E061: Chebyshev ψ(x) and prime powers

Preview figure for E061
Preview figure for E061

Tags: number-theory, quantitative-exploration, visualization, arithmetic-functions, mangoldt, pnt, summatory See: Valid Tags.

Highlights

  • Plot \(\psi(x)\) and the error \(\psi(x)-x\).

  • Make the role of prime powers visible (jumps at p^k).

Goal

Build intuition for Chebyshev functions as “smoothed” prime counters.

Background (quick refresher)

Research question

Over a moderate range, what does \(\psi(x)-x\) look like and where do the main jumps occur?

Method

  • Compute Λ(n) (log p on prime powers) and cumulative ψ(x).

  • Plot ψ(x) and ψ(x)-x; optionally annotate largest jumps.

How to run

  • make run EXP=e061

  • uv run python -m mathxlab.experiments.e061

Outputs

This experiment follows the standard output contract:

  • out/e061/figures/ — generated figures (PNG)

  • out/e061/report.md — short narrative report

  • out/e061/manifest.json — snapshot metadata for the gallery

Published run snapshot

If this experiment is included in the docs gallery, include the published snapshot (report + params).

  • n_max: 400000

  • ψ(n_max) - n_max: +108.161

Figures:

  • fig_01_psi_vs_x.png

  • fig_02_psi_minus_x.png

params.json (snapshot)
{
  "n_max": 400000
}

References

See Montgomery and Vaughan [2006], Apostol [1976].