\documentclass[12pt]{article} \usepackage{amsmath,mathrsfs,bbm} \usepackage{amssymb} \textwidth=4.825in \overfullrule=0pt \thispagestyle{empty} \begin{document} \noindent % % {\bf Jean-Baptiste Gramain} % % \medskip \noindent % % {\bf On a Conjecture of G. Malle and G. Navarro on Nilpotent Blocks} % % \vskip 5mm \noindent % % % % In a recent article, G. Malle and G. Navarro conjectured that the $p$-blocks of a finite group all of whose height 0 characters have the same degree are exactly the nilpotent blocks defined by M. Brou\'e and L. Puig. In this paper, we check that this conjecture holds for spin-blocks of the covering group $2.{\mathfrak A}_n$ of the alternating group ${\mathfrak A}_n$, thereby solving a case excluded from the study of quasi-simple groups by Malle and Navarro. \end{document} .