Papers

In this paper we clarify the relation between Geometric Thermodynamics and Information Geometry based on the Fisher matrix. On the macroscopic odd-dimensional contact manifold of thermodynamic variables, we introduce for the first time a metric, whose pull-back on the isoentropic symplectic submanifolds transverse to the Reeb field is Kählerian. The pull-back of such metric on equilibrium states, that are lagrangian submanifolds, is the Fisher Hessian. Then we consider the Souriau-like Thermodynamics that uses Calabi-Vesentini (CV) manifolds as Kaehlerian microscopic event manifolds and the Killing moment maps as observable functions. A systematic use of the theory of compact abelian structures and the setup of Special Kähler Geometry in which CV manifolds are encoded allows us to perform the explicit integration defining the partition function for any entry in the CV Tits Satake universality class. The additional actions completing the abelian structure are non linear Casimir functions of the Killing moment-maps and suggest a generalization of Souriau thermodynamics that partially breaks the isometry group symmetry by means of the non vanishing mean values of the Casimir functions in a manner similar to the spontaneous magnetization in ferromagnetism. Our new exact Gibbs distributions provide the analogue for Cartan Neural Networks of the Gaussian probability distributions in flat space used in conventional Machine Learning.

The BCS-motivated idea of Weinberg and Salam on dynamical EW symmetry breaking is revived: The Higgs sector of the EW gauge model of three fermion flavors (families) is replaced with the chiral gauge $SU(3)_f$ quantum flavor dynamics (QFD) strongly coupled at a huge scale $\Lambda$. I. With all chiral fermions in flavor triplets the anomaly freedom demands the welcome BSM extension of the SM fermion sector by one EW-sterile neutrino $\nu_R$ per flavor. II. The QFD distinguishes flavors by generating at strong coupling the chirality-prohibited (i.e. calculable) fermion masses: Three different Majorana masses $M_f \sim \Lambda$ of $\nu_R$, and three different, arguably small Dirac masses $m_f$ of SM fermions degenerate for all species in each flavor. 1. Complete spontaneous breakdown of $SU(3)_f \times U(1)$ by $M_f$ implies: (i) All flavor gluons acquire self-consistently masses $\sim M_f$. (ii) There is the $\nu_R$-composite pseudo-NG Majoron. (iii) There are three very heavy $0^{+}$ $\nu_R$-composite Higgs bosons. 2. Spontaneous breakdown of the EW $SU(2)_L \times U(1)_Y$ symmetry to $U(1)_{em}$ by $m_f$, in sharp contrast with the Higgs mechanism, implies: (i) The $W$ and $Z$ bosons acquire masses $\sim g(\sum m^2_f)^{1/2}$ and $\sim (g^2+g^{'2})^{1/2}(\sum m^2_f)^{1/2}$ respectively, defining the effective Fermi scale $v=246 \rm GeV$. (ii) There are three SM-fermion-composite $0^{+}$ Higgs bosons $h_f$ at this scale. III. The UV-finite EW dynamical perturbation theory of Pagels and Stokar splits the flavor-degenerate masses of SM-fermions by their electric charges and the ratios $m_f/m_{W,Z}$. Six Majorana neutrino masses are calculable by seasaw.

Extensive list of 4+4-dimensional Manin triples that was presented recently can be used to find new solutions of supergravity equations via Poisson-Lie T-plurality. To get the solutions we start with 1+3-dimensional flat backgrounds on Poisson-Lie groups corresponding to semi-Abelian Manin triples. For application of the Poisson-Lie T-plurality we identify Manin triples that form various decompositions of the same Drinfeld double. Beside flat backgrounds and plane-parallel waves solving supergravity equations, plurality transformation also produces curved backgrounds with torsion satisfying (generalized) supergravity equations. Many of the Poisson-Lie transformations can be understood as homogeneous Yang-Baxter deformations. Of special interest are the non-unimodular deformations leading to solutions of generalized supergravity equations.

Holography of Information (HoI) and the island formula are two recent approaches to the black hole information loss paradox that yield different Page curves. The difference between the Page curves has been argued to be rooted in the algebra that each approach focuses on. In this paper, we study the candidate algebras for the CGHS model. Making the usual assumptions that are made in HoI literature, we establish HoI for the CGHS model coupled to a massless scalar by constructing the radiative phase space and asymptotic algebras at future null infinity. We prove that the quantum state of the right-moving modes can be recovered from an arbitrarily small neighbourhood of the right future null infinity. We then argue that island reconstruction is incompatible with exact commutativity of the left and right radiative algebras. We discuss the possible distinction between the HoI and island approaches for the CGHS model.

We study energy transport between two quantum systems coupled through a random interaction. The central feature of our approach is to model the coupling as a Gaussian random matrix, which enables a simple and systematic perturbative expansion. In the large-$N$ limit, we derive explicit expressions for the energy transfer rate and heat conductance up to second order in the coupling strength. Using spectral methods and diagrammatic expansions, we obtain the leading- and next-to-leading-order contributions to the energy transfer rate. We illustrate our results through explicit calculations for Gaussian, constant, semicircular, and Gamma densities of states.

We formulate a semiclassical stress tensor deformation dictionary in the context of the dS/CFT correspondence. Using the metric-flow formulation, we propose that stress tensor deformations of the putative boundary theory are encoded holographically as mixed boundary conditions for the bulk metric at future infinity. The coupled flow equations determine the deformed boundary metric and stress tensor, thereby specifying the source–response relation of the deformed boundary theory. We test the proposal in Kerr-dS$_3$/CFT$_2$, where the conserved charges constructed from the holographic boundary stress tensor agree exactly with the boundary spectrum obtained from the field-theoretic flow equation, providing a nontrivial consistency check of the dictionary. As an application, we compute the holographic pseudo entropy of boundary intervals from complexified geodesic saddles in the deformed Kerr-dS$_3$ geometry, and present explicit results for the $T\bar{T}$ and root-$T\bar{T}$ deformations.

In a recent work \href{https://doi.org/10.1103/PRXQuantum.2.010325}{PRX QUANTUM 2 (2021) 010325}, a new way of investigating quantum gravity signatures using quantum information theoretic techniques, have been proposed. The primary result of this analysis revealed that non-Gaussianity can arise only through the consideration of a quantum model for the gravity part. Compared to classical gravity, only quantum gravity can result in non-quadratic operators in the Hamiltonian which leads to the non-Gaussian behavior. In our current analysis, we have considered a more realistic scenario taking into effect leading order post-Newtonian corrections in the analysis. We have stayed with the same model of a Bose-Einstein condensate placed inside a harmonic trap potential which indeed works as the detector of the non-Gaussianity generated due to quantum gravitational effects. Bose-Einstein condensates are experimentally well studied; apart from being a single quantum system, they include Feshbach resonances, which helps tuning the strength of the electromagnetic interactions which in principle can be set to zero. This is important since it can help distinguish quantum gravity from electromagnetic interactions without affecting gravitational interactions, and any non-Gaussianity can then be solely attributed to quantum gravity. We observe that the signal to noise ratio gets slightly damped due to the post-Newtonian effects taken under consideration.

We study the relativistic nature of the interactions that, at tree level, generate spin correlations between two electrons in Møller scattering, as well as in an extended process involving a witness particle $C$. The corresponding processes, $e^{-}e^{-}\rightarrow e^{-}e^{-}$ and $e^{-}e^{-}C\rightarrow e^{-}e^{-}C$, are analyzed both in the center-of-mass frame and, for the former process, in a Lorentz-boosted frame where Wigner rotations arise. It is found that, through a nonrelativistic approximation of the scattering amplitudes, dipole-dipole and current-dipole interactions are responsible for the emergence of these correlations. This is evidenced by the variation of the von Neumann entropy of one electron for initially separable states, and of $C$ for an initially prepared three-particle entangled W-state. In Wigner rotations, the invariance of entropy under local unitary transformations is maintained at the expense of the emergence of quantum coherence in the density matrix at large rapidities. As a consequence, the final states of both particles are evaluated and shown to encode information about the scattering process through their spin expectation values. This framework is then used to comment on the correlations in the inelastic process $e^{-}e^{+}\rightarrow\mu^{-}\mu^{+}$, for which some research has reported differing results.

We show that generic Maxwell fields can be represented within the matter-space framework by introducing two independent matter-space flows. In the one-flow formulation the electromagnetic field strength is the pull-back of a two-form on a three-dimensional matter space and therefore satisfies $F\wedge F=0$, so that a single flow captures only a degenerate, helicity-carrying sector. The minimal completion is obtained by writing $$F=G^{(1)}+G^{(2)},$$ where each sector field $G^{(I)}$ is the pull-back of a matter-space two-form from an independent flow. Each sector is individually degenerate, $G^{(I)}\wedge G^{(I)}=0$, while the full field satisfies $F\wedge F=2G^{(1)}\wedge G^{(2)}$; the invariant excluded by the one-flow theory is thus recovered as an inter-flow quantity. We interpret this structure in terms of mutual helicity: the total helicity decomposes into two self-helicity contributions and a mutual term whose exterior derivative is $F\wedge F$. Hence a configuration with vanishing mutual helicity lies in the degenerate sector, whereas a nondegenerate Maxwell field necessarily carries a nontrivial mutual helicity. A variational principle for the total field recovers the sourced Maxwell equation, the two matter-space variations combining into the full equation whenever the sector kernels intersect trivially. Generic electromagnetism is thereby reconstructed as the minimal coupled completion of two individually degenerate matter-space sectors.

We construct an exact rotating vacuum of the NS–NS sector, equivalently a Double Field Theory vacuum. The construction applies compact $\mathbf{SO}(2)$ S-duality to a rotating Einstein–scalar seed. The solution has four independent parameters $\{\mathfrak{m},j,\mathfrak{q},\zeta\}$. To our knowledge, this is the first explicit rotating solution of the pure NS–NS vacuum equations with all three NS–NS fields $\{g,B,\phi\}$ determined analytically, independent dilaton and $H$-flux charges, and no Maxwell sector. The static limit is obtained by taking the rotation parameter $j\to 0$. In this limit the geometry is not the spherical Burgess–Myers–Quevedo solution. Instead, it is an axial Zipoy–Voorhees branch carrying $H$-flux, so an oblate deformation remains after rotation is switched off. This geometric memory is absent in pure general relativity and in Einstein–Maxwell–dilaton–axion. The two static branches nevertheless share the same $\ell=0$ parametrized post-Newtonian data $\{MG,\beta_{\mathrm{PPN}},\gamma_{\mathrm{PPN}},h\}$. They give two inequivalent NS–NS geometries at identical monopole charges, with the degeneracy lifted at $\ell=2$. At the Kerr horizon locus the outer shell is generically singular in curvature. Above the threshold $|\mathfrak{q}|>\sqrt{\mathfrak{m}^{2}-j^{2}}$, polar geodesics are repelled outward and the rotation axis becomes regular in curvature at the shell. On that axis the inverse metric $g^{\mu\nu}$ stays finite while the lower-index Riemannian metric components diverge, whereas off the axis the inverse metric itself diverges. This axis-local degeneracy may offer a setting for non-Riemannian geometry in Double Field Theory, where $g_{\mu\nu}$ is not fundamental and the $\mathbf{O}(D,D)$ variables $\{d,\mathcal{H}_{AB}\}$ remain well defined.

Infrared divergences in QED cancel in inclusive observables through the Bloch–Nordsieck and KLN mechanisms. However, this cancellation removes only the unphysical infrared regulator. The detector resolution scale $\omega_{\max}$, which specifies the maximum energy of unresolved soft photons, remains in the observable cross section. We emphasize that this surviving scale has a natural interpretation as a coarse-graining scale in the reduced density matrix of the hard sector. Soft photons below $\omega_{\max}$ are not observed and are effectively traced over. The corresponding soft-sector overlap therefore becomes resolution dependent, $D_{ij}=D_{ij}(\omega_{\max})$. Observable infrared memory is consequently defined not only by the asymptotic soft sector itself, but also by the resolution scale separating observed and unobserved infrared degrees of freedom. This provides a bridge between the traditional infrared-safe cross-section formulation and the modern interpretation of soft photons as carriers of infrared memory and quantum information.

We consider a wide class of $2D$ tight - binding models of solid state physics. These models are, in the most general case, non - homogeneous. The topological invariant ${\cal N}_3$ responsible for the quantization of the Hall conductivity, for the specific case of the integer quantum Hall effect in $2D$, is expressed through the Wigner transformation of the two-point electron Matsubara Green function. We express this invariant as a pairing of the element of the $K^{-1}$ group (generated by the Green function) with the specific element of the cyclic cohomology group $HC^3$. According to a set of local index theorems the values of ${\cal N}_3$ can be shown to be integer for a limited class of tight - binding models. We concentrate on systems with a spectral gap, with the chemical potential inside the gap and an invertible Dirac operator $\hat Q$ throughout the Matsubara-frequency domain. The mobility-gap case is not considered here and will be addressed in forthcoming publications.

We study the post-inflationary open-string Hagedorn phase in perturbatively moduli stabilized brane-antibrane inflation. In this class of models, the volume modulus is stabilized by perturbative corrections rather than by non-perturbative effects to the superpotential, thereby avoiding the standard brane-antibrane $\eta$-problem. Since inflation ends through tachyon condensation and brane-antibrane annihilation, the endpoint is intrinsically stringy and need not be described immediately by an ordinary radiation bath. We analyze whether the energy released at annihilation can drive the visible sector into an open-string Hagedorn phase, and study the consequences for dark radiation. If the Standard Model (SM) branes lie in the same throat as where the annihilation occurs, we find that a modest fraction of the released energy deposited into surviving visible open strings is sufficient to enter the Hagedorn regime and can suppress the effective number of relativistic species $\Delta N_{\rm eff}$ below current observational bounds. If the SM lies in a different throat, the result depends on inter-throat energy transfer: prompt or delayed transfer can still yield a visible Hagedorn phase. However, the mechanism is most efficient when the local string scale in the SM throat is lower than or comparable to that in the annihilation throat.

For over four decades, Gribov's no-pole condition has been almost exclusively explored in Euclidean space, where the elliptic nature of the Faddeev-Popov operator provides a clear spectral boundary. In physical Minkowski spacetime, however, this operator becomes a hyperbolic wave operator, and the Euclidean positivity criterion collapses. We show that the natural Lorentzian replacement is a real-time boundary-value problem: a gauge configuration remains inside the first Gribov region as long as the Faddeev-Popov wave equation admits no source-free solutions obeying the Feynman boundary condition. For backgrounds localized in time, this condition translates to the injectivity of the negative-frequency block of the classical ghost scattering map. For stationary backgrounds, it becomes a spatial bound-state or threshold-resonance problem under Fourier transformation. Using a Wronskian identity, we prove that pure frequency mixing in stable self-adjoint time-dependent channels is structurally protected and cannot by itself produce the obstruction. While static chromomagnetic backgrounds reproduce the familiar zero-frequency horizon crossing, static chromoelectric potentials reach the horizon at finite, non-vanishing frequency - a uniquely Lorentzian phenomenon arising because $A_0$ couples directly to the ghost time derivative. We also cast the condition in Fredholm form and show that the exact restriction is a functional determinant, which the naive local continuation of the Gribov-Zwanziger action fails to reproduce, leaving the construction of a genuine local real-time action as the central open problem.

We study the finite-temperature stabilizer Rényi entropy of the open critical quantum spin chains. At Rényi index one half, this observable probes the distribution of thermal Pauli-string expectation values and can be written as a sum over absolute values of all square minors of a finite-temperature correlation matrix for the transverse-field Ising chain. We show that this exponentially large sum is exactly reducible to a single Pfaffian. The Pfaffian representation reveals a block Toeplitz–Hankel structure and allows us to extract the large-size scaling in several thermal regimes. In the crossover window where the inverse temperature is proportional to the system size, the stabilizer entropy factorizes into a saturated extensive contribution and a universal finite-size scaling function. We find that this scaling function is a level-eight eta quotient, rather than the ordinary free-boundary Majorana thermal factor. The deviation is exponentially hidden at low temperature but controls the high-temperature crossover, where it gives a Cardy-like asymptotic for the Pauli-string expectation-weight spectrum. These results show that finite-temperature stabilizer entropy reveals hidden defect-like conformal data invisible to ordinary thermodynamic probes.

We present classical magnetic–monopole (MM) and dyon solutions induced by global monopoles in string-inspired gravitational models. Although several ingredients of the construction have appeared previously, we examine a new synthesis via their organised use in a self-gravitating finite-energy monopole/dyon system with explicit mass, charge, core and stability diagnostics. The global monopole provides the topological seed, while the dilaton, Kalb–Ramond (KR) axion and Born–Infeld (BI) electromagnetic (EM) sector supply the string-inspired dressing. Two related branches are analysed: (i) a dilaton–BI magnetic branch, distinct from earlier constructions, and (ii) a dyonic extension in which the KR axion couples electric and magnetic sectors through an axion-Pontryagin-anomaly interaction. In both cases BI dynamics regularises the EM self-energy within a self-gravitating global-monopole construction, and the solutions possess a de Sitter core, a positive ADM-mass parameter range and satisfy the standard energy conditions. A further novel feature is a limiting branch in which the ADM mass tends to zero while the magnetic charge remains finite, the configuration being supported by magnetic charge and de Sitter core pressure.We also examine stability diagnostics. The stress–energy tensor gives finite force components and an outward-pointing radial force, indicating absence of core collapse within the mechanical stability criterion. In the exterior analytic region we analyse gauge-invariant EM perturbations using the Gervalle-Volkov framework. The helicity modes $\psi_\pm$ obey a self-adjoint Sturm–Liouville system. MM helicities decouple, while dyons exhibit axion-induced helicity mixing and birefringent polarisation structure. Positivity of the EM helicity block provides a necessary long-range stability diagnostic; the full coupled Einstein-matter spectral problem is discussed

Markovian open quantum theory assumes evolution with respect to an external classical time parameter, yet no preferred notion of time exists fundamentally in relativistic physics. We resolve this tension by formulating relativistic open quantum dynamics relationally through finite-resolution quantum clocks. Using the Schwinger-Tomonaga formalism, we derive a covariant master equation directly on spacetime hypersurfaces and show that the resulting reduced dynamics is generically non-Markovian even for local interactions. Environmental correlations and clock fluctuations jointly generate the memory kernel, while the Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) structure emerges only after relational coarse-graining, implying that exact Markovian evolution is effective rather than fundamental. In the sharp-clock limit, the formalism reduces to the Anastopoulos-Hu gravitational decoherence equation.

Scattering amplitudes of $n$ particles in nonabelian gauge theories admit factorizations of the general form $\mathcal{A}_n \;=\; \mathcal{A}^{\rm soft}_n \times \mathcal{A}^{\rm hard}_n$, where $\mathcal{A}^{\rm soft}_n$ is IR divergent, while $\mathcal{A}^{\rm hard}_n$ is IR finite and encodes the higher loop corrections to scattering. We specify a particular all-orders definition of this factorization for planar ${\cal N}=4$ super Yang-Mills (SYM) and argue that the resulting $\mathcal{A}_n^{\rm hard}$ obeys an uncorrected tree-level soft theorem. Moreover it furnishes a representation of the undeformed tree-level $\cal S$-algebra generated by a tower of soft gluons. The results follow from several commonly invoked assumptions for ${\cal N}=4$ SYM, including BDS one-loop exponentiation of the splitting function and amplitude/Wilson-loop duality.

An ultimate theory of a phase of matter should describe all its universal properties via quantities that are measurable numerically and experimentally. In this work, we present a microscopic universal theory of symmetry-enriched topological quantum spin liquids (TQSLs) in two spatial dimensions, which directly utilizes microscopically measurable quantities to describe the universal properties. This theory applies to generic TQSLs, which can be Abelian or non-Abelian, chiral or non-chiral. The symmetries are also general, which can include both internal and lattice symmetries, unitary and anti-unitary symmetries, and discrete and continuous symmetries. There can be spin-orbit coupling, the microscopic degrees of freedom may transform linearly or projectively under the symmetries, and the symmetries can permute anyons. The input of the theory is some microscopic states with anyons, operators that control the dynamics of anyons, and symmetry actions in the TQSL, and its output is a set of data characterizing the universal properties, whose underlying mathematical structure is a generalization of category theory. Based on this theory, we find an explicit bijective map between the universal data characterizing a TQSL with a symmetry described by a group $G$, where the symmetry actions may include both lattice and internal symmetries, and the corresponding universal data for a TQSL with only an internal symmetry group $G$, and thus establish a precise crystalline equivalence principle. We demonstrate our theory in symmetry-enriched TQSLs realized on quantum processors based on superconducting qubits, trapped ions, and Rydberg atoms, and in each example we verify the Lieb-Schultz-Mattis anomaly matching condition. Our theory provides a solid basis for identifying and manipulating symmetry-enriched TQSLs, which further paves the way for fault-tolerant quantum computation based on these systems.

In this paper, we study thermal partition functions of free exotic conformal field theories, focusing on conformal higher-derivative and conformal higher-spin fields, in the semi-universal limit $|\omega_i|\rightarrow 1$. It was recently conjectured in \cite{Anand:2025mfh} that, in this limit, the thermal partition function develops universal poles in $(1-|\omega_i|)$, while the corresponding residue functions are theory-dependent. We analyze conformal higher-derivative scalar, fermionic, and vector fields in the semi-universal limit. We then extend the study to the Weyl graviton, the Weyl gravitino, and conformal higher-spin fields (CHS) on $S^1_\beta\times S^3$, using both spectral mode-sum and operator-counting methods. In all cases, we find the expected pole structure, with residue functions whose behavior depends on the presence or absence of negative-twist states. For four-dimensional conformal higher-spin fields, we further reproduce the same residue-pole structure from the one-loop partition function of massless higher-spin fields in thermal AdS$_5$. Finally, we show that the semi-universal limit provides a useful diagnostic of negative-twist states, which indicate violations of ANEC-type bounds in these theories, whereas the traditional high-temperature expansion is insensitive to them.

It is a long-standing problem to prove that the number of distinct topological types of Calabi-Yau threefolds is finite. A related proposition, Reid's fantasy, conjectures that all Calabi-Yau threefolds are connected in a single moduli space through extremal transitions. Finiteness of topological types has been proven for the class of elliptic and genus one fibered Calabi-Yau threefolds, which recently have been shown to constitute the vast majority of known Calabi-Yau threefolds; the moduli space of elliptic CY3's is connected. In this letter, we demonstrate that all non-fibered Calabi-Yau threefolds in two of the largest known classes (toric hypersurfaces and complete intersections in products of projective spaces) are connected to fibered Calabi-Yau threefolds through a simple class of geometric transitions involving the shrinking of a single divisor from a fibered geometry. This suggests that non-fibered Calabi-Yau threefolds are rare special cases that are reached by simplifying fibered Calabi-Yau threefolds, and points to a natural path towards proving finiteness and Reid's fantasy for Calabi-Yau threefolds.

In this note we describe a systematic procedure for computing partition functions of noninvertible Rep ($G$) quantum symmetry actions on two-dimensional nonabelian $G$ orbifolds. We apply this procedure to multiplicity-free examples for several nonabelian groups, and check explicitly in those examples that the partition function of a two-dimensional Rep ($G$)-gauged $G$ orbifold, for nonabelian $G$, matches that of the original theory, as expected on general principles. This fills a minor gap in the literature, making quantum symmetries in two-dimensional nonabelian orbifolds more concrete.

We propose the linear combination of the anomalous magnetic moments of the muon and electron, $a_{\mu-e} \equiv a_\mu - (m_\mu/m_e)^2 a_e$, as a natural low-energy window quantity that may directly probe the current discrepancy between the data-driven and lattice-QCD evaluations of hadronic contributions. The rescaling ensures an exact cancellation of the short-range effects, thereby improving the UV behavior and bypassing a number of issues that arise in $a_\mu$ or $a_e$ separately. The hadronic-vacuum-polarization effect in $a^{\rm HVP}_{\mu-e}$, together with its uncertainty, is reduced as compared to $a^{\rm HVP}_{\mu}$ by $\sim 85\%$. This is promising for tests of New Physics, conditional to significant improvements in experimental measurements of $a_e$ and $\alpha$. One can foresee the improvements in tests of New Physics with some degree of flavor non-universality, as well as for the flavor-universal sub-GeV states.

Neutron stars consist of cold, dense, neutron-rich nuclear matter under charge neutrality and $\beta$-equilibrium. In most nuclear equation of state (EOS) studies, the isospin dependence of asymmetric nuclear matter is described using the conventional quadratic/parabolic approximation to the nuclear symmetry energy. However, its validity in the highly neutron-rich inner core of neutron stars remains uncertain. In this work, we systematically investigate the role of higher-order isospin corrections to the symmetry energy within the framework of Skyrme-like effective nuclear interactions. We first analyze the standard SLy4 parametrization and quantify deviations arising from successive higher-order terms in the expansion of the energy per nucleon with respect to the isospin asymmetry parameter. We then extend the analysis to a large population of physically viable Skyrme EOSs sampled over a broad parameter space constrained by conventional nuclear saturation density bounds, thermodynamic stability, and causality, as well as the requirement to support astrophysical neutron-star mass observations exceeding $2\text{M}_{\odot}$. We find that higher-order isospin corrections become increasingly important at supra-nuclear densities and can significantly modify composition-sensitive quantities under $\beta$-equilibrium, including the neutron-proton chemical potential difference, proton fraction, leptonic sector properties, and the direct-Urca process. In contrast, the $\beta$-equilibrated EOS, energy density, pressure, and sound speed remain comparatively insensitive to these corrections for most viable EOSs. Our results demonstrate that while the quadratic approximation captures bulk thermodynamic behavior reasonably well, higher-order isospin contributions play a non-negligible role in determining the detailed composition and microscopic properties of dense matter in neutron-star interiors.

Swampland and compactification data tell us where a chosen EFT description can lose parametric control; stochastic cosmology asks which histories survive near that edge. We turn this question into a survival problem for fluctuating moduli over cosmological time scales. Given a valid stochastic generator, hard loss surfaces, soft degradation profiles, and finite horizons define a survival probability, whose logarithm is the survival action. The Doob transform then converts this logarithmic survival cost into the drift of the ensemble conditioned to remain on the controlled side. Near a regular hard boundary with nonzero normal diffusion, the inward normal component of the conditioned response is universal: it is fixed at leading order by the proper distance to the wall and the normal diffusion coefficient. The same finite-horizon construction also determines loss probabilities, first-exit statistics, survival hazards, and the control margin required to retain a prescribed fraction of histories. In this way, tower/species cutoffs, weak-coupling limits, string and Kaluza-Klein thresholds, and carefully qualified potential-based diagnostics acquire stochastic boundary layers without becoming microscopic forces. The inverse map tests when a conditioned drift is compatible with a scalar operational loss surface and reconstructs its boundary-normal Doob class. The construction therefore gives a stochastic survival interface between quantum-gravity control data and the cosmological histories that remain inside the prescribed EFT domain.

We investigate the collision dynamics of complex kink solutions in the complex sine-Gordon (CSG) model, focusing on the influence of the relative phase and initial velocity. The model's internal \( U(1) \) symmetry gives rise to a variety of solitary wave solutions, including complex kinks, radiative profiles, and Q-ball configurations. Through numerical simulations, we reveal rich and nontrivial phase-dependent behaviors such as the emergence of red and blue critical speeds, radiative emissions, bion and breather formations, and phase-sensitive oscillation modes. Moreover, we identify extreme values in energy and field quantities at the collision point, uncovering discontinuities that signify transition thresholds in the dynamical system. These findings underscore the complex interplay between internal degrees of freedom and dynamical variables in non-integrable soliton systems, offering new insights into field theories with internal symmetries.

Gravitational-waves from astrophysical sources are characterized by their extreme faintness, which remains a primary obstacle for both current and next generation detectors. While rotating black holes dressed in superradiant clouds of ultralight bosons are recognized as promising probes of physics beyond the Standard Model, their capacity to actively emit and modulate gravitational radiation remains largely unexamined. Here we demonstrate that these gravitational atoms can function as natural amplifiers of gravitational-waves via a stimulated emission mechanism analogous to astrophysical masers. By formalizing the interaction between the bosonic cloud and an ambient stochastic gravitational-wave background, we establish the rigorous selection rules and threshold conditions that govern this amplification. Our analysis reveals that the emission rate depends critically on the boson mass, potentially yielding an enhancement of several orders of magnitude over spontaneous processes. For representative mass ranges, these amplified signals bridge the sensitivity gap between ground-based interferometers and pulsar timing arrays. These findings suggest that superradiant clouds can effectively boost previously undetectable signals, offering a novel observational frontier for exploring ultralight fields and the Kerr spacetime environment.

We study conserved worldsheet charges associated with spacetime supersymmetry in heterotic pure-spinor superstrings on curved ten-dimensional superspace backgrounds. Requiring BRST invariance and worldsheet conservation gives a covariant set of superspace constraints. In flat superspace these conditions reproduce the standard ten-dimensional supersymmetry generator. In curved superspace, they organize the requirements for global supersymmetry in terms of a normalizable spinor superfield.

A field theory in $3+1$ dimensions contains two fermions, two Abelian gauge fields, and one complex scalar, with dynamics fixed by a BRST symmetry. For a specific parameter configuration, the fermion mass matrix becomes non-Hermitian, and the propagators exhibit complex conjugate poles. We evaluate the one-loop fermion contribution to the two-point function of the composite operator $\phi^{\dagger}\phi$. Once the factor $i$ of the $e^{iS}$ normalization is removed, the contribution is real for real external momentum, which follows from the pairing of complex conjugate terms in the loop integral. The BRST construction of the action sets up a proof of renormalizability.

Particle physics models beyond the Standard Model often contain global symmetries to address various unanswered questions. However, a common criticism of theories based on global symmetries is that such symmetries are generally expected to be explicitly violated by gravitational effects at the Planck scale. In the case of a global $U(1)$ symmetry, this explicit breaking can reduce the symmetry to a discrete subgroup of $U(1)$, leading to the formation of cosmic strings attached to multiple domain walls (DWs). These DWs are usually cosmologically problematic, since their slow scaling behavior can eventually dominate the energy density of the Universe, giving rise to the well-known cosmological DW problem, which is strongly constrained by Big Bang Nucleosynthesis. In this work, we propose a mechanism for the annihilation of these DWs. If a fermion coupled to the symmetry-breaking scalar has a small bare mass, radiative corrections generate a temperature-dependent vacuum bias that drives DW collapse. As an example, we consider a majoron model with right-handed neutrinos, where gravity-induced operators produce a string-wall network. We show that a real bare Majorana mass is sufficient to induce complete DW annihilation for even-dimensional gravity-induced operators, whereas odd-dimensional operators require a complex bare Majorana mass whose phase lifts the residual vacuum degeneracy, enabling complete annihilation.