Has US inflation accelerated m/m significantly faster than eurozone inflation?

No, since 2020M03. No for header, yes for main (at 8% level), as of 2021M03.

Figure 1: US-Euro zone m/m y/y: main diff (blue), base diff (red). CPI for US, HICP for Eurozone. Seasonally adjusted HICP using X-13, logarithmic conversion. Inflation is calculated using logarithmic differences. Peak-to-trough dates as determined by the NBER are in grey. Source: BLS, EuroStat, via FRED and author’s calculations.

Core inflation in the US accelerated by 2.4 percentage points compared to the Eurozone in the period 2021M03-22M05. The relative acceleration is only 0.7 percentage points if we start from the start of the pandemic in the US, 2020M03.

This approach is to use the difference in inflation difference (see regression specification here) – corresponds to inflation rates or inflation differentials equal to I (0).