Dear all,

A short update on this week's work, and two figures I would be glad to

have your opinion on.

This week

- The review items (CCL READS/WRITES, checkpointing of the particle

  state, per-level AMR sampling, time interpolation with d_t g, and

  robust strong-curvature sampling) are now in the repo, together with

  the completed paper (English + Chinese) and the parameter files:

  https://github.com/wylyhzh/Geodesic

- New: robustness on the non-stationary GW150914 BBH background

  (3-level AMR, 2048 Cactus steps, 100 particles). All four samplers

  (aei, carpet, local27, local27lin) show no loss, no NaN, and pairwise

  agreement of order 8e-3.

Two attached figures (same GW150914 BBH background, 100-particle ring at r = 8M with a

strong inward radial velocity added to the circular-orbit IC):

  1. aei sampler: 50 of 100 particles dropped (442 NaN rows).

  2. local27lin sampler, same IC: 22 dropped (168 NaN rows).

With the standard (circular) ring IC the drops are aei = 6,

local27lin = 22; the extra drops in the aei strong-inflow run are

where the strong-curvature sampling path is most stressed.

Two questions

- Any advice on the thorn's path to ET inclusion?

- How should dropped particles be presented in such plots? I currently

  filter NaN rows when plotting; I am also considering marking each

  particle's last valid position, since the drops are physical plunges,

  not numerical failures.

Best regards,

Yuhua Li