Derighetti, Antoine2008-12-102008-12-102008-12-10200410.1215/ijm/1258138392https://infoscience.epfl.ch/handle/20.500.14299/32528WOS:0002242808000055764convolution operatorcontractive projectionamenable groupFø lner's conditionOn Herz's projection theoremtext::journal::journal article::research article