We construct new examples of compact Riemann surfaces which are non isometric but have the same spectrum of the Laplacian. Examples are given for genus and for all . In a second part we give examples of isospectral non isometric surfaces in which are realizable by paper models.
Corentin Jean Dominique Fivet, Nicolas Robin Montagne, Olivier Baverel
Jürgpeter Buser, Robert Silhol