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Graduate Problem Map

Graduate problems should make assumptions explicit. They should ask not only for an answer, but for the conditions under which the answer is meaningful.

StageProblem FamilyCanonical PageGraduate Emphasis
1Toolkit readinessDiagnostic Checklistdomains, spectra, distributions, convergence
2Formalism reviewExercises and Problemsprojectors, mixed states, commutators, postulates
3Approximation methodsAnharmonic Oscillator Perturbationexpansion parameter and matrix elements
4ScatteringGaussian Potential Bornnormalization convention and validity of Born approximation
5Semiclassical reasoningWKB Barrier Tunnelingturning points and exponential estimates
6Composite systemsPartial Trace Exerciseslocal statistics and entanglement diagnostics
7Identical particles and Fock spaceIdentical-Particle Exercises and Fock-Space Exercisesexchange, occupation numbers, second-quantized notation
8Numerical validationBenchmark Problemsconvergence and error interpretation
IDProblem TypeRequired Assumption
QM-PROB-G101Prove or apply a commutator identityoperator domains or finite-dimensional setting
QM-PROB-G201Use degenerate perturbation theorychosen degenerate subspace and perturbation order
QM-PROB-G301Evaluate a Born amplitudeweak, short-range potential and normalization convention
QM-PROB-G401Estimate WKB tunnelingslowly varying barrier away from turning points
QM-PROB-G501Compute a reduced density operatortensor-factor ordering and subsystem definition
QM-PROB-G601Validate a numerical eigenvalue calculationrefinement variable and reference result

A graduate solution should state:

  • the Hilbert space and domain assumptions;
  • the normalization convention;
  • whether the spectrum is discrete, continuous, or mixed;
  • the approximation parameter and retained order;
  • the role of symmetry or degeneracy;
  • the physical observable extracted from the calculation;
  • at least one limiting case or benchmark.
  • Treating a perturbative result as exact because the first correction is compact.
  • Treating a finite-dimensional example as proof of an infinite-dimensional domain-sensitive statement.
  • Calling a numerical plot evidence without a convergence study.
  • Treating an effective model as fundamental without stating its regime.
  • R. Shankar, Principles of Quantum Mechanics, 2nd ed., Springer, 1994.
  • J. J. Sakurai and J. Napolitano, Modern Quantum Mechanics, 3rd ed., Cambridge University Press, 2020.
  • C. Cohen-Tannoudji, B. Diu, and F. Laloe, Quantum Mechanics, Wiley, 1977.
  • M. Reed and B. Simon, Methods of Modern Mathematical Physics I: Functional Analysis, Academic Press, 1980.