On the variable bandwidth kernel estimation of conditional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e3468" altimg="si14.svg"><mml:mi>U</mml:mi></mml:math>-statistics at optimal rates in sup-norm

Salim Bouzebda, Nourelhouda Taachouche