All Research

Abstract

On a fixed spherical shell, we determine the last time at which nonnegative initial temperatures can produce one common signed whole-boundary heat flux. Admissible times form (0,τ), with a finite unattained cutoff. The boundary heat-kernel law fixes the shrinking concentration scale. After unit ground-state normalization, every weighted finite-q preparation problem, 1<q<∞, has a unique optimizer described by a scalar moment equation, and the cutoff limit has sharp costs and universal near-minimizer profiles. The conclusions include quantitative ground-weighted probability stability, second-moment control and physical angular rigidity. Separate endpoint arguments give atomic probability concentration at the L^1 endpoint and a filled-layer profile at the cap endpoint. Exactly feasible examples show the limits of higher-moment and strong cap-topology conclusions. An interior convex-hull criterion treats simultaneous finite schedules, and the smooth compatible class has the same norm infima. The shell-dependent boundary law connects feasibility, optimal preparation and concentration throughout the paper.