Jeans Mass in Cold Dense Gas and the Substellar Formation Floor

This paper computes the Jeans mass evaluated in cold, dense molecular gas, the simplest gravitational instability scale and a first estimate of the formation floor. Temperature and density enter with opposite signs, so quoting a single jeans mass without both numbers is meaningless. The headline computed values are: MJ_cold_dense = 300.9; MJ_typical = 951.5; MJ_diffuse = 3009. All values were obtained from the stated scalings and normalisations in the deposited code; this study is simulated and computed, not measured, and no new observations are reported. Where the framework supplies no value for a quantity the question requires, that absence is reported plainly as a negative result.