Equilateral bispectrum at redshifts z = 0.35, 1, and 3 (from top to bottom). We show the “direct” model (red solid line), already shown in Fig. 5, and the geometrical modification “tang.” (green dot-dashed line) given by the upper tangent that runs through the point of abscissa k₋. The small dashed vertical line shows the location  of the contact point of this tangent line with the “direct” curve.