Distances in sets of positive Korányi upper density in Heisenberg Group

We prove that any measurable set in the Heisenberg group, ${\mathbb{H}}^n$, of positive upper density has the property that all sufficiently large real numbers are realised as the Korányi distance between points in that set. The result can be seen as a Heisenberg group analogue to a corresponding Euclidean large distance set result in the $1986$ paper of Bourgain, \cite{1986Bourgain}. Along the way, to prove our main theorem, we give the decay" of the coefficients $R_{k}(λ, σ)$, appearing in the spectral decomposition of the group Fourier transform, $\hatσ(λ)$ $= \sum_{k=0}^{\infty} R_{k}(λ, σ) \mathcal{P}_{k}(λ)$, of the surface measure $σ$ on the Korányi sphere in $\mathbb{H}^n$, in a certain high frequency" region, that is, when $2(2k+n)\mathrm{\mid }\lambda \mathrm{\mid }\gg 1$; which seems to be new in the literature. We also show that the positive upper density cannot be qualitatively improved further.