Papers

Pressure provides a powerful thermodynamic route to access hidden structural states in functional materials, yet the microscopic origin of pressure-induced amorphization remains elusive in many complex chalcogenides. Here we report a detailed high-pressure structural study of AgSbTe2,combining synchrotron X-ray diffraction with density functional theory and molecular dynamics calculations up to 60 GPa. We uncover a pressure-driven transformation from the ambient R-3m phase to a fully disordered cubic Im3m phase, through an extended intermediate amorphous state. Enthalpy calculations reveal a near-degeneracy between the R3m and Im3m structures over a broad pressure range, dictating amorphization. Contrary to previously speculated cation vacancies, the amorphization is governed by a pronounced displacement instability of the Te sublattice. Remarkably, the time dependent decompression pathway controls the final structural state, resulting in either amorphous (slow decompression) or fully crystalline (fast decompression) states, indicative of a strong counterintuitive kinetic effect.

We have installed and operated a plastic scintillator detector counter to measure the flux of cosmic radiation during the 2023-2025 tour of the historical vessel Amerigo Vespucci. The Vespucci is the oldest ship of the Italian Navy and serves as a training vessel for Navy cadets. During its tour, some experiments were hosted onboard the vessel, providing unique opportunities for scientists working in different fields. We installed our detector upon the Vespucci's departure from Darwin in early October 2024. The detector collected cosmic-ray data during the journey from Darwin to Trieste, where the worldwide tour ended in March 2025. After about one month of stop in Trieste, the ship continued its tour in the Mediterranean sea, and arrived in Genova on June 10, 2025. We performed measurements of the cosmic radiation reaching the sea level across a wide latitude range, from 15{\deg} S to about 45{\deg} N. The lowest rate (averaged over all azimuth angles) was measured at a geographic latitude of about 7{\deg} N, and was about 16% less than the highest value, which was measured at Trieste, the northernmost location of the journey. Latitude effects on the cosmic radiation flux at sea level are due to the quasi-dipole geomagnetic field configuration, tilted by an angle of about 11{\deg} with respect to Earth's rotational axis.

In this work, we investigate eruptive phenomena associated with X-ray flares on AB Doradus using observations from XMM-Newton. Our aim is to detect such events with the help of continuous X-ray absorption. The variation in the hydrogen column density (NH) is used as a primary diagnostic to detect such absorption or spectral hardening in the soft X-ray band below 1 - 2 keV. These variations may represent the signatures of the eruptive processes associated with flares, such as stellar prominences, failed eruptions, or coronal mass ejections. We applied time-resolved spectroscopy technique to track changes in the absorption parameter during flaring episodes. Our analysis shows statistically significant enhancements in the NH, spanning from 0.3 - 3.4 x 10^20 cm^-2 during the flare and post-flare intervals. Out of six data sets, two sets containing multiple-overlapped flares show significant fluctuations and remaining showed no such variations in NH. These variations indicate the presence of dynamic absorbing material along the line of sight and point to ongoing physical processes within the stellar corona.

We investigate the transverse momentum ($p_T$) spectra and rapidity distributions of the light hadrons $\pi^{\pm}$, $K^{\pm}$, $p$, and $\bar{p}$ produced in Au+Au collisions at RHIC for $\sqrt{s_{\rm NN}} = 7.7$–39 GeV and different collision centralities. The produced medium is modeled as an expanding spherical fireball, with the radial expansion velocity determined from the rate of increase of the fireball radius. The particle spectra are calculated using the Cooper–Frye freeze-out prescription with a local equilibrium distribution function and a blast-wave-like flow profile. The model parameters are fixed from the midrapidity $p_T$ spectra of pions at kinetic freeze-out for different centralities. The same parameters are then used for the other hadron species, with the kinetic freeze-out chemical potential as the only additional free parameter. The model provides a good description of the STAR collaboration data for the $p_{T}$ spectra of light hadrons and predicts Gaussian-like rapidity distributions over the considered energy range across different centralities.

Cross-click operators, the POVM elements for simultaneous clicks in detectors assigned to different measurement bases, are used in QKD and entanglement-verification analyses with realistic threshold detectors to bound multiphoton contributions. Earlier applications verified the needed growth of the minimum eigenvalue $f^{(n)}$ on the $n$-photon subspace only numerically over finite sectors. This work gives an analytic characterization for passive linear-optical analyzers with arbitrary efficiency mismatch and dark counts. The key observation is that every silence operator is the second quantization $\Gamma(A)$ of an explicit single-photon contraction $A$, whose $n$-photon restriction is $A^{\otimes n}$ on $\mathrm{Sym}^n$. This yields: (i) monotonicity $f^{(n+1)}\ge f^{(n)}$; (ii) two-sided exponential bounds $\max_b \gamma_b|A_b|^n \le 1-f^{(n)} \le \sum_b \gamma_b|A_b|^n$, which determine the exact asymptotic convergence rate from single-photon spectral data; (iii) for ideal detectors and $n\ge1$, the exact formula $f^{(n)}=1-\sum_b p_b^n$; and (iv) an exact factorization $1-f^{(n_A,n_B)}=(1-f_A^{(n_A)})(1-f_B^{(n_B)})$ for the two-party cross-click operator. The results apply to polarization, time-bin, and spatial-mode analyzers within the stated threshold-detector model. As an application, we obtain closed-form photon-number weight bounds used in detection-efficiency-mismatch analyses, replacing finite-sector Fock-space numerics by formulas valid for all photon numbers.

The quasi-PDF is fundamentally different from the light-cone PDF, and large-momentum effective theory relates the two through perturbative matching. This has required considerable effort. One of the difficulties in matching is that no single renormalization scheme has been agreed upon for the quasi-PDF, and the resulting variety of prescriptions can obscure the physics underlying the matching. We study how the choice of scheme affects the renormalized quasi-PDF and the matching coefficient, and how the two are related, aiming to identify a scheme in which this dependence becomes transparent. As a first attempt, we consider the transverse-momentum cutoff scheme. It is not used in practice, since a hard momentum cutoff breaks Lorentz invariance, and it has generally been treated as an illustrative example exhibiting the linear divergence of the spatial Wilson line. A careful study, however, reveals a richer structure than expected. The ultraviolet divergence in this scheme depends not only on the cutoff itself, but also on an independent divergence associated with the momentum fraction of the quasi-PDF. Disentangling these two ultraviolet structures, and following the disentangling through the explicit one-loop calculation, uncovers further structure along the way. Once the ultraviolet contributions are correctly separated and assigned to the renormalization counterterm, a finite ambiguity remains, and we use it to restore the quark-number conservation broken by the cutoff. The resulting renormalized quasi-PDF and matching coefficient can be meaningfully compared with the result obtained in dimensional regularization, and we show how the two are reconciled.

We prove a priori exponential growth and decay estimates for locally square integrable eigenfunctions with complex eigenvalues of the non-self-adjoint Schrödinger operator. There appear two natural critical exponents, given by the imaginary parts of square roots of twice an eigenvalue. Any associated eigenfunction has the same exponential growth or decay rate as one of these, or greater than the upper one. The results may be seen as extensions of the Phragmén–Lindelöf theorem, the Agmon estimates and Rellich's theorem to complex eigenvalues. For the proofs we adapt a commutator scheme of Ito–Skibsted~(2020) to the non-self-adjoint framework, presenting a unified approach to all of them. In order to control contributions from the imaginary parts of a potential and an eigenvalue, an additional commutator estimate is employed.

Giant Star-forming Clumps (GSFCs) are kpc-scale regions of enhanced star-formation with stellar masses of $10^7$ to $10^9\,M_\odot$ that are commonly observed in high-redshift galaxies but are rarely detected in low-redshift ($z\lesssim0.5$) galaxy analogues. However, the availability of wide-field galaxy survey data makes it possible to identify potential star-forming clumps in large samples of low-redshift galaxies using object detection models that are based on Deep Learning (DL) techniques. We apply a novel DL-based object detection model to galaxies observed by the Hyper Suprime-Cam Subaru Strategic Survey (HSC-SSP) and CFHT Large Area U-band Deep Survey (CLAUDS). Our model is based on the the Faster Region-Based Convolutional Neural Network (Faster R-CNN or FRCNN) object detection framework but expanded to process the six $ugrizy$ filter band images simultaneously and identify not only clumps and their locations in the host galaxy but also additional contaminants. By adopting the Zoobot foundation DL-model as a feature extraction backbone, we also demonstrate one of the first applications of Zoobot in a downstream task for object detection. Our model achieves a detection completeness of $\gtrsim 0.9$ and purity of $\gtrsim 0.8$ which were validated on a large set of real galaxies into which simulated clumps were injected.

We really design the trimerized circuits for the non-Hermitian one-dimensional Su-Schrieffer-Heeger models. There are three models, the initial one just considers the nearest neighbor coupling, the enhanced one is extended to contain the next-nearest-neighbor coupling, and the final one is reenhanced by introducing the Peierls phase. We investigate the dynamics of the circuit Laplacians with respect to the models, find that the topological states appear in the initial model and the response intervals are substantially affected by the next-nearest-neighbor coupling channels and the Peierls phase. These results are practically demonstrated by numerical simulations and experimental measurements. As a conclusion, the trimerized circuits can provide an adjustable and simple platform to investigate new topological physical states.

We study a static, spherically symmetric black hole obtained from Einstein gravity coupled to a nonlinear electrodynamics model with a quark–antiquark confinement interaction. The metric extends Reissner–Nordström by a logarithmic correction controlled by $\zeta$, modifying both horizon structure and the near-singularity regime. The Hamilton–Jacobi tunneling method for Dirac fermions yields the Hawking temperature; the $\zeta$-dependent terms suppress the small-horizon divergence and signal a remnant. Quantum-gravitational fluctuations are incorporated through Barrow entropy with deformation index $\Delta$. Within the extended phase space we compute the internal energy, free energy, pressure, heat capacity, isothermal compressibility, and Joule–Thomson coefficient. The heat capacity locates $\Delta$-dependent stability regions; the compressibility stays negative across the domain analysed here, marking a mechanically rigid phase with no van der Waals criticality in this branch. The central result is a quadruple coincidence: the peak Hawking temperature, the heat-capacity divergence, the Joule–Thomson inversion, and the zero of the radial tidal force all sit at one radius $r_\star$ defined by $A''(r_\star)=0$, while the extremal horizon and the angular tidal-force zero coincide via $A'(r_h)=0$. These reduce the full critical-point analysis to two scalar equations on $A(r)$. Geometric tidal accelerations are mapped against the thermodynamic critical curves. Event Horizon Telescope observations of Sgr~A* translate into a constraint $\zeta\lesssim 0.7$ at $Q/M=0.5$, leaving a finite window open. The confinement term induces observable corrections to geodesic deviation.

We employ the nonperturbative many-body spin GW method to compute the single-particle Green's function, and the covariance method to evaluate the two-body correlation functions, for the Hubbard model of superconductors. The method, benchmarked at strong coupling and low temperatures, allows simulations on lattices up to $64\times64$, thereby enabling access to the thermodynamic limit. We find the key transition temperatures—namely the Néel temperature and the superconducting critical temperature $T_c$—to be in quantitative agreement with experimental data. Above the $d$-wave superconducting dome, there exists a broad pseudogap region in which the normal-state excitations are suppressed. These results indicate our approach may offer a new route toward investigating strongly correlated systems, especially cuprate superconductors.

We investigate band-structure effects on the absorption spectra of quantum impurities in Dirac materials. We uncover the formation of novel quasiparticles – Dirac-Fermi polarons – emerging from the dressing of impurities by excitations near the Dirac point. These quasiparticles are remarkably robust, persisting for both attractive and repulsive interactions, and across the full range of electron and hole doping. We show that their spectroscopic signature is a generic feature of Dirac materials, accessible with established techniques in both solid-state and ultracold atomic platforms. Our results establish polaron spectroscopy as a powerful probe of Dirac points at energies far from the Fermi surface, providing direct access to band-structure effects beyond conventional approaches.

The axion, a hypothetical particle proposed to solve the strong CP problem and considered a viable candidate for dark matter, has prompted extensive experimental efforts for its detection. This study presents a novel approach combining photon regeneration techniques ("light-shining-through-a-wall") with high-sensitivity Penning trap technologies to enhance the search for axions. Penning traps offer significant advantages, including precise electromagnetic field measurement, strong magnetic fields, and single-particle detection capabilities. By integrating these traps with resonantly enhanced photon regeneration using microwave cavities, our proposed method significantly increases sensitivity to axion-photon couplings. Preliminary calculations demonstrate an unprecedented achievable sensitivity, reaching an axion-photon coupling constant limit of $g_{a\gamma \gamma } \le 7.10\times 10^{-8}\mathrm{GeV ^{-1}}$ in just one day, specifically targeting axion energies below 1 MHz. This experimental setup presents a robust and controlled platform, circumventing astrophysical uncertainties, and represents a substantial advancement in laboratory searches for axions and our understanding of dark matter.

Young open clusters commonly exhibit extended or split upper main sequences, which are widely interpreted as signatures of broad, and in some cases bimodal, stellar rotation distributions. The physical origin of the component commonly associated with slow rotation in this framework remains debated. One proposed channel invokes merger-induced magnetic braking analogous to that seen in Ap stars, which predicts that a large fraction of the relevant stars should host strong, stable surface magnetic fields and exhibit the Ap-like chemical peculiarity responsible for the characteristic $5200\,\mathrm{\AA}$ flux depression. We test this prediction using Gaia XP spectra of A-type stars in a sample of eight young open clusters and a diagnostic of the $5200\,\mathrm{\AA}$ flux depression. If Ap-like magnetic braking made a dominant contribution to the extended main-sequence phenomenon, a substantially enhanced incidence of $5200\,\mathrm{\AA}$ depression would be expected. Instead, we find no evidence for such a large excess. These results disfavour Ap-like magnetic braking as the dominant explanation for the extended main sequence in young open clusters, while leaving open magnetic or non-magnetic channels that would not produce a clear Ap-like $5200\,\mathrm{\AA}$ signature.

Radiative forces acting on neutral bodies moving through a thermal bath represent a unique manifestation of the interplay between relativistic kinematics and thermal fluctuations. Vacuum friction is commonly formulated using the fluctuation–dissipation theorem or related statistical approaches, but such treatments can obscure the elementary momentum-transfer processes, especially in relativistic regimes. Here, we develop a kinetic momentum-transfer framework based on relativistic kinematics in which the radiative force and pressure are obtained by summing individual scattering and absorption events. This approach offers a transparent physical picture while ensuring a self-consistent treatment of Doppler shifts and relativistic transformations. We apply the method to three representative geometries: an isotropic dipolar particle, a thin resonant plate moving normal to its surface, and a thin resonant plate moving parallel to its surface. In the nonrelativistic limit, we derive explicit radiative drag coefficients, providing compact expressions for predicting vacuum friction in moving structures.

U-235 and U-238 are fundamental materials in thermal and fast neutron breeding studies. Accurate evaluation of their fission product yields is of critical importance for advanced reactor design and nuclear waste management. In this work, a baseline Bayesian neural network model (BNN0) with two hidden layers of 20 neurons each was constructed. An improved model, BNN3, was developed by incorporating additional physics-informed features, namely the odd-even effect, beta-decay energy, and isospin, into the network inputs. Comparative analyses of the general distributions of the fission yields and isotopic chain structures demonstrate that BNN3 exhibits significantly improved reconstruction accuracy and consistency with the target cumulative fission-yield distributions. For 16 representative fission products, the energy-dependent yield predictions of BNN3 show better agreement with both experimental data and evaluated libraries, accompanied by noticeably narrower confidence intervals. These results indicate that the incorporation of relevant physical information improves the model's sensitivity to underlying fission mechanisms and enhances its capability to reproduce the systematic characteristics of cumulative fission-yield distributions. Together, these strategies contribute to more accurate and robust nuclear data modeling, providing a methodological foundation for the evaluation and development of next-generation nuclear data libraries.

We give an operator-algebraic and representation-theoretic description of the Hilbert spaces of finite-$N$ bilocal holography. This work is a sequel to the finite-$N$ Hilbert space construction of arXiv:2602.20788 [hep-th]. The central result is the establishment of an invariant dual-pair operator algebra: before imposing the singlet constraint the Fock space carries commuting actions of the color group and of a bilocal Lie algebra, while the projection to the singlet sector selects a single irreducible representation of the invariant Lie algebra, which we call a master algebra. The finite-$N$ trace relations, beginning with the quadratic identities studied here, are shown to become representation-theoretic identities of the selected irreducible representation. We summarize the orthogonal, symplectic and unitary cases, identify the corresponding finite-$N$ constraints, compute the singlet Casimirs, and explain how finite traces and partition functions are obtained through characters of the resulting irreducible representations. This provides a novel, previously unknown mathematical description of the singlet space.

PQ solution to the strong CP problem probably encounters the axion domain wall problem. In this article, we propose a simple and testable solution, assuming that the $U(1)_{\rm PQ}$ possesses mixed anomaly to a hidden $SU(N_c)$ color. Then, the axion field receives a new cosine potential from the hidden instantons, which breaks the $Z_{N_{\rm DW}}$ subgroup explicitly. The new potential lifts the vacua degeneracy, but also drives the effective $\theta$ angle away from the origin, re-incuring the strong CP problem. However, we find that the dark QCD scale within the 0.1 to 3 MeV window survives, maintaining a delicate balance. Two observational signatures are explored: gravitational waves from domain wall collapse, already probed by current PTAs, and di-photon signals from axion-dark-glueball mixing, which require next-generation MeV telescopes. The scenario favors a cold dark QCD sector consistent with dark glueball relic constraints.

Standard routes to a light composite Higgs either rely on tuning a single channel near criticality or protect a pseudo-Nambu–Goldstone coordinate of a coset. We introduce a third mechanism class in which the protected object is an eigenvalue of the renormalized multi-operator scalar kernel of the strong sector. Two basis-invariant diagnostics, a sector participation number $\Psec$ and a sector gap ratio $\Rcoll$, identify collective lightness, but they cannot distinguish an accidental small determinant from a protected zero mode; the missing discriminator is the microscopic sensitivity $\Delta_g=\left|\partial\ln|m_H^2|/\partial\ln g\right|$. A protected collective Higgs is defined by $\Rcoll\gg1$, $\Psec>1$, and $\Delta_g=\mathcal{O}(1)$. We prove that this class is nonempty. A rank-one TC–DTC locking invariant forbids tree-level aligned curvature, while universal vectorlike DQCD bridge fermions, massless in the microscopic Lagrangian but acquiring a common DQCD constituent mass, obey $\partial_h^2\sum_A\Tr\mathcal{M}_A^2\big|_0=0$. The aligned scalar is therefore lifted only at joint two-spurion order, $m^2_{\mathrm{br}}=-(d_X/2\pi^2)g_T^2g_D^2(f_B^4/f_H^2)L_X$, giving $\Delta_{g_T}=\Delta_{g_D}=2$ at leading logarithmic order. The same DTC topology admits a collective top completion and a vector-decoupling route to reducing the positive technicolor contribution to $S$. The mechanism is falsifiable by sector-restricted lattice spectroscopy and coupling-response scans.

The remarkable ability of modern neural networks to generalize improves with increasing network capacity, even when the number of model parameters or effective degrees of freedom exceeds the number of training data points. This phenomenon is all the more surprising given that generalization error diverges when the number of model parameters approaches a critical value from below. Here we use dynamical mean field theory to show that this so-called "double descent" behavior is the outcome of a phase transition in the stochastic field theory describing the training process. We calculate the critical exponents and scaling function of the double descent phase transition, and show that it is marked by a breakdown of the fluctuation-dissipation theorem associated with broken ergodicity. The corresponding response function has the same functional form as the simple London model of the superconducting transition, with the rigidity of the wave function corresponding to the neural network's ability to generalize accurately.

Two-sided octonionic $E_6^L\times E_6^R$ unification carries a nominal second colour $SU(3)_{c'}$ which, gauged, would colour the charged lepton and must be suppressed by hand. We argue no such device is needed: the left-right symmetry acts in spacetime, not internally – in the gravi-weak reading $SU(2)_R$ is the gravitational frame group and the exchange is ordinary parity on the Dirac field; a spacetime operation cannot double the internal colour, so $SU(3)_{c'}=SU(3)_c$, one vector-like colour with a colour-singlet electron. The right sector contributes one colour-blind datum, $\sqrt m$ (values: the exceptional-Jordan trace split, an input; $N_R$ fixes only the colour representation). An anomaly no-go proven here shows every anomaly-free $U(1)$ on visible fermions lies in span$\{Q,B-L\}$, which the $\sqrt m$ pattern does not, in any sign or chirality assignment. The gauged dark-electromagnetic $U(1)_{dem}$ – the mirror electroweak chain's unbroken remnant – therefore carries the parity-mirror of electric charge on the dark sector: the visible fermions are dem-neutral (kinetic mixing the sole portal; no visible fifth force), and $\sqrt m$ enters visible physics only as the spectral label of the Jordan mass operator. The same recognition recovers hypercharge as the consistency relation $Y=Q-T^3_L$, $Q=N/3$, with no right-sector generator. As an application, the spontaneous parity forbids the QCD vacuum angle ($\theta_{QCD}=0$, conditional on the gravi-weak identification), while the flavour rotors have real determinant, so $\arg\det M=0$ at tree level (exact for the Cabibbo rung, texture-contingent in full), coexisting with a nonzero CKM phase. Loop stability – where minimal gauged-$SU(2)_R$ parity solutions fail – is plausibly evaded (no gauged $W_R$) but open, pending the Higgs-bridge matrix elements. We tag throughout what is derived, what is input, and what is open.

We show that with the introduction of new right-handed neutrinos $N_R$, the Peccei–Quinn ($PQ$) transformation in the DFSZ (Dine–Fischler–Srednicki–Zhitnitsky) model depends only on the $PQ$ charge of the scalar singlet $\phi$, namely $PQ_\phi$, and is independent of the sine and cosine of $\arctan(v_u/v_d)$. The model consists of four new scalars: a charged Higgs boson $H^\pm$, a CP-odd scalar $A$, and two CP-even scalars with masses at the EW scale (of a few hundred GeV), and a superheavy inflaton $\Phi$. The scalar fields have been presented in the form of unitary matrices, in which there is no mixing between the axion and the Goldstone boson $G_Z$. As a result, there are two kinds of couplings between the axion and fermions, namely Yukawa-like interactions and anomaly-induced ones associated with derivative axion couplings. {The model belongs to the DFSZ I kind since the axion - photon coupling with $\fr E N = \fr 8 3$.} The trilinear Higgs self-coupling is investigated. We have shown that, in the parameter region where new scalar fields such as the singly charged Higgs boson $H^\pm$ and the CP-odd scalar $A$ have masses around 150 GeV and the vacuum expectation value of one Higgs doublet ($v_u$) is of the order of a few GeV, the coupling modifier $\kappa_\lambda$-a probe of new physics-is consistent with the current experimental constraints.

We present a relativistic study of the exclusive double-charmonium processes $e^-e^+ \to \gamma^*\gamma^* \to \chi_{c1}+\eta_c$ and $e^-e^+ \to \gamma^*\gamma^* \to h_c+h_c$ at $\sqrt{s}=10.6$ GeV in the framework of the $4\times4$ Bethe-Salpeter equation. Since these channels are forbidden in single-photon annihilation, they proceed purely through two-photon quark-rearrangement mechanisms and thus provide a clean probe of relativistic quarkonium dynamics. Using parameters fixed from mass spectroscopy in our earlier work, we obtain leading-order predictions for the total cross sections and their energy dependence. The predicted cross sections are of order $10^{-3}$ fb and exhibit a hierarchy that originates from the radial structure of the meson wave functions, which determines the overlap integrals contributing to the production amplitude. While the absolute magnitudes of the cross sections differ from NRQCD estimates, the qualitative ordering of the channels is consistent with NRQCD expectations. We find a smooth power-law falloff of the cross section for both $\chi_{c1}+\eta_c$ and $h_c+h_c$. These results provide benchmark predictions for future searches at high-luminosity $e^-e^+$ colliders.

Hall measurements in superconducting bilayer nickelate films show sign reversals that cannot be explained by rigid-band electron doping alone. We combine a DFT+CDMFT-derived correlated multi-orbital quasiparticle model with a $T$-matrix treatment of oxygen-vacancy scattering in a semiclassical Boltzmann transport framework. We find that multiband compensation is insufficient by itself: in-plane vacancies selectively suppress the transport channel dominated by the $d_{x^2-y^2}$ orbital and drive $R_H$ through zero, whereas inner-apical vacancies make $R_H$ more negative. These results identify pocket-resolved and orbital-selective oxygen-vacancy scattering as the microscopic origin of the Hall coefficient sign reversal and provide a framework for oxygen-stoichiometry-dependent transport in nickelate films.

Massive black hole binaries (MBHBs) and the higher-order multiples produced by repeated galaxy mergers evolve through regimes that cosmological simulations cannot resolve. These regimes determine merger delays, spins, recoils, and host galaxies at coalescence. We extend the RAMCOAL subgrid model to follow massive black hole triplets within hydrodynamical galaxy simulations. In the original three-stage binary model, black holes evolve as sink particles, undergo dynamical friction, and form bound binaries that harden through stellar scattering, gas torques, circumbinary-disc coupling, and gravitational-wave emission. When a hierarchical triplet becomes chaotic, RAMCOAL samples a library of outcomes from direct N body experiments and follows the resulting mergers, exchanges, and ejections alongside the accretion and spin evolution of each black hole. Isolated-galaxy tests with different triplet geometries show that orbital configuration alone can change which pair merges and its coalescence time. For the first time, we follow an MBH triplet to coalescence within a hydrodynamical simulation of gas-rich galaxies, coupling triplet-driven mergers to host-galaxy evolution. Subgrid integration costs less than 1 ms of single-core time per MBH system and time step, independently of particle resolution. The resulting coalescence properties reflect the environment encountered during subgrid evolution. RAMCOAL thus provides a step towards merger catalogues linking gravitational-wave signatures to the galaxies in which the black holes evolve.

This study presents a comprehensive investigation of the pressure dependent structural, electronic, optical, mechanical, and bonding properties of orthorhombic boron rich chalcogenides B6S and B6Se. Calculations were performed using density functional theory across a wide range of hydrostatic pressures. The computed elastic constants, bulk, Young, shear moduli, and Poisson ratio, revealed mechanical robustness and strong resistance to deformation, even under significant compression. Electronic band structure and density of states analyses indicate that the materials exhibit indirect bandgap semiconducting behavior. Optical results reveal clear pressure induced spectral shifts, particularly in the visible and ultraviolet regions, suggesting modified light matter interaction under compression. Phonon dispersion curves verified the dynamical stability of both materials within the investigated pressure range. Hardness estimations, combined with elastic parameters, and melting temperatures, further indicate that B6S and B6Se possess significant mechanical strength suitable for applications under harsh environments. The thermal properties suggest that both these compounds possess features suitable to be used as excellent thermal barrier coating materials.

Infrared divergences (IRDs) are usually treated as pathologies to be cancelled, regularized, or hidden in dressed asymptotic states. This paper develops a complementary and constructive viewpoint: an IRD is the signature of an itinerant vacuum – a quantum vacuum that wanders continuously through a family of inequivalent states as a classical order parameter evolves. Each value of the order parameter carries its own coherent vacuum, so moving the order parameter means traversing a succession of orthogonal vacua. The IRD is the field-theoretic cost of this wandering, and the $1/f$ noise, gravitational memory, and non-Gaussian fluctuations that emerge from it are its observable classical remnants. The technical core is an exact separation in the real-time closed-time-path (CTP) effective action. The infrared-divergent imaginary part of the influence functional must not be left as a divergent coefficient in a deterministic equation of motion; it is instead converted, by a Hubbard–Stratonovich identity, into a classical stochastic source. This step is an algebraic identity of the generating functional and requires no prior coarse graining or decoherence assumption: the retarded kernel encodes the memory of past vacuum transitions, while the noise kernel encodes the quantum uncertainty of the next one. We apply this construction to four parallel arenas – soft QED, scalar fields in de Sitter space, soft gravitons, and non-equilibrium phase transitions – and show that the same itinerant-vacuum mechanism underlies $1/f$ current noise, the primordial power spectrum, gravitational memory, and order-parameter dynamics. A geometric formulation in terms of a Hilbert-space bundle over the vacuum manifold is outlined as an outlook.

Resource-efficient computation is of central importance in the noisy intermediate-scale quantum (NISQ) era, where decoherence, gate errors, and restricted qubit connectivity severely limit the reliable execution of quantum algorithms. In this work, we demonstrate that incorporating circuit design considerations is crucial for developing resource-efficient variational quantum algorithms. By focusing on the Hadamard test circuit architecture, hardware-aware qubit connectivity, and problem-specific adaptive framework, we analyze how circuit design constraints can systematically reduce the measurement overhead associated with repeated evaluations of the candidate gate pool in adaptive algorithms. Specifically, we demonstrate reductions in the required measurement resources ranging from at least 25% to as high as 50% - 55%. To assess the effectiveness of our approach, we investigate the ground state problem of the nonlinear Schrödinger equation. Overall, our work contributes to resource-friendly strategies for quantum computation and underscores that algorithmic frameworks should systematically integrate circuit design constraints with hardware-aware and problem-specific structures to enhance the practical feasibility of quantum devices in the NISQ era.

Fluctuations in the cosmic electron density are imprinted on the dispersion measures (DMs) of fast radio bursts (FRBs), making DMs a promising probe of cosmology and the spatial distribution of ionized baryons. In this work, we present the first measurement of the angular auto-power spectrum of FRB DMs, using 3455 apparently non-repeating bursts from the CHIME/FRB Catalog 2. We detect an angular correlation signal at $>3\sigma$ significance, associated with large-scale electron-density fluctuations. By fitting the measured spectrum to theoretical models, we constrain two key parameter combinations: $\Omega_{\rm b}h^2$-$H_0$, which probes the cosmic baryon density and expansion rate, and $\Omega_{\rm b}h^2$-$f_{\rm d}$, which traces the baryon fraction in cosmic large-scale structure (LSS). We further assess the robustness of the power-spectrum method against systematic uncertainties arising from the assumed FRB redshift distribution and from the DM contributions of host galaxies (${\rm DM}_{\rm host}$), the Galactic halo (${\rm DM}^{\rm MW}_{\rm halo}$), and the Milky Way interstellar medium (${\rm DM}^{\rm MW}_{\rm ISM}$), using mock samples. Our results demonstrate that the angular power spectrum is largely insensitive to uncorrelated DM components such as ${\rm DM}_{\rm host}$, thereby effectively mitigating the impact of poorly constrained host-galaxy systematics. In contrast to the traditional ${\rm DM}_{\rm LSS}$-$z$ relation, this method does not require individual redshift measurements–it relies only on the overall redshift distribution–and it partially breaks the parameter degeneracies in the $\Omega_{\rm b}h^2$-$H_0$ and $\Omega_{\rm b}h^2$-$f_{\rm d}$ planes. These findings establish the DM angular power spectrum as a robust cosmological probe and a powerful baryon tracer.

We demonstrate that the polarity of the Josephson diode effect in Corbino Josephson junctions can be deterministically controlled by the Josephson-vortex number, which arises as a generic consequence of structured spatial inhomogeneity. By solving the continuum Andreev spectral problem, we identify a mechanism in which the vortex number selectively filters specific spatial Fourier harmonics of the local inhomogeneity. This harmonic selection reshapes the amplitudes and relative phases of higher-order Josephson current harmonics, ultimately reversing the critical-current asymmetry. Numerical simulations of both an effective one-dimensional edge model and full two-dimensional lattice models confirm the robustness of this mechanism. Crucially, our results show that a vortex-parity-dependent reversal of diode polarity is not an exclusive signature of Majorana physics, but can emerge generically from geometric and structural inhomogeneities in Corbino junctions.