New articles on Mathematical Physics


[1] 2508.05453

Shell energies derived from three-dimensional isotropic strain-gradient elasticity

We derive a class of two-dimensional shell energies for thin elastic bodies exhibiting small-length scale effects modeled via strain-gradient elasticity. Building on the final author's earlier work on plate models, the kinetic and stored surface energies arise as the leading cubic order-in-thickness expressions for three-dimensional kinetic energies with velocity-gradient effects and a broad class of isotropic stored energies, each possessing an intrinsic length scale $\ell$. These include both classical Toupin-Mindlin and more recent dilatational strain-gradient elastic stored energies. A key insight of this work is that consistent asymptotic reductions of strain-gradient theories necessarily begin at cubic order-in-thickness due to the natural scaling assumption $\ell = O(h)$ where $h$ is the thickness of the body. In the limit as the intrinsic length scales vanish, the theory reduces to Koiter's classical shell energy. We illustrate the theory using the shell energy derived from dilatational strain-gradient elasticity, computing the body force, edge tractions and edge double force densities required to support a variety of finite deformations.


[2] 2508.05520

Rational Extended Thermodynamics for Non-Newtonian Fluids with Finite Relaxation Time

We introduce a one-dimensional, hyperbolic model for non-Newtonian fluids with finite relaxation time, derived within the framework of Rational Extended Thermodynamics (RET). Unlike classical parabolic models, our formulation preserves finite signal speeds, thermodynamic consistency, and mathematical well-posedness. The model captures viscoelastic phenomena via a nonlinear evolution of stress, converging to power-law rheology in the vanishing relaxation limit. Notably, it mimics the Phan-Thien-Tanner model under steady shear, but derives from first principles, offering a predictive alternative to empirical rheology.


[3] 2508.05586

Bohr-Sommerfeld Quantization Rules for 1-D Semiclassical Pseudo-Differential Operator: the Method of Microlocal Wronskian and Gram Matrix

In this paper, we revisit the well known Bohr-Sommerfeld quantization rule (BS) of order 2 for a self-adjoint 1-D semiclassical pseudo-differential operator, within the algebraic and microlocal framework of B. Helffer and J. Sjöstrand. BS holds precisely when the Gram matrix consisting of scalar products of certain WKB solutions with respect to the "flux norm" is not invertible. This condition is obtained using the microlocal Wronskian and does not rely on traditional matching techniques. It is simplified by using action-angle variables. The interest of this procedure lies in its possible generalization to matrixvalued Hamiltonians, like BdG Hamiltonian.


[4] 2507.09568

A-type open $SL(2,\mathbb{C})$ spin chain

For the noncompact open $SL(2, \mathbb{C})$ spin chain the eigenfunctions of the special matrix element of monodromy matrix are constructed. The key ingredients of the whole construction are local Yang-Baxter $\mathcal{R}$-operators, $Q$-operator and raising operators obtained by reduction from the $Q$-operator. The calculation of various scalar products and the proof of orthogonality are based on the properties of $Q$-operator and demonstrate its hidden role. The symmetry of eigenfunctions with respect to reflection of the spin variable $s \to 1-s$ is established. The Mellin-Barnes representation for eigenfunctions is derived and equivalence with initial coordinate representation is proved. The transformation from one representation to another is grounded on the application of $A$-type Gustafson integral generalized to the complex field.


[5] 2508.04783

Accretion of a Vlasov gas by a Kerr black hole

We investigate the accretion of a collisionless, relativistic kinetic gas by a rotating Kerr black hole, assuming that at infinity the state of the gas is described by a distribution function depending only on the energy of the particles. Neglecting the self-gravity of the gas, we show that relevant physical observables, including the particle current density and the accretion rates associated with the mass, the energy, and the angular momentum, can be expressed in the form of closed integrals that can be evaluated numerically or approximated analytically in the slow-rotation limit. The accretion rates are computed in this manner for both monoenergetic particles and the Maxwell-Jüttner distribution and compared with the corresponding results in the non-rotating case. Whereas it is shown that the angular momentum accretion rate vanishes exactly, it is found that the rotation of the black hole has a small but non-vanishing effect on the mass and the energy accretion rates, which is remarkably well described by an analytic calculation in the slow-rotation approximation to quadratic order in the rotation parameter. The effects of rotation on the morphology of the accretion flow are also analyzed.


[6] 2508.04817

On the Kaluza-Klein geometric theory in affine spaces

In this work, we develop a generalization of Kaluza-Klein theory by considering a purely affine framework, without assuming a prior metric structure. We formulate the dimensional reduction using the geometry of principal fiber bundles and the Ehresmann connection, introducing adapted bases that allow an explicit decomposition of tensors, vectors, and connections. This formalism provides a natural geometric definition of the electromagnetic field as the difference between the horizontal space and the space generated by the observer's frame. We demonstrate that the presence of a nontrivial electromagnetic field requires the non-integrability of the horizontal distribution, and we derive a complete ansatz for decomposing the affine connection into fields defined on the reduced space. Under assumptions such as vanishing torsion, autoparallel fibers, and suitable normalization conditions, we show that the reduced theory corresponds to the Einstein-Maxwell system for purely radiative electromagnetic fields. Furthermore, we propose an interpretation where the metric emerges dynamically from the affine structure through the dynamics of the electromagnetic field.


[7] 2508.04819

Hybrid oscillator-qudit quantum processors: stabilizer states and symplectic operations

We construct stabilizer states and error-correcting codes on combinations of discrete- and continuous-variable systems, generalizing the Gottesman-Kitaev-Preskill (GKP) quantum lattice formalism. Our framework absorbs the discrete phase space of a qudit into a hybrid phase space parameterizable entirely by the continuous variables of a harmonic oscillator. The unit cell of a hybrid quantum lattice grows with the qudit dimension, yielding a way to simultaneously measure an arbitrarily large range of non-commuting position and momentum displacements. Simple hybrid states can be obtained by applying a conditional displacement to a Gottesman-Kitaev-Preskill (GKP) state and a Pauli eigenstate, or by encoding some of the physical qudits of a stabilizer state into a GKP code. The states' oscillator-qudit entanglement cannot be generated using symplectic (i.e., Gaussian-Clifford) operations, distinguishing them as a resource from tensor products of oscillator and qudit stabilizer states. We construct general hybrid error-correcting codes by relating stabilizer codes to non-commutative tori and obtaining logical operators via Morita equivalence. We provide examples using commutation matrices, integer symplectic matrices, and binary codes.


[8] 2508.04823

Quantum Graph States: Bridging Classical Theory and Quantum Innovation, Workshop Summary

This workshop brought together experts in classical graph theory and quantum information science to explore the intersection of these fields, with a focus on quantum graph states and their applications in computing, networking, and sensing. The sessions highlighted the foundational role of graph-theoretic structure, such as rank-width, vertex-minors, and hypergraphs, in enabling measurement-based quantum computation, fault-tolerant architectures, and distributed quantum sensing. Key challenges identified include the need for scalable entanglement generation, robust benchmarking methods, and deeper theoretical understanding of generalized graph states. The workshop concluded with targeted research recommendations, emphasizing interdisciplinary collaboration to address open problems in entanglement structure, simulation complexity, and experimental realization across diverse quantum platforms.


[9] 2508.04840

Exact Solutions of the Schrödinger-Dunkl Equation for a Free Particle in a Finite and Infinite Cylindrical Well

In this paper, we study the Schrödinger equation with Dunkl derivative for a free particle confined in a cylindrical potential well. We consider both the finite and infinite height cases. The Dunkl formalism introduces reflection operators that modify the structure of the Hamiltonian and affect the parity of the solutions. By working in cylindrical coordinates, we obtain exact analytical expressions for the radial and axial wavefunctions in terms of Bessel functions. The energy spectrum and the solutions are classified according to the eigenvalues of the reflection operators in the three coordinates. We analyze in detail the conditions under which the wavefunctions acquire definite parity and discuss the resulting constraints on the Dunkl parameters.


[10] 2508.04869

Spectral statistics of preferred orientation quantum graphs

We study the spectral statistics of quantum (metric) graphs whose vertices are equipped with preferred orientation vertex conditions. When comparing their spectral statistics to those predicted by suitable random matrix theory ensembles, one encounters some deviations. We point out these discrepancies and demonstrate that they occur in various graphs and even for Neumann-Kirchhoff vertex conditions, which was overlooked so far. Detailed explanations and computations are provided for this phenomena. To achieve this, we explore the combinatorics of periodic orbits, with a particular emphasis on counting Eulerian cycles.


[11] 2508.04891

The Limiting Spectral Distribution for Sparse Elliptic Random Matrices

This paper studies sparse elliptic random matrix models which generalize both the classical elliptic ensembles and sparse i.i.d. matrix models by incorporating correlated entries and a tunable sparsity parameter $p_n$. Each $n\times n$ matrix $X_n$ is formed by entry-wise multiplication of an elliptic random matrix by an elliptic matrix of Bernoulli($p_n$) variables, where $np_n\to\infty$, allowing for interpolation between dense and sparse regimes. The main result establishes that under appropriate normalization, the empirical spectral measures of these matrices converge weakly in probability to the uniform measure on a rotated ellipsoid in the complex plane as the dimension $n$ tends to infinity. Interestingly, the shape of the limiting ellipsoid depends not just on the mirrored entry-wise correlation structure, but also non-trivially on the sparsity limit $p=\lim\limits_{n\to\infty}p_n\in[0,1]$. The main result generalizes and recovers many classical results in sparse and dense regimes for elliptic and i.i.d. random matrix models.


[12] 2508.04972

BC-type open $SL(2,\mathbb{C})$ spin chain

We diagonalize the $B$-element of monodromy matrix for noncompact open $SL(2,\mathbb{C})$ spin chain with boundary interaction. The monodromy matrix is defined in terms of $SL(2,\mathbb{C})$ $L$-operator and boundary $K$-matrix. The eigenfunctions of $B$-operator are constructed iteratively using raising $\Lambda$-operators. The key role in the calculations plays the Baxter $Q$-operator commuting with the $B$-operator. The main building blocks for $\Lambda$- and $Q$-operators are $\mathcal{K}$-operator -- the general solution of reflection equation and $\mathcal{R}$-operator -- the reduction of the general solution of the Yang-Baxter equation. Two types of the symmetry of eigenfunctions are established. The first kind is the invariance under permutations and reflections of spectral variables, or in other words, under the action of Weyl group of B and C root systems. The second kind is the symmetry with respect to transformation $(s,g) \to (1-s,1-g)$, where $s$ is the spin variable and $g$ is the parameter of $K$-matrix. We prove that obtained system of eigenfunctions is orthogonal and complete. The calculation of the scalar product of eigenfunction is given in initial coordinate representation. We derive the Mellin-Barnes integral representation for eigenfunctions and use it to prove the comleteness.


[13] 2508.04990

Generalization of anomaly formula for time reversal symmetry in (2+1)D abelian bosonic TQFTs

We study time-reversal symmetry in (2+1)-dimensional abelian bosonic topological phases. Z_2 x Z_2 classifies the time-reversal anomalies in such systems symmetry-protected topological (SPT) phases in (3+1) dimensions and can be diagnosed via partition functions on manifolds such as RP^4 and CP^2. These partition functions are related by an anomaly formula of the form Z(RP^4) * Z(CP^2) = theta_M, where theta_M is the Dehn twist phase associated with the crosscap state. Meanwhile, the existence of gapped boundaries is constrained by so-called higher central charges, denoted xi_n, which serve as computable invariants encoding obstruction data. Motivated by the known relation Z(CP^2) = xi_1, we propose a generalization of the anomaly formula involving both the higher central charges xi_n and a new time-reversal invariant eta_n. By introducing a distinguished subset M^n of the set A of anyons, we establish the relation eta_n * xi_n = (sum of theta(a)^n over a in M^n) divided by its absolute value. This generalizes the known anomaly formula. We analyze the algebraic structure of the subset M^n, derive consistency relations it satisfies, and clarify its connection to the original anomaly formula.


[14] 2508.05039

Generalized Wigner-Smith theory for perturbations at exceptional and diabolic point degeneracies

Spectral degeneracies, including diabolic (DP) and exceptional (EP) points, exhibit unique sensitivity to external perturbations, enabling powerful control and engineering of wave phenomena. We present a residue-based perturbation theory that quantifies complex resonance splitting of DP and EP type spectral degeneracies using generalized Wigner-Smith operators. We validate our theory using both analytic Hamiltonian models and numerical electromagnetic simulations, demonstrating excellent agreement across a range of cases. Our approach accurately predicts degenerate resonance splitting using only scattering data, offering a powerful framework for precision tuning, inverse design, and practical exploitation of non-Hermitian phenomena.


[15] 2508.05046

Optimal Qubit Purification and Unitary Schur Sampling via Random SWAP Tests

The goal of qubit purification is to combine multiple noisy copies of an unknown pure quantum state to obtain one or more copies that are closer to the pure state. We show that a simple protocol based solely on random SWAP tests achieves the same fidelity as the Schur transform, which is optimal. This protocol relies only on elementary two-qubit SWAP tests, which project a pair of qubits onto the singlet or triplet subspaces, to identify and isolate singlet pairs, and then proceeds with the remaining qubits. For a system of $n$ qubits, we show that after approximately $T \approx n \ln n$ random SWAP tests, a sharp transition occurs: the probability of detecting any new singlet decreases exponentially with $T$. Similarly, the fidelity of each remaining qubit approaches the optimal value given by the Schur transform, up to an error that is exponentially small in $T$. More broadly, this protocol achieves what is known as weak Schur sampling and unitary Schur sampling with error $\epsilon$, after only $2n \ln(n \epsilon^{-1})$ SWAP tests. That is, it provides a lossless method for extracting any information invariant under permutations of qubits, making it a powerful subroutine for tasks such as quantum state tomography and metrology.


[16] 2508.05117

Algebra structure of conformal Killing-Yano forms in geometries with skew-symmetric torsion

We consider conformal Killing-Yano forms corresponding to the antisymmetric generalizations of conformal Killing vectors to higher degree forms in the presence of skew-symmetric torsion. Integrability conditions for torsionful conformal Killing-Yano forms are found and a graded Lie bracket for conformal Killing-Yano forms to constitute a graded Lie algebra structure is proposed. It is found that a graded Lie algebra structure for a special subset of torsionful conformal Killing-Yano forms can be constructed for a closed and parallel skew-symmetric torsion on constant curvature and Einstein manifolds. Similar structure for generalized hidden symmetries defined from generalized connection in generalized geometry is also constructed.


[17] 2508.05120

Turaev-Viro invariant from the modular double of $\mathrm {U}_{q}\mathfrak{sl}(2;\mathbb R)$

We define a family of Turaev-Viro type invariants of hyperbolic $3$-manifolds with totally geodesic boundary from the $6j$-symbols of the modular double of $\mathrm U_{q}\mathfrak{sl}(2;\mathbb R)$, and prove that these invariants decay exponentially with the rate the hyperbolic volume of the manifolds and with the $1$-loop term the adjoint twisted Reidemeister torsion of the double of the manifolds.


[18] 2508.05126

Initial value space of the fourth order Painlevé system with $A_5^{(1)}\times A_1^{(1)}$ symmetry

The initial value spaces of the Painlevé equations are proposed by Okamoto. They are symplectic manifolds in which the Painlevé equations are described as polynomial Hamiltonian systems on all coordinates. In this article, we construct an initial value space of the fourth order Painlevé system with affine Weyl group symmetry of type $A_5^{(1)}\times A_1^{(1)}$.


[19] 2508.05134

Twisted Homotopy Algebras: Supersymmetric Twists, Spontaneous Symmetry Breaking, Anomalies and Localisation

Twisting and classical background fields are two foundational techniques in supersymmetric quantum field theory, central to developments ranging from the Higgs mechanism to topological twisting and supersymmetric localisation. While traditionally treated as distinct procedures, they appear on an equal footing in the homotopy-algebraic approach to quantum field theory. In this work, we formalise this connection by interpreting both twisting and the introduction of classical backgrounds as instances of twisting curved quantum $L_\infty$-superalgebras. Using the language of homotopy algebras and the Batalin-Vilkovisky formalism, we provide a unified algebraic framework that encompasses topological/holomorphic twists, spontaneous symmetry breaking, computation of anomalies, and supersymmetric localisation à la Festuccia--Seiberg. As a byproduct, we introduce a notion of twisting for quantum $L_\infty$-algebras and a homotopy-algebraic reformulation of the one-particle-irreducible effective action.


[20] 2508.05191

Operator lift of Reshetikhin-Turaev formalism to Khovanov-Rozansky TQFTs

Topological quantum field theory (TQFT) is a powerful tool to describe homologies, which normally involve complexes and a variety of maps/morphisms, what makes a functional integration approach with a sum over a single kind of maps seemingly problematic. In TQFT this problem is overcame by exploiting the rich set of zero modes of BRST operators, which appear sufficient to describe complexes. We explain what this approach looks like for the important class of Khovanov-Rozansky (KR) cohomologies, which categorify the observables (Wilson lines or knot polynomials) in 3d Chern-Simons theory. We develop a construction of odd differential operators, associated with all link diagrams, including tangles with open ends. These operators become nilpotent only for diagram with no external legs, but even for open tangles one can develop a factorization formalism, which preserve Reidemeister/topological invariance -- the symmetry of the problem. This technique seems much more ``physical'' than conventional language of homological algebra and should have many applications to various problems beyond Chern-Simons theory. We also hope that this language will provide efficient algorithms, and finally allow to computerize the calculation of KR cohomologies -- for closed diagrams and for open tangles.


[21] 2508.05270

Commuting integrable maps from a deformed D$_4$ cluster algebra

In this paper we revisit an integrable map of the plane which we obtained recently as a two-parameter family of deformed mutations in the cluster algebra of type D$_4$. The rational first integral for this map defines an invariant foliation of the plane by level curves, and we explain how this corresponds to a rational elliptic surface of rank 2. This leads us to construct another (independent) integrable map, commuting with the first, such that both maps lift to compositions of mutations in an enlarged cluster algebra, whose underlying quiver is equivalent to the one found by Okubo for the $q$-Painlevé VI equation. The degree growth of the two commuting maps is calculated in two different ways: firstly, from the tropical (max-plus) equations for the d-vectors of the cluster variables; and secondly, by constructing the minimal space of initial conditions for the two maps, via blowing up $\mathbb{P}^1 \times \mathbb{P}^1$.


[22] 2508.05610

On a 5D UV completion of Argyres-Douglas theories

We discuss a novel UV completion of a class of Argyres-Douglas (AD) theories by its embedding into the renormalisation group flow from five dimensional $\mathcal{N}=1$ superconformal field theories (SCFT) on $S^1$. This is obtained via analysing these theories in the light of ($q$-)Painlevé/gauge theory correspondence, which allows to compute the five dimensional BPS partition functions as an expansion in the Wilson loop vev with integer $q$-polynomials coefficients. These are derived formulating the gauge theory on a blown-up geometry and using a five-dimensional lift of (topological) operator/state correspondence. We discuss in detail the phase diagram of the four dimensional limits, pinpointing the special AD loci. Explicit computations are reported for $\tilde E_1$ SCFT and its limit to H$_0=(A_1,A_2)$ AD theory.


[23] 2012.14747

On the Preservation of Quasilocality by the Integration-Out Transformation

We demonstrate that the integration-out step of the renormalization group transformation preserves the quasilocality of the effective action. This is shown in the case of a single, real, scalar field on a torus, but the proof holds more generally. The main result can be thought of as showing the flow invariance of the quasilocal subset under the flow generated by the Polchinski equation.


[24] 2407.03706

Regularity of the (N-1)-particle electronic reduced density matrix for molecules with fixed nuclei and N electrons

We consider an electronic bound state of the usual, non-relativistic, molecular Hamiltonian with Coulomb interactions, fixed nuclei, and N electrons (N>1). Near appropriate electronic collisions, we determine the regularity of the (N-1)-particle electronic reduced density matrix. Published in Letters in Mathematical Physics.


[25] 2506.01873

A gradient-enhanced approach for stable finite element approximations of reaction-convection-diffusion problems

We develop a micromorphic-based approach for finite element stabilization of reaction-convection-diffusion equations, by gradient enhancement of the field of interest via introducing an auxiliary variable. The well-posedness of the coupled-field approach is established, together with an error estimate. Through a set of 1D and 2D numerical examples the high accuracy and enhanced stability of the approach in approximating solutions associated with complex problems is demonstrated, for situations of varying reactivity and convection.


[26] 2506.13581

A note on Hall conductance and Hall conductivity in interacting Fermion systems

In this note we consider lattice fermions on $\mathbb{Z}^2$ with a gapped ground state and show how to apply the NEASS approach to linear response to derive a formula for the Hall conductance in terms of the ground state expectation of a commutator of modified step functions. This formula is usually derived by a charge pumping argument going back to Laughlin. Here we show that it can also be obtained as the linear response coefficient of the microscopic current response to an adiabatic increase of the chemical potential on a half plane (or more generally on any cone-like region). Indeed, in a manner reminiscent of the bulk-boundary correspondence, we show that raising the chemical potential in any cone-like region gives rise to a current that flows along its boundary and is nearly linear in the increase in chemical potential. We also discuss the connection with the double commutator formula with modified position operators for the Hall conductivity derived in arXiv:2411.06967 as the linear response coefficient of the macroscopic current response to the adiabatic application of a constant electric field.


[27] 2507.13321

Automorphic equivalence within gapped phases of infinitely extended fermion systems

We prove automorphic equivalence within gapped phases of infinitely extended lattice fermion systems (as well as spin systems) with super-polynomially decaying interactions. As a simple application, we prove a version of Goldstone's theorem for such systems: if an infinite volume interaction is invariant under a continuous symmetry, then any gapped ground state is also invariant under that symmetry.


[28] 2508.02579

A notion of partial order in the Choose the Leader model

In this work we continue the study of non-chaotic asymptotic correlations in many element systems and discuss the emergence of a new notion of asymptotic correlation -- partial order -- in the Choose the Leader (CL) system. Similarly to the newly defined notion of order, partial order refers to alignment of the elements in the system -- though it allows for deviation from total adherence. Our presented work revolves around the definition of partial order and shows its emergence in the CL model in its original critical scaling. Furthermore, we discuss the propagation of partial order in the CL model and give a quantitative estimate to the convergence to this state. This new notion (as well as that of order) opens the door to exploring old and new (probabilistic) models of biological and societal nature in a more realistic way.


[29] 2308.06331

Interaction energies in paranematic colloids

We consider a system of colloidal particles embedded in a paranematic -- an isotropic phase of a nematogenic medium above the temperature of the nematic-to-isotropic transition. In this state, the nematic order is induced by the boundary conditions in a narrow band around each particle and it decays exponentially in the bulk. We develop rigorous asymptotics of the linearization of the appropriate variational model that allow us to describe weak far-field interactions between the colloidal particles in two dimensional paranematic suspensions. We demonstrate analytically that decay rates of solutions to the full nonlinear and linear problems are similar and verify numerically that the interactions between the particles in these problems have similar dependence on the distance between the particles. Finally, we perform Monte-Carlo simulations for a system of colloidal particles in a paranematic and describe the statistical properties of this system.


[30] 2308.10232

Gelation in cluster coagulation processes

We consider the problem of gelation in the cluster coagulation model introduced by Norris [\textit{Comm. Math. Phys.}, 209(2):407-435 (2000)], where pairs of clusters of types $(x,y)$ taking values in a measure space $E$, merge to form a new particle of type $z\in E$ according to a transition kernel $K(x,y, \mathrm{d} z)$. This model possesses enough generality to accommodate inhomogeneities in the evolution of clusters, including variations in their shape or spatial distribution. We derive general, sufficient criteria for stochastic gelation in this model. As particular cases, we extend results related to the classical Marcus--Lushnikov coagulation process, showing that reasonable `homogenous' coagulation processes with exponent $\gamma>1$ yield gelation; and also, coagulation processes with kernel $\bar{K}(m,n)~\geq~(m \wedge n) \log{(m \wedge n)}^{3 +\epsilon}$ for $\epsilon>0$.


[31] 2311.12478

Is mathematics like a game?

We re-examine the old question to what extent mathematics may be compared with a game. Mainly inspired by Hilbert and Wittgenstein, our answer is that mathematics is something like a rhododendron of language games, where the rules are inferential. The pure side of mathematics is essentially formalist, where we propose that truth is not carried by theorems corresponding to whatever independent reality and arrived at through proof, but is defined by correctness of rule-following (and as such is objective given these rules). Goedel's theorems, which are often seen as a threat to formalist philosophies of mathematics, actually strengthen our concept of truth. The applied side of mathematics arises from two practices: first, the dual nature of axiomatization as taking from heuristic practices like physics and informal mathematics whilst giving proofs and logical analysis; and second, the ability of using the inferential role of theorems to make surrogative inferences about natural phenomena. Our framework is pluralist, combining various (non-referential) philosophies of mathematics.


[32] 2409.09974

TASEP in half-space

In this work, we present the multi-point probability distribution of the totally asymmetric simple exclusion process (TASEP) in a half-space, starting from a general deterministic initial condition. More precisely, let $h(t,x)$ denote the height function of TASEP at position $x$ and time $t$; we provide an explicit formula for \begin{equation*} \mathbb{P}(h(t,y_1)\leq s_1, \ldots, h(t,y_m)\leq s_m). \end{equation*} The formula presented is well-suited for the scaling limit analysis. By applying a 1:2:3 scaling, we derive the probability distribution for the half-space KPZ fixed point, which is conjectured to be the universal process for the limit of the KPZ universality models restricted to a half-space.


[33] 2410.18694

Quantifying the rotating-wave approximation of the Dicke model

We analytically find quantitative, non-perturbative bounds to the validity of the rotating-wave approximation (RWA) for the multi-atom generalization of the quantum Rabi model: the Dicke model. Precisely, we bound the norm of the difference between the evolutions of states generated by the Dicke model and its rotating-wave approximated counterpart, that is, the Tavis-Cummings model. The intricate role of the parameters of the model in determining the bounds is discussed and compared with numerical results. Our bounds are intrinsically state-dependent and, in particular, capture a nontrivial dependence on the total angular momentum of the initial state; this behaviour also seems to be confirmed by accompanying numerical results.


[34] 2410.24143

Quantum Groups as Global Symmetries II. Coulomb Gas Construction

We study a conformal field theory that arises in the infinite-volume limit of a spin chain with $U_q(sl_2)$ global symmetry. Most operators in the theory are defect-ending operators which allows $U_q(sl_2)$ symmetry transformations to act on them in a consistent way. We use Coulomb gas techniques to construct correlation functions and compute all OPE coefficients of the model, as well as to prove that the properties imposed by the quantum group symmetry are indeed satisfied by the correlation functions. In particular, we treat the non-chiral operators present in the theory. Free boson realization elucidates the origin of the defects attached to the operators. We also comment on the role of quantum group in generalized minimal models.


[35] 2412.02347

Exploiting $\vartheta -$functions for the identification of topological materials

An exact analytical expression is derived for Bloch states in three dimensions, based on the only assumption that the electronic wavefunction can be expanded in terms of Gaussian type orbitals. The resulting expression features multidimensional $\vartheta -$functions (and their derivatives) on which the action of discrete space group symmetries is evaluated analytically and contrasted against the symmetry transformations proper of modular forms. We integrate group theoretical arguments with continuity requirements of the Bloch states to produce a viable algorithm for the determination of band inversions in materials with a non-trivial topological electronic band structure; the proposed methodology is then applied to two simplified materials models.


[36] 2412.10698

On holographic duals of certain isolated weighted Gorenstein cDV singularities

Based on an important mathematical conjecture, together with hypothesis of homological mirror symmetry in the context of Landau-Ginzburg models, we show that a class of compound Du Val singularities do not admit a crepant resolution. Most of these singularities sit in the type cEn. This implies that those singularities are not dual to four dimensional N =1 superconformal quiver gauge theories through stacks of D3 branes placed at the singularities. We verify this statement on the physics side by enumerating consistent gauge theories.


[37] 2502.18921

Calogero-Sutherland-type quantum systems, generalized hypergeometric functions and superintegrability for integral chains

We reinvestigate the Calogero-Sutherland-type (CS-type) models and generalized hypergeometric functions. We construct the generalized CS operators for circular, Hermite, Laguerre, Jacobi and Bessel cases and establish the generalized Lassalle-Nekrasov correspondence. A family of operators are constructed based on the spherical degenerate double affine Hecke algebra. In terms of these operators, we provide concise representations and constraints for the generalized hypergeometric functions. We analyze the superintegrability for the $\beta$-deformed integrals, where the measures are associated with the corresponding ground state wave functions of Hermite, Laguerre, Jacobi and Bessel type CS models. Then based on the generalized Laplace transformation of Jack polynomials, we construct certain two integral chains and analyze the superintegrability property.


[38] 2503.20691

Quantum group origins of edge states in double-scaled SYK

Double-scaled SYK (DSSYK) is known to have an underlying quantum group theoretical description. We precisely pinpoint the quantum group structure, improving upon earlier work in the literature. This allows us to utilize this framework for bulk gravitational applications. We explain bulk discretization in DSSYK from the underlying irreducibility of the representations. We derive trumpet and brane amplitudes using character insertions of the quantum group, simplifying earlier calculations. Most importantly, we factorize the bulk Hilbert space dual to DSSYK in the quantum group description using a complete set of edge degrees of freedom living at a bulk entangling surface. An analogous treatment for $\mathcal{N}=1$ DSSYK is provided in the same quantum group theoretical framework.


[39] 2504.04331

Shedding Light on Gravity: Black Hole Shadows and Lensing Signatures in Lorentz Gauge Theory

Recent advances, including gravitational wave detections and imaging of black hole shadows, have strongly validated general relativity. Nevertheless, ongoing cosmological observations suggest potential limitations of general relativity, spurring interest in modified theories of gravity. This work investigates the Lorentz-gauge formulation of gravity-a novel framework that addresses key conceptual challenges in quantum gravity and cosmology by leveraging the recent black hole solutions presented in Ref. \cite{Koivisto:2024asr}. By analyzing black hole shadow structures and gravitational lensing effects-both weak and strong deflection regimes-we highlight unique observational signatures of Lorentz gauge gravity. Our findings provide valuable tools for future observational tests, potentially distinguishing these modified gravity models from general relativity and advancing our understanding of spacetime geometry and fundamental gravitational interactions.


[40] 2507.17750

Scaling Properties of Current Fluctuations in Periodic TASEP

We study current fluctuations in the Totally Asymmetric Simple Exclusion Process (TASEP) on a ring with $N$ sites and $p$ particles. By introducing a deformation parameter $\gamma$, we analyze the tilted operator that governs the statistics of the time-integrated current. Employing the coordinate Bethe ansatz, we derive implicit expressions for the scaled cumulant generating function (SCGF), i.e. the largest eigenvalue, and the spectral gap, both in terms of Bethe roots. Their asymptotic behaviour is characterized by using the geometric structure of Cassini oval. In the thermodynamic limit at fixed particle density, we identify a dynamical phase transition separating fluctuation regimes. For $\gamma>0$, the SCGF exhibits ballistic growth with system size, $\lambda_1 \sim N$. In contrast, for $\gamma<0$, the SCGF converges to $-1$ as $N\to\infty$. This transition is reflected in the spectral gap, which controls the system's relaxation timescale. For $\gamma>0$, the gap closes at polynomial speed, $\Delta \sim N^{-1}$, consistent with rapid relaxation with enhanced current. For $\gamma<0$, the gap vanishes exponentially, $\Delta \sim \exp(-cN)$, signaling metastability with diminished current. Our non-perturbative results provide insights into large deviations and the relaxation dynamics in driven particle systems.


[41] 2507.20106

Absence of nontrivial local conserved quantities in the Hubbard model on the two or higher dimensional hypercubic lattice

By extending the strategy developed by Shiraishi in 2019, we prove that the standard Hubbard model on the $d$-dimensional hypercubic lattice with $d\ge2$ does not admit any nontrivial local conserved quantities. The theorem strongly suggests that the model is non-integrable. To our knowledge, this is the first extension of Shiraishi's proof of the absence of conserved quantities to a fermionic model. Although our proof follows the original strategy of Shiraishi, it is essentially more subtle compared with the proof by Shiraishi and Tasaki of the corresponding theorem for $S=\tfrac12$ quantum spin systems in two or higher dimensions; our proof requires three steps, while that of Shiraishi and Tasaki requires only two steps. It is also necessary to partially determine the conserved quantities of the one-dimensional Hubbard model to accomplish our proof.


[42] 2507.21209

Anomalies of global symmetries on the lattice

't Hooft anomalies of global symmetries play a fundamental role in quantum many-body systems and quantum field theory (QFT). In this paper, we make a systematic analysis of lattice anomalies - the analog of 't Hooft anomalies in lattice systems - for which we give a precise definition. Crucially, a lattice anomaly is not a feature of a specific Hamiltonian, but rather is a topological invariant of the symmetry action. The controlled setting of lattice systems allows for a systematic and rigorous treatment of lattice anomalies, shorn of the technical challenges of QFT. We find that lattice anomalies reproduce the expected properties of QFT anomalies in many ways, but also have crucial differences. In particular, lattice anomalies and QFT anomalies are not, contrary to a common expectation, in one-to-one correspondence, and there can be non-trivial anomalies on the lattice that are infrared (IR) trivial: they admit symmetric trivial gapped ground states, and map to trivial QFT anomalies at low energies. Nevertheless, we show that lattice anomalies (including IR-trivial ones) have a number of interesting consequences in their own right, including connections to commuting projector models, phases of many-body localized (MBL) systems, and quantum cellular automata (QCA). We make substantial progress on the classification of lattice anomalies and develop several theoretical tools to characterize their consequences on symmetric Hamiltonians. Our work places symmetries of quantum many-body lattice systems into a unified theoretical framework and may also suggest new perspectives on symmetries in QFT.


[43] 2507.22833

Real Noncommutative Convexity II: Extremality and nc convex functions

We continue with the theory of real noncommutative (nc) convexity, following the recent and profound complex case developed by Davidson and Kennedy. The present paper focuses on the theory of nc extreme (and pure and maximal) points and the nc Choquet boundary in the real case, and on the theory of real nc convex and semicontinuous functions and real nc convex envelopes. Our main emphasis is on how these interact with complexification. For example some of our paper analyzes carefully how various notions of `extreme' or `maximal' interact with our earlier concept of the complexification of a convex set. Several new features appear in the real case, particularly in later sections of our paper, including the novel notion of the complexification of a nc convex function, and the complexification of the convex envelope of a nc function. With an Appendix by T. Russell.