The Daugavet property in the Musielak-Orlicz spaces

We show that among all Musielak-Orlicz function spaces on a a-finite non-atomic complete measure space equipped with either the Luxemburg norm or the Orlicz norm the only spaces with the Daugavet property are L-1, L-infinity, L-1 circle plus(1) L-infinity and L-1 circle plus(infinity) L-infinity. In particular, we obtain complete characterizations of the Daugavet property in the weighted interpolation spaces, the variable exponent Lebesgue spaces (Nakano spaces) and the Orlicz spaces. (C) 2015 Elsevier Inc. All rights reserved.