Papers

Short-orbit gaseous exoplanets are the best targets to study atmospheric dynamics. A time series of emission observations collected at various photometric filters (phase curves) provides insights into atmospheric flows. Modern observations reveal a wide variety of phase curves, but their utility for probing atmospheric circulation as a function of altitude has not yet been explored in detail. We aim to understand the properties of phase curves and their connection to underlying atmospheric flows, as well as to define a set of multiwavelength observations that could be used to resolve these flows as a function of altitude. We utilized a subset of the solar metallicity models from the grid of ADAM/GCM and state-of-the-art radiative transfer codes to predict phase curves. We made predictions for a variety of photometric filters on board the Spitzer, TESS, CHEOPS, HST, and JWST missions, and explored the sensitivity of each filter to flows at various atmospheric depths. Our calculations show that the main parameter that regulates the phase-curve offsets in our models is the atmospheric temperature, although high metallicity can also have strong impact by reducing phase-curve offsets. This is not fully supported by available observations, which possibly indicates a missing physical process in the models. The predicted contribution functions suggest that the best combination of photometric filters to study atmospheric flows is NIRCam filters because they are sensitive to a wide range of pressures between 10 bar and 1e-4 bar depending on planet temperature, respectively. High-resolution spectroscopy is predicted to detect differential Doppler shifts of 1-4 km/s between molecular bands formed at different altitudes, providing an independent probe of vertical circulations.

Integration of quantum optical technique on-chip is crucial for large scale applications of quantum technology, which were proven in a free space environment to be superior to the corresponding classical technology. Squeezed states of light can be used for enhancing the sensitivity of quantum sensors and for fault-tolerant quantum computing. Although chip-based squeezed light generation has advanced significantly, practical impact remains limited because coupling losses between the chip and off-chip detectors destroy delicate quantum correlations, restricting the amount of observed squeezing. Here, we overcome this limitation by implementing the idea of on-chip quantum measurement with the aid of a parametric amplifier and applying it to the squeezed state generated by a silicon nitride (SiN) microring resonator. In our scheme, two matched SiN micro-rings are sequentially constructed. The first ring generates a squeezed state, whereas the second ring acts as a high-gain parametric amplifier (PA) that measures the squeezed state before the light experiences significant off-chip loss. This architecture is inherently loss-tolerant: the amplifier elevates the quantum noise well above the vacuum level, making the measurement insensitive to downstream losses. We directly observe a quantum noise reduction of 4.6 dB from the first ring, despite a chip-to-fiber coupling loss exceeding 5 dB. This work also demonstrates the first monolithic SU(1,1) interferometer with an estimated 5 dB signal-to-noise enhancement compared to traditional linear interferometers, and thus establishes a practical pathway for chip-based quantum sensors.

These lecture notes provide an introduction to the generation of initial conditions for cosmological N-body simulations. Starting from the definition and properties of Gaussian random fields, we discuss their role in cosmology and the efficient generation of such fields using Fourier methods. The Vlasov-Poisson system is introduced as the governing framework for cold collisionless matter, and its solution via characteristics and Lagrangian perturbation theory (LPT) is detailed. We discuss the use of LPT for initializing N-body simulations, emphasizing the importance of high-order LPT and late-time starts to minimize truncation and discreteness errors. Finally, we discuss time integration schemes, including PT-informed integrators, and their role in accurately evolving the system. These notes aim to bridge the gap between theoretical perturbation methods and practical simulation techniques.

We study the geometry of mixed fields, consisting of a connection and a $B$-field on a principal circle bundle over a Riemann surface, from the perspective of gauge theory and T-duality. Motivated by the foundational work of Atiyah–Bott and Segal, we introduce a twisted Yang–Mills functional whose critical locus, in the flat case, is governed by the simultaneous vanishing of the curvature and the $H$-flux. We show that the gauge group is a semi-direct product of abelian groups parametrised by an integer $\lambda$. The moduli spaces are constructed by presymplectic reduction and shown to be Heisenberg contact manifolds for $\lambda \neq 0$, whose topology we characterise completely. We show that T-duality preserves the twisted Yang–Mills functional and acts on the configuration space of flat mixed fields. We identify the subgroups of gauge transformations that are compatible with the T-duality map and describe the induced action on the singular quotient of T-dualizable flat mixed fields. Precisely at $\lambda =1$ does T-duality descend to an involutive contactomorphism of the moduli space.

The intermediate scattering function and its value at zero time, which is the static structure factor, are both characteristic functions. An exact equation of motion for the ISF carrying a local rate and a memory function is then obtained. To interpret this equation, the ISF is expressed in terms of relaxation modes. The local rate is fixed by a sum rule which reversibility turns into an equilibrium average. The de Gennes narrowing is establshed as a theorem. The memory function being non-negative, the closed form that results is a rigorous lower bound on the ISF at every momentum transfer and every time, and its accuracy is itself predicted. In the diffusive regime, the closed form keeps the single-exponential shape to which spin-echo data are routinely fitted, with both coefficients renormalized by the interaction: the amplitude becomes the SSF of the layer and the dephasing rate the dressed one-adsorbate rate divided by it, explicit in momentum transfer, time, coverage and temperature. When introducing the lateral interaction, a single correlation parameter fixes the equilibrium structure and the renormalized hop rate: exactly along a one-dimensional channel, and on the surface as the nearest-neighbour correlation of a pair approximation completed by a collective (random-phase) structure factor. The result contains no adjustable parameter and is exact at vanishing interaction for every coverage and momentum; the Darken relation comes with it, the correlation between successive moves separated off as a computable factor. Applications to Na/Cu(111) and H/Pt(111) are analysed and discussed.

Cell adhesion to viscoelastic substrates is mediated by focal adhesions (FAs), which dynamically couple actomyosin contractility to the extracellular matrix. Although substrate stress relaxation is known to regulate adhesion stability and cell migration, a predictive physical framework linking viscoelasticity to force transmission and adhesion dynamics remains lacking. Here we review briefly what is known about the active wetting and de-wetting of FAs on viscoelastic substrates and synthesize existing experimental and theoretical work into a two-timescale physical framework to describe the phenomena reported. At short timescales, oscillatory actomyosin-driven displacements are transmitted through molecular clutches, leading to frequency-dependent energy transfer to the substrate. We show that this transfer is maximized at an optimal frequency set by a balance between elastic energy storage and viscous dissipation, establishing a resonance-like mechanism that selects both the effective FA stiffness and traction force amplitude. At longer timescales, this mechanically optimal state couples to adhesion remodelling through an effective surface tension, enabling FA growth and disassembly to be interpreted as active wetting and de-wetting processes. The model predicts that adhesion stability and steady-state size are controlled by substrate stiffness and viscoelastic timescales, as well as mechanosensitive feedback mediated by Piezo1-dependent calcium signalling.

We investigate the geometric structure of the set of spectra of bipartite absolute separable states ($\mathrm{ASEP}_{m,n}$) and absolute positive partial transpose states ($\mathrm{APPT}_{m,n}$), i.e., bipartite quantum states that remain separable or PPT, respectively, under all global unitary transformations. First, we establish general geometric properties of absolute convex sets of matrices, their spectra and extreme points. Regarding absolute separability, we present a permutation-symmetric reformulation of the absolute PPT criterion and use it to demonstrate that $\mathrm{APPT}_{m,n}$ is a spectrahedron for all $m\leq n$: in particular, all its faces are exposed. While $\mathrm{ASEP}_{2,n}$ is a spectrahedron, too, for $\mathrm{ASEP}_{m,n}$ we can in general only show that it is a semialgebraic set for all $m,n\geq 3$. Furthermore, we provide a complete characterization of the faces and extreme points of $\mathrm{APPT}_{m,n}$ and demonstrate that the dimension of a face is determined by the rank of a certain matrix, with maximal proper faces having dimension $mn-m-1$. In the quantitative setting, we provide a rigorous lower bound on the maximal attainable purity of $\mathrm{APPT}_{m,n}$ via an inscribed polytope $\mathcal{P}_{m,n}$ and conjecture that the maximal purity of $\mathrm{APPT}_{m,n}$ (along with its spectra) coincides with the polytope for arbitrary dimensions except when $m=n=2$. Additionally, we also provide a rigorous upper bound on the minimal von Neumann entropy of $\mathrm{APPT}_{m,n}$ and demonstrate numerically that the minimum entropy eventually coincides with the polytope $\mathcal{P}_{m,n}$ as the local system dimension $n$ increases. Finally, we show that the relative spectral volume of $\mathrm{APPT}_{m,n}$ decays exponentially in $n$ by a constant multiplicative factor of the relative volume of the inscribed polytope $\mathcal{P}_{m,n}$.

The equilibrium state of a monoaxial chiral magnet surrounded by a non-magnetic medium (such as air or vacuum) is a helical texture characterized by a single, well-defined wave vector. No metastable states have ever been observed in such systems. Recently, however, it was demonstrated that when a chiral magnet is in close contact with two uniaxial ferromagnets, a large number of metastable helical states emerge in addition to the equilibrium state [Phys. Rev. B 109, 214424]. These helical states are distinguished by their wave number (helicity). In the present work, we elucidate the topological origin of the stabilization of these states –a mechanism we term dynamical topological protection– and investigate their static and dynamic properties. We find that, as a consequence of this dynamical topological protection, the winding number of the helical states remains constant under the application of sufficiently weak magnetic fields and polarized electric currents. Furthermore, when a polarized current is applied to a metastable helical state, a static configuration is reached. This state retains the original winding number, but its winding number density becomes non-homogeneously distributed, concentrating near the interface with one of the ferromagnets. The dynamic response to sufficiently large magnetic fields and currents provides mechanisms to switch between different helical states. Since the magnetic properties depend on helicity, these metastable helical states are highly promising for applications in spintronics and magnonics.

A wide range of variability mechanisms exist among intermediate mass and massive stars, which are not yet fully understood. Using complementary data sources for a large population of B- and O-type stars, we aim to study the prevalence and interplay of different types of variability, including binarity, pulsation, and rotation, to prepare for future modelling. To this end, we analyse high-resolution HERMES spectra and 2-min cadence TESS photometry and characterise the diverse variability observed within a population of 873 O- and B-type stars. The spectroscopic data were normalised using machine-learning techniques, compared to a grid of synthetic TLUSTY spectra to determine stellar parameters, and used to identify radial velocity variability. Photometric time series were analysed using standard frequency analysis methods to detect pulsations and rotational modulation signatures. We find that more than 93 per cent of the sample exhibits photometric variability. Photometric variability caused by pulsations is identified in 82 per cent of the sample, with dominant contributions from $\beta$ Cep and slowly pulsating B-type stars, as well as stochastic low-frequency variability. Based on a limited number of spectroscopic epochs, at least 14 per cent of the stars show evidence of binarity, including both eclipsing and spectroscopic systems. This work represents one of the largest homogeneous surveys of variability for intermediate-mass and massive stars in the Northern hemisphere, and complementing similar efforts in the Southern hemisphere. It provides a statistical framework for future studies of stellar structure and evolution, particularly in the context of asteroseismology.

The possibility to study the nature of fully-charmed tetraquark state $X(6900)$ from its inclusive photoproduction off nuclei near the kinematic threshold is investigated within the collision model based on the nuclear spectral function. The model accounts for $X(6900)$ production in direct photon–nucleon interactions as well as three different scenarios for its internal structure: compact tetraquark, molecule of the two hidden-charm $J/\psi$ and $\psi(3770)$ mesons and the mixture of both of them. We calculate within these scenarios the absolute and relative excitation functions on $^{12}$C and $^{184}$W nuclei at near-threshold photon energies of 30–40 GeV, the absolute momentum differential cross sections and ratios of them for the $X(6900)$ meson production off these target nuclei at laboratory polar angles of 0$^{\circ}$–5$^{\circ}$ and for photon energy of 35 GeV as well as the A-dependences of its transparency ratios at photon energy of 35 GeV. We show that these observables reveal a definite sensitivity to the $X(6900)$ intrinsic structure. Therefore, they might be useful for the determination of this structure from the comparison of them with the experimental data from the future experiments at the upcoming experimental facilities, such as the planned electron-ion colliders in the United States and China.

A measurement is presented for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass $m_{\ell\ell} <$ 30 GeV, using $pp$ collision data at $\sqrt{s} =$ 13.6 TeV recorded by the ATLAS detector at the Large Hadron Collider during the years 2022-2024, corresponding to an integrated luminosity of 164 fb$^{-1}$. The best-fit value of the signal strength parameter, defined as the ratio of the observed signal yield to the one expected in the Standard Model, is measured to be $\mu = 0.64^{+0.44}_{-0.39}$ compared with the expected value of $\mu = 1.00^{+0.47}_{-0.41}$. The corresponding observed (expected) signal significance is 1.7 (2.5) standard deviations under the background-only hypothesis. The result is combined with a similar search performed using 139 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} =$ 13 TeV collected during the years 2015-2018. This combination gives an observed (expected) signal strength of $\mu = 1.03^{+0.35}_{-0.32}\,(\mu = 1.00^{+0.34}_{-0.32})$, corresponding to an observed (expected) significance of 3.4 (3.3) standard deviations.

Unitary matrix models, among other things, play an important role in representing the irregular conformal block and hence LEEA of some asymptotically free susy gauge theories. Here, we develop a method of how to determine the qualitative structure of phase diagram by the deformation of classical potential, and illustrate this by the examples that contain term up to $\cos n\alpha$, $n \leq 3$. We point out that a set of $\beta$ functions on critical “lines" is nowhere a vanishing vector. This generalizes the $n =1$ GWW case and tells us the third order (rather than second order) phase transition in conformity with the range of values for the susceptibility exponent.

Rare-earth based garnets provide a viable platform for studying the frustrated driven magnetic properties of the hyperkagome lattices. Herein, we report a comprehensive study of the magnetic properties and crystal electric field (CEF) scheme of a new Nd$^{3+}$ based hyperkagome antiferromagnet, Nd$_3$Li$_3$W$_2$O$_{12}$ belonging to the garnet family via magnetization, heat capacity, and inelastic neutron scattering (INS) measurements. Magnetization measurement reveals a dominant antiferromagnetic interaction with a low temperature Curie-Weiss temperature $\theta_{\rm CW}^{\rm LT} \simeq -0.2$ K. Two broad maxima are observed in the magnetic heat capacity data under magnetic fields, implying multilevel Schottky anomalies due to the effect of CEF and display a two-step magnetic entropy release. No magnetic long-range order is observed down to 0.1 K. The CEF excitations of the Nd$^{3+}$ ($J=9/2$) ion with $D_2$ point group symmetry, probed via INS experiments, show non-dispersive excitations characterizing the transitions among the CEF energy levels. The simultaneous fit of the INS spectra at different temperatures enabled the mapping of the CEF Hamiltonian and the energy eigenvalues of the Kramers' doublets. The simulation using the obtained CEF parameters reproduces the experimental magnetic susceptibility, magnetic isotherms, and magnetic heat capacity data. The thermodynamic properties and INS-derived crystal-field scheme confirm a Kramers' doublet ground state with an effective spin $J_{\rm eff} = 1/2$ at low temperatures.

In this work, we take the $X(2370)$ with $J^{PC}=0^{-+}$ as a glueball consists of three valence gluons, and construct a six-quark current based on rigorous current-field duality to obtain the glueball-quark Lagrangian. Then we perform Fierz transformation to bosonize the quark current into a series of three pseudoscalar mesons. At last, we obtain ratios among the partial decay widths of the glueball to three pseudoscalar mesons in a model-independent way, which are compatible with the experimental data from the BESIII Collaboration and support assigning the $X(2370)$ as a glueball.

The Liquid Scintillator Neutrino Detector (LSND) experiment aimed at investigating neutrino oscillations, particularly the transformation of muon-type antineutrinos (\(\overline{\nu}_\mu\)) into electron-type antineutrinos (\(\overline{\nu}_e\)). This phenomenon challenges the Standard Model's assumption of massless neutrinos. The LSND employed a large organic liquid scintillator (LS) to detect low-energy neutrino interactions, enhanced by the addition of metal ions such as gadolinium (Gd) for improved signal sensitivity and noise suppression. Theoretical modeling and simulations are used in this paper to accurately interpret experimental results. The FLUKA Monte Carlo code was employed to simulate particle interactions and transport in the detector. Key processes modeled included neutrino interactions (\(\overline{\nu}_e + p \to e^+ + n\)), neutron capture (\(n + p \to d + \gamma\)), and the corresponding light output in the scintillator. The simulations accounted for quenching effects using Birks' law, enabling precise predictions of light yield and detector response to secondary particles. Neutrino fluxes from decay-at-rest (DAR) and decay-in-flight (DIF) processes were calculated, capturing the energy spectra of neutrinos generated by pion and muon decays. Pion production cross-sections and light output efficiency for various particles were also modeled to understand detector performance comprehensively. The theoretical modeling and simulation framework validated the experimental observations and provided insights into the detector's sensitivity and limitations. The LSND results hinted at deviations from the Standard Model, stimulating further investigations into neutrino oscillations and the potential existence of sterile neutrinos.

The detection of Earth-like exoplanets via astrometry necessitates centroiding precision at the 0.3 microarcsec level, thereby imposing stringent constraints on the focal plane geometry of space telescopes. The AGATE focal plane instrument, a proposed component of the NASA Habitable Worlds Observatory (HWO), aims to achieve this objective through the calibration of the intra-pixel response function of CMOS detectors to an accuracy of 50 micropixel (220 nm The present paper proposes a Young's fringes-based calibration method, derived from those employed by JPL and IPAG, for the purpose of mapping the pixel response barycenter offsets across the detector. Using a Pyxalis GIGAPYX-4600 CMOS sensor, we demonstrate via simulations and laboratory measurements that (1) a precision of 500 micropixel is achievable with 10,000 frames (current setup); (2) inter-pixel capacitance crosstalk and fringe hyperbolicity are dominating the errors at small and large scales, respectively; and, (3) an iterative inverse problem approach with a hyperbolic fringe model is proposed to overcome paraxial approximation limits for 1 Gpix focal planes. These results pave the way for on-board calibration of HWO's astrometric instrument, ensuring the sub-microarcsec precision required for exo-Earth detection.

By investigating the origin of the evolutionary discrepancy between the H-function and entropy, we elucidate that the H-function fails to serve as a valid arrow-of-time criterion in the rigorously derived Boltzmann equation for the hard-sphere gas model under the Boltzmann-Grad limit.

The photospheric abundance pattern of the components is a sensitive probe of mass and angular momentum transfer in Algols. With the aim to trace the evolutionary history and disclosed efficiency of mass transfer in Algols we collected new high-resolution spectra for about a dozen Algols with the hermes spectrograph at the Mercator Telescope on La Palma, Canary Islands. In the present paper, which is the first in the series, we present the results of a comprehensive analysis of Z Vul, a hot Algol-type system. We derived the absolute stellar quantities and elemental abundances for the components. The carbon-to-nitrogen (C/N) ratio is the most sensitive tracer of thermonuclear processing and mass transfer. It is found to be within expected value for gainer but donor lacks the severe C/N inversion traditionally expected for a deeply stripped star. An extensive grid of over three million evolutionary models was calculated with the Cambridge STARS code which allows determination of the best-fitting and all surviving models. Constraints from the He and CNO abundances indicate that Z Vul underwent an episode of nearly conservative mass transfer during the Main Sequence life-time of the originally more massive component (Case A). Our detailed chemical tagging confirms that the surface abundances of the mass-losing component represent the delicately stripped outer layers still not reaching the CNO-rich core. This underscores the need of coupling high-resolution spectroscopic abundances with interior stellar profiles to accurately reconstruct the evolutionary history of interacting binaries.

We investigate monolayer MoS$_{2x}$Se$_{2(1-x)}$ alloys across the full composition range using optical spectroscopy. We demonstrate continuous tuning of the optical gap over $\sim$0.35 eV, accompanied by a systematic reduction of the B–A exciton splitting, in agreement with density functional theory calculations. Temperature-dependent measurements reveal a progressive increase of the average phonon energy from Se-rich to S-rich alloys that follows a simple reduced-mass scaling model. Polarization-resolved spectroscopy further shows a monotonic increase of the circular polarization from nearly zero in MoSe$_2$ to $\sim$15% in MoS$_2$ at 78 K. The observed evolution of the polarization is attributed to alloy-induced modifications of the electronic structure that modify bright–dark exciton mixing and the associated valley depolarization. These findings establish alloy engineering as an effective strategy for controlling excitonic properties in TMD monolayers.

Black phosphorus (BP) has attracted attention as a light-emitting layered semiconductor for mid-infrared (MIR) photonics owing to its direct and thickness-tunable bandgap energy, highly anisotropic optical transitions, and potentially suppressed Auger recombination. However, spontaneous and stimulated emission dynamics governed by carrier recombination in BP have remained unexplored because time-resolved emission spectroscopy is challenging in the MIR region. Here we develop a time-resolved MIR emission microscope combining wavelength upconversion with superconducting single photon detection. This approach enables observation of emission dynamics in photoexcited BP at a wavelength around 4.6 {\mu}m with sub-100-ps temporal resolution. Temperature-dependent measurements reveal a crossover from excitonic to electron-hole plasma emission at around 70 K, supported by independent results in the characteristic transition temperature, pump-fluence dependence, and rise and decay dynamics of MIR emission. In a suspended BP structure, we further observe a nonlinear increase in the emission intensity above a well-defined pump threshold. Spectral narrowing and intense picosecond emission pulses appear above the threshold, providing solid evidence of stimulated emission assisted by optical feedback from a Fabry-Pérot cavity. These results elucidate ultrafast carrier dynamics and optical gain formation in BP and establish time-resolved upconversion spectroscopy as a powerful approach for investigating MIR photonic materials and devices.

We give an analytic construction of a tau function for the $q$-difference sixth Painlevé equation ($q$PVI) as a Fredholm determinant through the general Riemann-Hilbert problem associated with it. We show that the tau function is an analytic function on its domain of definition that vanishes at a particular point if and only if the corresponding Riemann-Hilbert problem is point-wise not solvable there. We express the corresponding $q$PVI transcendents in terms of the tau function as well as three copies of it with some of the parameters shifted. Then the vanishing of any of these four tau functions corresponds to the transcendents taking value in a specific corresponding exceptional line on the initial value space of $q$PVI. Finally, we derive an asymptotic expansion of the tau function for small times $t$.

In this work, we show how the specimen drift can be actively compensated by controlling the stage with precision down to the picometre scale. We do this by dynamic control, a generic real-time feedback framework designed to actively stabilize electron microscopy experiments by continuously monitoring an experimental variable from the detector data stream and compensating its evolution during acquisition. The framework, applicable to a broad range of controllable experimental instabilities, includes automated calibration procedures, operates in parallel with image acquisition and is implemented as a software plugin without requiring any hardware modification of the microscope. Results for live drift correction are shown for a selection of TEM and STEM instruments using conventional mechanical stages as well as piezoelectric stages. Experimental results are presented for medium resolution TEM, high-resolution TEM, HR-STEM and in situ observations. With piezoelectric stages, specimen stabilization down to the picometre scale was achieved allowing drift-corrected atomic-resolution imaging. Specimen stage-based stabilization significantly improves long-exposure imaging and in situ experiments by increasing the effective exposure time, preserving the field of view, maintaining identical optical conditions and eliminating the need for numerical alignment of large datasets. Beyond the specific application presented here, dynamic control provides a versatile framework for real-time regulation of electron microscopy experiments and opens new perspectives for quantitative imaging, automated in situ studies and multimodal acquisitions.

Non-contact measurement of small vibrations perpendicular to a surface supports the evaluation of mechanical structures, but in camera-based interferometry, increasing the frame rate makes a trade-off with the field of view and spatial resolution. By recording only brightness changes, event cameras avoid this trade-off and reach high temporal and spatial resolution; our previously reported event topology-based visual vibrometer recovers vibration from apparent motion. This high-speed, high-resolution sensing is well suited to full-field measurement, yet such vibration produces too little apparent motion to capture its waveform. Here we show that event-based spatial-carrier interferometry reconstructs that waveform from moving interference fringes. That displacement moves the fringes, and signed event-density maps built from the event stream are demodulated at the spatial carrier to recover the interferometric phase and fix the otherwise ambiguous motion direction at turning points. Reconstructed waveforms agree with laser Doppler vibrometry over broad drive-frequency and amplitude ranges, with limits set by the maximum fringe speed and the sensor performance. Reconstruction is limited by a minimum aperture of about two fringe periods along the carrier and one along the fringes, which allows the surface to be mapped region by region. These results provide an empirical basis for full-field, spatially resolved interferometric vibrometry with event cameras as a non-contact measurement technique.

Meteorites containing both metal and silicates indicate that some planetesimals were partially differentiated and/or processes mixed planetesimal cores and mantles post-differentiation. Time-resolved paleomagnetic records in these meteorite groups can shed light on the differentiation and mixing histories of such bodies. Previous studies measured paleomagnetic remanences in two such meteorite groups, the IIE irons and the Main Group pallasites, and used thermal evolution and dynamo generation modelling to recover parent body properties. However, these studies assumed that these meteorites only recorded magnetic fields generated by core solidification; an assumption recently shown to be invalid. We use a refined planetesimal thermal evolution and dynamo generation model that considers thermal and compositional drivers of dynamo generation simultaneously to re-evaluate the parent body properties of the IIE irons and Main Group pallasites and constrain the formation mechanisms of these meteorites. We find that none of the remanences require core solidification, but later formed remanences are more likely to record dynamos driven by core solidification. The Main Group pallasites and IIE iron parent bodies likely had radii of $\sim$400km with core radius fractions of $\sim$0.5 and $\sim$0.7, respectively. Impacts shaped both parent bodies: the Main Group pallasites formed too far from the core-mantle-boundary to result from ferromagmatism and instead formed by impacts, and the IIE iron's core radius fraction suggests the parent body experienced mantle-stripping collisions. Overall, combining meteorite paleomagnetism with thermal evolution and dynamo generation models provides insights into the long-term evolution of differentiated planetesimals, their interior structures, and metal-silicate mixing on these bodies.

Space-time metamaterials offer unprecedented control over electromagnetic waves by enabling simultaneous manipulation of spatial and temporal degrees of freedom. However, analytical descriptions of their scattering processes remain fragmented, with existing approaches typically requiring configuration-specific derivations or transformations to specialized reference frames that become impractical for accelerated or multi-interface structures. In this tutorial, we introduce the space-time event scattering and extension method (STESEM), a universal framework for electromagnetic scattering at arbitrary space-time interfaces. By decomposing the scattering process into a local interaction event and a subsequent extension along invariant traveling-wave coordinates, STESEM formulates space-time scattering directly in the laboratory frame without requiring coordinate transformations. The method provides a unified description of scattering amplitudes, frequency transitions and phase transformations for arbitrary incident waveforms and interface trajectories. We demonstrate the framework by deriving the complete scattering responses of canonical space-time structures, including stationary and instantaneous interfaces, space-time corners, uniformly moving interfaces, wedges and accelerated boundaries. Beyond providing analytical solutions, STESEM reveals the physical principles underlying these distinct phenomena and shows that complex space-time scattering processes can be constructed from elementary moving-interface interactions. This framework establishes a systematic foundation for analyzing and designing advanced space-time metamaterials, enabling extensions toward dispersive, bianisotropic and higher-dimensional systems.

We present a generation-resolved analysis of shower-type, spin- and polarization-dependent quantum electrodynamics (QED) cascades initiated by head-on collisions of ultraintense laser pulses ($a_0 = 200$–$1000$) with $10$~GeV electron bunches. Using a Monte Carlo model that tracks cascade evolution across distinct generations, we shows that radiation reaction strongly suppresses high-generation yields. The positron energy spectrum exhibits a systematic softening with increasing $a_0$, and the average photon polarization $\overline{\xi}_3$ increases with pulse duration $\tau$ due to polarization-selective depletion in nonlinear Breit–Wheeler pair production. We identify a scaling relation $a_0^2\tau$ that governs both the maximum cascade generation $G_{\max}$ and the fraction of backward-emitted photons $F_r$, thereby establishing experimentally accessible diagnostics for laser intensity and pulse duration using two observables: $F_r$ and the positron peak energy $\varepsilon_+^{\rm peak}$. These generation-dependent signatures suggest a potential shot-resolved, post-interaction approach for characterization of ultraintense laser parameters in the strong-field QED regime.

Protected superconducting qubits such as the $0$-$\pi$ qubit promise to substantially suppress error rates, facilitating fault-tolerant quantum computing with fewer qubits. Measuring these qubits is challenging due to their protected nature, and thus far no concrete proposal exists for how to measure them without breaking their protection. Here we show how to perform protected measurements of the $0$-$\pi$ qubit in two orthogonal bases. The protection of these measurements is facilitated by their quantum non-demolition nature, allowing faults on ancillary measurement qubits to be tolerated. As experimental progress pushes protected qubits further into the low error-rate regime, our techniques will be crucial for fault-tolerant universal control.

We investigate the conservative dynamics of relativistic charged particles in a Schwarzschild spacetime threaded by an externally supported dipolar magnetic field. The gravitational sector is treated exactly in isotropic coordinates, while the electromagnetic field is described by the leading asymptotic term of the relativistic exterior dipole solution. This formulation provides an analytically tractable relativistic extension of the classical Størmer problem and allows the circular-orbit and stability structure to be studied explicitly. For the outward-Lorentz branch, characterized by a positive signed magnetic coupling for positive azimuthal motion, we find a non-trivial competition between radial and vertical stability. Weak magnetic coupling shifts the radially marginal orbit inward, whereas at stronger coupling vertical instability becomes the limiting mechanism and the inner boundary of stable circular motion moves outward. The associated vertical epicyclic mode progressively softens and vanishes at the vertical stability boundary. The marginally bound sequence exhibits a distinct strong-coupling behaviour, illustrating that energetic and stability boundaries need not evolve together. The radial and vertical epicyclic frequencies also generate characteristic commensurabilities that may provide natural sites for nonlinear orbital coupling. Because the magnetic field is treated as a test field, these charged-particle effects leave the vacuum Schwarzschild null-geodesic structure unchanged. Magnetic signatures in compact-object observations must therefore arise through the dynamics and radiation of charged matter, plasma propagation effects, or physics beyond the test-field approximation. The framework developed here provides an analytical basis for studying nonlinear dynamics, radiation reaction, and more realistic compact-object magnetospheres.

We develop a continuum theory for proliferating active matter starting from a microscopic stochastic model of self-propelled particles undergoing birth, death, and nonlocal competition. Beginning from the master equation, we derive mean-field evolution equations for the particle density and polarization fields and close the resulting hierarchy through a von Mises ansatz, providing a coupled hydrodynamic description applicable to a broad class of proliferating active systems. As an application, we study the recently introduced Active Brownian Bug model, in which the form of flocking emerges despite the absence of explicit alignment interactions. Linear stability analysis predicts both Turing and Hopf instabilities, whose analytical thresholds agree with numerical simulations. The continuum model reproduces the principal dynamical regimes of the underlying particle system, including homogeneous states, stationary periodic clusters, and coherently propagating flocking states. These results establish a general continuum framework for proliferating active matter and provide a physical interpretation of collective motion driven by the interplay between activity and population dynamics.

Fault-tolerant quantum processors based on topological codes execute programs through lattice surgery, where operations must be mapped, routed, and supplied with magic states across a 2D grid of physical patches. Non-Clifford operations require these magic states, produced either by distillation factories or by cultivation, each trading footprint against preparation latency, and delivering a magic state to the data patches that consume it requires routing through the same shared layout as every other operation. Yet placement, routing, scheduling, and magic-state supply cannot be optimized in isolation: two operations with no circuit-level dependency can still contend for the same ports, routes, or magic-state terminals once placed, so a compiler that decouples instruction scheduling from magic-state generation, or hard-codes a single generation protocol, is forced to trade execution time against layout footprint instead of co-optimizing both across protocols. We present Harvest, a resource-aware compilation approach for lattice-surgery that co-optimizes magic-state consumption with circuit-aware placement and congestion-aware routing under a protocol-agnostic resource model, then reclaims unused layout footprint after scheduling. Across standard benchmark suites (QAOA, QFT, QASMBench), Harvest achieves an average speedup of $4.83\times$ (up to $17.8\times$) over sequential execution, improves schedule length by up to $1.35\times$ through circuit-aware placement, and reclaims up to $72.0\%$ of unused magic-state patches and $33.9\%$ of unused routing patches.