Disciplines / Research questions

Physics

691 research topics · 2739 questions

generalized Gibbs ensemble3 questions
  1. Deep thermalization in interacting integrable quantum systems: constructing the analogue of the deep generalized Gibbs ensemble beyond free fermions

  2. Extending the nonlinear integral equation formulation of the sine-Gordon generalized Gibbs ensemble beyond the individual-boundedness restriction

  3. Determining the number of Lagrange multipliers needed for generalized Gibbs ensemble descriptions of realistic integrable quantum systems

generalized hydrodynamics(GHD)2 questions
  1. Quantum Generalized Hydrodynamics beyond the quadratic, zero-entropy, Euler-scale regime

  2. Rigorous emergence of generalised hydrodynamics in generalised TTˉT\bar{T}-deformed classical free-particle systems with arbitrary two-body scattering shifts

Hall–Littlewood and qq-Whittaker process2 questions
  1. Bulk Gaussian (Edwards–Wilkinson) scaling limits of the (2+1)(2+1)-dimensional qq-Whittaker growth model at fixed q∈(0,1)q\in(0,1)

  2. Bijective proofs, algebraic structure, ubiquity, and quasi-open six-vertex asymptotics for the free-boundary q-Whittaker and Hall-Littlewood symmetry identities

Hard Hexagon and Related Models7 questions
  1. Algorithmic Pirogov–Sinai theory at the phase boundary: efficient counting and sampling in the phase-coexistence regime for lattice models

    Open for about 8 years
  2. Phase diagram of the loop O(n)O(n) model with large nn and its hard-hexagon limit

    Open for about 11 years
  3. Global analytic structure of the hard-hexagon partition function per site in the complex fugacity plane: dominant eigenvalue branches beyond Baxter's solution

    Open for about 13 years
  4. Exact evaluation of the entropy W(k)W(k) of kk-colorings of the square lattice (kk-species close-packed hard-square lattice gas): vertex-model, transfer-matrix, and graph-expansion routes

    Open for about 56 years
  5. Controlled determination of the critical parameters of the disordered-columnar transition in the 2x2 hard-square (2-NN exclusion) lattice gas

    Open for about 9 years
  6. Higher-order terms, convergence, and quantitative validity of the high-activity z−1/2z^{-1/2} expansion for the hard square lattice gas with nearest- and next-nearest-neighbor exclusion

    Open for about 14 years
  7. Common crossing of finite-width density curves at the critical point of the hard-square lattice gas

    Open for less than 1 year
Hard-hexagon critical activity3 questions
  1. Localized-magnon saturation physics of frustrated antiferromagnets beyond the smallest-area hard-core description: extra ground states, residual entropy, hard-square thermodynamics, and microscopic U and V parameters

  2. Nonunitary string-net PEPS: tube-algebra central idempotents without C*-structure, gapped non-Hermitian parent Hamiltonians, convergent fixed-point algorithms, and extensions to logarithmic CFTs

  3. Limits of the R-matrix analysis of Mayer cluster coefficients: the spectrum-shift regime, reality of the matrix elements, and error-controlled critical activities

Hard-hexagon critical exponent3 questions
  1. Thermodynamic-limit analytic structure of the non-integrable hard-square lattice gas: zero locus, equimodular gaps, the z=−1z=-1 conjectures, and a discriminant criterion for integrability

  2. Critical exponents from Mayer cluster coefficients: completing the R-matrix asymptotic theory beyond its validated range

  3. Analytic structure of the hard-hexagon partition function per site in the complex fugacity plane: dominant transfer-matrix eigenvalue branches, the necklace region and its zeros, and the algebraic origin of the extra eigenvalues

Hard-hexagon model3 questions
  1. Conjectural foundations of the inversion-relation solution for solvable IRF lattice models: thermalization, analyticity of the free energy, and the unidentified coset CFT G\mathcal{G}

  2. Thermodynamic-limit analytic structure of the hard-hexagon partition function at complex fugacity: the necklace of zeros and the transfer-matrix eigenvalue branches beyond Baxter's solution

  3. Exact entanglement characterization of the Rokhsar-Kivelson quantum hard-square lattice gas: Rényi entropies, integrable entanglement spectra, and the extension beyond two-leg ladders

Hard-hexagon order parameter2 questions
  1. Fine structure of the available-site fraction in the exactly solved hard-hexagon model near the phase transition

  2. Hard-hexagon partition function for complex fugacity: thermodynamic-limit persistence of the zero necklace and transfer-matrix eigenvalue branches beyond Baxter's solution

Hard-square model4 questions
  1. Melting scenario of the period-3 phase of the hard-square model with diagonal interactions: Lifshitz point location, anisotropic critical exponents, and floating-phase boundaries

  2. Exact values of the hard-square entropy constant and the bipartite hard-square constant for grid-graph independent-set enumeration

  3. Existence, sharpness, and location of the uniqueness threshold of the hard-core lattice gas on the square lattice Z2\mathbb{Z}^2 (conjectured λc(Z2)≈3.796\lambda_c(\mathbb{Z}^2)\approx 3.796)

  4. Unresolved phase diagram, Gibbs-measure classification, and sharp correlation decay for the 2×22\times2 hard-square lattice gas

Hecke algebra1 questions
  1. Polynomial integrability of the Temperley-Lieb loop model: non-degenerate principal-Hamiltonian spectra and the transfer-operator-to-Hamiltonian decomposition for all system sizes

    Open for about 4 years
height function3 questions
  1. Asymptotic variance constant and Gaussian scaling limits for the square-ice height function and generalized solid-on-solid models

  2. Disorder-induced regions and the height-function scaling limit in the square-lattice dimer model with layered quenched disorder

  3. Uniqueness of limit shapes for the six-vertex model with rare corners and restricted Mallows permutations at general bias

higher-order TRG3 questions
  1. Systematically improvable three-dimensional tensor-network renormalization group: controlled entanglement filtering of the area-law obstruction and extraction of universal data in 3D lattice models

  2. Grassmann tensor-network coarse-graining for four-dimensional lattice QCD: full gauge-fermion treatment with controlled truncation accuracy

  3. Provable error bounds for randomized higher-order tensor renormalization group methods (R-HOTRG, MDTRG, Triad-MDTRG)

Ice-Type Models4 questions
  1. Residual entropy of ordinary ice: the exact ice-rule configuration count and a precision experimental test of Pauling's estimate

    Open for about 90 years
  2. Continuum limit of the Feynman checkerboard model as a complex-weight six-vertex model in an absorbing strip

    Open for about 2 years
  3. Approximation complexity of the six-vertex model in the white region and on planar graphs

    Open for about 8 years
  4. Exact growth constant for colourings of the square lattice with more than three colours

    Open for about 49 years
impurity models1 questions
  1. Ferromagnetic-impurity and gapless-bulk regimes of the exactly solved Kondo impurity at the edge of a superconducting wire

infinite PEPS3 questions
  1. Parent Hamiltonian and Gossamer-Tail Control for Chiral Projected Entangled-Pair States: Bulk Gaps of the Z3 Kitaev Chiral Spin Liquid

  2. Certified extraction of anyon sectors and modular data from infinite PEPS: completeness of transfer-matrix fixed points and correlation-length scaling

  3. Decidability of normalizability, symmetry classification, canonical forms, and the parent-Hamiltonian spectral gap within physically relevant subclasses of projected entangled pair states

interacting particle systems1 questions
  1. Open problems for the boundary-driven zero-range process with long jumps: hydrodynamic limits and dynamical large deviations, boundary asymptotics of the hydrostatic profile, and the critical and condensation regimes

intertwiner3 questions
  1. The periodic-diffeomorphism case of the intertwiner volume conjecture for the Kauffman bracket skein algebra

    Open for about 3 years
  2. Completing the theory of vertical (particle-number-changing) intertwiners in the rational Calogero model

    Open for about 1 year
  3. Completing the permutation-coefficient theory of gl(n) Yangian intertwiners: general parameter permutations, general rank and evaluation order, contour dependence, and factorization equivalence

    Open for about 1 year
IRF/face model2 questions
  1. Constructing quantum R-matrix blocks in tensor-product multiplicity sectors and rederiving them from rational CFT data

  2. Factorization of reduced density matrices and closed representations of the nearest-neighbour two-point function in integrable face models

Ising Model on the Bethe Lattice5 questions
  1. Extremality of the Disordered Phase of the Ising Model with Competing Interactions on a Cayley Tree

    Open for about 9 years
  2. Analytic classification of the invariant sets, positive fixed points, and higher-period orbits of the recursion operator for the Ising model with competing binary and ternary interactions on a third-order Cayley tree

    Open for about 5 years
  3. Exactness of closed-form self-consistent equations for the bond-diluted Ising model on the Bethe lattice

    Open for about 12 years
  4. Exact solution of the quenched bond-diluted Ising model on the Bethe lattice at finite coupling (p<1p<1, q>2q>2)

    Open for about 12 years
  5. Validity and explanatory power of the finite-variable reduced dynamics for Glauber dynamics of the bond-diluted Ising model on a Bethe lattice

    Open for about 16 years
Ising–dimer mapping3 questions
  1. Explicit identification of the local and Fourier inverse Kasteleyn matrices for the critical Z-invariant Ising model on periodic isoradial graphs

    Open for about 17 years
  2. Completing exact bosonization of the critical Ising model in bounded domains: flat-boundary dimer observables, the half-integer electric endpoint, and lattice-to-continuum constants

    Open for about 14 years
  3. A general structural theory for dimer models on non-bipartite periodic graphs: weak limits of Boltzmann measures and spectral curves

    Open for about 17 years
Ising/free-fermion special case1 questions
  1. Free-fermion diagonalisation of the 8-vertex class-B chain at arbitrary length N, and the generality of the free-fermion condition for integrable R-matrices

    Open for about 5 years
Izergin–Korepin determinant4 questions
  1. Basis-parametrized determinant representations for the six-vertex model with partial domain wall boundary conditions

    Open for about 3 years
  2. Extending the modified-operator linear-system method for six-vertex partition functions to reflecting boundaries, the trigonometric antiperiodic case, and higher rank

    Open for about 2 years
  3. The Izergin–Korepin nineteen-vertex domain wall partition function beyond the root of unity: closed forms, reflection boundaries, eigenvector components, and structural characterization

    Open for about 11 years
  4. Six-vertex domain-wall partition function at roots of unity beyond the third: functional-equation evaluation

Jacobi elliptic functions1 questions
  1. Elementary magnitude bounds for Jacobian elliptic functions with complex modulus beyond the regime ∣m∣≤1|m|\le1, ∣z∣<π/2|z|<\pi/2

Kagomé eight-vertex model1 questions
  1. Adjudicating conflicting exact spontaneous-magnetization formulae for the isotropic kagomé Ising lattice and deriving the closed-form anisotropic magnetization

Kagomé lattice Ising-type model2 questions
  1. Microscopic origin of the anomalous critical scattering at the kagome-ice plateau termination in Ho2Ti2O7 under a tilted [111] field

    Open for about 19 years
  2. Exact finite-temperature characterization of the disordered regions of the generalized kagomé-lattice Ising model with pair and triplet interactions

    Open for about 7 years
Kagomé Lattice Eight-Vertex Model2 questions
  1. Open problems for the free-fermion eight-vertex models on the square lattice: singularities of staggered free-fermion models, invariant variables, and the general even–odd finite-torus mapping

    Open for about 9 years
  2. Universality classes of the non-Ising transitions in the six-vertex model on the kagome lattice

    Open for about 1 year
Kagomé–square lattice model transformation3 questions
  1. Exact or provably controlled quantum decoration transformations for non-commuting quantum spin lattice models

    Open for about 10 years
  2. Explicit Kagome-type decorated-lattice construction from the gauge/YBE decoration transformation and its place in the integrability web

    Open for about 2 years
  3. Yang-Baxter integrability of the 3D quantum crystal melting Hamiltonian: Kagome-lattice Boltzmann weights, a commuting transfer matrix, and the mass-gap conjecture

Kasteleyn orientation2 questions
  1. The Pfaffian recognition problem beyond planar, bipartite, and near-bipartite graphs (Problem 42 of Kothari–de Carvalho–Lucchesi–Little)

    Open for about 8 years
  2. Extending the Pfaffian Sign Theorem for the dimer model to other lattices on the torus and to higher-genus and non-orientable surfaces

    Open for about 8 years
KPZ universality class3 questions
  1. Boundaries of Kardar-Parisi-Zhang universality for the chronon in time-crystalline matter

  2. Simultaneous Hausdorff dimension of the geodesic splitting sets in the directed landscape across all time levels

  3. Exact solvability, stationary structure, and KPZ universality of the quantum ASEP and its quantum Kardar-Parisi-Zhang dynamics

Kramers–Wannier duality4 questions
  1. Sector dependence of the exact Kramers–Wannier duality in exactly solvable SO(nn) spin chains: the Ramond sector and its Spin(nn)1_1 duality-defect interpretation

    Open for about 3 years
  2. Generalizing non-invertible Kramers-Wannier and Kennedy-Tasaki transformations beyond one dimension: higher-form gauging, SSPT classification beyond two dimensions, the fermionic exchange origin, and non-invertible Lieb-Schultz-Mattis constraints

    Open for about 2 years
  3. Self-dual Kramers-Wannier points as non-invertible symmetries: phase transitions and criticality of LDPC codes in non-Euclidean geometries

    Open for about 2 years
  4. The precise map between Chang/Magruder self-duality of continuum phi^4 theory and Kramers-Wannier / Ising-Z2-gauge lattice duality

    Open for about 5 years
Landen transformation3 questions
  1. Selected parameter values of the one-parameter series solutions of the modular Schwarzian equation: algebraicity, D-finiteness, D-D-finiteness, and the diagonals of rational functions

  2. Ordering-independent period matrix of the Case (b) separable N=2 sine-Gordon breather

  3. Does parameter-space modular invariance organize gapped integrable models? Virasoro characters, dualities, and the complex-argument extension of the XYZ chain

Lee–Yang model2 questions
  1. One-to-one correspondence between defect form-factor solutions and local defect operators in the scaling Lee–Yang model

  2. Transseries completion of the Yang–Lee string equation: full Stokes data, the oscillatory negative-x region, and the other low-dimensional string equations

limit shape3 questions
  1. Zero-temperature crystallization of the doubly periodic Aztec diamond dimer model beyond smooth tropical curves and iterated limits

  2. Arctic-circle behavior and domino shuffling for random perfect matchings of Aztec castles (Problem 5.2 of Leoni–Musiker–Neel–Turner)

  3. Smoothness of multinomial dimer limit shapes in dimensions d>2d>2 (Kenyon-Wolfram, Question 10.2)

Loop model and conformal field theory1 questions
  1. Rigorous proof of the closed-form three-point structure constants of critical loop models for all allowed Kac labels

Has Lorentz symmetry been broken?5 questions
  1. Rigorous indirect bounds on quark-sector CPT violation from the neutral-kaon mass difference

    Open for about 17 years
  2. Coupling of nonlinear electrodynamics to Lorentz-symmetry violation: the electric-background sector, non-CFJ operators, and detectability of the nonlinear-LSV interference terms

    Open for about 4 years
  3. Viability and phenomenological consistency of opposite d/s CPT phases as a CPT-violation mechanism in the Standard Model

    Open for about 6 years
  4. Spontaneous Lorentz breaking by Faddeev–Popov ghost condensation in perturbative quantum gravity: the curved-background generalization

    Open for about 15 years
  5. Is foliation-induced Lorentz-symmetry breaking in quantum gravity a relevant perturbation beyond leading order?

    Open for about 7 years
Macdonald processes3 questions
  1. Fredholm determinantal representations and asymptotics of periodic Macdonald processes at positive charge u>0u>0

  2. Positivity, canonical mixing decompositions, and rigorous Whittaker scaling limits in the classification of nearest-neighbor Markov dynamics on Macdonald processes

  3. Multipoint scaling limits, Pfaffian structure, and the Whittaker degeneration chain for half-space Macdonald processes

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