TY - JOUR ID - JavierGonzálezVieli2013 LB - JavierGonzálezVieli2013 AU - Javier González Vieli, Francisco TI - A note on bounded harmonic functions over homogeneous trees ST - A note on bounded harmonic functions over homogeneous trees JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2013 VL - 33 IS - 4 SP - 697 EP - 700 DO - http://dx.doi.org/10.7494/OpMath.2013.33.4.697 UR - http://dx.doi.org/10.7494/OpMath.2013.33.4.697 AB - Let \(\mathcal{T}_k\) be the homogeneous tree of degree \(k\geq 3\). J.M. Cohen and F. Colonna have proved that if \(f\) is a bounded harmonic function on \(\mathcal{T}_k\), then \(|f(x)-f(y)|\leq \|f\|_\infty\cdot 2(k-2)/k\) for any adjacent vertices \(x\) and \(y\) in \(\mathcal{T}_k\). We give here a new and very simple proof of this inequality. KW - bounded harmonic function KW - homogeneous tree SN - 1232-9274 ER -