An octonionic contact (OC) manifold is always spherical. We construct the OC Yamabe operator on an OC manifold and prove its transformation formula under conformal OC transformations. An OC manifold is scalar positive, negative or vanishing if and only if its OC Yamabe invariant is positive, negative or zero, respectively. On a scalar positive OC manifold, we can construct the Green function of the OC Yamabe operator and apply it to construct a conformally invariant tensor. It becomes an OC metric if the OC positive mass conjecture is true. We also show the connected sum of two scalar positive OC manifolds to be scalar positive if the neck is sufficiently long. On the OC manifold constructed from a convex cocompact subgroup of F₄₍₋₂₀₎, we construct a Nayatani-type Carnot–Carathéodory metric. As a corollary, such an OC manifold is scalar positive, negative or vanishing if and only if the Poincaré critical exponent of the subgroup is less than, greater than or equal to 10, respectively.

渗透压接触（OC）歧管始终为球形。我们在OC流形上构造OC Yamabe算子，并在保形OC变换下证明其变换公式。且仅当其OC Yamabe不变为正，负或零时，OC歧管才是标量正，负或消失。在标量正OC流形上，我们可以构造OC Yamabe算子的Green函数，并将其应用于构造共形不变张量。如果OC正质量猜想为真，则它将成为OC度量。我们还显示，如果颈部足够长，则两个标量为正的OC歧管的连接总和为标量为正。关于由F _4（−20）的凸协紧子群构成的OC流形，我们构建了Nayatani类型的Carnot–Carathéodory指标。作为推论，当且仅当子组的庞加莱临界指数分别小于，大于或等于10时，此类OC歧管才是标量正，负或消失。