Lower bound of black hole hair in pure Lovelock theory of gravity

Abstract: As an alternative to the "no hair conjecture," the "no short hair conjecture" for hairy black holes was established earlier. This theorem stipulates that hair must be present above 3/2 of the event horizon radius for a hairy black hole. It is assumed that the nonlinear behavior of the matter field plays a key role in the presence of such hair. Subsequently, it was established that the hair must extend beyond the photon sphere of the corresponding black hole. We have investigated the validity of the "no short hair conjecture" in pure Lovelock gravity. Our analysis has shown that irrespective of dimensionality and Lovelock order, the hair of a static, spherically symmetric black hole extends at least up to the photon sphere.