exists a chain selection rule (albeit a very strange one) which in the above game requires forks of length at least o . p/E Our results show the necessity of additional assumptions to create a secure PoSpace based longest-chain blockchain. The Chia network in addition to PoSpace uses a verifiable delay function. Our bounds show that an additional primitive like that is necessary.}, author = {Baig, Mirza Ahad and Pietrzak, Krzysztof Z}, booktitle = {29th International Conference on Financial Cryptography and Data Security}, isbn = {9783032070340}, issn = {1611-3349}, location = {Miyakojima, Japan}, pages = {127--142}, publisher = {Springer Nature}, title = {{On the (in)security of Proofs-of-space based longest-chain blockchains}}, doi = {10.1007/978-3-032-07035-7_8}, volume = {15752}, year = {2026}, } @phdthesis{21651, abstract = {Blockchains enable distributed consensus in permissionless settings, where participants are unknown, dynamically changing, and do not trust each other. While Bitcoin, based on Proof-of-Work (PoW), was the first protocol in this model, significant research has focused on permissionless protocols using alternative physical resources, specifically Proof-of-Space (PoSpace) and Verifiable Delay Functions (VDFs). This thesis investigates the theoretical limits and design space of longest-chain protocols in the fully permissionless and dynamically available settings using these three resources. First, we address the feasibility of blockchains relying solely on storage as a resource. We prove a fundamental impossibility result: there exists no secure longest-chain protocol based exclusively on Proof-of-Space in the fully permissionless or dynamically available settings. Further, we quantify the adversarial capabilities required to execute a double-spend attack. Our result formally justifies the necessity of coupling PoSpace with time-dependent primitives (such as VDFs) or to move to less permissive settings (quasi-permissionless or permissioned) to ensure security. Second, we generalize Nakamoto-like heaviest chain consensus to protocols utilizing combinations of multiple physical resources. We analyze chain selection rules governed by a weight function Γ(S, V,W), which assigns weight to blocks based on recorded Space (S), VDF speed (V ), and Work (W). We provide a complete classification of secure weight functions, proving that a weight function is secure against private double-spend attacks if and only if it is homogeneous in the timed resources (V,W) and sub-homogeneous in S. This framework unifies existing protocols like Bitcoin and Chia under a single theoretical model and provides a powerful tool for designing new longest-chain blockchains from a mix of physical resources.}, author = {Baig, Mirza Ahad}, isbn = {978-3-99078-078-7}, issn = {2663-337X}, publisher = {Institute of Science and Technology Austria}, title = {{On secure chain selection rules from physical resources in a permissionless setting}}, doi = {10.15479/AT-ISTA-21651}, year = {2026}, } @article{21436, abstract = {The cobalt-intercalated transition metal dichalcogenide CoxTaS2 hosts a rich landscape of magnetic phases that depend sensitively on x. While the stoichiometric compound with x = 1/3 exhibits a single magnetic transition, samples with x≤0.325 display two transitions with an anomalous Hall effect (AHE) emerging in the lower temperature phase. Here, we resolve the spin structure in each phase by employing a suite of magneto-optical probes that include the discovery of anomalous magneto-birefringence: a spontaneous time-reversal sensitive rotation of the principal optic axes. A symmetry-based analysis identifies the AHE-active phase as an anisotropic (2+1)Q state, in which magnetic modulation at one wavevector (Q) differs in symmetry from that at the remaining two. The (2+1)Q state naturally exhibits scalar spin chirality as a mechanism for the AHE and expands the classification of multi-Q magnetic phases.}, author = {Kruppe, Jonathon and Rodriguez, Josue and Xu, Catherine and Analytis, James and Orenstein, Joseph and Sunko, Veronika}, issn = {2397-4648}, journal = {npj Quantum Materials}, publisher = {Springer Nature}, title = {{Anisotropic multi-Q order in CoxTaS2}}, doi = {10.1038/s41535-026-00856-w}, year = {2026}, } @article{21714, abstract = {Be stars are rapidly rotating main-sequence stars that play a crucial role in understanding stellar evolution and binary interactions. In this Letter, we propose a new formation scenario for black hole (BH) + Be star binaries (hereafter BHBe binaries), where the Be star is produced through the wind Roche lobe overflow (WRLOF) mechanism. Our analysis is based on numerical simulations of the WRLOF process in massive binaries, building on recent theoretical work. We demonstrate that the WRLOF model can efficiently form BHBe binaries under reasonable assumptions on stellar wind velocities. Using rapid binary population synthesis, we estimate the population of such systems in the Milky Way, predicting ∼1800−3200 currently existing BHBe binaries originating from the WRLOF channel. These systems are characterized by high eccentricities and exceptionally wide orbits, with typical orbital periods exceeding 1000 days and a peak distribution around ∼10,000 days. Due to their long orbital separations, these BHBe binaries are promising targets for future detection via astrometric and interferometric observations.}, author = {Li, Zhenwei and Jia, Shi and Wei, Dandan and Ge, Hongwei and Chen, Hailiang and Zhang, Yangyang and Chen, Xuefei and Han, Zhanwen}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, number = {2}, publisher = {IOP Publishing}, title = {{Formation of Be stars via wind accretion: Case study on Black Hole + Be star binaries}}, doi = {10.3847/2041-8213/ae3008}, volume = {996}, year = {2026}, } @article{21718, abstract = {In this paper, we consider the big algebra recently introduced by Hausel for the GLn-action on the coordinate ring of the matrix space Mat(n,r). In particular, we obtain explicit formulas for the big algebra generators in terms of differential operators with polynomial coefficients. We show that big algebras in type A are commutative and relate them to the Bethe subalgebra in the Yangian Y(gln). We apply these results to big algebras of symmetric powers of the standard representation of GLn. .}, author = {Ngo, Nhok T}, issn = {1815-0659}, journal = {Symmetry, Integrability and Geometry: Methods and Applications}, publisher = {National Academy of Science of Ukraine}, title = {{Big algebra in type A for the coordinate ring of the matrix space}}, doi = {10.3842/SIGMA.2026.024}, volume = {22}, year = {2026}, } @article{21721, abstract = {Swimming bacteria move through a fluid by actuating their moving body parts. They are force-free and can be described as hydrodynamic force dipoles: pushers or pullers. This modelling description is broadly used in biological physics and active matter research, and it has successfully predicted, for example, the superfluid behaviour of suspensions of pushers or the bend instability and emergence of turbulent flows in active nematics. However, this description accounts only for the translational motion of the swimming body and neglects the effects of hydrodynamic torque dipoles, which are relevant to bacteria with rotary motor-driven flagella, such as swimming Escherichia coli. Here we show that the torque dipole of confined swimming E. coli can power the persistent rotation of symmetric discs. The torque dipole leads to a traction force on the discs, an additive mechanism that is both contactless and independent of the orientation of the bacteria. Our results indicate that the torque dipole of swimming E. coli is notable in confined geometries, which is relevant to bacterial transport through porous materials, biofilms and the development of chiral fluids.}, author = {Grober, Daniel B and Dhar, Tanumoy and Saintillan, David and Palacci, Jérémie A}, issn = {1745-2481}, journal = {Nature Physics}, publisher = {Springer Nature}, title = {{The hydrodynamic torque dipole from rotary bacterial flagella powers symmetric discs}}, doi = {10.1038/s41567-026-03189-4}, year = {2026}, } @article{21730, abstract = {Hydrogen peroxide (H2O2) is a crucial member of the reactive oxygen species (ROS) family, playing roles in cellular signalling and immune responses in human health. Moreover, it is a potential biomarker of diabetes when present in aberrant concentrations. Therefore, monitoring trace levels of H2O2 has become a research hotspot for analytical and sensor chemists. In this context, we report a rhodamine-based fluorescent probe (RN), which shows excellent fluorescent enhancement at 555 nm upon the addition of H2O2 along with a low limit of detection (LOD) of 0.67 ppm and fast response (∼2 min). The probe is highly selective for H2O2, showing no fluorescence enhancement with other ROS. RN is synthesised in a one-pot chemical reaction using rhodamine 6G (R6G) and 4,7,10-trioxa-1,13-tridecanediamine (TTDA). H2O2 detection in pre-treated milk samples proves its real-world viability. We found that RN shows low cytotoxicity, which allowed us to successfully explore its potential to monitor H2O2 generation in a diabetic L929 skin cell line and diabetic mice liver tissue. This result demonstrates promising features for assessing early diabetic progression through fluorescence imaging.}, author = {Mondal, Moumita and Ghorai, Pravat and Samadder, Asmita and Freunberger, Stefan Alexander and Banerjee, Priyabrata}, issn = {2050-7518}, journal = {Journal of Materials Chemistry B}, publisher = {Royal Society of Chemistry}, title = {{H2O2 responsive rhodamine-based probe for monitoring early-stage diabetes diagnosis}}, doi = {10.1039/d5tb02687c}, year = {2026}, } @phdthesis{20991, abstract = {Rapid local adaptation to new environments is critical for species persistence, especially in introduced populations. The evolutionary success of these populations is fundamentally dictated by the organization of genetic variation—the genomic architecture—in the face of severe demographic constraints, such as the founder effects and genetic bottlenecks that frequently accompany colonization. A central question in evolutionary biology is whether rapid adaptation relies on major-effect loci, such as chromosomal inversions, or on many small-effect loci dispersed across the genome. Furthermore, the genomic architecture strongly influences the extent to which evolutionary outcomes are predictable. Using introduced populations of the marine snail, Littorina saxatilis, as a model, this thesis investigates how genetic variation and genomic structure drive adaptation following introduction. We employed a population genomics approach on experimentally and accidentally introduced populations to dissect the specific genomic features that underpin divergence in newly colonized environments. In Chapter 2, we tested the predictability of local adaptation through an uncommon 30-year transplant experiment in nature. By distinguishing allele and chromosomal inversion frequency changes from neutral expectations, we found that evolutionary change was highly predictable at the macro-scale (phenotypes and chromosomal inversions), but less robust at the level of individual collinear loci. This result demonstrates that evolution can be predictable when a population possesses sufficient standing genetic variation (SGV), with chromosomal inversions acting as key integrated units that facilitate a rapid response to selection. Building on this, Chapter 3 applied whole-genome sequencing to three accidentally introduced populations (Venice, San Francisco, and Redwood City) to investigate their likely source and genomic patterns of divergence. We identified genomic regions of remarkable divergence potentially associated with local adaptation, and likely fuelled by SGV, while explicitly acknowledging the difficulty in disentangling selection signals from the genome-wide effects of demographic processes. Furthermore, we found that the divergence patterns relied extensively on the collinear genome in these introduced populations, and less clearly on the chromosomal inversions. This observation contrasts with local adaptation observed in the experimental system that relied on both collinear loci and highly selected chromosomal inversions, highlighting how demographic history and genomic architecture influence the detectable signature of local adaptation. A major limitation to conducting large-scale comparative evolutionary studies is the lack of data standardization, which prevents the integration of community knowledge and high-resolution environmental and genetic data. Chapter 4 addresses this by developing a community database for the Littorina system. This platform implements standardized protocols for the integration of diverse phenotypic and environmental data from multiple Littorina species. Likewise, the platform also centralizes the availability of associated genomic data through links to external repositories. This database represents a crucial tool to test complex, large-scale evolutionary hypotheses. Collectively, this thesis strongly reinforces the fundamental importance of SGV as the raw material for successful local adaptation, a conclusion supported by evidence in both experimental and accidental introductions. Furthermore, this work highlights the critical role of the genomic architecture—specifically chromosomal inversions—in driving the predictability and effectiveness of adaptive responses. Our findings underscore how the interplay between SGV and genomic architecture dictates the trajectory and detectability of evolution in colonizing populations, while simultaneously providing a necessary tool to advance comparative evolutionary genomics in emerging model organisms.}, author = {Garcia Castillo, Diego Fernando}, isbn = {978-3-99078-077-0}, issn = {2663-337X}, pages = {199}, publisher = {Institute of Science and Technology Austria}, title = {{The genomic architecture of local adaptation in introduced populations}}, doi = {10.15479/AT-ISTA-20991}, year = {2026}, } @article{21537, abstract = {Nanophotonics has revolutionized the control of light-matter interactions in various fields of fundamental science and technology. In this work, we propose Implosion Fabrication (ImpFab) as a versatile nanophotonics fabrication platform providing the highest spatial resolution, material versatility, and full volumetric control. ImpFab uniquely combines top-down lithography with bottom-up nanoparticle assembly within a hydrogel scaffold, enabling precise control over optical material properties, such as refractive index, by adjusting printing parameters. We showcase the potential of ImpFab by fabricating three-dimensional photonic crystals and quasicrystals, as well as demonstrating optical structures with spatially modulated unit cell material properties. Our results highlight the potential of ImpFab in producing nanostructures with tailored optical functionalities, which are crucial for applications in sensing, imaging, and information processing, and opening new avenues in developing non-Hermitian photonic systems with spatially controlled gain and loss.}, author = {Salamin, Yannick and Yang, Gaojie and Mills, Brian and Grossi Fonseca, André and Roques-Carmes, Charles and Yang, Quansan and Beroz, Justin and Kooi, Steven E. and de Miguel Comella, Marc and Mak, Kiran and Vaidya, Sachin and Oran, Daniel and Swain, Corban and Sun, Yi and Maayani, Shai and Sloan, Jamison and Amin Elfadil Elawad, Amel and Lopez, Josue J. and Boyden, Edward S. and Soljačić, Marin}, issn = {2047-7538}, journal = {Light: Science & Applications}, publisher = {Springer Nature}, title = {{Three-dimensional nanophotonics with spatially modulated optical properties}}, doi = {10.1038/s41377-025-02166-5}, volume = {15}, year = {2026}, } @article{21555, abstract = {Spin-polarized electron beam sources enable studies of spin-dependent electric and magnetic effects at the nanoscale. We propose a method of creating spin-polarized electrons on an integrated photonics chip by laser-driven nanophotonic fields. A two-stage interaction separated by a free-space drift length is proposed, where the first stage and drift length introduces spin-dependent characteristics into the probability distribution of the electron wave function. The second stage uses an adjusted optical near field to rotate the spin states utilizing the spin-dependent wave-packet distribution to produce electrons with high ensemble average spin expectation values. This platform provides an integrated and compact method to generate spin-polarized electrons, implementable with millimeter scale chips and tabletop lasers.}, author = {Woodahl, Clarisse and Murillo, Melanie and Roques-Carmes, Charles and Karnieli, Aviv and Miller, David A. B. and Solgaard, Olav}, issn = {1079-7114}, journal = {Physical Review Letters}, number = {6}, publisher = {American Physical Society}, title = {{On-chip laser-driven free-electron spin polarizer}}, doi = {10.1103/3c1m-d3hh}, volume = {136}, year = {2026}, } @article{21583, abstract = {Non-Hermiticity naturally arises in physical systems that exchange energy with their environment. The presence of non-Hermiticity leads to many topological physics phenomena and device applications. In the non-Hermitian energy band theory, the foundation of these physics and applications, both energies and wave vectors take complex values. The energy bands thus become a Riemann surface, and such an energy-band Riemann surface underlies all important signatures of non-Hermitian topology. Despite a long history and recent theoretical interests, the energy-band Riemann surface has not been experimentally studied. Here, we provide a photonic observation of the energy-band Riemann surface of a non-Hermitian system. This is achieved by a tunable imaginary gauge transformation in photonic synthetic frequency dimensions. From measured topologies of the Riemann surface, we reveal the complex-energy winding, the open-boundary-condition spectrum, the generalized Brillouin zone, and the branch points. Our findings demonstrate a unified framework in the studies of diverse effects in non-Hermitian topological physics through an experimental observation of energy-band Riemann surfaces.}, author = {Cheng, Dali and Wang, Heming and Zhong, Janet and Lustig, Eran and Roques-Carmes, Charles and Fan, Shanhui}, issn = {2375-2548}, journal = {Science Advances}, number = {12}, publisher = {American Association for the Advancement of Science}, title = {{Experimental observation of energy-band Riemann surface}}, doi = {10.1126/sciadv.aec8239}, volume = {12}, 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{21743, abstract = {We present symplectic structures on the shape space of unparameterized space curves that generalize the classical Marsden–Weinstein structure. Our method integrates the Liouville 1-form of the Marsden–Weinstein structure with Riemannian structures that have been introduced in mathematical shape analysis. We also derive Hamiltonian vector fields for several classical Hamiltonian functions with respect to these new symplectic structures.}, author = {Bauer, Martin and Ishida, Sadashige and Michor, Peter W.}, issn = {1432-1467}, journal = {Journal of Nonlinear Science}, number = {2}, publisher = {Springer Nature}, title = {{Symplectic structures on the space of space curves}}, doi = {10.1007/s00332-026-10266-8}, volume = {36}, year = {2026}, } @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{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}, }