Isospectralidad Variedades compactas planas Analysis on homogeneus spaces Analysis on real and complex Lie groups Análisis de grupos de Lie complejos Análisis de grupos de Lie reales Análisis en espacios homogéneos Compact flat manifolds Constante de Hermite Counting solutions of Diophantine equations Formas de Humbert Grupos de Lie semisimples Hermite constant Humbert forms Isospectral Isospectrality Minima of forms Other geometric groups, including crystallographic groups P-spectrum Quadratic forms Representación espinorial Representación por formas hermíticas Representation by hermitian forms Representation problems Semisimple Lie groups and their representations Analysis on manifolds Análisis en variedades Análisis global Asymptotic Behavior Comportamiento asintótico