Y. Maeda

EMBARK: An Atlas of the Earth-Departure Interstellar Reachable Set, Surveyed on a Real Catalog as a Function of Departure Epoch and Technology Level

Abstract (English) When humanity launches interstellar probes with propulsion technologies that actually exist, how does the set of reachable stellar systems grow as a function of departure epoch t and technology level P? Using a clean eligible catalog of 37,498 stars built on Ga...

EMBARK: An Atlas of the Earth-Departure Interstellar Reachable Set, Surveyed on a Real Catalog as a Function of Departure Epoch and Technology Level

Abstract (English) When humanity launches interstellar probes with propulsion technologies that actually exist, how does the set of reachable stellar systems grow as a function of departure epoch t and technology level P? Using a clean eligible catalog of 37,498 stars built on Ga...

The faint-end radial-velocity tail of Gaia DR3: external verification of extreme values and a continuum of discrepancies in the 100 pc sample

Abstract Close-encounter studies rely on Gaia DR3 radial velocities (RVs) to the faint limit of the RVS. Our earlier encounter atlas found that stars with G>13.5 and |RV|>150 km/s but disc-like tangential motion inflate the sub-parsec encounter rate sevenfold, and conjectured tha...

Contact processes on ballistic Poisson particles: criticality, fronts, and when motion helps colonization

Version note (v2). Appendix C made self-contained; label precision (Section 4 claim); C-series footnote; hypothesis precision (C6a isotropy, survival definition). No change to mathematical content. Abstract (English) Motivated by observed stellar kinematics, we introduce a contac...

Contact processes on ballistic Poisson particles: criticality, fronts, and when motion helps colonization

Abstract (English) Motivated by observed stellar kinematics, we introduce a contact process on particles moving ballistically in R³: a Poisson point process whose points carry i.i.d. velocities, with entry-driven fire-and-forget transmission at range R (success probability p, del...

Interstellar flight profiles and observational signatures of positive-energy warp shells

Accelerating warp shells built entirely from positive-energy matter were recently shown to exist: the radiative momentum warpshell of Le (arXiv:2606.22531) steers by photon-rocket recoil under a closed-form cost law and an acceleration–compactness frontier. What that construction...