Stefan Schlamp

We propose a Hybrid Piecewise Intensity model linking point-process econometrics to the physical architecture of electronic exchanges, decomposing trade arrivals in the 100 ms around macroeconomic announcements into four latency-aligned phases. Calibrated on nanosecond Eurex and CME data (2019--2025), modal Phase~1 peaks occur at 1.16 μs (Eurex) and 6.64 μs (CME), tracking each venue's network transmission floor. Comparing private embargo-based (PMI) and government-led (NFP, FOMC) releases, we find reaction-speed differences consistent with protocol-induced latency advantages, though confounds remain. The CME concentrates profitability within 200 μs with deteriorating risk-adjusted returns thereafter; Eurex sustains stable Sharpe ratios across longer horizons.

Low-coherence self-referencing velocimetry optically measures the relative velocity between a point in a particle-laden fluid and a (potentially moving) reference surface. Low-coherence light scattered off the particles and off the reference surface is coupled into an interferometer with variable optical delay in one arm and an acousto-optical modulator in the second arm. The measurement location is set relative to the reference surface. Its location can be scanned along a line by adjusting the optical delay in the interferometer. The spatial resolution is typically tens of micrometers. Only one low-coherence light beam is required for each component of the velocity vector. Proof-of-principle measurements in Taylor–Couette flow are presented.

Molecular dynamics simulations of dense nitrogen show that nonspherical molecules have a weak tendency to align their molecular axis such that it lies parallel to the plane of a shock wave front. As a consequence, there is also an even weaker tendency for the molecular rotation axis to align perpendicular to the shock front. The underlying mechanism is discussed and it is argued that this phenomenon can only be observed for dense fluids and only when considering realistic molecular interactions. A single relevant nondimensional parameter is proposed.