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An integral expression for the Dunkl kernel in the dihedral setting. (English) Zbl 06815248

Summary: Using the results in [12] where a construction of the Dunkl intertwining operator for a large set of regular parameter functions is provided, we establish an integral expression for the Dunkl kernel in the context of the dihedral group \(\mathcal{D}_n\) with constant parameter function \(k\in\mathbb{C}\) and arbitrary order \(n\geq2\). Our main tool is a differential system that leads to the explicit expression of the Dunkl kernel whenever an appropriate solution of it is obtained. In particular, an explicit expression of the Dunkl kernel \(E_k(x,y)\) is given when one of its argument \(x\) or \(y\) is invariant under the action of any reflection in the dihedral group. We obtain also a generating series for the homogeneous components \(K_m(x,y)\), \(m\in\mathbb{Z}^+\), of the Dunkl kernel and provide new sharp estimates for the Dunkl kernel in the large context \(k\in\mathbb{C}\), \(n\geq2\) and \(-2nk\neq 1,2,3,\dots\).

MSC:

47B48 Linear operators on Banach algebras
33C52 Orthogonal polynomials and functions associated with root systems
33C67 Hypergeometric functions associated with root systems
31B05 Harmonic, subharmonic, superharmonic functions in higher dimensions

References:

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