4·î12Æü(ÌÚ) 15:30 -- 17:00 Vilmos Komornik (Universite Louis Pasteur, France) ``On some theorems of Ingham and Kahane'' ¡ã¸¦µæÈ¯É½Í׻ݡä n 1936, Ingham improved a previous result of Wiener on nonharmonic Fourier series. Modifying his weight function we obtain optimal results improving several earlier theorems of Kahane, Ullrich, Zuazua et al. We illustrate the usefulness of these results in control theory.