Is the death penalty unconstitutional for failing to impose a specific burden of proof?

We have held that " [t]he death penalty is not unconstitutional for failing to impose a specific burden of proof as to the existence of aggravating circumstances, the greater weight of aggravating circumstances over mitigating circumstances, or the appropriateness of a death sentence. " ( People v. Parker (2017) 2 Cal.5th 1184, 1232, 218 Cal.Rptr.3d 315, 395 P.3d 208 ; see also People v. Rangel , supra , 62 Cal.4th at p. 1235, 200 Cal.Rptr.3d 265, 367 P.3d 649 [discussing burden of proof regarding " Pen. Code, 190.3, factor (b) or factor (c) evidence"].) As

[6 Cal.5th 1059]