Table lookup, often referred to as quantum read only memory (QROM), is one of the most widely used subroutines in quantum algorithms, and constitutes the majority share of algorithmic overheads in most practical applications of quantum computers. It involves the coherent loading of $N$ bitstrings of length $b$ in superposition, and naively has a non-Clifford cost of $N$ Toffolis. It is known that given access to $b\, λ$ dirty qubits, one can reduce the Toffoli cost of QROM to $2\frac{N}λ + 4b(λ- 1)$. In this work, we first present an optimization to reduce this cost to $2\frac{N}λ + 2b(λ- 1) + 2λ-6$ by replacing the ``SelectSwap" architecture with ``SelectCopy". We then provide a further optimization for the qubit-constrained regime where the Toffoli cost is typically $\sim 2\frac{N}λ$, and reduce it to $\sim (1+\frac{1}{b})\frac{N}λ$, cutting the cost by approximately $50\%$ and effectively matching the performance of clean-qubit QROM using dirty qubits for practical values of $b$. Lastly, we provide a parametric family of methods that allow the interpolation of the prefactor of the $\frac{N}λ $ term from $2$ to ($\, 1+\frac{1}{b}\,$) to obtain the best cost for different qubit availability regimes.

We study a local patch of an axion-like dark sector in Minkowski spacetime, containing an initially homogeneous and isotropic non-Abelian $SU(2)$ condensate, and a real pseudoscalar field $χ$, coupled to an Abelian $U(1)$ gauge field which could be that of usual electromagnetism. The pseudoscalar couples directly to both gauge sectors through Chern-Simons interactions, while the $U(1)$ field couples to the $SU(2)$ condensate only indirectly, through the pseudoscalar. We show analytically that a homogeneous oscillating $SU(2)$ background $Q(t)$ acts as a periodic source for $χ$, generating a homogeneous oscillatory condensate $\dotχ$ that in turn modulates the frequency of the $U(1)$ helicity modes. In the linear regime this produces a Hill equation, and when the first harmonic dominates it reduces to a Mathieu equation. We derive the approximate resonance conditions, the leading Floquet exponent, and the conditions for a two-stage enhancement $Q \to χ\to U(1)$. We also highlight an important point: in the exactly periodic, zero-bias limit, the indirect resonance is not intrinsically chiral, because the two Abelian helicities are related by a half-period time shift.

We highlight a generic connection between extensions of the Standard Model featuring low-scale semi-simple embeddings of $\rm{U}(1)_{\rm EM}$ and the phenomenology of magnetic monopoles in the early Universe. In particular, flavour non-universal models provide a well-motivated framework to address the hierarchical structure of Yukawa couplings while allowing new dynamics close to the TeV scale compatible with experimental bounds. In these constructions, the sequential breaking of semi-simple gauge groups through intermediate stages containing an unbroken $\rm{U}(1)$ factor generically leads to the production of light magnetic monopoles whose masses are set by scales far below the scale of Grand Unified Theories. Combining cosmological, astrophysical, and direct-search constraints, the parameter region naturally predicted by these models requires low-scale inflation to dilute the monopoles, followed by reheating below the monopole-production scale, typically around $10^{3}\text{--}10^4\,\mathrm{TeV}$. These results significantly reduce the otherwise large allowed inflationary window and establish a direct connection between flavour physics and the thermal history of the early Universe: future evidence for flavour non-universal interactions would point towards a low-scale reheating, while probes of primordial gravitational waves could directly constrain the scale at which semi-simple groups can appear in flavour models.

The preparation of quantum states is a fundamental requirement for many quantum algorithms. A native route to preparing physically structured states is based on short-time simulation of dynamical processes, such as real or imaginary time evolution. This work presents a resource-efficient framework for the approximation thereof with \textit{bowtie \ac{VarQTE}} which uses classical simulation where possible and quantum resources where necessary. We introduce a framework that leverages existing causal light-cones to minimize quantum resource requirements in the evaluation of gradient and quantum geometric tensor terms by utilizing classical simulation methods for causally relevant subcircuits. This in turn enables exact parameter updates according to McLachlan's variational principle and, thereby, improves numerical stability. We conduct a comparison with a state preparation method that is based on a tensor-network compiled Trotter algorithm: approximate quantum compilation (AQC). In recent work, this approach has shown impressive performance. However, its key-bottleneck is the necessity to have a classical (approximate) representation of the target state. Our numerical experiments indicate that bowtie VarQTE can achieve comparable fidelities without this requirement. We further illustrate how bowtie VarQTE can facilitate a state-preparation pipeline that combines the simulation of imaginary and real time evolution for a sample-based quantum algorithm. In fact, results on 2D systems show how bowtie VarQTE can reduce the quantum requirements compared to standard, sample-based Krylov diagonalization calculations. Our results indicate that VarQTE is a promising primitive for the preparation of physically structured quantum states that reduces requirements on quantum resources by leveraging existing structures and the associated possibility of enabling classical simulations.

Observation of gravitationally induced quantum entanglement is often interpreted as a direct evidence of non-classical gravity. While the form and the degree of non-classicality have been rigorously studied from a foundational perspective, classical models reproducing experimental signatures of such entanglement remain underexplored. Motivated by the experimental simplicity, nearly all existing optomechanical approaches assume Gaussian initial states, and due to the weakness of gravity the quantum Newtonian potential is truncated at the second order. However, this regime admits a classical description in terms of the Wigner-Weyl representation, including features typically associated with quantum entanglement. A clear distinction between classical and quantum predictions emerges only beyond this setting. We comprehensively analyze the possibilities and provide operational witnesses for detection of non-classicality via Wigner negativity, and detection of non-quantumness via negativity of the Weyl operator. Our results demonstrate that the experimental requirements on certifying gravitational entanglement are more stringent than previously anticipated.

We theoretically demonstrate that a superconducting circular current induced in a semiconductor results in emission of orbital-angular-momentum (OAM) entangled photon pairs upon carrier recombination. Combining the macroscopic Ginzburg-Landau theory and the microscopic Bardeen-Cooper-Schrieffer (BCS) theory, we investigate the emission of a superconducting light-emitting diode (SLED) with a spatially varying phase profile in the superconducting order parameter. We show that in the active region of the SLED with a circular supercurrent, radiative recombination processes inherit the order parameter phase and result in photon pairs emitted into modes of different OAM quantum numbers. We demonstrate that coherent superposition of superconducting qubit eigenstates can also be mapped onto a coherent superposition of emitted photon states. We also show that other recombination processes due to thermally excited quasi particles do not significantly degrade the state purity. Our results introduce an original scheme for generating OAM-entangled photons enabling a new method of transmitting superconducting qubit information to photonic channels thereby bridging the gap between solid-state and photon-based platforms for quantum communications and information processing.

In a tidal disruption event (TDE), a star is destroyed by the tidal field of a supermassive black hole. The stellar debris is initially placed on highly elliptical orbits, and a longstanding question in TDE theory is: How does the stellar debris circularize into a disc and accrete? The originally proposed answer to this question is self-intersection shocks, where relativistic apsidal precession results in a strong collision between the incoming and outgoing material. However, global simulations of TDEs tend to find enhanced hydrodynamical dissipation prior to any intersections of the debris orbits, with the material ``fanning out'' into a wide-angle and partially-unbound outflow upon passing through pericenter. We show that this dissipation is numerical in origin and arises from a combination of 1) the change in the kinematics of the debris as it passes through pericenter, with its velocity profile along the stream transitioning from strongly diverging pre-pericenter to strongly converging post-pericenter, and 2) the dependence of numerical algorithms (viscosity switches for particle-based methods and Riemann solvers for Godunov-based schemes) on the diverging vs. converging nature of the fluid. We support this conclusion with analytical and numerical modeling. We discuss possible resolutions to these issues as well as the implications of our findings in the context of observations.

This work addresses the challenges of robust covariance estimation and interpretable outlier detection for multivariate functional data with separable covariance structure. We develop a method that simultaneously improves robustness and interpretability in this context by establishing a connection between stochastic processes with separable covariance structures and the corresponding matrix-variate distribution of their basis representations. Leveraging this connection, we employ the recently developed matrix-variate counterpart of the Minimum Covariance Determinant estimator (MMCD) in conjunction with a truncated multivariate functional Mahalanobis semi-distance to robustly estimate mean and covariance for multivariate functional data. For interpretable outlier detection, we generalize multivariate outlier explanations based on Shapley values to decompose overall multivariate functional outlyingness into time-coordinate-specific contributions. Importantly, we reduce the otherwise exponential computational complexity (relative to the number of components) to linear complexity, while retaining the key properties of the Shapley value. This integrated framework combines robust Mahalanobis distances, MMCD estimators, and Shapley value-based outlyingness decomposition to provide a robust and interpretable approach for analyzing multivariate functional data with separable covariance structures. The effectiveness of this approach is demonstrated through both theoretical analysis and practical applications, including simulations and real-world examples.

Recent XRISM observations suggest that gas mixing induced by sloshing contributes to core heating. We systematically investigate the suppression of cooling flows in galaxy cluster cool cores through three-dimensional hydrodynamic simulations that incorporate both sloshing-driven turbulence and active galactic nucleus (AGN) heating. The AGN heating is modeled as thermal energy input that mimics cosmic-ray heating. Sloshing is represented by simple waves with amplitudes α= 0, 0.15, and 0.3 times the sound speed and wavelengths λ= 200, 1000, and 2000 kpc. We evolve each model from an isothermal initial condition to t = 8 Gyr. Without AGN heating, sloshing suppresses cooling, but it cannot stop it completely unless the core is fully disrupted. Longer wavelengths promote deeper mixing and greater suppression. Sloshing can cause cooler gas to move more quickly than hotter gas. This phenomenon has been observed in a few clusters by XRISM. When AGN heating is included, the dense central gas is heated efficiently, substantially delaying or preventing the onset of a cooling flow. However, for intermediate wave lengths, sloshing can displace the densest gas away from the AGN heating zone, reducing the feedback effect and paradoxically enhancing net cooling relative to the wave-free case. These results highlight a non-trivial coupling between sloshing and AGN feedback, with implications for interpreting XRISM velocity and temperature maps of cool-core clusters.

The Gaia mission has provided precise astrometry and spectrophotometry for billions of stars in the Milky Way, enabling the identification and kinematic characterization of stellar streams. These streams, remnants of disrupted globular clusters and dwarf galaxies, have revealed the structure of the Milky Way's dark matter halo. We show that stellar streams also encode information about the initial mass function of globular clusters. We combine cold dark matter simulations that model the evolution and disruption of embedded globular clusters with observations of stellar streams and globular clusters to infer the initial cluster mass function. We find that initially more massive clusters produce more massive streams, but deposit a smaller fraction of their initial mass into those streams. Using stream mass and angular momentum measurements, we recover a declining, power-law-like initial mass function with a slope $α= 1.3\pm0.05$ for streams $\gtrsim 1000\,M_{\odot}$. This work establishes stellar streams as a novel probe of the early mass distribution of globular clusters.

Triple systems have progressively been recognized as ubiquitous in our universe and provide a good testing ground for wave generation and propagation in nontrivial environments. We study the dynamics of triple systems in a fully nonlinear setting. In particular, we analyze numerical relativity simulations of head-on collisions of black holes in the presence of a companion. We show evidence for Doppler and gravitational redshift in the ringdown, and clear signs of amplification by lensing. In certain cases, we also show the appearance of a second image, with hints of resonant mode excitation. Our results pave the way for the understanding of mergers in the vicinity of massive companions. Even in extreme setups we do not find collapse to black holes from lensed gravitational radiation.

We prove a version of the completeness hypothesis that follows from the coexistence of symmetry and gravity: tree-level gravitational scattering mandates single-particle states in all possible irreducible representations of the symmetry group constructible from a single seed charge. Our main assumption is that the leading high-energy behavior of scattering is universal irrespective of charge, thus satisfying the equivalence principle. Curiously, we discover that these newly-deduced states contribute democratically - that is, with equal interaction strengths - to scattering.

We investigate magnetic-energy dissipation, current-sheet dynamics, and nonthermal particle acceleration in three-dimensional relativistic reconnection in an electron--ion plasma with a realistic mass ratio. Using particle-in-cell simulations of a double Harris current sheet, we explore a range of ion magnetisations and guide-field strengths to determine how guide fields regulate the overall magnetic energy dissipation. At low magnetisation, $σ_i=0.1$, increasing the guide field suppresses reconnection: magnetic-energy dissipation decreases, the growth of tearing modes is weakened, and nonthermal particle acceleration remains inefficient. At higher magnetisations, $σ_i=1$ and $σ_i=5$, the behaviour changes qualitatively. In the zero-guide-field case, strong drift-kink activity corrugates and broadens the current sheet, inhibiting efficient tearing-mediated reconnection. A weak guide field suppresses this drift-kink-driven disruption, allowing the current sheet to remain laminar and more coherent and thereby enhancing magnetic-energy dissipation. However, once the guide field becomes too strong, reconnection is again suppressed: the onset is delayed, tearing activity weakens, current-sheet compression is reduced, and the system retains a larger fraction of its initial magnetic energy. This non-monotonic behaviour is reflected consistently in magnetic-energy evolution, Fourier analysis of the tearing and kink modes, current-sheet thickness, and nonthermal particle acceleration. The most dissipative cases are not necessarily the zero-guide-field runs, but rather those in which the guide field balances drift-kink suppression without strongly impeding the tearing modes. Our results show that the overall system evolution is controlled not only by the available magnetic energy, but also by the guide-field-regulated morphology and stability of the reconnecting current sheet.

One of the most useful spectral diagnostics of accreting black hole systems is the Fe K$α$ fluorescence line. Detected in many systems, it is often used to estimate the black hole spin, as its breadth is attributed to relativistic kinematics near the spin-dependent innermost stable circular orbit (ISCO). In a companion paper, we showed how continuum spectra emitted by accreting black holes can be derived from snapshots of general relativistic magnetohydrodynamics simulations by combining radiation transfer solutions for the disk body and the corona. In this paper, we focus on the Fe K$α$ line, solving its transfer problem on the basis of local ionization and thermal balance. Its equivalent width is $\sim 25-225$ eV, depending mainly on viewing angle, for an accretion rate of 1$\%$ Eddington. Contrary to common assumptions, the illuminating X-ray spectrum and ionization parameter $ξ$ can be strong functions of radius; e.g. $ξ\propto r^{-1.5}$ in this simulation. Consequently, the region of the disk near the ISCO is completely ionized and contributes almost no Fe K$α$ photons; most of the flux is made at radii $\gtrsim 10 r_g$. The lines are broadened by a combination of relativistic Doppler shifts, Compton broadening in the disk atmosphere, and the differing line energies emitted by different Fe ions. These new mechanisms expand the parameter space of acceptable models, including the possibility of broad line profiles without large black hole spin; physical trends revealed by the simulations can refocus fitting efforts on the most relevant sections of the parameter space.

International scientific collaboration is organized primarily by researcher-level logic and network dynamics in which scientists seek partners at the frontier of their field with little consideration of national affiliation. Research security policies that raise the friction costs of international collaboration are often assumed to operate against this logic, aiming to produce selective withdrawal from sensitive fields to deny knowledge transfer to specific countries. This paper tests that assumption against eight years of bibliometric evidence from China's scientific output from 2018 through 2025 across 27 Scopus subject categories. China's internationally co-authored publication share declined universally across all fields after 2018, consistent with China's push for domestic capacity maturation, but the pattern of decline is inconsistent with the deterrence prediction. Fields with high dual-use proximity, including computer science, materials science, physics and astronomy, chemical engineering, and engineering, showed the least contraction (3-6 percentage points), while fields with minimal dual-use salience (psychology, nursing, dentistry, and health professions) showed the steepest declines (8-24 percentage points). The findings suggest that governments raised the friction level but did not redirect the network nor suppress collaboration in sensitive areas. Researchers practiced adaptive participation, maintaining frontier collaborations while adjusting the form and language of their engagement. This pattern matches what the invisible college theory and the Ostrom knowledge commons framework predict.

Autonomous agents deployed in regulated domains must produce a verification artifact per consequential output: a record an auditor can re-execute offline, capturing what was claimed, against what source, by whom, when, and how. Production verification today splits into two unstandardized halves. Probabilistic verdict patterns (self-consistency voting, reviewer LLM ensembles) produce judgments, not artifacts. Artifact-producing patterns (RAG, tool-augmented traces, generator-verifier loops) produce vendor-specific records no external auditor can reconstruct without bespoke integration. Pramana defines the missing wire format. Every consequential agent output is wrapped in a typed ClaimAttestation with one of four variants (measurement, inference, analogy, citation), each paired with a verify() operation against the recorded source. verify() is deterministic for MeasurementClaim and CitationClaim. For InferenceClaim and AnalogyClaim, determinism is conditional on the oracle (audit-replayable when LLM-backed). The four-way typology derives from classical Indian epistemology (pramana, valid means of knowledge). The lifecycle is specified in TLA+ and exhaustively verified under TLC across three symmetry-reduced models: 38,563 distinct reachable states, zero invariant violations. The Python reference implementation passes 84 tests. An A2A and MCP wire-extension manifest layers three deployment-grade invariants: reachability, SLA bound, and offline re-verifiability. An exploratory pilot (n=100, 2,275 reviewer calls) probes LLM-as-judge in code generation. The strongest observation is a 40-percentage-point raw FPR delta across corpora, consistent with reference-solution quality contributing significantly. The pilot does not validate Pramana on its own; the structural argument and formal verification do that.

Context. Since the eighties, the combination of program analysis techniques has been increasingly recognized as a promising approach to overcome the limitations of standalone methods. While individual techniques, based on either static or dynamic analysis, address important challenges in software dependability, their integration often yields synergistic effects on precision, coverage and insights. Objective. This paper surveys a significant portion of the modern literature on combining program analysis techniques, consisting of 248 primary studies, with the aim of cataloging the types of interactions and synergies that were exploited to define combined-program-analysis techniques so far. The goal is to provide a structured understanding of why and how program analysis techniques can be conjoined, and which benefits can arise from their interactions. Method. We devise an original taxonomy that classifies combined-program-analysis techniques according to their aimed synergistic effects, inter-analysis workflows and interaction schemata (to which we refer to as mapping functions). We then map the primary studies to the taxonomy, answering research questions on which synergistic effects those studies pursued via the combination of analysis techniques, which inter-analysis workflows they embodied, and which types of mapping functions they exploited. Conclusion. Our taxonomy and literature mapping reveal the commonalities and the differences, in terms of goals and patterns, in the design of combined-program-analysis techniques. Thereby we provide a framework of concepts that can foster the ability of researchers and practitioners to reason on existing combined-program-analysis techniques, and steer further research on new useful combined-program-analysis techniques and analysis frameworks.

With the rapid development of information and communication technologies in recent years, the transmission capacity of single-core optical fibers has nearly reached its physical limit. Space-division multiplexing based on multi-core fibers offers an effective solution to this bottleneck. Multi-core fibers feature high integration and large transmission capacity, and their unique structural characteristics also give them special value in fiber-optic sensing applications. Among various types of multi-core fibers, coaxial dual-core fibers (CDCFs) have shown promising performance in particle trapping, signal emission, and spectral analysis. To enable reliable interconnection between different types of multi-core fibers and single-core fiber arrays, this paper presents the design and fabrication of a fan-in device for coaxial dual-core fibers with different core diameters. The proposed method relies solely on cold-processing techniques and does not require any fusion splicing or thermal processing. The device is implemented on a V-groove substrate. Through structural design, fabrication, and experimental characterization, the average insertion loss of the ring core and the central core at a wavelength of 980 nm is measured to be 2.15 dB and 1.25 dB, respectively, demonstrating the successful fabrication of a coaxial dual-core fan-in device.

Near-field electromagnetic focusing is central to 6G communication, sensing, and integrated sensing and communication (ISAC) systems. However, for a fixed aperture, the resolution-constrained usable range of conventional single-layer transmissive metasurfaces is far shorter than the classical Rayleigh distance. This discrepancy stems not from fundamental near-field physics limitations, but from inadequate wavefront control, implementation imperfections, and the quadratic degradation of axial resolution with distance.To quantify this gap, we distinguish the Rayleigh distance from the engineering-usable near-field distance (UNFD), defined as the maximum range where predefined focusing gain and resolution requirements are jointly satisfied. Under identical aperture, feed, and input power constraints, we investigate how stacked intelligent metasurfaces (SIMs) extend UNFD via cascaded wavefront shaping. A unified framework combining effective-phase-distance and discrete Green's-function operator perspectives is developed, interpreting multilayer SIM design as an operator approximation problem for ideal near-field focusing.We derive low-complexity analytical models revealing an inherent distance-resolution dilemma: lateral resolution degrades linearly with distance, while axial resolution degrades quadratically, making axial performance the dominant bottleneck. Multilayer stacking mitigates this by improving wavefront curvature matching and reducing residual phase error. Engineering correction factors for practical imperfections and a higher-order phase framework for extreme near-field operation are incorporated. Numerical simulations confirm that increasing layer count pushes UNFD closer to the Rayleigh limit, but gains saturate as accumulated losses offset control flexibility benefits.

The ``holography of information'' (HoI) principle argues that gravity can encode information redundantly in asymptotic observables. Although HoI is ultimately a nonperturbative claim, its standard motivation uses semiclassical gravitational constraints, the boundary nature of the Hamiltonian, and vacuum-sector cyclicity. We ask what happens when the same semiclassical path-integral reasoning allows topology sums that generate baby-universe or $α$-sector data. Our analysis is conditional: such sectors need not survive in every unitary completion, and the Baby Universe Hypothesis of McNamara and Vafa instead suggests $\dim\mathcal H_{\rm BU}=1$ in consistent $d>3$ quantum gravity. If $\mathcal H_{\rm BU}$ is nontrivial, as in the Marolf--Maxfield formulation and in ensemble-like examples such as JT gravity, then HoI is naturally refined to an $α$-sectorwise statement, $\overline{\mathcal A_\infty^{(α)}|0_α\rangle}=\mathcal H_α$, rather than completeness on the full topology-summed Hilbert space. In a fixed $α$-sector, HoI may obstruct AMPS factorization and allow a smooth horizon; in an unconditioned topology-summed state, the sector-independent obstruction is not automatic. A Bell-pair diagnostic shows that a sector-independent smooth interior requires aligned interior reconstructions, or access to the sector label. Thus the HoI-based absence of firewalls becomes conditional on global sector data, in tension with the generally covariant expectation emphasized by Bousso that horizon normalcy should be determined by local semiclassical geometry. If the exact theory collapses $\mathcal H_{\rm BU}$ to one dimension, the obstruction discussed here is absent.

The Quantum Approximate Optimization Algorithm (QAOA) is a leading candidate for demonstrating quantum advantage on near-term devices, yet the physical origins of its efficacy remain poorly understood. In this work, we study QAOA for random $k$-SAT problems within a universal-mixer $k$-local search framework, establishing a formal correspondence between adiabatic state transfer and the QAOA ansatz. This correspondence yields a rigorous performance guarantee for random instances with clause density $m=O(n^{1+ε})$ and circuit depth $Θ(n^2)$. We further investigate the NISQ regime with shallow circuits of depth $p=O(n)$. Surprisingly, the optimal parameters do not become stochastic under depth compression, but instead remain confined to a structured low-dimensional region, which we identify as a smooth adiabatic manifold. Numerical evidence indicates that this manifold persists across different circuit depths and arises from the variational suppression of adiabatic leakage. Based on this structure, we propose the smooth adiabatic-manifold parameterization (SAMP) strategy, transforming parameter optimization from an unstructured high-dimensional search into a guided refinement process. Numerical experiments on random 3-SAT instances show that SAMP achieves sublinear optimization scaling with circuit depth while providing robust zero-cost initialization for deep circuits.

Interpolation and smoothing using cubic and generalized splines are fundamental tools in data analysis and statistical modeling. Recently, fast computational algorithms were developed for natural $L$-splines of order four, which arise as piecewise solutions to the differential operator $L_ξ^2 = (\frac{d^2}{dt^2} - ξ^2)^2$. In this paper, we extend this mathematical framework to the important case of clamped (or complete) boundary conditions, where the first derivatives at the interval endpoints are prescribed. We explicitly construct the governing linear system for the interpolation problem and mathematically prove that the resulting tridiagonal matrix is strictly row diagonally dominant, thereby guaranteeing its invertibility and the numerical stability of the fast algorithm. The proposed method is implemented in MATLAB. Furthermore, the developed clamped $L$-splines provide a foundation for constructing multivariate clamped polysplines, which serve as a promising alternative to Physics-Informed Neural Networks (PINNs) for solving partial differential equations in Mathematical Physics.

The NetMob Data Challenge releases a comprehensive public transportation dataset from Niterói, addressing the lack of high-quality mobility and passenger demand data. Based on operational records from March 2026, the dataset combines four main sources: GPS telemetry from buses, approximately 7.2 million ticketing transactions, auxiliary transit data (routes, stops, and weather), and urban infrastructure and socio-demographic information. Together, these sources provide a detailed view of both transit supply and passenger demand. The data were preprocessed, cleaned, and anonymized to preserve privacy and improve reliability, including the removal of operational inconsistencies and anonymization of passenger identifiers. Access is restricted to challenge participants who accept the Terms and Conditions and sign an NDA. The paper describes the data collection and preprocessing pipeline, dataset organization, and mobility patterns observed in the system. The dataset supports research on topics such as public transportation efficiency, demand forecasting, accessibility analysis, service reliability, and the influence of external factors like weather on urban mobility.

Public confidence in democratic institutions has declined across many OECD countries over recent decades, while political participation and policy influence remain unevenly distributed across socioeconomic groups. Concurrently, democratic backsliding, declining electoral participation, and persistent concerns regarding institutional transparency and accountability have raised questions about whether existing governance structures are capable of sustaining broad-based legitimacy in complex modern societies. These developments motivate a central institutional design question: can governance systems be restructured to expand participation, improve transparency, and strengthen accountability without undermining stability or decision quality? This thesis proposes Programmable Participatory Governance (PPG), a formal governance framework designed to address these institutional deficits through the integration of democratic theory, institutional economics, and cryptographically verifiable distributed systems. PPG synthesises insights from deliberative and participatory democracy, collective action theory, direct democratic governance, and distributed computation to define a programmable architecture for transparent, verifiable, and scalable civic coordination. The framework is formally specified and evaluated through simulation and systems-oriented architectural analysis. The thesis examines how programmable governance mechanisms can support participatory decision-making while preserving procedural integrity, auditability, and institutional resilience under conditions of large-scale coordination. The objective is not to replace existing democratic institutions outright, but to explore how computationally mediated governance structures may augment or improve contemporary democratic processes in contexts where conventional institutions exhibit persistent structural limitations.

Nuclear batteries require radioisotopes with specific combinations of half-life, decay mode, and radiation properties, yet most candidate fuels lack scalable production routes. We show how the future availability of deuterium-tritium (D-T) fusion neutrons could enable manufacturing nuclear battery radioisotopes at many orders of magnitude higher rate than at present. We assess the capability of 14 MeV D-T fusion neutrons to produce nuclear battery radioisotopes by simulating feedstock material irradiation with neutrons. Promising radioisotope candidates include ${}^{147}$Pm, ${}^{63}$Ni, ${}^{39}$Ar, and ${}^{137}$Cs. Some feedstocks allow a radioisotope to be produced at scale while also closing the tritium fuel cycle, resulting in hundreds to over one thousand kilograms of high specific activity radioisotope per gigawatt thermal year of D-T fusion irradiation. We perform OpenMC simulations of an enriched ${}^{148}$Nd blanket for a tokamak, demonstrating that tritium self-sufficient designs can produce over one ton of ${}^{147}$Pm per gigawatt thermal year, equivalent to $\sim$one billion Curies per year of ${}^{147}$Pm. Operation of such a blanket would represent an unprecedented increase of nuclear battery radioisotope production capability.

Plasmonic optical tweezers based on Double Nanohole (DNH) structures are an emerging tool for label-free single-molecule manipulation. However, their current performance is hindered by low signal-to-noise ratios for small proteins, fabrication variability, and thermal damage risks from high laser power requirements. To address these limitations, we present a comprehensive optimization of DNH parameters using systematic simulations and morphological characterization. We evaluate critical structural features, including gap size, gap length, gap curvature, wedged tapers, adhesion layers, and the inclusion of interior pillars. By tailoring these variables, we aim to maximize trapping stiffness, local electric field confinement, and transmission variation upon trapping (ΔTT), while minimizing the required optical power. The resulting optimized DNH design substantially outperforms reference structures, delivering an almost 3-fold increase in electric field enhancement and a 5-fold improvement in the trapping transmission signal. These refinements provide a robust framework for developing highly efficient, reproducible optical tweezers for advanced single-molecule biophysics.

We derive a generating function for the number of integer compositions of $n$ into $k$ parts (i.e., $k$-compositions of $n$) with a given number of inversions, and obtain similar results for $k$-compositions of $n$ with a given number of descents. Our approach relies on a known bijection that associates each integer composition $σ$ with a pair $(π,λ)$, where $π$ is a permutation and $λ$ is an integer partition. We show that the distribution of inversions and the distribution of descents over $k$-compositions are related, respectively, to the distribution of (maj,inv) and to the distribution of (inv,des) over permutations of $\{1,2,\ldots,k\}$, where maj, inv, and des denote the classical permutation statistics major index, inversion number, and descent number, respectively.

In this paper, we introduce a Clifford algebra framework for Julia-type dynamics driven by the geometric product. The nonlinear iteration \[ f(\vec{x}) = (\vec{x}\diamond \vec{n})^p \diamond \vec{n} + \vec{c}, \qquad p \ge 2, \] is studied in a real $n$-dimensional inner-product space $V$, where $\vec{x}, \vec{n}, \vec{c} \in V$ and $\vec{n}$ is a unit vector. The main result reveals a previously unreported invariance phenomenon: although the geometric product generates higher-grade multivector components at intermediate stages, a built-in grade-reduction mechanism ensures complete collapse back to the vector subspace. Consequently, the Clifford Julia operator is shown to be closed on $V$, and the iteration defines a well-posed nonlinear dynamical system in arbitrary dimensions. This invariance is established through a structural decomposition of the Clifford product and an inductive closure argument, supported by explicit verification in low-dimensional cases and a general proof in $\mathbb{R}^n$. The results demonstrate that classical Julia dynamics can be consistently extended beyond the complex plane into higher-dimensional geometric algebra without loss of geometric interpretability. The framework opens a new direction for fractal-type dynamics in Clifford algebras, providing a unified algebraic setting for higher-dimensional invariant-preserving iterative systems.

We describe and axiomatize finite solitaire puzzles and zero sum sequential games graph theoretically. Zermelo's theorem telling that there is a win for one of the players or a draw follows from the definitions. The god number is a geometric quantity that quantifies the number of moves necessary to solve the puzzle. In the solitaire case, the god number is the minimal distance from the initial state $v$ to the solution space $A$. If $v$ and $A$ are not specified, the god number is the graph diameter. God number computations are related to combinatorial sorting problems and is a NP-complete problem in general even when restricted to concrete sliding problems. In the two-player case, the god number is a minimax critical value: it minimizes the maximal game event length over the set of all strategies. A strategy is a sub-graph of the game graph that contains the initial vertex. The definition is done so that a ``mate in k" chess problem has god number k. As for examples: in the solitaire case, we look at group games like Rubik type problems, transposition games related to sorting, at sliding puzzles like the 15 puzzle or rainbow ball, or the tower of Hanoi. For two-player games, we illustrate the story using examples of small chess games, a small card game or tic-tac-toe type problems.

In this paper, we introduce a rotating Kaluza-Klein black hole characterized by a massive vector field and a scalar field. We begin by identifying the horizons and mapping the allowed parameter space to differentiate black hole solutions from naked singularities. The thermodynamic analysis shows a phase transition by examining Hawking temperature and heat capacity. We also conduct a topological study of the thermodynamic potentials. The Hawking temperature indicates a conventional critical point, while the off-shell generalized free energy classifies the system into a specific universal group. We further investigate the geometry of the ergosphere and how it relates to the black holes spin. Additionally, we look at astrophysical signs, such as the black hole shadow and the features of the thin accretion disk. Our results indicate that while the extra-dimensional changes significantly shift phase transition points and modify the shadow size, the essential topological class remains stable. This study provides a solid framework for distinguishing higher-dimensional gravity models through both thermodynamic and observational signs.