An Effective Temperature for Particles Created at a Bounce

On a cosmological bounce background with a single minimum of the scale factor and unit duration, in units set by that duration, the quantities reported here are obtained by direct numerical evolution of the field modes from the contracting branch to the expanding branch. The low-wavenumber fit gives an effective temperature of 0.721 in bounce units, with a coefficient of determination of 0.8062 and an intercept of -0.320, measurably offset from the zero a true thermal form requires. At the highest computed wavenumber the actual occupation is 6.051e-18, while the thermal extrapolation predicts 9.553e-07. The calculation is performed on a stated model background with stated vacuum conventions, and the code and full-precision output are deposited with the paper. This study is simulated and computed from those assumptions; it is not a measurement.