Papers

Near-extremal black holes can amplify higher-derivative corrections to general relativity, making them sharp probes of the perturbative control of gravitational effective field theory. We study this question in quadratic gravity with a dynamical scalar degree of freedom, focusing on dynamical Chern-Simons and scalar Gauss-Bonnet gravity. Using pseudospectral methods, we construct rapidly rotating exterior solutions at fixed surface gravity and fixed horizon angular velocity, and follow this controlled family toward extremality. In dynamical Chern-Simons gravity, the sequence approaches an asymptotically flat extremal exterior whose near-horizon limit agrees with the dynamical-Chern-Simons-deformed near-horizon extremal Kerr geometry and inherits its enhanced $SO(2,1)\times U(1)$ symmetry. In scalar Gauss-Bonnet gravity, the same limiting procedure behaves differently: the scalar develops an unavoidable logarithmic singularity at the horizon, the exterior metric develops a small boundary layer near the horizon, and the scalar-Gauss-Bonnet-deformed near-horizon extremal solution is not connected to a regular asymptotically flat exterior. We then use curvature invariants and tidal forces to diagnose the breakdown of the perturbative effective-field-theory expansion. We find that scalar curvature invariants can remain finite at the horizon even when tidal forces measured by infalling observers diverge as inverse powers of the surface gravity. These results separate distinct notions of effective-field-theory breakdown near extremality and provide a perturbative validity estimate that can be compared with current bounds on the dynamical Chern-Simons and scalar-Gauss-Bonnet couplings.

We apply a machine learning framework to search for Lax connections in two-dimensional non-linear sigma models using local current data. For the $SU(2)$ principal chiral model and the symmetric coset $S^2 = SU(2)/U(1)$, the method successfully recovers the full spectral-parameter families without using the known spectral curves as training targets. For the non-symmetric coset $T^{1,1}$, the optimization converges to reproducible low-loss maps that distill into a compact block-diagonal ansatz. However, analytic verification shows that this candidate is a “fake Lax” connection which satisfies on-shell flatness but fails to encode the two-dimensional equations of motion, whereas its point-particle reduction yields a genuine mechanical Lax pair. These results demonstrate that machine learning can effectively propose candidate ansätze and identify spectral structures, but low flatness loss alone does not certify genuine integrability, underscoring the necessity of analytic validation.

Topological twisting provides a powerful framework for constructing lattice formulations of supersymmetric gauge theories. In three dimensions, a twisted version of ${\cal N} = 4$ super Yang–Mills theory can be discretized so that one nilpotent scalar supersymmetry is preserved exactly at nonzero lattice spacing. The remaining seven supersymmetries are broken by lattice artifacts of ${\cal O}(a)$, where $a$ is the lattice spacing. An important question is whether these supersymmetries are automatically restored in the continuum limit $a \to 0$, or whether fine-tuning of the lattice couplings is required. In this work, we derive the additional twisted supersymmetries by combining discrete $R$-symmetries of the continuum theory with the action of the scalar supercharge. This construction suggests that restoration of rotational symmetry in the continuum limit implies restoration of $R$-symmetry, leading to an automatic enhancement to the full ${\cal N} = 4$ supersymmetry without further tuning. These results may enable nonperturbative lattice studies of three-dimensional supersymmetric gauge theories relevant to string theory and mirror symmetry.

The tube algebra, which carries the structure of a $C^*$ weak Hopf algebra, is a fundamental tool for characterizing topological excitations in topological phases. In this work, we generalize the tube algebra framework to codimension-2 defects in $(2+1)$D gapped phases described by Turaev–Viro–Barrett–Westbury TQFTs, with particular emphasis on Levin–Wen string-net models. We show that such codimension-2 defects are described by a defect tube algebra, which naturally carries the structure of a comodule algebra over the weak Hopf tube algebra associated with the topological excitations. Boundary and domain wall defects are then characterized by the representations of the corresponding boundary and domain wall defect tube algebras. In particular, a domain wall defect tube algebra can be regarded as a generalized Drinfeld double of the tube algebras associated with the two adjacent boundary defects. More generally, for a domain wall joining $N$ bulk phases, the associated domain wall defect tube algebra can be viewed as an $N$-tuple algebra. This perspective extends naturally to general $k$-defects, namely codimension-2 defects joining $k$ codimension-1 defects, for which the resulting generalized tube algebra carries the structure of a multicomodule algebra.

Static tidal Love numbers of four-dimensional Schwarzschild black holes vanish in general relativity, whereas higher-curvature interactions can generate a nontrivial response. We investigate the parity-even cubic Weyl correction directly in metric variables and derive the electric, static response for every integer multipole $\ell \geq 2$. Organizing the angular reduction through $L=\ell(\ell+1)$, we obtain exact radial actions and show that perturbative order reduction converts the three metric equations into a constrained two-dimensional first-order system. Eliminating one field yields a scalar equation whose homogeneous operator is precisely the general-relativistic static tidal operator. A Frobenius and Green-function analysis gives the gauge-invariant Zerilli–Moncrief running coefficient $\beta_{\ell}^{\rm ZM}=\epsilon_{\rm e}\,7L^{2}(L-2)^{2}(L-4)(L-6)/12$ and identifies the factor $L-6$ as the reason why the quadrupole is the unique physical electric multipole without logarithmic running. We solve the quadrupole exactly, obtaining the fixed-integer branch ratio $-2400\,\epsilon_{\rm e}$ and explaining why it differs from the analytically continued canonical Love number $k_{2}^{E}=448\,\epsilon_{\rm e}$. For the octupole, we construct the complete horizon-regular global metric solution and exhibit the cancellation of horizon logarithms between the two Green-function channels. Finally, we derive the normalization map to the canonical electric beta functions and the corresponding running of finite-size worldline coefficients. The canonical result agrees with the modified-Teukolsky calculation, while the metric-action approach reveals the radial mechanism behind the exceptional quadrupole and provides the full metric reconstruction.

Recent observational data arising from the DESI collaboration has hinted at a possible departure from the standard $\Lambda$CDM cosmological model, preferring instead the presence of a dynamical dark energy component. Specifically, the associated equation of state of the dark energy features a crossing into the so-called phantom regime, which is challenging to accommodate in canonical single scalar-field scenarios. However, this behavior can be effectively described by an interacting dark sector, where the specific dark energy equation of state remains above the phantom divide whilst the dark matter component deviates from the standard cold dark matter evolution. In this work, we explore this possibility in the context of an axion dark sector, where both the dark energy and dark matter are represented by two interacting axion-like fields. We show that given the required mass hierarchy for these fields to play such roles, their dynamics can be effectively placed in the coupled quintessence framework, where their motion follows from a sourced continuity equation in the fluid description. In this regime, we perform a statistical analysis of this scenario with current data, finding that a sub-Planckian dark energy axion decay constant stays well within the observational bounds without the need to fine-tune the associated field's initial conditions. We also perform a comparison with $\Lambda$CDM, where we find that the model provides a better fit to the data while staying competitive from a Bayesian perspective.

The gauge structure of the Weyl Gravitoelectromagnetic (GEM) formalism has been investigated, showing that although the theory admits additional propagating modes, only an effective spin-2 sector contributes to physical observables. Building on this result, the formalism is applied to Bhabha scattering mediated by the tensor field $A_{\mu\nu}$, and the Newtonian gravitational potential is derived in the zero-temperature limit. Finite-temperature effects are incorporated through the Thermo Field Dynamics (TFD) formalism. While the Newtonian interaction is recovered at low temperatures, it becomes progressively suppressed in the high-temperature regime, revealing a thermal screening mechanism. The physical origin of this behavior and its possible dependence on the underlying scattering process are briefly discussed.

In the standard model of cosmology, it is assumed that dark matter is pressureless with equation of state $w=0$ and dark energy has $w=-1$. We test these assumptions jointly using DESI DR2 distance measurements, including the recent Lyman-$\alpha$ full-shape Alcock-Paczynski (AP) information, DES supernovae, and two complementary CMB treatment. When constant $w_{dm}$ and $w_{de}$ are varied together, we find $w_{dm}=0.000968^{+0.000501}_{-0.000496}$ and $w_{de}=-0.9380^{+0.0259}_{-0.0262}$ (68%). With an alternative CMB treatment that marginalizes over the lensing spectrum, the corresponding constraints are $w_{dm}=0.000870^{+0.000408}_{-0.000410}$ and $w_{de}=-0.9353^{+0.0258}_{-0.0254}$. Both standard $\Lambda$CDM values are disfavored at approximately $2\sigma$ in the joint extension. Neither parameter departs significantly from its standard value when only that parameter is varied. This behavior arises because late-time distances favor $w_{de}>-1$, while maintaining the early-Universe physical matter density requires a compensating positive $w_{dm}$, which changes the mapping to the matter density today. Allowing dynamical dark energy further highlights the complexity of the situation: phantom crossing for dark energy makes $w_{dm}=0$ consistent with the data, whereas a positive $w_{dm}$ preference persists when crossing is forbidden. Interestingly, the Pad'e-$w$ parameterization that provides a flexible description of a class of quintessence models (with no phantom crossing), along with $w_{dm}$ free, is even mildly favored over the phantom-crossing $w_0w_a$ model according to both the best-fit $\chi^2$ and the DIC under both CMB treatments. One can conclude that the apparent preference for phantom crossing may instead reflect deviations in the dark-matter sector rather than dark-energy dynamics alone. [abridged]

We propose a quantum description of the ultracold Reissner-Nordström de Sitter black hole via a specific flat space limit of the double-scaled SYK model. Fluctuations in this regime reduce to flat JT gravity, which is ill-behaved as a quantum system. We show that including the first subleading correction to the dilaton potential breaks the leading order Hagedorn degeneracy but does not resolve the structural problem. Finally, we leverage the gauged description of the sine dilaton gravity model to propose a novel quantization of the near-horizon dynamics of ultracold black holes. This leads to a new proposal for the partition function where states in the asymptotics of the spectrum are suppressed dynamically, and features of a discretized spacetime arise. We obtain a non-perturbative low temperature behavior of the partition function, which is quite different than the cold and Nariai physics. Our result can be interpreted as a dynamical way to enforce cosmic censorship on the quantum system.

We study the quantization of algebraic varieties defined by equations involving Casimir polynomials of compact semisimple Lie algebras. The Casimir polynomials belong to the Poisson center of the corresponding Lie-Poisson algebra. For this purpose, we employ a recently developed matrix regularization of Lie-Poisson algebras. In particular, using its formulation based on reducible representations, we construct quantizations of these algebraic varieties through their decomposition into coadjoint orbits, including singular orbits. As a concrete example, we present the construction of fuzzy $S^7$ in detail.

We consider a real massless scalar field in punctured Minkowski spacetime, endowed at the removed origin with the stable one-parameter family of Robin boundary conditions $G(0)-\beta G'(0)=0$, $\beta\geq0$. We obtain the boundary-induced part of the static ground-state Wightman function in closed form and study the response of a uniformly accelerated Unruh-DeWitt detector. The puncture breaks the boost symmetry underlying the stationary Unruh response, so the boundary-induced pullback is nonstationary in proper time. The corresponding subtracted detector contribution can either enhance or suppress the ordinary Minkowski response and depends on the Robin parameter, the detector gap, and the portion of the trajectory sampled. For the unshifted, radially aligned trajectory studied in detail, we prove that the boundary-induced pullback is absolutely integrable in the two proper-time variables. Consequently, as the smooth interaction is extended over the full detector history, this contribution approaches a finite limit and remains $O(1)$, producing no additional term linear in the interaction duration. The formal Neumann limit is singular: the boundary-induced two-point function grows logarithmically because of an infrared singularity in the $s$-wave sector, and the numerical response exhibits growth consistent with this asymptotic behavior.

We propose and numerically validate an efficient single-eigenstate diagnostic for the eigenstate thermalization hypothesis (ETH) based on a perturbed eigenstate quench protocol. By introducing a weak random perturbation to an energy eigenstate to break its stationarity, we characterize the time-averaged subsystem evolution speed as a function of the subsystem-to-total system size ratio. The diagnostic relies on a robust qualitative distinction: eigenstates satisfying ETH exhibit an S-shaped curve with a clear inflection point near half the system size, while ETH-violating eigenstates display a convex J-shaped profile. We benchmark the criterion across paradigmatic one-dimensional spin chains covering chaotic, integrable, many-body localized, and quantum many-body scar regimes, obtaining full agreement with established thermalization phenomenology. Our method circumvents the need for explicit thermal ensemble construction, providing a robust, experimentally feasible probe of eigenstate thermalization at the single-eigenstate level.

We study wavefunctions of quantum gravity in asymptotically AdS$_3$ spacetimes and their relation to $T\bar{T}$-deformed torus partition functions. We show that the deformed partition function is given by an invertible integral transform of bulk wavefunctions, with a kernel encoding the relation between the $T\bar{T}$ coupling and the radial or temporal coordinate in the bulk. The invertibility of the transform allows the bulk wavefunction to be reconstructed from the family of $T\bar{T}$-deformed partition functions. In the CFT limit, the kernel effectively localizes at the asymptotic boundary, recovering the standard holographic relation in which the partition function on the torus is determined by the boundary value of the bulk wavefunction. For finite deformation, the kernel shifts the effective holographic screen away from the asymptotic boundary and broadens it into a finite bulk region. A $T\bar{T}$-deformed partition function at fixed coupling corresponds to a finite-width bulk wavepacket centered around a radial or temporal location set by the deformation scale. In Euclidean signature, the construction arises naturally from wavefunctions of Rindler AdS$_3$, while after a double Wick rotation it admits a Lorentzian interpretation in terms of closed AdS$_3$ torus universes without asymptotic boundaries. Finally, we discuss the extension of the present construction to de Sitter torus universes and its implications for de Sitter holography, and comment on possible generalizations to more general spatial topologies and higher-dimensional spacetimes.

We investigate the holographic timelike entanglement entropy (HTEE) in a five-dimensional anisotropic background, dual to a strongly coupled anisotropic plasma. Using the complex extremal surface method, we compute the HTEE analytically in the high-temperature, small-anisotropy limit $aT \ll 1$. We consider two different orientations of the boundary timelike interval: one perpendicular to the anisotropy direction and one parallel to it. We find that the imaginary part of the HTEE is not a universal property of the geometry but depends sensitively on the orientation of the extremal surface relative to the anisotropy. This demonstrates that the imaginary part arising from the UV logarithmic divergence is a probe-dependent quantity. Our results suggest that the imaginary part of HTEE can serve as a diagnostic of the coupling between the extremal surface and the anisotropic degrees of freedom of the dual field theory.

We investigate fermion level crossing in the electroweak instanton background, taking into account the Euclidean-time dependence of the fermion energy throughout our analysis, from the field equations to the spectral flow of fermion energy levels. Modifying the standard fermion ansatzes, we show that, irrespective of the model parameters, the duration over which the fermion energy spectrum flows from one continuum to another corresponds to exactly one unit change in the Chern–Simons number of the instanton. We further demonstrate that incorporating this time dependence is essential for establishing a one-to-one correspondence between the number of fermion zero modes and the instanton winding number, providing a numerical confirmation of the index theorem in the context of instanton backgrounds.

Multiple lattice evidences support the existence of a confining but chirally symmetric stringy fluid regime of QCD above the chiral symmetry restoration temperature at T_{ch} ~ 155 MeV. This regime is characterized by an approximate chiral spin symmetry and its extensions which means that the propagating excitations represent the chirally symmetric quarks connected into color singlets by the chromoelectric string. Clear \pi,\pi' peaks above T_{ch} were extracted on the lattice from the spatial and temporal correlators, which become broader with temperature and disappear roughly at $3T_{ch}$. The meson-like excitations above T_{ch} were studied within the manifestly confining and chirally symmetric model. It has been demonstrated that the chiral symmetry restoration in the confining regime happens because of Pauli blocking of the levels, required for the existence of the quark condensate, by the thermal quark excitation. The same Pauli blocking leads to a huge swelling of the low-spin mesons above T_{ch} which become infinitely large in the chiral limit. This property should be crucial for the explanation of the high collectivity and a very small mean-free path of the constituents above $T_{ch}$ seen experimentally. Here we demonstrate that the swelling of pions above T_{ch} is a model-independent effect required by current algebra.

We study how holographic phase transitions imprint their scaling laws on the local Kasner geometry inside Einstein-scalar black holes. At fixed double-trace coupling, we derive the near-critical scaling of the deviation of the first-epoch Kasner exponent from the Schwarzschild value: $p_t^{(1)}+\frac{1}{3} \propto O^2 \propto (T_c-T)^{1/r}$, where $O$ denotes the boundary condensate and $r$ labels ordinary criticality ($r=1$), tricriticality ($r=2$), and higher multicriticality ($r\geq3$). A super-exponential scalar potential generates a sequence of Kasner epochs separated by scalar-field bounces. We further find that any later epoch that can be tracked continuously across the transition inherits the same temperature exponent, while its coefficient depends on the epoch. Numerical solutions confirm these predictions for the ordinary and tricritical cases. Finally, we show analytically that the leading irrelevant exponent of the infrared fixed point governs the low-temperature Kasner scaling, and verify the resulting scaling numerically for the first Kasner exponent.

Theoretical interpretations of horizon-scale observations often rely on the idealized assumption of an isolated vacuum Kerr geometry. However, astrophysical black holes are expected to be embedded within dense dark matter distributions that can modify the local spacetime geometry. In this work, we propose a theoretical framework to model a rotating compact object surrounded by a bounded dark matter envelope governed by a Modified Chaplygin Gas (MCG) equation of state. To ensure strict adherence to the Einstein Field Equations, we construct a piece-wise, three-region spacetime using a fully coupled Tolman-Oppenheimer-Volkoff (TOV) integration, allowing the fluid's pressure to taper naturally to zero and dynamically define the outer boundary. Rotation is introduced via a pressure-corrected Kerr-form ansatz where the temporal component is obtained directly from the integrated hydrostatic potential. Using this geometrically rigorous configuration, which explicitly evaluates the exact 4D equatorial metric determinant rather than relying on vacuum approximations, we solve the circular equatorial geodesics and determine the innermost stable circular orbit (ISCO). Evaluating the thin accretion disk thermodynamics via the Novikov-Thorne formalism reveals that the deep gravitational potential well of the MCG envelope acts as a strong driver for viscous dissipation, systematically shifting the peak thermal flux, effective temperature, and multi-colour blackbody spectral luminosity to higher energy bands. Furthermore, we identify a clear structural degeneracy: a static or slowly rotating black hole embedded in a dense MCG structure can elevate radiative efficiencies up to $\eta \approx 6.5\%$. This framework is presented as a structured proposal to quantify environmental systematic uncertainties in standard black hole spin-estimation techniques.

We develop a non-perturbative analytic tensor network formulation of $\mathcal{PT}$-symmetric scalar field theories defined on complex integration contours. Applying this formulation to the two-dimensional $\mathcal{PT}$-symmetric $\phi^4$ theory at negative quartic coupling, we derive an explicit analytic expression for the initial tensor and show that its components separate into even and odd sectors according to the parity of the sum of the tensor indices. We further formulate the theory on an alternative complex contour and analytically establish, in arbitrary dimensions, an exact finite-volume relation between the lattice partition function defined on this contour and the real part of the analytic continuation of the Hermitian lattice $\phi^4$ partition function to negative quartic coupling.

We use the AdS/CFT correspondence to show that for two spherical Wilson surfaces, both in the fundamental representation of $SU(N)$ gauge group, in the six-dimensional $(2,0)$ theory, in the large $N$ limit there is a first order Gross-Ooguri phase transition at a certain critical separation distance that we obtain numerically.

We study Gibbs states projected onto the symmetric sector of contractible one-form symmetries. In a three-dimensional cluster-model interpolation, this projection stabilizes symmetry-protected topological and projected-paramagnetic phases, both sharply distinct from thermal disorder. A flux-twisted membrane invariant distinguishes these three phases by the values $-1,+1,0$, respectively. These values are exact on the endpoint, self-dual, zero-temperature, and infinite-temperature lines; elsewhere their quantization requires positive spatial-sheet, winding-line, and interface tensions. Quantum Monte Carlo supports the quantization through tension diagnostics and direct finite-size estimates.

In this study, we investigate higher-dimensional static and stationary Bianchi-type solutions in an $R^2$ gravity theory using the formalism of exterior differential forms. We construct a broad class of exact higher-dimensional Bianchi-type solutions in an $R^{2}$-corrected gravity theory. It is shown that the theory admits hyperscaling violating black hole solutions associated with homogeneous but anisotropic horizon geometries, encompassing both static and stationary configurations. We further analyze some thermodynamic properties of these backgrounds and demonstrate that higher-curvature corrections give rise to unconventional features. In particular, we show that within the critical sector, the solutions possess a finite Hawking temperature despite an identically vanishing Wald entropy, signaling an unusual thermodynamic regime. These configurations arise at the critical point of the theory, where the effective gravitational coupling vanishes and the space of admissible constant-curvature geometries is enlarged.

Measurement-based quantum simulation (MBQS)—a recently proposed architecture for simulating lattice gauge theories—implements Hamiltonian dynamics by consuming a model-specific entangled resource state with adaptive mid-circuit measurements, rather than by a gate-based circuit. The local constraints in lattice gauge theories are mirrored by the higher-form symmetries of the resource state. Here we report, to our knowledge, the first experimental realization of MBQS of real-time dynamics in the $(2+1)$-dimensional $\mathbb{Z}_2$ gauge theory using the Quantinuum System Model H2 trapped-ion processor. We observe coherent evolution of gauge-invariant observables on $2\times2$ and $3\times3$ spatial lattices, consuming virtual three-dimensional cluster states of 200 and 288 resource-state qubits that are generated from instantaneous blocks of 48 and 54 qubits within the 56-qubit register by measurement, reset, and re-entanglement. The measurement record that drives the evolution simultaneously provides one-form-symmetry syndromes at no additional cost, enabling postselection that strongly suppresses observed Gauss-law violations and improves aggregate agreement with ideal Trotterized dynamics. Our results demonstrate that MBQS is a viable, symmetry-aware architecture for simulating lattice field theories on present-day hardware.

2-group global symmetries intertwine 0-form and 1-form symmetries in an interesting way. We analyze universal constraints on lines which are charged under the 1-form subgroup of a 2-group, and show that they generically break the 0-form symmetry explicitly. This gives rise to a family of line defects parameterized by the broken symmetry generators, whose existence is invariant under the renormalization group flow of the bulk-defect system. The symmetry breaking is enforced by a `family anomaly,' which is a topological obstruction to a symmetric defect. Our main tools are the Wess-Zumino consistency condition and a generalized anomaly inflow formalism for defects and boundaries. For nonabelian continuous 2-groups the family anomaly stems from a higher Berry connection on the moduli space of defects, and constrains response functions that probe the local action of the broken symmetry. In the continuous abelian case we apply differential cohomology to the 2-group background fields to uncover a subtle generalization of the Wess-Zumino condition, while in the discrete case we recast it in terms of the associativity of symmetry defects. We give numerous illustrative examples, computing when possible explicit forms of the tilt operator (which probes the linear response of the defect to the broken symmetry) and its higher analogs, which are crucial for matching the family anomaly. We also discuss universal features such as how symmetry violation by charged line defects is related to symmetry breaking hierarchies in the bulk, and highlight a number of subtle points including the distinction between simple and non-simple lines, and Postnikov class resolution.

We study the entanglement entropy of a conformally coupled scalar field at its ground state in $(3+1)$-dimensional AdS space in global coordinates. We consider spherical entangling surfaces centered at the origin of AdS and allow for general boundary conditions at the conformal boundary. Through numerical and analytical means, we show that the UV-divergent part of the entropy has a universal form, while the UV-finite part is sensitive to the boundary conditions. We determine the dependence of the latter part on mixed boundary conditions that interpolate between Dirichlet and Neumann.

We determine in closed form the $N$-independent constant terms in the all-order $1/N$ expansions of the topologically twisted index and of the associated Bethe potential for the ABJM theory, as well as the Bethe potential constant of the ADHM theory. We reconstruct these constants analytically from high-precision Bethe-Ansatz numerics, verify them down to the level of non-perturbative corrections, and find them to be closely related to the constant map function $A$ governing the round three-sphere partition function. The resulting expressions for the ADHM and ABJM constants pass the non-trivial test dictated by 3d mirror symmetry. Via recently established factorization relations, they also determine in closed form the $N$-independent constant contribution to the squashed three-sphere partition function, through the first two leading orders in its large-squashing expansion. These constants supply precisely the piece left undetermined in the recent exact results for 3d supersymmetric partition functions to all orders in the $1/N$ expansion, and thereby mark an important step toward completing them, both in field theory and in the dual quantum gravity description.

Pre-inflationary axion cosmologies admit a broad range of initial velocities and angles that generate a landscape of misalignment histories, whose nonlinear fate and small-scale structure remain uncertain. We use lattice simulations to follow the QCD axion in the kinetic misalignment scenario through the QCD crossover into the non-relativistic regime, towards matter-radiation equality. In the meV mass range, this landscape contains a continuum of ”summit-landing" solutions sensitive to both the initial angle and velocity. Nonlinear fragmentation reduces the comoving axion number and modifies the relation between the misalignment history and present relic abundance. For sufficiently large axion masses, strong self-interactions drive the small-scale spectrum towards the attractor found for post-inflationary axions, so that distinct early histories can lead to similar late-time structures.

The effective twisted superpotential governs the supersymmetric partition functions of three-dimensional $\mathcal{N}=2$ theories in the Cardy limit and, at large $N$, the gravitational blocks that are glued into the entropy function of supersymmetric $\mathrm{AdS}_4$ black holes. We determine its on-shell structure for $\mathrm{U}(N)_k\times\mathrm{U}(N)_{-k}$ ABJM theory at the universal twist, using a machine-learning discovery pipeline—physics-informed symbolic regression with integer-relation detection—applied to Bethe-vacuum data of up to $800$ digits. Its perturbative part terminates after two terms, a shifted-rank $3/2$-power and an $N$-independent constant map, which we obtain in closed form for every integer level. Its type-IIA genus expansion admits a closed coefficient formula at arbitrary genus, involving binomial and Bernoulli-number terms, and is asymptotic. For $k=1,2,4$ the entire finite-$N$ remainder is a single absolutely convergent divisor-sum $q$-series, obtained by applying a first-order differential operator to the Eichler integral of a weight-four Eisenstein series on $\Gamma_0(2)$ or $\Gamma_0(4)$. This closed form reproduces the data to $\sim\!10^{-797}$.

Non-Abelian anyons offer a route to fault-tolerant and universal quantum computing, but experimental access to their defining braiding and fusion data remains limited by the resource overhead of implementing extended anyonic processes on quantum hardware. Here we introduce and experimentally realise a measurement-only protocol based on temporally ordered ribbon operations that reconstructs the non-Abelian braiding and fusion primitives of the quantum double model $D(S_3)$ without physical anyon transport. We implement a reduced two-qutrit version of the protocol on Quantinuum's H2 trapped-ion processors, realising ancilla-assisted ribbon operations and anyonic charge projections in a qubit encoding. We reconstruct the squared braiding phases and fusion amplitudes using an adapted Hadamard test and post-selected measurements, respectively. The associated braiding and fusion transformations reproduce their ideal actions with average normalised output-state fidelities of $\overline{\mathcal{F}}_{R}=0.9988$ and $\overline{\mathcal{F}}_{F}=0.9987$. Combining these primitives produces a non-Clifford braid and a non-stabilizer resource state, supporting measurement-only anyonic encodings as building blocks for larger topologically encoded quantum processors.

We apply the two-particle irreducible (2PI) formalism as a framework for a consistent thermal resummation in studies of cosmological phase transitions. Considering a model with two mixing real scalar fields, we work within the Hartree approximation and renormalize the 2PI effective action, while introducing a connection to physical parameters. This yields the Hartree-resummed finite-temperature effective potential, which is valid for all temperatures and avoids the limitations of conventional methods based on the high-temperature approximation. With this potential, we study one- and two-step transitions within the model, and compare our results with those obtained using resummation schemes widely employed in the literature. Finally, we evaluate the gravitational wave spectrum generated from first-order phase transitions, demonstrating the impact of the choice of resummation scheme on the predicted spectrum.