Astrophysics
Known-exoplanet population study
Mass-radius and period-radius diagrams (e.g. the radius valley) from the NASA Exoplanet Archive, with the selection cuts stated.
Astrophysics
Redshifts and emission lines from SDSS spectra
Redshift, line fluxes and a BPT classification for a galaxy sample, from SDSS line catalogues or the spectra themselves.
Astrophysics
Hubble constant from Pantheon+ supernovae
H0 / Omega_m posterior from the Pantheon+SH0ES distance moduli with the full covariance matrix, with a corner plot.
Astrophysics
Gravitational-wave population from published posteriors
Mass and spin distribution of merging black holes by hierarchical inference over the GWTC posterior samples.
Astrophysics
Analyse my cosmological simulation output
Halo profiles, projections and power spectra from a simulation snapshot the researcher uploads.
Computational physics
Check an integrator's order and conservation
Measured convergence order and energy/momentum drift of an integrator (symplectic vs Runge-Kutta) on a test problem.
Computational physics
Long-term stability of a planetary system
MEGNO / Lyapunov map and survival time of a multi-planet system over millions of orbits.
Computational physics
Solve a PDE and prove the convergence order
Finite-difference solution of a heat/wave/Poisson problem with a grid-refinement study against the exact solution.
Computational physics
Monte Carlo estimate with an honest error bar
Monte Carlo integral or expectation with variance reduction and a convergence plot.
Computational physics
Spectrum of my time series
Power spectral density (Welch/multitaper), peaks and their significance for a signal the researcher supplies.
Computational physics
Derive equations of motion and simulate them
Lagrangian to equations of motion symbolically, then integrated and plotted (phase portraits, energy).
Computational physics
Fit a simulation's parameters by gradient
Differentiable simulation fitted to data by automatic differentiation.
Computational physics
Solve a stiff ODE or DAE system
Stiff kinetics or an index-reduced DAE solved with an implicit integrator, with a solver-tolerance study.
Condensed matter
Tight-binding bands and density of states
Band structure and DOS of a lattice model, checked against the analytic dispersion.
Condensed matter
Topological invariant of a model
Chern number or Z2 invariant of a Hamiltonian, with the Berry-curvature or Wilson-loop plot.
Condensed matter
Ground state of an interacting 1D model by DMRG
Energy, correlations and entanglement entropy of a spin or Hubbard chain with TeNPy or quimb.
Condensed matter
Exact diagonalisation of a small interacting cluster
Spectrum and correlation functions of a Heisenberg or Hubbard cluster by Lanczos.
Condensed matter
Screen a materials database for a property
Candidates ranked by band gap, stability or magnetism from open DFT databases.
Condensed matter
Classical spin Monte Carlo for a magnetic transition
Ordering temperature and susceptibility of a Heisenberg/Ising magnet on a lattice.
Fluid and continuum mechanics
2D incompressible flow benchmark
Lid-driven cavity or flow past a cylinder with drag, lift and Strouhal number against published reference values.
Fluid and continuum mechanics
Linear stability of a shear flow
Orr-Sommerfeld eigenvalues, neutral curve and critical Reynolds number.
Fluid and continuum mechanics
Structural finite-element check against a reference
Stress and deflection of a beam/plate/solid against an analytic or NAFEMS benchmark value.
Fluid and continuum mechanics
Topology optimisation of a structure
Minimum-compliance layout at a volume fraction (SIMP), with a mesh-independence check.
Fluid and continuum mechanics
Bifurcations and chaos in a low-dimensional system
Bifurcation diagram, Lyapunov exponent and period-doubling constants.
Fluid and continuum mechanics
Recover governing equations from data
Sparse identification (SINDy) of a dynamical system from measured trajectories, with a noise-robustness test.
Nuclear physics
Decay an inventory forward in time
Activities, decay heat and gamma lines of a nuclide inventory over time.
Nuclear physics
Binding energies against a mass model
AME2020 binding energies vs the semi-empirical mass formula, with shell-closure residuals.
Nuclear physics
Measured cross sections against evaluated libraries
EXFOR measurements plotted and compared against ENDF/B-VIII and JEFF evaluations for a reaction.
Nuclear physics
Nucleosynthesis reaction network
Energy generation and abundance flow for a burning stage from a REACLIB network.
Nuclear physics
Astrophysical reaction rate from a cross section
Thermonuclear rate vs temperature from an S-factor or narrow resonances, with its uncertainty.
Nuclear physics
Analyse my gamma-ray spectrum
Peak fits, energy/efficiency calibration and nuclide identification for a detector spectrum.
Optics and electromagnetism
Mie scattering of particles
Extinction, scattering and backscatter efficiencies vs size parameter and wavelength.
Optics and electromagnetism
Thin-film stack reflectance
Reflectance/transmittance spectra of a multilayer coating from real dispersion data.
Optics and electromagnetism
Diffraction pattern or telescope PSF
Fraunhofer/Fresnel propagation of an aperture and the PSF with aberrations.
Optics and electromagnetism
Resonator modes and Q factor (2D FDTD)
Cavity resonances, Q factors and transmission of a 2D photonic structure.
Optics and electromagnetism
Photonic-crystal band structure
Band diagram and band gaps of a photonic crystal slab.
Optics and electromagnetism
Grating diffraction efficiency (RCWA)
Diffraction efficiencies of a periodic grating vs wavelength and angle.
Optics and electromagnetism
Lens design and ray tracing
Sequential ray trace of a lens with real glasses: spot diagrams, aberrations and a tolerance check.
Optics and electromagnetism
Analyse my measured S-parameters
Touchstone network data de-embedded, fitted and plotted (Smith chart, return loss).
Particle physics
Rediscover the Z and J/psi in collision data
Dimuon invariant-mass spectrum from CMS open data with fitted resonance masses and widths.
Particle physics
Bump hunt with local and global significance
Search for a resonance in a mass spectrum with a look-elsewhere-corrected significance.
Particle physics
Upper limits with a HistFactory model
95% CL CLs limits on a signal from binned templates.
Particle physics
Jet clustering and substructure
Anti-kt jets and substructure observables of boosted objects on open data or supplied events.
Particle physics
Standard Model prediction vs the world average
Literature synthesis of a precision observable (e.g. muon g-2): each value, source and tension in sigma.
Particle physics
Efficiency and scale factor by tag-and-probe
Reconstruction/ID efficiency vs pT/eta in data and simulation, and their ratio.
Plasma physics
Characterise a plasma regime
Debye length, plasma frequency, beta, collisionality and the regime they imply, for stated conditions.
Plasma physics
Kinetic dispersion relation
Roots of the plasma dispersion function (Landau damping, ion-acoustic waves) against analytic limits.
Plasma physics
1D electrostatic particle-in-cell
Two-stream instability growth rate from a PIC run against linear theory.
Plasma physics
Solar-wind driving of geomagnetic storms
OMNI solar-wind coupling functions against Dst/AE over a storm set, with lag correlations.
Plasma physics
Turbulence spectrum from spacecraft magnetometer data
Spectral index and break frequency of solar-wind or magnetosheath turbulence (Wind, MMS).
Plasma physics
Free-boundary tokamak equilibrium
Grad-Shafranov equilibrium and the coil currents that produce a target shape.
Plasma physics
MHD benchmark problem
Brio-Wu shock tube or Orszag-Tang vortex with a finite-volume MHD solver, checked against reference solutions and div B.
Plasma physics
Analyse my Langmuir-probe sweep
Electron temperature, density and floating/plasma potential from an I-V characteristic.
Quantum physics
Decoherence of a driven qubit
T1/T2 and Rabi dynamics from a Lindblad master equation.
Quantum physics
Variational algorithm on a spin Hamiltonian
VQE or QAOA with gradients, converged energy and comparison with exact diagonalisation.
Quantum physics
Noisy circuit simulation at scale
Circuits under a device noise model, up to the memory limit of a statevector/density matrix.
Quantum physics
Surface-code error-correction threshold
Logical error rate vs physical error rate across code distances, and the crossing point.
Quantum physics
Tomography and randomised benchmarking
State/process tomography and RB decay on a simulated device.
Quantum physics
Bound a Bell scenario by semidefinite programming
NPA-hierarchy bound on a Bell expression with the SDP certificate.
Quantum physics
Tensor-network simulation of many qubits
MPS/tensor-network simulation of a low-entanglement circuit beyond statevector size.
Quantum physics
Molecular Hamiltonian and VQE
Qubit Hamiltonian of a small molecule and a VQE energy against full CI.
Quantum physics
Optimal control of a quantum gate
GRAPE/CRAB pulse that implements a gate at target fidelity under constraints.
Relativity and mathematical physics
Curvature of a metric
Christoffel, Riemann, Ricci and Einstein tensors, and whether the metric solves the field equations.
Relativity and mathematical physics
Geodesics in a curved spacetime
Orbits, perihelion precession, light bending or a black-hole shadow by geodesic integration.
Relativity and mathematical physics
Random-matrix spectral statistics
Level-spacing distribution and spectral form factor against GOE/GUE predictions.
Relativity and mathematical physics
Asymptotic expansion of an integral or special function
Series/asymptotic forms derived symbolically and checked numerically to high precision.
Relativity and mathematical physics
Small lattice gauge simulation
Pure-gauge U(1)/SU(2) Monte Carlo with Wilson loops and the string tension.
Relativity and mathematical physics
Bethe ansatz vs exact diagonalisation
Bethe-ansatz energies of an integrable chain checked against exact diagonalisation.
Statistical mechanics
Critical point and exponent by finite-size scaling
Critical temperature and an order-parameter exponent with statistical and systematic errors separated.
Statistical mechanics
Cluster Monte Carlo that beats critical slowing down
Wolff/Swendsen-Wang updates with measured autocorrelation times vs Metropolis.
Statistical mechanics
Density of states by Wang-Landau
g(E) of a lattice model and thermodynamics at any temperature from one run.
Statistical mechanics
Error bars for correlated Monte Carlo data
Integrated autocorrelation time and binning/blocking error for a Monte Carlo series.
Statistical mechanics
Percolation threshold and cluster scaling
p_c and cluster-size exponents by finite-size scaling.
Statistical mechanics
Lennard-Jones fluid against NIST reference data
Energy and pressure of LJ configurations compared with the NIST Standard Reference Simulation values.
Statistical mechanics
Stochastic-process simulation
Exclusion processes, kinetic Monte Carlo or Gillespie simulations with scaling exponents.