서울대학교 램프사업단

Harnessing through-space orbital interactions for multicentred organosulfur catalysis

admsnulamp — Fri, 11 Sep 2026 10:06:58 +0000

Abstract Frontier molecular orbital engineering provides a powerful means to control chemical reactivity and unlock new catalytic functions in main-group compounds. However, prevailing approaches largely rely on geometric distortion, a design principle that has proven highly successful for multivalent p-block centres, but remains poorly suited to divalent chalcogen systems owing to its element-specific nature. Here we introduce a conceptually distinct strategy that exploits through-space orbital interactions to tailor electronic structure in divalent organosulfur compounds. By anchoring four sulfur atoms to a single carbon centre, a spirocyclic scaffold enforces spatial overlap between sulfur p orbitals, giving rise to a four-centred highest-occupied molecular orbital of elevated energy. This design unveils a multicentred main-group catalyst that enables electrophilic arene halogenation with pronounced reactivity, distinguishing it from prototypical organosulfur compounds. Mechanistic studies reveal that multi-atom cooperativity co-localizes enhanced nucleophilicity in the sulfide state with unusual halogen-transfer capability in the corresponding sulfonium state. This catalytic platform is compatible with complex arenes that are otherwise difficult to functionalize and expands the toolkit for late-stage modification of drug-like scaffolds. DOI: http://dx.doi.org/10.1038/s41929-026-01602-y

Symmetry-protected phonon topology and low lattice thermal conductivity in square-octagonal chalcogenides

admsnulamp — Fri, 11 Sep 2026 10:01:34 +0000

Abstract Unconventional lattice geometries provide an effective platform for realizing symmetry-protected topological phonon states that can strongly influence lattice thermal transport. In this work, we explore the relationship between topological phonon band features and thermal transport in square-octagonal (so) chalcogenide monolayers, namely MoS2 and SnS, by combining first-principles calculations with phonon Boltzmann transport theory. Symmetry analysis reveals the presence of nontrivial phonon band topology in the form of symmetry-protected nodal lines. Crossings between nodal lines carrying different symmetry eigenvalues produce fourfold Dirac points that enhance the phonon group velocity (vg), whereas nearly flat nodal lines lead to a strong suppression of vg. The coexistence of these features, together with substantial phonon softening and enhanced anharmonic scattering around the topological band crossings, markedly suppresses the lattice thermal conductivity (kappa l). As a result, room-temperature kappa l values of 4.0 W mK-1 for so-SnS and 18.7 W mK-1 for so-MoS2 are obtained, representing reductions by more than a factor of two and eight, respectively, relative to their hexagonal phases. Our results uncover a direct connection between phonon band topology and heat transport in two-dimensional materials, highlighting lattice symmetry and topological band engineering as promising routes for tailoring thermal properties. These findings further suggest opportunities for designing topological phononic and thermoelectric devices with controllable heat flow. DOI: http://dx.doi.org/10.1039/d6ta04944c

Spin-Valley Anderson Impurity in Moiré Systems: Phase Diagram, Pairing, and Pseudogap

admsnulamp — Fri, 11 Sep 2026 09:57:17 +0000

Abstract Recent experiments support that the magic-angle graphene family can be modeled by a periodic array of correlated quantum impurities immersed in a Dirac sea. This work analytically demonstrates that, with (anti-)Hund's interactions that can originate from electron-phonon couplings, a single impurity can exhibit novel quantum phase transitions, and readily nurture the pairing potential and pseudogap phenomenon relevant to this moir & eacute; family. For broad applicability, we tackle a spin-valley Anderson impurity with general symmetry-allowed (anti-)Hund's parameters (JD, JS), and derive its full phase diagram at half-filling. While the model reduces to well-known Kondo problems in certain limits, we uncover that in the large JD regime, the low-energy physics is controlled by a novel "pair-Kondo" coupling between the bath and an impurity valley-doublet. Using bosonization-refermionization mapping, we show there is a BKT transition from a Fermi liquid with pair-Kondo resonance, into an anisotropic doublet phase that exhibits a non-analytic zero-energy kink in the impurity spectral function, and non-universal power-law scaling in impurity susceptibilities. Importantly, by analyzing the pairing potentials across the phase diagram, we unveil ubiquitous existence of attractive channels under general (anti-)Hund's interactions. More crucially, we analytically reveal the pseudogap shoulders represent multiplet excitations induced by the injected electron or hole, and derive ans & auml;tze of correlation self-energy that reproduce the pseudogap phenomenon in the lattice. All results are established analytically, with further verification by numerical renormalization group calculations. DOI: http://dx.doi.org/10.1088/0256-307X/43/8/080708

Provenance of the Late Palaeozoic Sedimentary Succession in the Huainan Coalfield (North China): Implications for the Tectonic

admsnulamp — Fri, 11 Sep 2026 09:53:50 +0000

Abstract While previous studies have reported a link between provenance changes and the tectonic-paleogeographic evolution of basins in the North China Craton (NCC) and the Qinling Orogenic Belt during the late Palaeozoic, the mechanisms of the provenance transition and tectonic-paleogeographic evolution of the southeastern margin of the NCC and its adjacent basins remain unclear. To investigate the tectonic processes that were responsible for the provenance changes, we conducted a detailed study of the Carboniferous-Permian successions sampled from a drill hole in the Huainan Coalfield, such as sandstone petrology, U-Pb geochronology of detrital zircon grains in sandstones using LA-ICP-MS, and Lu-Hf isotope analysis. The Qt-F-L plots suggest that except for the provenance of the Benxi Formation, which was mainly continental arc, the overlying Formations (Taiyuan, Shanxi, Xiashihezi, and Shangshihezi) were predominantly derived from volcanic-magmatic arc, indicating a shift in sediment source from a recycled orogenic belt for the Carboniferous units to a volcanic-magmatic arc for the Permian units. The ZTR values in the overlying Formations are significantly higher than that in the Benxi Formation, reflecting an increase in mineral maturity and longer transport pathways. Detrital zircon age patterns and E Hf(t)-age plots suggest zircon ages in the Benxi Formation are predominantly Neoproterozoic to Mesoproterozoic, whereas those in the overlying Formations are mainly Late Palaeozoic, with overall negative E Hf(t) values, reflecting clear changes in the source. The tectonic evolution model of the NCC during the late Palaeozoic was reconstructed using the above analyses and the existing paleogeographic framework of the area. In the late Carboniferous, subduction of the Mianlue Ocean plate beneath the Qinling Orogenic Belt started and led to uplift and erosion of the North Qinling Orogenic Belt, resulting in a north-south elevation gradient in the North China region. In the early to middle Permian, accelerated subduction of the Paleo-Asian oceanic plate led to rapid uplift of the northern flank of the NCC, forming the Yinshan-Yanshan and Xingmeng orogenic belts. The significant influx of distal sediments and cyclicity of sedimentary provenance in the Huainan region record the uplift and erosion of the Qinling Orogenic Belt, and reconstruction of these changes is crucial for a comprehensive understanding of the late Palaeozoic sedimentary processes and tectonic-paleogeographic evolution of North China. DOI: http://dx.doi.org/10.1002/gj.70440

Petrographic and geochemical reassessment of the Cambrian Jangsan Formation, Korea: Original composition and paleoenvironmental

admsnulamp — Fri, 28 Aug 2026 18:50:48 +0000

Abstract The Cambrian Jangsan Formation, the thickest basal Cambrian sandstone unit of the Sino-Korean Craton, records the onset of Phanerozoic sedimentation on the Korean Peninsula. Long classified as quartz arenite or quartzose sandstone, the formation contains abundant interstitial sericite whose origin has remained uncertain. If such interstitial material derives from labile detrital grains, conventional framework-based classification may misrepresent the original composition. This study integrates petrographic data from 17 sections, including newly identified localities where detrital precursors of sericite are preserved, with whole-rock geochemical data from two representative sections. The results indicate that the sandstones underwent a complex diagenetic evolution from shallow to deep burial, including mechanical and chemical compaction, quartz cementation and dissolu tion, and sericitization of detrital feldspar. When this alteration is accounted for, the inferred original compo sitions span quartz arenite, sublitharenite, subarkose, and arkose, dominated by subarkose, in contrast to their present classification as diagenetically modified quartz arenite or quartz wacke. Such post-depositional compositional maturation may have biased previous interpretations toward high-energy, long-transport shallow-marine settings. Instead, the inferred subarkosic compositions, absence of marine indicators, immature textures, and new outcrop observations suggest that at least part of the formation is more consistent with fluvial deposition. These results highlight the need to account for diagenetic modification when interpreting deposi tional settings from sandstone composition, particularly in pre-Silurian successions where terrestrial and marine deposits are difficult to distinguish. DOI: http://dx.doi.org/10.1016/j.jseaes.2026.107267

Depth-Dependent Chlorine Cycling at the Magmatic-Hydrothermal Interface of Mid-Ocean Ridges: Insights from Hornfelsic Diabase

admsnulamp — Thu, 27 Aug 2026 15:30:07 +0000

Abstract The conductive boundary layer (CBL) at the magmatic-hydrothermal interface of mid-ocean ridges (MORs) regulates the fundamental exchange of heat and chemical species between cooling magmas and circulating seawater. While this interface is well-documented at shallow, fast-spreading ridges and in ophiolites, its nature in deep-seated magmatic environments-particularly along slow-spreading ridge segments hosting oceanic core complexes (OCCs)-remains poorly constrained. Here, we investigate the physicochemical properties of this interface through a detailed microstructural, geochemical, and fluid inclusion analysis of hornfelsic diabase, the primary constituent of the CBL, recovered from the Onnuri OCC on the Central Indian Ridge. Our results characterize two distinct lithologies: hornblende hornfelsic and pyroxene hornfelsic diabase. Clinopyroxene geothermometry yields peak metamorphic temperatures of 815-987 degrees C, with evidence of localized hydrous partial melting and the formation of amphibole-rich diorite. Despite these intense thermal conditions, the Onnuri hornfels exhibits remarkably low chlorine (Cl) signatures in both amphiboles (<663 ppm) and fluid inclusions (2.0-5.0 wt % NaCl eq.), reflecting interaction with fluids of seawater-like salinity. This geochemical signature contrasts sharply with the high-Cl brines and Cl-rich amphiboles typical of shallow fast-spreading systems. We demonstrate that this divergence is fundamentally rooted in the pressure-regulated phase behavior of seawater. Seawater P-T phase analysis identifies a critical hydrostatic pressure threshold of 80-100 MPa; beyond this limit, phase separation is effectively suppressed, whereas at lower pressures, it becomes increasingly pronounced as pressure declines. Consequently, the high-pressure regime prevents the formation of a basal brine layer-promoting interaction with low-salinity, seawater-like fluids-while the low-pressure regime facilitates brine accumulation. To evaluate whether this mechanism can be applied on a global scale, we performed a meta-analysis of mid-ocean ridge basalt (MORB) chemistry and hydrothermal vent datasets. Our analysis of global MORB datasets demonstrates that magma storage depth exerts the ultimate control over crustal Cl assimilation, with long-term, segment-scale magmatic flux operating as the underlying driver of this vertical architecture. Furthermore, hydrothermal vent fluid data exhibit a corresponding depth-dependent variability, with Cl concentrations stabilizing near seawater values as heat source depth increases. By synthesizing these multi-disciplinary constraints, we propose a unified, depth-dependent model for Cl cycling at the magmatic-hydrothermal interface. We conclude that the emplacement depth of the magmatic heat source, governed by segment-wide magmatic flux, serves as the primary determinant of the hydrostatic pressure of the hydrothermal cell, thereby controlling subseafloor brine formation, the extent of crustal Cl assimilation, and the chemical stability of hydrothermal vent fluids in the global MOR oceanic crust. DOI: http://dx.doi.org/10.1093/petrology/egag064

Ongoing Morphological Transformation from Elliptical to Spiral Galaxies Induced by Gas Accretion from Neighboring Galaxies

admsnulamp — Thu, 27 Aug 2026 15:26:02 +0000

Abstract We present results from spectroscopic observations of three interacting galaxy systems, each associated with a primary galaxy-VCC 1748, SDSS J1106, and 2MASX J0834-which have been proposed as potential examples of reverse morphological transformation from elliptical to spiral types driven by external gas accretion. Using Gemini/GMOS longslit spectroscopy, we obtain spectra along long slits connecting the regions of interest between the two galaxies in each pair. We model the spatially binned spectra with the penalized pixel-fitting (pPXF) method to derive velocity fields and radial profiles of gas-phase metallicity, stellar metallicity, and stellar population age. Among the three systems, only the VCC 1748 system provides spectra with sufficiently high signal-to-noise ratios (S/Ns) to reveal coherent velocity and metallicity structures extending between the companion spiral galaxy and its elliptical target. The velocity profile along the gas bridge of the system is smooth and continuous from the companion spiral arm to the target galaxy, and the elliptical target, VCC 1748, exhibits younger stellar populations and a high star formation rate (SFR) in its newly formed disk regions compared to its central parts. These findings indicate in situ star formation at the newly formed spiral arm of the elliptical target, consistent with ongoing gas inflow from the spiral companion into the elliptical target. Altogether, the results capture an intermediate stage of morphological evolution in which an originally quiescent elliptical galaxy begins to assemble a rotationally supported disk through interaction-driven gas accretion. DOI: http://dx.doi.org/10.3847/1538-4357/ae8d1d

The roles of PROP sensitivity, sweet liking, and stevia consumption frequency in the relative sweetness and sensory profiles of

admsnulamp — Thu, 27 Aug 2026 14:50:37 +0000

Abstract Consumer evaluations of high-potency sweeteners often show substantial variability in relative sweetness (RS) and sensory profiles. This study examined whether genetic bitter taste sensitivity, sweet liking, and stevia exposure history explain individual variability in the sweetness evaluations of rebaudioside A and rebaudioside M. A total of 106 adults completed two-alternative forced-choice comparisons against 4% and 8% sucrose references to estimate RS, with sucrose-caffeine mixtures included to probe bitterness-related modulation. Iso-sweet samples were subsequently evaluated using a rate-all-that-apply (RATA) test to characterize sensory profiles. Participants were classified by 6-propyl-2-thiouracil (PROP) sensitivity, sweet-liking level (low/moderate/high) and stevia consumption frequency (low/high). PROP sensitivity was not significantly associated with RS estimates, concentration-response functions, or RATA-derived sensory profiles. In contrast, sweet liking significantly differentiated responses. Low sweet-likers showed higher RS at the 4% sucrose level than moderate or high sweet-likers, whereas group differences were attenuated at 8%. In the RATA task, moderate and high sweet-likers reported stronger non-sweet attributes, whereas low sweet-likers reported stronger sweet aftertaste. Stevia consumption frequency also differentiated response patterns, particularly under conditions where the balance between sweet and non-sweet cues shifted. The high-frequency group reported stronger non-sweet attributes and lower RS, suggesting greater perceptual separation of non-sweet cues from sweetness. These findings indicate that variability in RS judgments and sweetness profiles is not primarily driven by PROP sensitivity, but rather reflects differences in how consumers weight sensory cues based on liking and experience. This highlights the importance of consumer heterogeneity in evaluating sweetener performance and reduced-sugar product design. DOI: http://dx.doi.org/10.1016/j.foodqual.2026.106074

Post-translational chemical modification of E3 ligase for efficient target protein degradation

admsnulamp — Thu, 27 Aug 2026 14:41:56 +0000

Abstract Targeted protein degradation (TPD) has emerged as a powerful therapeutic strategy, with proteolysis-targeting chimeras (PROTACs) leading efforts to address previously undruggable targets. However, PROTACs face challenges such as low bioavailability and poor pharmacokinetic properties which limit their biological applications. Here, we report a strategy termed post-translational chemical modification targeting chimera (PTcM-TAC), which integrates ligand-directed chemistry into the PROTAC framework to achieve sustained target protein degradation through covalent modification of E3 ligases. PTcM-TAC incorporates an electrophilic dibromophenyl benzoate warhead into the linker connecting the E3 ligase ligand and the protein-of-interest (POI) ligand, enabling selective transfer of the POI ligand onto the recruited E3 ligase while releasing the E3-binding moiety. Mechanistic studies, including LC-MS/MS peptide mapping, pull-down assays, and structural modeling, demonstrated site-selective modification of CRBN by the PTcM-TAC. The resulting ligand-labeled E3 ligase enables sustained pseudo-catalytic target recognition through a simplified binary interaction, thereby maintaining degradation activity even after compound washout. Furthermore, we successfully applied the PTcM-TAC strategy to another representative E3 ligase, von Hippel-Lindau (VHL), which exhibited substantially sustained degradation activity compared with conventional PROTACs. To our knowledge, PTcM-TAC represents the first liganddirected chemical strategy that converts transient PROTAC-mediated ternary complex formation into binary target recognition via post-translational chemical modification of an E3 ligase. We believe that PTcM-TAC could provide a platform for next-generation targeted protein degraders to overcome the current limitation of PROTAC approach. DOI: http://dx.doi.org/10.1016/j.bioorg.2026.110328

Dynamical Test of Cosmic Acceleration: k-nearest Neighbor Cross Correlation of Cosmic Microwave Background and Cosmic Infrared

admsnulamp — Thu, 27 Aug 2026 13:34:12 +0000

Abstract The physical origin of cosmic acceleration remains one of the central questions in modern cosmology. The integrated Sachs-Wolfe (ISW) and Rees-Sciama (RS) effects, which arise from the evolution of gravitational potentials, provide a dynamical test of cosmic acceleration. We measure the cross correlation between the Planck temperature map of the cosmic microwave background (CMB) and a foreground-free map of the 100 mu m cosmic infrared background (CIB) from Y.-K. Chiang, using the k-nearest neighbor cumulative distribution function (kNN-CDF). As the CIB map is reconstructed from similar to 600 million Wide-field Infrared Survey Explorer galaxies extending to z approximate to 2.5, the measurement is equivalent to a galaxy-CMB cross correlation. We find evidence for a positive cross correlation, rejecting the null hypothesis of no correlation at p = 0.02 (2.3 sigma) using the chi 2 test. We further quantify its amplitude with AkNN, defined relative to an assumed cosmological model, and obtain AkNN = 0.95 +/- 0.20 (4.8 sigma) with respect to Lambda CDM mock data including the ISW and RS effects. The kNN-CDF analysis improves the detection significance by similar to 20% over the two-point correlation function. We also explore evolving dark energy by constructing two tomographic maps from the full CIB map; the results are consistent with Lambda CDM. Finer tomographic reconstruction of the CIB, for example from multiband data of SPHEREx, would further tighten constraints on evolving dark energy. DOI: http://dx.doi.org/10.3847/1538-4357/ae8786

Thyroid cancer-associated EZH1 Q571R mutation drives chromatin compaction and H3K27me3 invasion into active chromatin

admsnulamp — Fri, 07 Aug 2026 19:34:17 +0000

Abstract Dysregulation of Polycomb Repressive Complex 2 (PRC2) contributes to cancer. Of its catalytic subunits, Enhancer of Zeste (EZH) 1 and EZH2, EZH2 mutations are extensively studied, but the role of EZH1 in cancer remains largely unexplored. Here, we investigate the thyroid cancer-associated EZH1Q571R mutation and uncover a mechanism that extends beyond catalytic gain of function. Using biochemical, single-molecule, epigenomic, and transcriptomic analyses, we demonstrated that EZH1Q571R significantly enhances chromatin compaction and stimulates PRC2-EZH1 catalytic activity, thereby rewiring PRC2-chromatin interactions. This altered engagement enables PRC2 activity within H3K36me2-marked chromatin typically refractory to H3K27 methylation, leading to widespread epigenetic and transcriptional reprogramming. Notably, enhanced chromatin compaction is observed with EZH1Q571R but not with the corresponding EZH2Q570R mutation, indicating an EZH1-specific mechanism. Functionally, EZH1Q571R accelerated tumor growth in vivo and induced pronounced micronuclei formation ex vivo, reflecting aberrant chromatin compaction and genome instability. Together, our study demonstrates that EZH1Q571R promotes a permissive epigenomic landscape for the progression of follicular thyroid cancer. DOI: http://dx.doi.org/10.1016/j.molcel.2026.06.021

ORTHOGONAL POLYNOMIALS IN THE SPHERICAL ENSEMBLE WITH TWO INSERTIONS

admsnulamp — Fri, 07 Aug 2026 19:25:33 +0000

Abstract We consider asymptotics of planar orthogonal polynomials P-n,P-N (where degP(n,N )n) with respect to the weight |z-w|(2NQ1) /(1+|z|(2))(N)(1+Q(0)+Q(1))+1 (Q(0), Q(1) >0) in the whole complex plane. With n, N -> infinity and N-n fixed, we obtain the strong asymptotics of the polynomials, asymptotics for the weighted L(2 )norm, and the limiting zero counting measure. These results apply to the pre-critical phase of the underlying two-dimensional Coulomb gas system, when the support of the equilibrium measure is simply connected. Our method relies on specifying the mother body of the two-dimensional potential problem. It relies too on the fact that the planar orthogonality can be rewritten as a non-Hermitian contour orthogonality. This allows us to perform the Deift-Zhou steepest descent analysis of the associated 2 x 2 Riemann-Hilbert problem. DOI: http://dx.doi.org/10.1137/25M1764025

Constructing a Mock Galaxy Catalog for the All-sky Spectroscopic Survey of Nearby Galaxies (A-SPEC) Using the Machine-assisted

admsnulamp — Fri, 07 Aug 2026 19:23:04 +0000

Abstract We present a methodology for constructing a mock galaxy catalog for the All-sky SPECtroscopic survey of nearby galaxies (A-SPEC) using the Machine-assisted Semi-Simulation Model. The model is trained on the cosmological magnetohydrodynamical simulation IllustrisTNG to predict baryonic properties of subhalos from dark-matter-only features and is applied to our own N-body simulation tailored to satisfy the requirements of A-SPEC. We have improved the model's accuracy by introducing additional features such as subhalo anisotropy parameters and modified definitions of the subhalo environment, which result in the coefficient of determination R2 = 0.96, 0.90, 0.70, 0.79 for stellar mass, gas mass, star formation rate, and gas metallicity, respectively. The resulting mock galaxies reproduce the luminosity-dependent clustering of the target galaxies when tuned to match the number density. We discuss avenues for further improvement, including the role of environment in the predictions. We release the mock galaxy catalog with the baryonic properties predicted from the model. DOI: http://dx.doi.org/10.3847/1538-4365/ae80aa

Revealing Local Coordination-Modulated Oxygen Evolution Reactivity in High-Entropy Layered Double Hydroxides

admsnulamp — Fri, 07 Aug 2026 19:17:20 +0000

Abstract Layered double hydroxides (LDHs) are promising electrocatalysts for the oxygen evolution reaction (OER), but their sluggish kinetics and structural instability under industrial operating conditions severely limit their practical applications. Here, we demonstrate that high-entropy NiCoZnFeCr-LDHs (HE-LDHs), in which the Fe3+: Cr3+ ratio is precisely controlled, can modulate redox behavior, local coordination, and catalytic activity. NiCoZnFe0.8Cr0.2-LDH achieves superior OER performance with an overpotential of 199 mV at 10 mA cm-2 with a Tafel slope of 37 mV dec-1, while maintaining outstanding durability at 1 A cm-2 over 1200 h, among the best reported for non-noble LDH-based catalysts. Operando spectroscopic analyses reveal that compositional variations tune the oxidation behavior of metals and the local phase evolution, including the reconstruction of Ni species into gamma-NiOOH during OER, together with a particularly significant alteration in Zn local coordination from octahedral to tetrahedral. Density functional theory calculations support that the tetrahedral Zn induces electron localization on adjacent oxygen sites, enabling internal hydrogen bonding that substantially lowers the energy barriers of the potential-determining steps and stabilizes reaction intermediates in the lattice oxygen-mediated mechanism (LOM). This work provides fundamental insights into the structure-activity relationships by composition tuning in multicomponent OER catalysts. DOI: http://dx.doi.org/10.1002/smll.74576

From Dense Gas Clouds to Supermassive Black Hole Seeds: Hybrid Hydro/Direct N-body Simulations of Runaway Collision-driven Inte

admsnulamp — Fri, 07 Aug 2026 19:14:12 +0000

Abstract A population of dense stellar systems at high redshift has recently been uncovered by JWST. To investigate the formation of supermassive black hole (SMBH) seeds in these dense environments without invoking any ad hoc seeding mechanisms, we present star cluster-scale simulations performed with an updated version of the hydrodynamics code Enzo-Abyss, which self-consistently integrates the gravity using a direct N-body method coupled with stellar evolution. By modeling initially dense, metal-poor gas clouds with varying turbulence, we consistently find the formation of dense clusters resembling early-stage nuclear star clusters (NSCs), as well as the formation of very massive stars (VMSs) ranging from 343 M circle dot to 5108 M circle dot via runaway collisions, irrespective of stellar wind feedback strength. Following the direct collapse of these VMSs, the resulting intermediate-mass black holes (IMBHs) grow through Eddington-limited gas accretion and tidal disruption events (TDEs). In our most optimistic model, we find a mass accretion rate of 1.64 & times; 10-4 M circle dot yr-1, with TDEs contributing 23% of the total accretion over similar to 10 Myr. Assuming a steady gas supply into the NSC driven by rapid structural assembly in the high-redshift environment, together with a constant TDE rate, we project that an IMBH with an initial mass of 6747 M circle dot at the center of the NSC can grow to similar to 62,000 M circle dot within 100 Myr of its formation. Our numerical study, conducted within a single self-consistent framework that incorporates the essential physical processes, suggests that VMSs can form in dense gas clouds, collapse into IMBHs, and subsequently provide viable seeds for the SMBHs observed at high redshift. DOI: http://dx.doi.org/10.3847/1538-4357/ae742e

Embedding Independent Length Scale of Flat Bands

admsnulamp — Fri, 07 Aug 2026 19:09:44 +0000

Abstract In flat-band systems with quenched kinetic energy, most of the conventional length scales related to the band dispersion become ineffectual. Although a few geometric length scales, such as the quantum metric length, can still be defined, because of their embedding dependence, i.e., the dependence on the choice of orbital positions used to construct the tight-binding model, they cannot serve as a universal length scale of the flat-band systems. Here, we introduce an embedding independent length scale flat of a flat band that is defined as the localization length of an in-gap state proximate to the flat band. Because flat is derived from the intrinsic localization of compact localized states, it is solely determined by the Hamiltonian and provides a robust foundation for embedding-independent observables. We show analytically that the superconducting coherence length in a flat-band superconductor is given by flat in the weak-coupling limit, thereby identifying flat as the relevant length scale for many-body phenomena. Numerical simulations on various lattice models confirm all theoretical predictions, including the correspondence between flat and the superconducting coherence length. Our results highlight flat as an intrinsic, embedding-independent length scale governing exponential localization associated with flat bands. DOI: http://dx.doi.org/10.1103/tgtq-nrrt

q-deformation of the Marchenko-Pastur law

admsnulamp — Thu, 09 Jul 2026 19:32:42 +0000

Abstract We study a q-deformed random unitary ensemble associated with the little-q Laguerre weight, which provides a discrete analogue of the classical Laguerre unitary ensemble. In the double scaling regime q = e(-lambda/N), where N is the system size and lambda >= 0, we derive the limiting spectral distribution as N -> infinity, which yields a q-deformation of the Marchenko-Pastur law. The limiting density undergoes a phase transition at an explicitly determined critical value lambda(c) : for lambda < lambda(c), the support consists of a single band region, whereas for lambda > lambda(c) an additional saturated region emerges adjacent to the band region. Our derivation of the limiting distribution is based on three complementary approaches: the method of moments, the analysis of a constrained equilibrium problem, and the asymptotic zero distribution of orthogonal polynomials. As a consequence, we establish the convergence of the empirical measure as well as a large deviation principle. In addition, we derive closed-form expressions for the spectral moments using the combinatorial structure of orthogonal polynomials, and obtain large-N expansions for these moments. DOI: http://dx.doi.org/10.1093/imrn/rnag134

Boltzmann sampling by diabatic quantum annealing

admsnulamp — Thu, 09 Jul 2026 19:26:49 +0000

Abstract Boltzmann sampling is a central component of many computational frameworks, including numerous algorithms in machine learning. Although quantum annealers have been investigated as potential fast Boltzmann samplers, their dependence on environmental noise makes precise control of the effective temperature difficult, introducing uncertainty into the sampling process. As an alternative, we propose diabatic quantum annealing-a faster, purely unitary process-as a controllable Boltzmann sampler in which the effective temperature is determined by the annealing rate. Using the ferromagnetic Ising model and the Sherrington-Kirkpatrick model as test cases, we demonstrate that this method achieves rapid and accurate sampling in the high-temperature regime. DOI: http://dx.doi.org/10.1103/9bc4-ddkc

Comparison of identifiability conditions in linear additive noise models

admsnulamp — Thu, 09 Jul 2026 19:22:55 +0000

Abstract This study investigates five prevalent identifiability conditions for linear additive noise models (ANMs): (i) equal error variance (EV), (ii) the conditional variance-based (CV), (iii) the diagonal entries of the inverse covariance matrix-based (DI), (iv) LiNGAM, and (v) variance-sortability conditions. It demonstrates that the CV condition identifies a strictly larger set of models than the DI condition. Hence, when it is unclear which condition holds for a given dataset, an algorithm based on the CV condition is expected to be more reliable for causal structure recovery than one based on the DI condition. Furthermore, we show that none of the EV, DI, or CV conditions has a nested (subset or superset) relationship with the other identifiability conditions such as LiNGAM or variance-sortability. The real dataset, 2022 Baseball Statistics, analyzed in Section 5 is available at http://eng.koreabaseball.com. DOI: http://dx.doi.org/10.1007/s42952-026-00379-x

Spatiotemporal migration of slip localization zones along the Hambaeksan Fault, South Korea

admsnulamp — Thu, 09 Jul 2026 18:27:18 +0000

Abstract Fault zones commonly contain multiple principal slip zones (PSZs) that record distinct episodes of deformation, yet the detailed processes of the migration of activity among PSZs are poorly constrained. In fault zones that juxtapose lithologies with different mechanical properties, the interplay between mechanical heterogeneity, lithological contrasts, and thermal weakening during seismic slip is expected to have a primary influence on where and how slip localizes, but direct evidence of this process in natural fault zones is scarce. Here we present a microstructural, mineralogical, and thermal characterization of the Hambaeksan Fault, a strike-slip fault juxtaposing Ordovician carbonate rocks (Joseon Supergroup) against Carboniferous-Permian siliciclastic rocks (Pyeongan Supergroup) in the Taebaeksan Basin, South Korea. Integrated field, microscopic, and spectroscopic analyses reveal a similar to 45-cm-wide fault core comprising four compositionally distinct breccia units and two PSZs that record contrasting deformation histories. The PSZ at the lithological boundary preserves evidence for hightemperature seismogenic slip, including the incipient graphitization of carbonaceous material (similar to 300 degrees C) and kaolinite dehydroxylation (similar to 400 degrees C) accompanied by injection structures resulting from thermal pressurization. In contrast, the PSZ within the shale breccia lacks these thermal indicators. We propose a model of fault evolution in which thermal modification of the primary PSZ via frictional heating-induced fluidization and destruction of the slip zone foliation resulted in an increase in frictional resistance, thereby promoting the migration of slip localization into the mechanically weaker, phyllosilicate-rich shale breccia. The results show that frictional heating and mechanical heterogeneity control the migration of slip localization between lithologically contrasting sequences in fault zones. DOI: http://dx.doi.org/10.1016/j.jsg.2026.105755