Papers

Chain inflation offers an alternative to standard slow-roll dynamics, with accelerated expansion proceeding through a sequence of rapid quantum tunneling events between metastable vacua. At the high energy scales relevant for the early Universe, scalar fields are generically expected to couple non-minimally to gravity via operators like $\xi R\phi^2$, allowed by symmetry and required as counterterms for interacting theories in curved spacetime. We study the dynamical and observational consequences of this coupling for chain inflation. We find the modifications to the model for arbitrary $\xi$ and focus on interesting phenomenology for $\xi ={\cal O}( 10)$. We show that, in the Einstein frame, the non-minimal coupling induces a field-dependent amplification of the Euclidean bounce action, thus modifying the tunneling rate across the chain. We develop an analytic framework connecting this modified tunneling dynamics to the scalar spectral index, its running, the primordial curvature power spectrum, and the stochastic gravitational wave background from bubble collisions. As one consequence, the non-minimal coupling breaks the rigid relation between the scalar tilt and inflationary scale that drives the minimally coupled pure tilted cosine model to very low energies ($V_*^{1/4}\lesssim 3\,\rm{GeV}$, where $V_*$ is the value of the inflationary potential when the CMB-relevant modes exit the horizon), allowing for viable high-scale chain inflation with $V_*^{1/4}\sim 10^{11}\,\rm{GeV}$. Furthermore, non-minimally coupled chain inflation at high scales produces a peaked stochastic gravitational wave signal in the dHz-kHz bands, accessible to upcoming interferometers such as the Einstein Telescope and Cosmic Explorer. Finally, the model predicts a distinct running of the spectral index that will be testable by the Simons Observatory, making it a prime target for multi-messenger cosmology.

Axions and axion-like particles are a compelling candidate for physics beyond the standard model. While many axion searches are focused on the linear coupling to photons $\theta F \tilde{F}$, the possibility of a quadratic coupling to the electromagnetic kinetic term, $\theta^2 F^2$, leads to novel phenomenology and new opportunities for testing axion-like particles. In this work we propose mechanisms for generating this coupling in string theory, which can be broadly classified as classical, perturbative, and non-perturbative. In benchmark examples, we find that both perturbative and non-perturbative quantum contributions such as instantons lead to couplings that are suppressed, $g \ll 1$ in units of $1/f^2$ where $f$ is axion decay constant, though easily larger than analogous coupling of the QCD axion that is generated through loops of charged pions. These analyses suggest that quadratic axion couplings to gauge fields are ubiquitous in string theory, and should be taken seriously as a probe of the string theory axiverse, both of string theory candidates for dynamical axions, such as dark matter or dark energy, and for spectroscopy of the string theory axiverse.

The superradiant instability of rotating black holes can generate a significant overdensity of bosonic matter around them, together forming a gravitational atom. This mechanism allows one to probe a large part of the parameter space of scalars, axions and vectors that lies beyond the reach of traditional detection strategies. Modelling the dynamics of these systems in binaries is, however, subtle, due to the competing nature of the different perturbations. In this work, we provide a consistent scheme to treat these perturbations, including both the minimal set of internal ones (relativistic corrections and self-gravity) and the external tidal field. Within the worldline effective field theory framework, we then calculate the Love numbers of gravitational atoms, for the first time also for the most interesting case of spinning clouds. Certain spinning states are found to have negative (static) Love numbers, with a magnitude parametrically enhanced relative to the scaling for the non-spinning states – in phenomenologically relevant scenarios by a factor $\mathcal{O}(10^2\text{--}10^3)$. Finally, we consider the binary evolution in the early inspiral, assessing the impact of the competing perturbations on shifted resonances, which for dense clouds can alter the nature of some of the hyperfine and fine transitions (sinking instead of floating). This dynamical picture allows us to identify at which stages the permanent multipoles are the strongest indicators of new light bosons, and at which the induced ones take over, while keeping track of both types of finite-size effects even during the resonance. More broadly, our results demonstrate that gravitational atoms are a useful toy model for studying the theoretical aspects of tidal response in gravitational-wave physics.

We numerically study the outcome of symmetry breaking motivated by Grand Unified models. Our results show the formation of biased domain walls for a range of parameters together with magnetic monopoles. The interactions of walls and monopoles leads to novel processes such as the absorption of monopoles on walls, production of monopoles when domain walls annihilate, collapse of walls with magnetic charge that can, with gravity taken into account, produce magnetically charged black holes, and production of a stochastic gravitational wave background from biased domain walls. Our findings open new avenues for probing the grand unification epoch by cosmological observables.

The growth of primordial perturbations during the matter-dominated era is primarily driven by dark matter. Ultralight scalar fields (ULDM) are a promising candidate for this role, conventionally modeled as operating in a classical, high-occupation regime. In this work, we develop a first-principles field-theoretic framework to investigate the impact of ULDM on linear cosmological perturbations during matter domination, explicitly retaining its quantum nature. Deriving a closed equation for the graviton field dynamics, we compute and regularize its source terms for a generic Gaussian initial state of the ULDM field within the adiabatic (WKB) approximation, employing the middle-point working assumption for non-local terms. After gauge-fixing we find that, contrary to previous claims, the classical condensate of ULDM has no influence on gravitational wave propagation. However, the time-dependent graviton effective mass induced by quantum pressure of the squeezed state can drive parametric resonance in specific primordial gravitational wave modes. We demonstrate this growth is negligible for non-relativistic ULDM at matter-radiation equality under the assumption of a power-law squeezing spectrum for masses in the range $m \sim 10^{-21}{-}10^{-24}$ eV.

We study static quark–antiquark interactions in rotating SU(3) gluodynamics using quenched lattice simulations at imaginary angular velocity. At zero temperature, we extract the static potential from Wilson loops for quark–antiquark pairs aligned with the rotation axis, for transverse pairs with one source on the rotation axis, and for symmetric transverse pairs across the rotation axis. Within the present accuracy, no significant rotation dependence or anisotropy is observed in the zero-temperature potential. At finite temperature, imaginary rotation suppresses the color-averaged free energies obtained from Polyakov-loop correlators in both longitudinal and transverse geometries. Axial-diagonal comparisons are used to identify a bulk region where open-boundary artifacts are reduced. In this region, the large-distance longitudinal free-energy shift is well described by $\Delta F_z(R_{xy})=A R_{xy}^2+B$. The transverse channels exhibit the same qualitative suppression, while their distance dependence additionally reflects the radial arrangement of the static sources and is compatible with a radial single-source free-energy shift in the bulk region. For the finite-temperature observables studied above $T_c$, the response weakens as the temperature is increased. These results provide lattice evidence for a position- and geometry-dependent response of bare static-source free energies to imaginary rotation in a gluonic medium.

We investigate the extended phase space thermodynamics of a static, spherically symmetric regular black hole immersed in a string cloud background. By identifying the negative cosmological constant as a thermodynamic pressure, our analysis indicates that the quantum-inspired regularizing core and the string cloud density significantly affect the thermal stability of the black hole. We specifically illustrate a stringent scale invariance linked to the regularizing core, while the dimensionless string cloud parameter substantially alters the universal Van der Waals critical compressibility ratio. The significant geometric inconsistencies result in computed critical exponents that align with those of mean-field theory. We specify the Joule-Thomson expansion to define the isenthalpic heating and cooling regimes, so providing a comprehensive thermodynamic characterization of this non-singular spacetime.

The quantum Fisher information (QFI) of the vacuum of three quantum field theories is evaluated with respect to the mass parameter of each theory. All field theories are considered on a $(d+1)$-dimensional Euclidean spacetime. We consider the Klein-Gordon field and the free Dirac field. For the free KG case, we find a $m^{d-2}$ dependence of the QFI, and thus no dependence for $d=2$, in agreement with the holographic duality characterizing the theory. The vacuum QFI with respect to the free Dirac field mass is shown to be UV-divergent for $d=2$ and $d=3$, mass-dependent for $d=1$, and zero for $d=0$.

In this note we construct, from a gauge theory perspective, the world-line action for a particle moving on a time-like curve in Weyl geometry. The action we find is dimensionless, Weyl invariant, additive and, in general, non-local due to an open Wilson line which we have to add in order to account for a general Weyl field. In special cases, this Wilson line can be local, but the geometry becomes integrable. The action can not be used to measure the proper time as it is dimensionless and no mass parameter is allowed in the symmetric phase of the theory. We show that the usual conditions for defining proper time: affine parametrization, dimension of time and additivity supplemented by the requirement of Weyl invariance can not be fulfilled simultaneously and therefore no satisfactory notion of proper time exists in the symmetric phase. Under spontaneous symmetry breaking the particle acquires a mass, the action becomes Riemannian and the proper time can be again defined. We also construct a classically equivalent quadratic action by using an einbein on the world-line and show that the non-locality can be seen to arise from integrating out a constrained field.

Anisotropic flow in ultra-relativistic light-ion collisions is sensitive to the initial geometry of the colliding nuclei. We investigate whether elliptic flow measurements can constrain the parameters of the proposed $\alpha$-clustered nuclear density distributions of $^{16}$O and $^{20}$Ne at LHC energies. Using the hybrid framework IP-Glasma+MUSIC+iSS+UrQMD, we simulate OO and Ne–Ne collisions at $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV for the Woods–Saxon and $\alpha$-clustered configurations with varying cluster compactness. The elliptic flow coefficient $v_2\{2,|\Delta\eta|>1\}$ is calculated in the kinematic acceptances of ALICE, CMS, and ATLAS detectors and is compared with the Run~3 OO and Ne–Ne experimental measurements. It is observed that the final-state elliptic flow is significantly sensitive to the nuclear geometry, especially in OO collisions, where different configurations lead to distinct centrality dependencies and peak positions of $v_{2}$. By performing a systematic variation of the cluster size and inter-cluster separation in $^{16}$O and $^{20}$Ne nuclei, this work attempts to identify the cluster parameter range that provides the best agreement with the experimental data. These results show that the flow observables in TeV-energy light-ion collisions can be used to optimize the nuclear structure parameters of light nuclei.

In this article, we use the expression of the Schwarzian derivative to set up differential equations to find answers to three fundamental questions in the context of QFT in curved spacetime, specifically in two dimensions. One of the ways in which one can derive the Unruh effect in two dimensions is to use the anomalous transformation law of the energy-momentum tensor for a CFT that involves a Schwarzian derivative (Virasoro Anomaly). We answer the following three questions. The first question is as follows: If we have a spacetime with a massless scalar field in vacuum, what are all the subsets of spacetime such that the subset has a thermal distribution of particles for the left-moving and/or right-moving sectors? We obtain a general solution to this question by setting up and solving a third-order nonlinear differential equation based on the expression of Schwarzian. Based on the general solution, we can generate various subsets of the given spacetime that have a thermal flux/density of particles, of which the Rindler spacetime is one. The second question is an inverse question in which we suppose we are given a spacetime with a thermal distribution of particles; what are the possible purifying spacetimes (the “parent” spacetimes with the field in vacuum state whose reduced state in the given spacetime yields the observed particle content)? We similarly obtain a general class of solutions by setting up and solving a second differential equation. In this context, we also define “partial purification” where we obtain a spacetime that purifies only the left-moving or right-moving sector. The third question concerns locating spacetimes with the same particle content starting from the same “parent” spacetime. These sibling spacetimes are generated again by obtaining the general solution of a third differential equation based on the expression of Schwarzian.

The tidal deformability of a compact object is encoded in a single function of frequency, the retarded Green's function relating the induced multipole to the applied tide. Causality, reality, passivity, and the high-frequency conditions required for a positive-measure dispersion representation allow this response to be rescaled into a holomorphic self-map of the upper complex frequency half-plane. Using the Schwarz–Pick theorem, already employed to derive the quantum chaos bound in black hole physics, we provide a bound on the rate of the tidal response with respect to the frequency. For a neutron star the dynamical Love number is bounded in terms of the static one and of the frequency of the first internal mode, with the single-mode ($f$-mode) model saturating the bound. For a black hole, the bound gives information on the dissipative tidal-heating coefficient.

Flavor mixing and CP violation in the Standard Model are conventionally parameterized by Euler angles that entangle the physical contributions of the up- and down-type quark sectors, obscuring the origin of CP violation itself. We present a non-perturbative geometric framework that resolves this entanglement through the commutativity condition $[\mathbf{M}_R^2,\mathbf{M}_I^2]=0$ for the Hermitian components of the mass-squared matrices, reducing the 18 real degrees of freedom of a general $3\times3$ Yukawa matrix to five independent parameters and yielding an exact Cartesian-like parameterization. Explicit diagonalization directly gives fermion masses, CKM matrix elements, and the CP phase $\delta$ in closed form, cleanly separating the distinct physical contributions of the up- and down-type sectors. Mapping flavor space onto a two-dimensional vector geometry, we derive the Jarlskog invariant $J$ in exact closed form and show that CP violation is governed by a discrete topological selection rule ($\eta_{\text{relative}}\in\{0,\pm1\}$) together with the vector cross-product $\mathbf{v}_u\times\mathbf{v}_d=xy'-x'y$. Across all 36 $S_3\times S_3$ flavor topologies, this yields an exact $18/18$ classification into CP-violating ($J \neq 0$) and CP-conserving ($J\equiv 0$) cases, associated with two distinct CP-suppression mechanisms: geometric alignment through a vanishing vector cross-product and algebraic cancellation of imaginary contributions under permutation. At tree level, fitting to experimental CKM elements yields agreement at the $\mathcal{O}(10^{-2})$ level, establishing this framework as a transparent analytical baseline for future non-commutative flavor extensions.

We consider the unitary time evolution of an interface in the regime of spontaneously broken symmetry of the two-dimensional quantum Ising model. The interface is induced by an initial condition interpolating between the two degenerate ground states in one of the spatial dimensions. The interpolation is left generic in order to investigate the dependence of the late time dynamics on the initial condition. Exploiting the basis of asymptotic quasiparticle states of the bulk theory, the order parameter is analytically determined at large times in the rough phase. The mechanism allowing the breakdown of this phase as the distance from criticality increases emerges from the theory.

We investigate non-thermal particle production during first-order phase transitions in the presence of ultra-relativistic thick bubble walls with non-trivial internal structure. Extending the framework of bubble-expansion particle production, we consider bubble walls containing multiple ripples and study how such spatial modulations affect the production of heavy particles coupled to the order parameter field. By modeling an oscillatory thick-wall profile, we derive the transition probability for particle splitting processes in the wall background, and identify a new contribution associated with momentum transfer from the wall microstructure. In addition to the conventional channel, we find an enhanced production mode arising from resonant momentum exchange with the ripples. For sufficiently large numbers of ripples, the new contribution can dominate the production rate and significantly increase the abundance of particles much heavier than the phase-transition scale. Our results demonstrate that the internal structure of expanding bubble walls can play an important role in particle production and should be taken into account when assessing the cosmological implications of strongly first-order phase transitions.

We obtain a static topological charged black hole solution within Einstein-dilaton theory with nonlinear electromagnetic field represented by an infinite series over Maxwell field invariant. In contrast with standard Einstein-Maxwell-dilaton (EMD) theory where the black hole might have no more than two horizons, the nonlinear generalization might give rise to a solution with arbitrary number of horizons. We examine energy conditions and show that for the nonlinear electromagnetic field itself all the energy conditions are fulfilled outside of the black hole, whereas for the dilaton field the only condition which is not violated outside is the Null Energy Condition (NEC). We also study thermodynamics of the black hole and show that the thermal behaviour of the solution is considerably richer than for its standard EMD cousin. To have complete description of the thermodynamics we also use the Euclidean method, which allows us to consider the so-called Grand Canonical and Canonical Ensembles. The results obtained by different approaches show their consistency. The Euclidean description naturally allowed us to consider global stability, which is shown to have some common features with standard EMD solution, or even Reissner-Nordström black hole. But there some new peculiarities caused by the nonlinear field, namely we might have additional stable phases and a triple point. To examine near critical behaviour we consider the extended phase space approach, where the cosmological constant is supposed to be a thermodynamic variable. Making use of the extended formalism we also obtain the Smarr relation.

The Mielke–Baekler geometries are three-dimensional reductive homogeneous spacetimes together with a choice of invariant connection which is compatible with a lorentzian metric. The spacetimes generalise Minkowski and (anti)de~Sitter spacetimes in that the invariant metric connection can have torsion, a peculiarity of three dimensions. Using coadjoint orbits and the techniques of nonlinear realisations, we construct worldline actions for massive and massless spinning particles moving in these spacetimes. We pay particular attention to the so-called teleparallel branch, in which the curvature of the invariant connection vanishes. Apart from the trivial Minkowski case, this singles out anti-de~Sitter spacetime, as the only of these lorentzian manifolds admitting an invariant Weitzenböck connection; that is, a flat connection with torsion. The introduction of a Wess–Zumino term describing spin has, as a main consequence, the appearance of dynamical sectors (denoted “regular” and “critical”), with a different number of physical degrees of freedom. In particular, in the massive case, we discuss the formulation of the dynamics in terms of either the Weitzenböck or the Levi-Civita connection, and the emergence of a Papapetrou-type forcing term in the critical sector. For the massless particle we study the Noether symmetries of the action, which, for the spinless case, include the conformal transformations. For nonzero spin, only the Killing subset survives as genuine Noether transformations in the regular sector, while in the critical sector any conformal Killing contribution can be set to zero by a gauge transformation.

We construct a linearly stable scalar-field model that realizes both an upward crossing of the dark-energy equation of state, from $w_{\rm DE}<-1$ to $w_{\rm DE}>-1$, and weakened gravitational clustering in the cold dark matter (CDM) sector. An exponential potential breaks shift symmetry and drives the background from a stable phantom phase toward the nonphantom regime, while a pure momentum-transfer interaction increases the dynamical inertia of CDM without altering its background dilution law. We derive the background and linear perturbation equations and establish the no-ghost and Laplacian-stability conditions. For perturbations deep inside the Hubble radius, where the quasi-static approximation applies, the effective gravitational coupling for CDM can fall below Newton's constant, suppressing late-time growth and small-scale matter power, while the baryonic coupling remains enhanced by Galileon braiding. A modified CLASS calculation, including the scalar-field perturbation and the full Boltzmann hierarchies, reveals signatures of transient braiding around radiation–matter equality. For the representative stable solutions studied here, these signatures include an enhancement of matter power toward the lowest wavenumbers probed numerically and a reduction of CMB temperature power over the multipole range $2\leq\ell\leq30$. We also find small shifts in the acoustic scale and the position of the first temperature peak. These results motivate a full likelihood analysis of the model.

The effective action of string theory has a highly constrained structure due to the numerous symmetries of the underlying theory. Recently, a method known as the Generalized Bergshoeff-de Roo identification was developed, which exploits diffeomorphism, Lorentz and gauge invariance, along with T-duality, to derive higher-derivative couplings in the effective action within the framework of Double Field Theory. This method has been revisited and further refined to generate couplings directly within the standard Supergravity framework.

\noindent Given an AKSZ theory $\mathbb{T}$ on a manifold $M$, with target a graded vector space $Y$, we formulate a 1-dimensional theory $\mathbb{t}$ on graphs (the “first quantisation picture for $\mathbb{T}$”), whose partition functions reproduce the Feynman graphs of $\mathbb{T}$. More precisely, the theory $\mathbb{t}$ is itself a 1d AKSZ theory with the target built out of $M$, and involving a coupling to 1d supergravity. It yields a form on the space of metric graphs (with length $T$ of an edge and its de Rham differential $\mathrm{d} T$ interpreted as the zero-modes of the graviton and gravitino, respectively); its integral yields the sum of Feynman graphs of $\mathbb{T}$. We study the theory $\mathbb{t}$ in the BV-BFV formalism; a gauge-fixing of $\mathbb{T}$ corresponds to a gauge-fixing of $\mathbb{t}$. At the classical level, $\mathbb{t}$ assigns to vertices certain Lagrangian submanifolds $L_k$ in Cartesian powers $\Phi^{\times k}$ of the phase space $\Phi$ of $\mathbb{t}$. These submanifolds can be thought of as defining a cyclic $\mathrm{L}_\infty$-algebra in Weinstein's symplectic category (“dequantising” the cohomological vector field on the target %target AKSZ dg structure of $\mathbb{T}$). In the path integral construction of $\mathbb{t}$, Lagrangians $L_k$ determine sewing conditions for fields on the incident edges at a $k$-valent vertex. We give examples of this paradigm, such as when $\mathbb{t}$ on edges is the Witten-Morse supersymmetric quantum mechanics (which corresponds to a particular type of gauge-fixing for $\mathbb{T}$ and $\mathbb{t}$). In the example where $\mathbb{T}$ is the non-abelian Chern–Simons theory with structure Lie algebra $\mathfrak{su}(2)$, we describe the vertex Lagrangian $L_{\mathrm{W}}$ (the “Wigner Lagrangian” ).

We propose a quantum sensor network for direct detection of quantum chromodynamics (QCD) axion dark matter using entangled superconducting qubits. In the presence of a static magnetic field, the oscillating axion field induces a coherent qubit rotation described by an encoding angle proportional to the axion-photon coupling and an unknown dark-matter phase. Treating the phase as an additional unknown parameter turns axion detection into a two-parameter quantum estimation problem. We formulate these signals in Cartesian coordinates, thereby avoiding the singularity that arises in the weak-signal regime and establishing a regular framework for multiparameter quantum estimation. Using this framework, we optimize the quantum sensor network and combine it with Bayesian inference to reconstruct the axion-photon coupling. The optimized protocol accurately recovers the KSVZ and DFSZ benchmark couplings over the mass range $m_a\in[0.1,10]~\mu{\rm eV}$, generalizes to previously unseen masses, and remains robust against realistic superconducting-qubit decoherence and gate errors.

We modify the Standard Model by making the longitudinal component of the photon physical, propagating with small speed $c_L \ll 1$. This modification breaks gauge invariance and Lorentz symmetry, defining a preferred reference frame. No new fields or scales are introduced, and the photon mass is protected by a Galilean higher-form symmetry. The theory has a smooth $c_L\to0$ limit: the new modes decouple from standard matter and ordinary gauge theory predictions are recovered. Experimental constraints are severe. Charged particles Cherenkov-emit these slow modes, experiencing hard recoils against the preferred frame. The recoil rate decreases with $c_L$, but the momentum transfer remains of the order of the particle's momentum. Dark matter detectors, sensitive to keV-scale nuclear recoils, imply an order-of-magnitude bound $c_L \lesssim 10^{-60}$, tens of orders of magnitude stronger than speed-difference bounds. At such values, $c_L$ is better understood as a recoil-rate factor rather than a physically relevant speed. The slow modes, practically fixed in space, make the reference frame a material medium capable of absorbing momentum from charged particles.

Parastatistics is an exotic type of exchange statistics beyond fermions and bosons. Paraparticles transform in higher dimensional representations of the exchange symmetry group, analogous to non-Abelian anyons, yet consistently defined in any dimension. Although paraparticles have long been proposed, they were widely believed to be physically equivalent to fermions or bosons. Nevertheless, a recent paper proposed a different theory, called $R$-parastatistics, and demonstrated that nontrivial $R$-paraparticles can emerge as quasiparticles in condensed matter systems, and are observably distinct from both fermions and bosons. This paper develops the theoretical foundation and several extensions of $R$-parastatistics, with particular emphasis on its observable consequences. Central to this paper is a general theory of local observables extending the basic family introduced before. First, we define local observables that distinguish particle types. Second, we formulate local observables at special point defects that probe the internal indices of $R$-paraparticles, crucial for observing $R$-parastatistics and for the proposed applications in quantum information. Third, we introduce local observables that create or annihilate particle-antiparticle pairs, important for building a relativistic quantum field theory for $R$-paraparticles. We further introduce generalized hidden symmetries that act on internal indices of $R$-paraparticles while preserving the local observable algebra, providing a basis for proving local indistinguishability and for connecting to a categorical description of $R$-paraparticles. This work sets a solid theoretical foundation for understanding the fundamental physical properties of $R$-paraparticles and pave the way for finding them in nature.

We develop a coordinate-independent algebraic description of zero-field boundary conditions for the pure spinor string on $AdS_5\times S^5$ in the closed-string channel. The construction is organized by involutive automorphisms of $\mathfrak{psu}(2,2|4)$ that exchange the odd sectors of the $\mathbb Z_4$ grading. Their fixed subalgebras provide candidate half-BPS, Lorentzian D-brane geometries with vanishing background world-volume flux, consistent with the standard $AdS_2$, $AdS_3\times S^1$, $AdS_4\times S^2$, and related embeddings. Together, the seven representatives realize the Lorentzian zero-flux D1, D3, D5, and D7 probe sectors considered here. We then construct a local ansatz for the matter and ghost boundary interactions and derive a system of consistency equations for the tangential superconnection, transverse embedding, and four ghost-gluing couplings. The resulting system is a set of Dirac-Born-Infeld-like equations of motion on the brane world-volume.

We study the nucleon spectra in two holographic set-ups: Einstein-dilaton and Starobinsky-dilaton gravity models. The Einstein-dilaton holographic model, also known as improved holographic QCD, have been proposed some time ago to describe confinement and glueball spectra. Recently, it has been applied to the case of mesons and nucleons. In this work, we reconsider the Einstein-dilaton holographic model to discuss the nucleon spectra introducing new parameters that allow us to improve the comparison with experimental data. Then, we extend this idea to the context of Starobinsky-dilaton gravity defining another improved holographic model. We use this new holographic model to reanalyse the nucleon spectra and also compare them with soft-wall model and experimental data.

In six-dimensional $\mathcal{N}=(1,0)$ supergravity, the structure of tensor moduli space is governed by primitive BPS string charges known as BPS generators and their intersection pairing. We derive bounds on the intersection numbers of these generators from a purely effective field theory (EFT) perspective. Although gauge anomaly cancellation constrains intersections between generators supporting gauge algebras, bounds for E-strings intersecting generators with self-intersection numbers $-2$ and $-3$ have previously remained incomplete. We show that the Zariski decomposition, interpreted as the charge lattice counterpart of the attractor mechanism, together with current algebra embeddings on the E-string worldsheet theory, yields strong universal bounds on these intersection numbers. These results establish the finiteness of tensor charge intersection numbers up to duality. The underlying structure was identified through AI-guided investigation and is proven here analytically using EFT arguments.

We investigate the relation between fundamental complements and regional operator algebras in global de Sitter space. For a finite union of open arcs on the time-symmetric circle of global dS$_2$, we show that the fundamental complement is determined by the largest complementary gap: a gap contributes precisely when its angular length is at least $\pi$, and at most one gap can do so. In higher-dimensional global de Sitter space, the corresponding criterion is containment of an open hemisphere. We then study the operator-algebraic consequences in an abstract Möbius-covariant chiral conformal net. Each regional algebra is crossed with its vacuum modular flow using a shared auxiliary clock. We derive an exact criterion for inclusions between the resulting continuous cores and show that vacuum correlations obstruct this criterion when the larger region contains an additional spacelike arc. A compatible family can nevertheless be obtained on the finite Boolean algebra generated by a fixed collection of separated arcs by using a split product state. Motivated by the holograms prescription of Bousso and Penington, we introduce a representation-dependent commutant model for regional algebras. When the protected gap overlaps a fixed reference arc, the assigned algebra is a proper von Neumann subalgebra of the reference Type-II$_1$ factor. For an explicit two-arc family, adding an arbitrarily short antipodal component removes the fundamental complement and changes the assigned algebra discontinuously to the full reference algebra.

We introduce a novel cosmological model that provides an effective description of the back-reaction of super-Hubble fluctuations on the cosmological background, a generic effect expected to arise in any cosmological scenario without requiring additional ingredients. At the phenomenological level, it can be interpreted as an interacting dark sector scenario in which the sign of the energy transfer changes periodically over time. We constrain the model using CMB, BAO, and Type Ia supernova data. We find that a significant amplitude of the oscillatory interaction is allowed by the data, although there is no statistically significant preference for this model over $\Lambda$CDM.

In the weak-coupling approach, thermalization of the quark-gluon plasma and the evolution of jet-like perturbations in the medium can be described by the same underlying QCD effective kinetic theory (EKT). In this work, we show how the EKT reduces to the standard energy-loss and angular-broadening evolution of jet-quenching in the high-energy regime, while providing a consistent description near the thermal scales. Building on this, we derive a parton shower directly from EKT that reproduces the full linearized Boltzmann equation, combining elastic and inelastic collisions to capture both hard-parton energy loss and thermal equilibration on an equal footing. This shower lets us extend EKT to inhomogeneous perturbations, connecting jet evolution to the medium's hydrodynamic response, including wakes, Mach cones, and multi-particle correlations.

CasimirRFM is a Mathematica package for the study of compactifications on Riemann-flat manifolds and the computation of one-loop Casimir energies in higher-dimensional field theories and supergravity. It implements an efficient numerical evaluation of lattice sums using Ewald summation, and computes both lower-dimensional Casimir potentials and local higher-dimensional Casimir energy densities, allowing for general massless spectra and twisted boundary conditions. The package provides tools for constructing and analysing the finite groups defining these manifolds, determining invariant metrics and cohomology bases, identifying compatible spin structures, and computing moduli-space metrics. Moreover, it evaluates the traces of holonomy elements in the graviton, $p$-form, spinor, and Rarita-Schwinger representations. We describe the mathematical formulation and numerical implementation of the package, and illustrate its use through a compactification of Type IIB supergravity on $T^6/\mathbb{Z}_8$, including the computation of the Casimir potential and the visualization of localised Casimir-brane contributions.