Acoustic Horizon Temperature in a Bose-Einstein Condensate Analogue and Its Relation to a Bounce Temperature Scale

This paper examines what horizon temperature a condensate acoustic black hole analogue reaches for realistic velocity gradients, and how that scale should and should not be compared with cosmological bounce temperatures. The system considered is a condensate flow with velocity gradients of 100 to 10,000 per second at the acoustic horizon, and the observable is analogue horizon temperature in nanokelvin. Evaluating the ordinary behaviour of the system and the spin-torsion contribution under explicit assumptions about polarisation and uniformity, and inverting the comparison at the stated laboratory precision, gives a quantitative bound rather than a qualitative assertion of smallness. The computed record is: rows contains 3 evaluated points; point 1 gradient_per_s = 100; point 1 T_K = 1.216e-10; point 1 T_nK = 0.1216; point 2 gradient_per_s = 1,000; point 2 T_K = 1.216e-09; point 2 T_nK = 1.216; point 3 gradient_per_s = 10,000; point 3 T_K = 1.216e-08; point 3 T_nK = 12.16; T_at_1000_nK = 1.216. The torsion-related contribution is far below the level that would alter the ordinary behaviour of the system at current precision, and the value that would have produced a visible residual is stated so that future improvements can be assessed against it directly. No new measurement is reported. This study is simulated and computed from stated assumptions, not measured.