Disciplines / Research questions

Physics

691 research topics · 2739 questions

One-Dimensional Configuration Sums and Conformal Characters4 questions
  1. Energy-preserving bijection between RSOS paths and transfer-matrix string patterns in the physical combinatorics of critical RSOS and XXX models

  2. Classification of modular partial Nahm sums: Nahm's problem for lattice-coset restrictions

  3. Proof of the finitized bosonic character conjecture for the one-dimensional configuration sums of 2×22\times2 fused RSOS models

  4. Native finitization of Bressoud (k−1)(k-1)-restricted paths for Zk\mathbb{Z}_k parafermionic characters: a canonical length assignment

The Difficult Problem of the Origin of Large Amounts of 26Al^{26}\mathrm{Al} Nuclei in the Interstellar Medium of the Milky Way3 questions
  1. The Galactic 26Al problem: systematics of the 1.809 MeV inference chain and the origin of the solar nebula's 26Al

    Open for about 20 years
  2. Can the 14^{14}N(16^{16}O,α\alpha)26^{26}Al fusion channel in explosive oxygen burning of supernovae account for the Galactic 26^{26}Al inventory?

    Open for about 20 years
  3. Constraining the 26Al(n,p)26Mg^{26}\mathrm{Al}(n,p)^{26}\mathrm{Mg} and 26Al(n,α)23Na^{26}\mathrm{Al}(n,\alpha)^{23}\mathrm{Na} stellar destruction rates at explosive-burning temperatures (T9≈0.3T_9\approx0.3–2.52.5)

    Open for about 40 years
Gravitational Wave Detection8 questions
  1. Operational significance assignment for continuous gravitational-wave detections from known pulsars: signal-agnostic sky-bin excision, extreme-tail inference, and cross-pipeline validation of the sky-shifting method

    Open for about 5 years
  2. Mapping KAGRA+ upgrade-design choices to detection capability across gravitational-wave source classes: low-frequency sensitivity, event-rate uncertainty, waveform systematics, and core-collapse-supernova modeling limits

    Open for about 6 years
  3. Gravitational-wave burst detection of unknown morphology in pulsar timing array data under timing-model degeneracy and correlated noise

    Open for about 16 years
  4. Model-based cross-correlation search for gravitational waves from Scorpius X-1: separating intrinsic amplitude from unknown spin inclination, and bounding the coherence time under spin wandering

    Open for about 11 years
  5. Rigorous per-band population-average upper limits in all-sky continuous gravitational-wave searches

    Open for about 7 years
  6. Predictive sensitivity modeling and follow-up uncertainty in deep hierarchical all-sky searches for continuous gravitational waves

    Open for about 3 years
  7. Establishing scientifically credible detection capability for high-frequency (MHz-GHz) gravitational waves

    Open for about 5 years
  8. Reliable equation-of-state constraints from binary-neutron-star post-merger gravitational waves: out-of-sample model systematics, training-data limits, and exotic-matter robustness

    Open for about 6 years
Is Eternal Inflation Possible?8 questions
  1. Is there any coherent measure for eternal inflation?

    Open for about 14 years
  2. Controlled stochastic eternal inflation versus the refined swampland de Sitter conjecture: is the exclusion robust?

    Open for about 7 years
  3. The holographic measure on the exit from eternal inflation: establishing the smooth-exit conjecture beyond toy models and extending it to realistic decelerating cosmologies

    Open for about 9 years
  4. Eternal inflation in swampy landscapes: quantitative transition rates, the flyover mechanism, and a measure for the domain-wall multiverse

    Open for about 7 years
  5. Initial-condition dependence and rigorous eternality criteria for hilltop eternal inflation

    Open for about 10 years
  6. A UV-complete, swampland-compatible multiverse: eternal inflation, realistic tunneling rates, and the minimum inflationary duration in an actual landscape

    Open for about 2 years
  7. Microphysical realization of the breathing comoving Hubble multi-inflation scenario under the trans-Planckian censorship conjecture

    Open for about 6 years
  8. Incidence of eternal inflation at small field scales and in multifield random-potential landscapes

    Open for about 4 years
Realizing Quantum Mass Standards Using the "Watt Balance" Method3 questions
  1. Reducing the combined measurement uncertainty of the BIPM Kibble balance realization of the kilogram: parasitic motion, electrical, alignment, and magnet-drift limitations

    Open for about 6 years
  2. Maintaining consensus for the redefined kilogram: reconciling discrepant independent realizations for consistent mass dissemination

    Open for about 7 years
  3. Suppressing alignment-related type-B uncertainties in the KRISS Kibble balance to reach a 10−810^{-8}-level realization of the kilogram

    Open for about 6 years
Simulating Superconductors with Ultracold Atomic Gases7 questions
  1. Induced interactions and pairing in multi-component optical-lattice Fermi gases beyond weak-coupling mean field

    Open for about 17 years
  2. Effective extended-Hubbard description and scale-up of exact configuration-interaction benchmarks for ultracold fermions in optical plaquettes

    Open for about 9 years
  3. Controlled phase diagram and critical behavior of the collision-induced pair-hopping Bose-Hubbard model for bosonic atoms in state-dependent optical lattices

    Open for about 19 years
  4. Beyond-mean-field stability and dissipative regime of cavity-induced finite-momentum (FFLO-like) pairing in ultracold lattice Fermi gases

    Open for about 6 years
  5. Finite-temperature superconducting transition of the two-dimensional mixed-dimensional bilayer t–J model: BKT critical temperature and pairing signatures with interlayer density coupling

    Open for about 5 years
  6. Phonon-mediated Cooper pairing of light atoms in the large-scattering-length optical-lattice electron-phonon simulator

    Open for about 12 years
  7. Intermediate-coupling phase diagram of the two-dimensional extended Hubbard-Holstein model: preformed pairs, BKT condensation, and pseudogap signatures at λ ≈ 1 and ℏω_ph ≈ t

    Open for about 5 years
Establishing the Basic Units of the International System of Units (SI) Using Fundamental Physical Constants5 questions
  1. Physical origin of the mode-dependent inconsistencies in cylindrical acoustic gas thermometry: even–odd A0,lA_{0,l} dependence, nonlinear gas–shell coupling, and negative excess half-widths

    Open for about 15 years
  2. How many dimensional units does a quantum-gravity spacetime grant? The quantum-gravitational generalization of the minimal-standards count of fundamental constants

    Open for about 2 years
  3. Origins of the input-data inconsistencies that force uncertainty expansion in the CODATA fundamental-constants adjustment: the fine-structure constant, the Newtonian constant of gravitation, and hydrogen/deuterium spectroscopy

    Open for about 2 years
  4. Linking the atomic and macroscopic mass scales in the post-2019 SI: atom-counting realization of the kilogram at competitive uncertainty

    Open for about 7 years
  5. Closing the quantum metrology triangle at the 10−810^{-8} level: cryogenic-capacitor frequency dispersion versus direct single-electron current architectures

    Open for about 41 years
Five Challenges in Applying Statistical Physics Methods to Constraint Satisfaction Problems3 questions
  1. Reconstruction versus mixing for Glauber dynamics on sparse random graphs

    Open for about 16 years
  2. Extremal Bethe-state decomposition of the Gibbs measure of general random constraint satisfaction problems

    Open for about 16 years
  3. Dembo–Montanari-precision finite-size scaling for the kk-core of sparse random graphs beyond the settled 2-core

    Open for about 19 years
Studying Hadron Physics and Strongly Coupled Quark Matter Using the AdS/CFT Duality Method9 questions
  1. Simultaneous holographic description of pion static observables and the spacelike pion electromagnetic form factor in bottom-up AdS/QCD with chiral symmetry breaking

    Open for about 19 years
  2. Holographic transport coefficients of dense QCD matter in paired, magnetized, and confined phases

    Open for about 4 years
  3. Backreaction, color superconductivity, and the fate of the quarkyonic phase in the holographic QCD phase diagram

    Open for about 5 years
  4. Localized D5-brane baryons and astrophysically viable parameter regions in the holographic D3/D7 quark-star model

    Open for less than 1 year
  5. Consistent scalar-meson and axial-vector sectors in holographic QCD for the hadronic light-by-light contribution to the muon g−2g-2

    Open for about 3 years
  6. Transport coefficients of strongly coupled dense quark matter with pairing, realistic flavor structure, and unquenched flavor backreaction

    Open for about 6 years
  7. Non-perturbative running of multi-quark operator dimensions in holographic QCD and the robustness of the sexaquark mass prediction

    Open for about 3 years
  8. Completing the multi-phase holographic description of dense QCD matter for neutron stars: transport coefficients for confined and paired phases, finite-temperature merger inputs, and the holography-versus-pQCD contrast at intermediate densities

    Open for about 4 years
  9. Quantitative weak equilibration rates for strongly coupled cold quark matter: quark masses, pairing, and model dependence

    Open for about 2 years
A Question Related to Scanning Tunneling Microscopy (STM)6 questions
  1. Quantitative STM tunneling-current prediction in the trapezoidal-barrier planar model: self-consistent image potential, low-bias accuracy, elevated-temperature emission, tip-shape corrections, and experimental validation

    Open for about 4 years
  2. General, robust, and physically interpretable deep-reinforcement-learning control of scanning-tunneling-microscope atom manipulation

    Open for about 3 years
  3. Fullerene-based tunneling probe of inter-valley coherence in moiré heterostructures: quantitative evaluation and experimental realization

    Open for about 2 years
  4. Testing the double-quantum-dot mechanism for spin resonance in STM current noise: second Larmor and difference-frequency resonances, the tip spin, and the absolute noise power

    Open for about 7 years
  5. Validity domain and k-space inversion of simultaneous I(V) and dI(V)/dz scanning tunneling spectroscopy

    Open for about 8 years
  6. Microscopic origin and channel decomposition of the element-specific tunneling-current modulation in synchrotron-radiation scanning tunneling microscopy

    Open for about 18 years
Lasers with and without population inversion5 questions
  1. Population inversion versus coherence in N2+ air lasing: discriminating emission mechanisms and building a predictive model for polarization-modulated strong-field pumping

    Open for about 12 years
  2. Experimental realization and robustness of lasing without population inversion in an Er3+-doped YAG crystal

    Open for about 14 years
  3. Nonlinear steady state and realizability of lasing with and without inversion in an optically thin gain medium near a metal surface

    Open for about 4 years
  4. Demonstrating amplification and lasing without inversion at 253.7 nm in mercury vapor (Doppler-free four-level double-dark-state scheme)

    Open for about 26 years
  5. Mechanism of gain and population inversion on the B2Σu+→X2Σg+B^2\Sigma_u^+\to X^2\Sigma_g^+ transition of N2+\mathrm{N_2^+} in air lasing

    Open for about 14 years
Finite Bond Dimension Truncation4 questions
  1. Rigorous criteria for operator-entanglement boundedness and truncation-error control in Heisenberg-picture DMRG simulation of one-dimensional quantum dynamics

  2. Rigorous compression theory and memory bounds for influence matrices of chaotic quantum many-body dynamics

  3. A comprehensive theory of finite-bond-dimension effects in matrix product state approximations beyond the conformal-field-theory scaling picture

  4. Predictive theory of finite-bond-dimension errors in the tensor renormalization group: convergence rates, effective correlation length, and spurious fixed points for universal critical data

Finite-Size Ground State Energy4 questions
  1. Finite-size effects and root structure of the inhomogeneous Bethe ansatz equations for the half-filled Hubbard chain with nonparallel boundary magnetic fields

  2. Finite-size energy of a one-dimensional Fermi gas beyond non-negative potentials: bound states and the zero-energy-resonance regime

  3. Finite-size scaling theory for boundary renormalization-group flows in gapless one-dimensional quantum systems

  4. Systematic analytic finite-size corrections for the periodic spin-1/2 isotropic antiferromagnetic Heisenberg chain: convergent Bethe-ansatz rapidity asymptotics, higher-order RG energy series, and excited states

Finite-Size Spectra and Continuum Limit2 questions
  1. Analytic control of the non-compact continuum limit of two coupled Potts models (the a3(2)a_3^{(2)} model in regime III): logarithmic finite-size amplitudes, density of states, energy exponents, and the underlying conformal field theory

    Open for about 12 years
  2. Continuum-limit identification of the staggered six-vertex model with integrable open boundaries: Euclidean or Lorentzian black-hole sigma model, and the emergence of the non-compact direction

    Open for about 5 years
Finite-Size Corrections2 questions
  1. Finite-size corrections, crossover scaling, and KDP-singularity rounding for the dimer model on the generalized checkerboard B and C lattices

  2. Higher-order non-analytic finite-size corrections in the random assignment problem

Finite Entanglement Scaling4 questions
  1. Extending the iPEPS Disorder-Parameter Framework and Its Finite Correlation Length Scaling to Continuous, Higher-Form, and Subsystem Symmetries

  2. Completing the self-congruent-point effective field theory for finite-entanglement scaling in critical matrix product states

  3. Origin and universality of the finite correlation length ξ(D)\xi(D) in variationally optimized Lorentz-invariant gapless iPEPS

  4. Rigorous derivation of the finite-bond-dimension scaling of the correlation length in tensor network renormalization

Symmetry Restoration in Mean-Field Approximations of Finite Quantum Many-Body Systems8 questions
  1. Finite-temperature variation after particle-number projection in nuclear mean-field theory: a tractable projected entropy and free energy in the paired phase

    Open for about 21 years
  2. Generality and measurability of extensive two-mode quantum discord in pair-correlated finite fermion systems

    Open for about 12 years
  3. Extending angular-momentum-projected Nilsson mean-field plus exactly solvable pairing: isovector proton-neutron pairing, the validity boundary of the K=0 truncation, effective charges, and heavier nuclei

    Open for about 10 years
  4. Variation after multi-symmetry projection: restoring angular momentum and parity inside the variational process, with isospin as the envisioned completion, using general Bogoliubov states and chiral three-nucleon interactions

    Open for about 5 years
  5. Well-defined particle-number projection and configuration mixing for nuclear energy density functionals: contour-independent multi-reference energies free of pole and branch-cut pathologies

    Open for about 19 years
  6. Symmetry restoration within the many-body-basis mean-field formulation of the Hubbard model: formulation, exact-diagonalization benchmark, and cost assessment

    Open for about 3 years
  7. Lipkin-method variation-after-projection for rotational and isospin symmetry restoration in nuclear energy-density-functional theory: quantitative assessment, kernel singularities, and range of applicability

    Open for about 17 years
  8. Generalizing the fermionic quantum-ring benchmark of symmetry breaking and restoration: U(1) gauge symmetry with particle-number projection, higher-dimensional spherium and glomium, and evaluation with dynamically correlated interactions

    Open for about 2 years
Finite-Temperature Free Energy2 questions
  1. Rigorous completion of the quantum transfer matrix approach to the thermodynamics of the spin-1/21/2 XXZ chain: all-temperature solvability of the non-linear integral equations and full classification of the subdominant spectrum

  2. Finite-temperature thermodynamics and finite-size structure of the one-dimensional Hubbard model with nonparallel boundary magnetic fields

Cosmic Standard Ruler——Baryon Acoustic Oscillations7 questions
  1. Establishing the galaxy density–ellipticity (GI) baryon acoustic oscillation channel as a validated percent-level standard ruler

    Open for about 3 years
  2. Are new pre-recombination physics or calibrator systematics behind the short sound horizon inferred from late-time distance indicators?

    Open for about 7 years
  3. The nonlinear BAO peak shift in the Lyman-alpha forest: sign, magnitude, and robustness to IGM modeling

    Open for about 2 years
  4. Robust sound-horizon-free measurement of H0H_0 from galaxy clustering at future-survey precision: validity of the rescaling methodology, the role of equality-scale information, and the power to constrain early-Universe solutions of the Hubble tension

    Open for about 6 years
  5. Origin of the DESI low-redshift baryon acoustic oscillation distance offsets: statistical fluctuation, unmodelled systematics, or new physics

    Open for about 2 years
  6. Catalogue-level validation of the BAO sound-horizon estimator–integral mismatch and its corrections at Stage-IV survey precision

    Open for about 11 years
  7. Model-minimal calibration of the low-redshift Universe: model-independent curvature, absolute BAO ruler scale, and redshift-stability of the standard ruler

    Open for about 11 years
Cosmic Magnetic Fields8 questions
  1. Spatial distribution of quark-hadron-fluctuation primordial magnetic bubbles at low redshift and their ultra-high-energy cosmic-ray consequences

    Open for about 19 years
  2. Completing the backreaction analysis of inflationary magnetogenesis: the self-consistent anisotropic phase, its primordial spectra, and strong-coupling viability in the Kanno–Soda–Watanabe scenario

    Open for about 17 years
  3. Robust detection and environmental separation of cosmic-web magnetic fields via Faraday rotation

    Open for about 7 years
  4. Can magnetic fields in cosmic-void interiors be established as observable relics of the primordial seed field?

    Open for about 16 years
  5. Origin of cosmic-web magnetism: discriminating primordial versus astrophysical magnetogenesis through joint radio observations and simulations

    Open for about 32 years
  6. Viability of a quasi-homogeneous cosmological seed field for the galactic mean-field dynamo

    Open for about 14 years
  7. Can purely astrophysical magnetogenesis magnetize the volume-filling intergalactic medium, or is a primordial seed required?

    Open for about 24 years
  8. Quantitative closure of the electroweak-magnetogenesis hypothesis for cosmic-void magnetic fields

    Open for about 11 years
First Generation Stars in the Universe8 questions
  1. Existence and detectability of low-mass metal-free (Population III) stars surviving in the Milky Way today

    Open for about 45 years
  2. Physical mass loss from Population III stars during quasi-static evolution: mechanisms, thresholds, and integrated amounts, and their consequences for pre-supernova masses and final fates

    Open for about 16 years
  3. Robust determination of the Population III initial mass function from extremely metal-poor star abundances under supernova explodability filtering

    Open for about 1 year
  4. Trans-iron nucleosynthesis in zero-metallicity rotating massive stars: primary neutron sources, the seed-absence limit, and yield scaling with mass, rotation, mergers, and explosion physics

    Open for about 17 years
  5. Surviving low-mass metal-free Population III stars: discovery or exclusion, and the low-mass end of the first-star initial mass function

    Open for about 45 years
  6. When did Population III star formation end? The persistence of metal-free star formation into the reionization era and its observability

    Open for about 20 years
  7. The missing pair-instability supernova chemical imprint in extremely metal-poor stars: explaining its absence and constraining the Population III initial mass function

    Open for about 24 years
  8. The origin of the most iron-deficient stars: surface-polluted Population III survivors or second-generation stars, and the search for pristine survivors

    Open for about 23 years
Afterglow of Cosmic Gamma-Ray Bursts6 questions
  1. The physical nature of EP241107a and gamma-ray-quiet Einstein Probe fast X-ray transients: afterglow absorption physics, absent prompt emission, and the faint-GRB-channel question

    Open for less than 1 year
  2. Physical origin of pre-prompt afterglow onset in gamma-ray-burst X-ray plateaus: a central-engine and ejecta model for the L0L_{0}–T0T_{0}–Eγ,isoE_{\gamma,\mathrm{iso}} scalings, or a quantitative refutation of the prior-activity interpretation

    Open for about 20 years
  3. Recovering unmodelled physical emission components in Gaussian-process-marginalized gamma-ray burst afterglow inference

    Open for about 6 years
  4. Afterglow polarimetry as a quantitative probe of non-axisymmetric gamma-ray burst jets: deformed visible regions, magnetic-field coherence, and multi-wavelength disentanglement

    Open for about 1 year
  5. The physical origin of the late-time very-high-energy emission component in gamma-ray burst afterglows

    Open for about 6 years
  6. Late-Time X-Ray Excess, Jet-Structure Degeneracy, and Reverse-Shock Systematics in the Structured Forward–Reverse-Shock Afterglow of GRB 170817A/GW170817

    Open for about 5 years
Evolution of Cosmic Strings7 questions
  1. Scaling of ZN\mathbb{Z}_N string networks with baryon-vertex junctions at large NN and in the local dual flux-tube theory

    Open for less than 1 year
  2. Completing the varying-tension growth mechanism for cosmic strings: loop production, percolation into networks, multi-modulus dynamics, and field-theoretic strings

    Open for about 2 years
  3. Microphysical determination of the inputs to the kinematically constrained multi-tension cosmic-superstring network model

    Open for about 16 years
  4. Asymptotic scaling of multi-tension cosmic string networks with bound states: unequal tensions, bound-state abundance, and semi-analytic calibration

    Open for about 18 years
  5. Loop decay in Abelian-Higgs cosmic string networks: the instability exciting internal modes, the Nambu-Goto-like loop fraction, and field-theory-based observational forecasts

    Open for about 5 years
  6. Quantitative calibration and validation of the charge-velocity-dependent one-scale (CVOS) model for current-carrying cosmic string networks

    Open for about 5 years
  7. Validated dynamics of cosmic string networks with time-varying tension: calibrating the generalized VOS model, the momentum parameter k(v), and the post-percolation fate

    Open for about 1 year
Are strangelets present in cosmic rays?8 questions
  1. Definite prediction of the galactic strangelet flux: from strange-star-merger multifragmentation spectra to observable cosmic-ray fluxes

    Open for about 11 years
  2. Testing the strangelet hypothesis for the cosmic-ray knee: is the primary flux between the knee and the ankle dominated by non-nuclear strange-quark-matter particles, and what is the true rigidity scale of the nuclear cutoffs?

    Open for about 30 years
  3. Strangelet interpretation of the 1–100 PeV cosmic-ray knee anomalies: microscopic interaction theory, strange-quark-star source physics, and observational confirmation

    Open for about 46 years
  4. Predictive modeling of a geomagnetically trapped strangelet population (the strangelet belt)

    Open for about 19 years
  5. Testing the strangelet-based model of the cosmic-ray spectrum: the strangelet component of the primary cosmic-ray flux above 1017 eV10^{17}\ \mathrm{eV}

    Open for about 29 years
  6. Quantitative test of the strangelet hypothesis for the cosmic-ray knee and its anomalous effects at 1–100 PeV

    Open for about 4 years
  7. Surface tension of the quark-matter/vacuum interface and the fragmentation of strange-star surfaces into strangelet crusts

    Open for about 21 years
  8. Cosmic-ray strangelets from HESS J1731-347: theory of 2SC–CFL strangelet production, multi-TeV Monte Carlo detectability, and gamma-ray line constraints with the Cherenkov Telescope Array

    Open for about 1 year
The golden age of cosmology4 questions
  1. Origin of the DAMA/LIBRA annual-modulation signal: identify the dark-matter scenario, or the systematic effect, responsible for the long-standing NaI(Tl) modulation

    Open for about 28 years
  2. Identifying the inflationary realization: primordial tensor confirmation, the fourth Hubble-flow function, and the reheating kinematics (ln⁡Rreh\ln R_{\mathrm{reh}})

    Open for about 16 years
  3. Coherent quantum geometry origin of the cosmological constant: nonperturbative computation of the QCD causal-diamond correlator and the identification Λ=3⟨ω2⟩\Lambda=3\langle\omega^2\rangle

    Open for about 6 years
  4. Root cause of the distance-ladder versus sound-horizon-free H0 discrepancy: coherent systematic, late-time departure from ΛCDM, or hybrid

    Open for about 2 years
Gravitational waves of cosmological origin5 questions
  1. Primordial gravitational-wave signatures of the NEC-violating DHOST bounce and validation of its analytic tensor-transfer results

    Open for about 5 years
  2. Robust prediction of the cosmic-string stochastic gravitational-wave background: loop-distribution and metastable-decay model dependence in the mapping from string tension to Ω_GW(f)

    Open for about 37 years
  3. Mapping the chiral-invariant-mass dependence of gravitational-wave spectra from first-order QCD phase transitions in the parity doublet model and breaking the order-parameter degeneracy

    Open for less than 1 year
  4. First-principles gravitational-wave spectrum of a hot plasma at intermediate momenta between the hydrodynamic and particle regimes

    Open for about 11 years
  5. Identifying the physical origin of the nanohertz stochastic gravitational-wave background in pulsar timing arrays

    Open for about 6 years
Early universe QCD phase transition processes6 questions
  1. Cosmological viability of the high-baryon-density first-order QCD phase transition: color-superconducting and magnetic-field corrections, primordial quark nugget survival, and nanohertz gravitational waves

    Open for about 1 year
  2. Percent-level imprint of the cosmic QCD transition on the primordial gravitational-wave spectrum: from lattice-QCD thermodynamics to uncertainty-controlled predictions of ΩGW(f)\Omega_{\rm GW}(f)

    Open for about 7 years
  3. First-order pion condensation at the QCD epoch: tricritical behavior at high isospin chemical potential and the primordial gravitational-wave imprint

    Open for about 1 year
  4. Order of the QCD transition at large baryochemical potential and metastable supercooling of the early universe

    Open for about 51 years
  5. Six-light-flavor first-order QCD confinement transition and its primordial-black-hole yield for the LIGO/Virgo mass scale

    Open for about 7 years
  6. Gravitational waves from turbulence at the cosmological QCD crossover: multi-dimensional dynamics, viscosity, and initial conditions

    Open for about 13 years
Neutrinos in the universe7 questions
  1. Disentangling neutrino nonradiative decay from astrophysical and flavor-physics uncertainties in the diffuse supernova neutrino background

    Open for about 23 years
  2. Making tritium-capture detection of the cosmic neutrino background decisive: breaking the rate-degeneracy mechanisms

    Open for about 12 years
  3. Cosmological determination of the absolute neutrino mass scale and the mass ordering

    Open for about 54 years
  4. Physical identification of the diffuse astrophysical neutrino flux: which source populations (especially the gamma-opaque component below ~100 TeV), spectral form, and prompt atmospheric background produce the IceCube all-flavor sky

    Open for about 12 years
  5. Local number density and momentum distribution of the cosmic neutrino background at the Solar System

    Open for about 23 years
  6. Radiative decay of the cosmic neutrino background: detecting or constraining it through the cosmic infrared background spectrum

    Open for about 27 years
  7. Origins of the high-energy astrophysical neutrino flux and the behavior of the spectrum above 1 PeV

    Open for about 12 years
Experimental observation of correlation dynamics inside atoms and molecules2 questions
  1. Experimental realization of the double-attosecond-pulse measurement of the electron-electron correlation time in helium double ionization

    Open for about 19 years
  2. Quantitative many-body theory of doubly-excited-state-mediated nonsequential above-threshold double ionization in strontium

    Open for less than 1 year
Nuclear drip lines and the updated chart of nuclides4 questions
  1. Rigorous uncertainty quantification for ab initio predictions of the limits of nuclear existence

    Open for about 7 years
  2. Growth of the Coulomb-induced enhancement of nuclear deformation and outward shift of the neutron drip line in heavy nuclei (Z > 60)

    Open for about 1 year
  3. Location of the neutron drip line in the calcium isotope chain

    Open for about 14 years
  4. Principled quantified extrapolation of the nuclear landscape to the particle drip lines

    Open for about 6 years
Cluster structure and cluster radioactivity of atomic nuclei5 questions
  1. Microscopic determination of the cluster preformation probability and surface-polarization parameter for exotic cluster radioactivity in trans-lead nuclei

    Open for about 3 years
  2. Thermal dissolution of cluster structures in finite nuclei: collective degrees of freedom and quantum fluctuations

    Open for about 4 years
  3. Four-particle correlator test of alpha-cluster formation and of the mean-field clustering criteria in nuclei

    Open for about 3 years
  4. Microscopic foundation of the cluster preformation probability in trans-lead cluster radioactivity: absolute magnitude, Ac≥28A_c\geq28 scaling, and the origin of the NpNnN_pN_n/NpNnIN_pN_nI linearity

    Open for about 37 years
  5. Cluster emission from neutron-rich heavy nuclei: reliable decay rates and their impact on r-process nucleosynthesis

    Open for less than 1 year
Halo phenomena in atomic nuclei2 questions
  1. Locating the sodium neutron dripline and validating the deformed-halo structure of 39^{39}Na: shape-decoupling observables, three-body dynamics, and finite-range pairing in the DRHBc framework

    Open for about 3 years
  2. Unsettled structure of the dripline two-neutron halo nuclei: binding energies, orbital content, and radii of 22C and 19B, with extension to the heaviest case 29F

    Open for about 5 years
Three-body model of atomic nuclei4 questions
  1. Consistent determination of chiral three-nucleon-force contact strengths: complete N3LO dynamics, simultaneous continuum and bound-state constraints, and consequences for nuclear structure

    Open for about 15 years
  2. Existence and Efimov character of the predicted shallow 1/2−1/2^- excited state of 23^{23}N in the 21^{21}N+nn+nn three-body system

    Open for about 11 years
  3. Uncertainty-quantified embedding of the three-body 22C{}^{22}\mathrm{C} model into reaction theory: direct comparison with measured interaction cross sections and the conflicting matter-radius extractions

    Open for less than 1 year
  4. Two-proton halo nuclei as three-body systems in halo effective field theory: existence and spectrum of an effective three-body bound state under Coulomb repulsion

    Open for about 11 years
Do atomic nuclei exhibit chirality?7 questions
  1. Unambiguous identification and characterization of chiral doublet bands in triaxial nuclei: distinguishing static chirality, chiral vibration, and non-chiral alternatives

    Open for about 20 years
  2. Nuclear chirality in 134^{134}Pr: surviving chiral geometry and the decisive observables for chiral-band assignments

    Open for about 29 years
  3. Robustness of nuclear chirality: why near-perfect chiral degeneracy in 194^{194}Tl is rare and how lifetime data can establish it elsewhere

    Open for about 10 years
  4. From dynamic to static nuclear chirality: the microscopic conditions for genuine spontaneous breaking of handedness in triaxial nuclei

    Open for about 29 years
  5. Establishing nuclear chirality: chiral-basis selection rules, multiple chiral doublets, and the unobserved textbook chiral doublet band

    Open for about 29 years
  6. Reliable identification of chiral doublet bands in real nuclei: disentangling the chirality fingerprints and establishing model-independent criteria

    Open for about 16 years
  7. Microscopic description of chirality onset across the cesium isotope chain and the boundaries of the A≈130 chiral island: pairing, chiral dynamics, and edge cases at 119Cs, 133Cs, and 134Cs

    Open for about 3 years
Microscopic mechanisms of nuclear shape transitions4 questions
  1. Completing the validation and microscopic foundation of the empirical signatures for shape coexistence and shape/phase transitions in even-even nuclei

    Open for about 3 years
  2. Microscopic origin of the first-order shape/phase transitions at N = 40, 60, and 90 and the quantitative link between self-consistent and collective-model potentials

    Open for about 2 years
  3. Robustness of microscopically inferred nuclear shape-phase-transition boundaries under complete beyond-mean-field treatment

    Open for about 10 years
  4. Controlled many-body truncation in the ab initio IM-GCM description of shape coexistence and the N=20N=20 island of inversion: multireference three-body correlations and cranked configurations

    Open for about 1 year
Relativistic symmetry in atomic nuclei—physical origin of spin and pseudospin symmetry5 questions
  1. Quantitative link between the in-medium scalar-vector balance and pseudospin symmetry restoration in relativistic nuclear functionals

    Open for about 7 years
  2. Regularized pseudo-spin-orbit splitting measure and validity of the constant-Σ approximation for pseudospin symmetry in bound and resonant nuclear states

    Open for about 2 years
  3. Higher-order similarity-renormalization-group and effective-mass corrections to pseudospin symmetry breaking, and the origin of its better conservation than spin symmetry in nuclei

    Open for about 13 years
  4. Quantitative mechanism of pseudospin-symmetry breaking and accidental restoration in relativistic mean-field nuclei: second-order systematics and predictions for neutron-skin and bubble nuclei

    Open for about 1 year
  5. Criteria for the origin and quality of pseudospin symmetry in nuclear Dirac mean fields

    Open for about 14 years

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