Sharp estimates for the Opdam-Cherednik $W$-invariant heat kernel for the root system $A_1$

For the first time, the estimates of the non-centered Weyl-group invariant heat kernel for curved Riemannian spaces and for Opdam-Cherednik Laplacians are studied systematically. We prove sharp estimates for the root system $A_1$ with arbitrary multiplicity $k>0$. Sharp estimates of Opdam-Cherednik’s radial heat kernel are conjectured for any root system.